JPH0525061U - Variable diameter pulley - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a variable diameter pulley having a short axial length, a small size, a small number of parts, and a simple structure. [Structure] Fixed pulley 1 having a conical surface 4 formed on the outer peripheral surface
And a fan-shaped mass 6 that has an inclined surface facing the conical surface 4 and is urged toward the outer peripheral side by centrifugal force, and these masses 6
The movable pulley 2 is mainly provided with a tension spring 8 for urging the conical surface 4 toward the center. Further, the mass 6 is engaged with the conical surface 4 so as to be movable in the radial direction of the stationary pulley 1, and the axial length is shortened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a variable diameter pulley used in a power transmission device or the like for transmitting the rotation of an automobile engine to a power steering pump.

[0002]

[Prior Art]

 A conventional power transmission device for a general power steering pump is that an endless belt is hung on a driving pulley on the engine side and a driven pulley on the pump side, and the power is transmitted from the engine side to the pump side at a rotation speed ratio of 1: 1. The torque is transmitted. Therefore, when the engine rotates at high speed, the pump also rotates at high speed, resulting in insufficient intake of oil, which causes problems such as abnormal noise due to cavitation.

Further, in the power steering pump, when the engine of the automobile exceeds a certain number of revolutions, it is not necessary to rotate at a higher speed. Therefore, in the case of a power steering pump, the flow control valve provided in the hydraulic circuit keeps the amount of oil sent to the gear constant in order to reduce the assist force during handlebar steering at high engine speeds. However, the remaining oil is bypassed to the suction side, but this has the problem of wasting energy.

Therefore, in order to solve the above-mentioned inconvenience, as shown in Japanese Patent Laid-Open No. 57-97949, a variable diameter is used to prevent a driven side such as a power steering pump from becoming a high rotation at the time of a high rotation of an engine. There was a pulley. In this variable diameter pulley, a fixed pulley fitted and fixed to a driven shaft and a movable pulley fitted to the driven shaft slidably in the axial direction are arranged with their conical surfaces facing each other. A flywheel is installed between the fixed side and movable side pulleys that urges the movable side pulleys in the direction to expand the space between them, and urges the movable side pulleys in the direction to reduce the space by centrifugal force. It is arranged on the rear side of the outer peripheral portion of the side pulley.

Then, the above-mentioned driving force transmission device is configured by using the variable diameter pulley as a driven pulley, and the rotational force is transmitted from the driving pulley on the engine side to the variable diameter pulley via the endless V belt. .. When the rotational speed of the engine increases, the rotational speed of the variable diameter pulley also increases, and the urging force of the flyweight due to the centrifugal force overcomes the urging force of the spring, the movable pulley approaches the fixed pulley, When the effective diameter of the variable pulley becomes large and the engine exceeds a certain number of revolutions, it limits the number of revolutions on the driven side to prevent high revolutions.

[0006]

[Problems to be solved by the device]

 The conventional variable diameter pulley described above uses a fly weight to bring the movable-side pulley closer to the fixed-side pulley, so the axial length becomes longer, and the centrifugal force of the flyweight causes the movable-side pulley to move in the axial direction. There was a problem that the moving mechanism had many parts and became complicated.

An object of the present invention is to solve the above-mentioned problems and to provide a variable diameter pulley having a short axial length, a small number of parts, and a simple structure capable of changing the effective diameter. It is something.

[0008]

[Means for Solving the Problems]

 The variable diameter pulley of the present invention comprises a conical surface formed on the outer periphery of a fixed pulley and a movable pulley, and the inclined surfaces of several fan-shaped masses on the circumference that are urged toward the outer periphery by centrifugal force. And a tension spring for urging these masses toward the center side are provided, and the fan-shaped masses are respectively engaged with the conical surface so as to be movable in the radial direction of the stationary pulley.

[0009]

[Action]

 The variable diameter pulley according to the present invention is used as a driven pulley that transmits the rotation of a driving pulley driven by an engine through an endless V-belt, for example. When the urging force overcomes the urging force of the tension spring, the fan-shaped mass moves radially outward with respect to the conical surface of the fixed pulley, so the effective diameter of the variable diameter pulley is increased to properly control the rotation speed on the driven side. However, it is possible to achieve the same function as the conventional one in which the movable pulley is moved by the flyweight described above.

Since the movable pulley is composed of several fan-shaped masses and a tension spring that biases these masses toward the center side as main members, the number of parts is small and the structure is simple. Further, since the fan-shaped mass is engaged with the conical surface formed on the outer peripheral portion of the fixed pulley so as to be movable in the radial direction, the axial length is small and the size is small.

[0011]

【Example】

 An embodiment of the present invention will be described below with reference to FIGS. In FIGS. 1 and 2, 1 is a fixed pulley, and 2 is a movable pulley. The fixed-side pulley 1 has a center hole 3 and is formed in a disk shape having a conical surface 4 formed on the outer peripheral portion. On the conical surface 4, four engaging grooves 5 are formed on the fixed pulley 1 at mutually orthogonal radii. The engaging groove 5 has a trapezoidal cross section as shown in FIG. is there. A spline 3a is formed on the peripheral surface of the center hole 3.

Further, the movable pulley 2 has four fan-shaped masses 6 on the circumference that face the conical surface 4 of the fixed pulley 1, and these masses 6 have recesses 7 that open at both end surfaces. Adjacent fan-shaped masses 6 which are respectively formed, are connected to each other by a tension spring 8 housed in a recess 7. Each of the fan-shaped masses 6 has a front shape obtained by dividing a ring into four equal parts in the radial direction and a cross section of an approximately isosceles triangle, and has an inclined surface 9 facing the conical surface 4 of the stationary pulley 1 and A sliding surface 10 slidably supported on the conical surface 4 in the radial direction is formed by the two equal sides of the triangle, and a V-shaped belt groove 11 is formed between the conical surface 4 and the inclined surface 9. ..

Further, an engaging protrusion 12 is formed in the inner peripheral portion of the sliding surface 10 in the arc direction in the radial direction of the stationary pulley 1. The engaging protrusion 12 has a trapezoidal cross section. , The engagement groove 5 formed on the conical surface 4 is slidably engaged. Next, an example of use of the variable diameter pulley according to this embodiment will be described. As shown in FIGS. 4 and 5, the drive shaft 13 on the engine side of the automobile is fitted with an appropriate drive pulley 14, and the driven shaft 15 on the power steering pump side is attached to the driven shaft 15 of the embodiment described above as a driven pulley. The variable pulley 16 is used, the center hole 3 of the fixed pulley 1 is fitted into the spline 3a, and the spline 3a is engaged with the spline of the driven shaft 15, so that the drive pulley 14 and the variable diameter pulley 16 have an endless V-belt 17. And the V belt 17 is pressed by the pressing pulley 18 for absorbing the slack to form a power transmission device.

When the power transmission device is stopped, as shown in FIG. 4, in the movable pulley 2 of the variable diameter pulley 16, the end faces of the adjacent fan-shaped masses 6 come into contact with each other by the urging force of the tension springs 8, Since it is located on the center side of the conical surface 4, the effective diameters of the drive pulley 14 and the variable diameter pulley 16 that is a driven pulley are the same, and the variable diameter pulley 16 has a small diameter.

In this state, when the engine of the automobile is driven, the drive pulley 14 rotates via the drive shaft 13, the variable diameter pulley 16 rotates by the V belt 17, and the driven shaft 15 rotates. Is transmitted to the power steering pump, which operates. When the engine is in a low rotation state, the fan-shaped mass 6 rotates integrally with the fixed pulley 1 of the variable diameter pulley 16, but since the centrifugal force acting on these masses 6 is larger than the centrifugal force acting on the mass 6, the tension spring 8 urges the mass. The effective diameter of the variable diameter pulley 16 remains small. Therefore, the rotation speed ratio between the engine side and the pump side is 1: 1.

When the rotational speed of the engine becomes higher than a certain level and the biasing force of the fan-shaped mass 6 of the variable-diameter pulley 16 due to the centrifugal force becomes larger than the biasing force of the tension spring 8, the fan-shaped mass 6 becomes While the tension spring 8 is being extended, it moves together with these springs 8 to the outer peripheral side of the conical surface 4 of the stationary pulley 1 as shown by the arrow in FIG. For this reason, as shown in FIG. 5, the effective diameter of the driven-side variable diameter pulley 16 becomes large and the rotational speed of the driven shaft 15 is limited. It can be controlled not to become.

Further, when the engine is rotated from high rotation to low rotation and the biasing force of the fan-shaped mass 6 due to the centrifugal force is reduced, the fan-shaped mass 6 is biased by the tension spring 8 to the center of the conical surface 4 of the stationary pulley 1. Returning to the side, the effective diameter of the variable diameter pulley 16 becomes small as shown in FIG. In the example of use, the drive pulley 14 is fitted to the drive shaft 13 while the fixed pulley 1 of the driven side variable diameter pulley 16 is fitted to the driven shaft 15 while being constrained in the rotational direction. It is preferable to move the V-belt 17 in the axial direction so that the V-belt 17 is orthogonal to the drive shaft 13 and the driven shaft 15 if necessary.

The variable diameter pulley of the present invention is not limited to a power transmission device for a power steering pump, but can be widely applied to power transmission devices such as an air pump, a water pump fan, and a compressor driven by an automobile engine. Moreover, the fan-shaped mass is not necessarily limited to four, and may be three or five or more. Further, the tension springs 8 are provided so as to connect the adjacent fan-shaped masses 6 to each other, but the invention is not limited to this configuration, and the tension springs 8 may be provided between the fan-shaped masses 6 and the fixed pool 1. It may be provided in the.

[0019]

[Effect of the device]

 As described above, the variable diameter pulley of the present invention has a fixed pulley having a conical surface on the outer peripheral portion and an inclined surface facing the conical surface, and has a circumferential surface that is urged to the outer peripheral side by centrifugal force. Equipped with a few upper fan-shaped masses and a movable pulley having a tension spring that urges these masses toward the center side, so that the fan-shaped masses can be moved in the radial direction of the fixed-side pulley on the conical surface. Since they are engaged with each other, the following effects can be obtained.

That is, the variable-diameter pulley according to the present invention can achieve the same function as the conventional one in which the movable pulley is moved by the flyweight described above, and at the same time, the movable pulley has several fans. Since the shaped mass and the tension spring that connects these are configured as the main members, the number of parts is small, the structure is simple, and it can be provided at low cost.

Further, since the fan-shaped mass is engaged with the conical surface formed on the outer peripheral portion of the fixed pulley so as to be movable in the radial direction, the axial length becomes small and easy to use.

[Brief description of drawings]

FIG. 1 is a front view showing a variable diameter pulley according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB of FIG.

FIG. 4 is a schematic front view showing an example of use of the variable diameter pulley according to the present invention when stopped and at low rotation.

5 is a schematic front view of FIG. 4 at the time of high rotation.

[Explanation of symbols]

 1 Fixed-side pulley 2 Movable-side pulley 4 Conical surface 5 Engagement groove 6 Fan-shaped mass 8 Tension spring 9 Inclined surface 10 Sliding surface 11 Belt groove 12 Engagement protrusion 16 Diameter variable pulley 17 Endless V-belt

Claims (1)

[Scope of utility model registration request] 1. A fixed-side pulley having a conical surface formed on an outer peripheral portion thereof, and a plurality of fan-shaped masses on a circumference having an inclined surface facing the conical surface and being urged toward the outer peripheral side by a centrifugal force. And a movable pulley having a tension spring for biasing these masses toward the center, and fan-shaped masses are respectively engaged with the conical surface so as to be movable in the radial direction of the fixed pulley. Variable diameter pulley.