JPH0594090U - Bicycle derailleur - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a bicycle derailleur capable of obtaining a plurality of spring forces with a single return spring and easily adjusting the spring force of the return spring. [Structure] At least one end of the return spring 11 has two or more contact surfaces 18 having different distances from the center of rotation.
The spring force adjusting member 16 provided with a and 18b is rotatably mounted, and the end portion of the return spring 11 is locked to one member constituting the pantograph link mechanism 6 via the spring force adjusting member 16. .

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bicycle derailleur, and more particularly to a bicycle derailleur capable of adjusting the spring force of a return spring.

[0002]

[Prior Art]

 A general bicycle derailleur has a structure in which a chain guide is supported by a base member attached to a frame via a shift link mechanism such as a parallelogram pantograph link mechanism, and by deforming the link mechanism, The chain guide is translated in the axial direction of the sprocket so that the chain can be switched.

Usually, the pantograph link mechanism includes a base member fixed to the fork end, a parallel outer link member and an inner link member swingably connected to the base member via a pin, and a pair of these members. And a movable member that is swingably connected to the other end of the link member and that supports the chain guide. Then, the rotation operation force of the operation lever attached to the appropriate portion of the frame is transmitted to the pan tag rough link mechanism through the operation cable to deform the mechanism.

Since the operation cable can transmit only the force in the pulling direction, a return spring for elastically biasing the pantograph link mechanism in a direction opposite to the deformation direction by pulling the operation cable is provided. Has been. Therefore, when the operation lever is operated in the pulling direction of the operation cable, the pantograph link mechanism is forcibly deformed in the direction to store the return spring, while when the operation lever is operated in the extending direction of the operation cable, the return wire is returned. The elastic return force of the spring causes the pan tag rough link mechanism to return and deform.

The return spring is inserted into a pin that connects two members that form the pantograph link mechanism, and both ends of the spring are locked to the inner side surfaces of the members, respectively. The link mechanism is elastically urged to deform in a certain direction.

[0006]

[Problems to be solved by the device]

 The elastic force of the return spring should be determined according to the characteristics of the pantograph link mechanism, the rotational operation force of the speed change operation lever to which the other end of the operation cable is connected, and the like. However, the same gear shift operation lever device is not always used for the same derailleur, and the spring force of the return spring may have to be changed.

Further, the spring force of the return spring has a great influence on the shift operability. That is, when the spring force of the return spring is increased, the force required to operate the gear shift operation lever is increased, while the chain can be re-engaged with a large spring force, so a quick gear shift operation can be performed. It will be possible.

However, in a bicycle for children, when the spring force of the return spring is increased, the operation force necessary for rotating the shift operation lever is increased, which may make the shift operation difficult. is there. Therefore, it is necessary to adjust the spring force of the return spring depending on the type of bicycle. Further, in a gear shift operation lever device including a so-called click mechanism, if the spring force of the return spring is strong, the locking force of the click mechanism must be increased. As a result, the rotational resistance of the operating lever is increased, the gear shift operability is degraded, and the gear shift operating lever device becomes large.

In order to solve the above problem, it is possible to prepare a plurality of return springs depending on the type of bicycle or the gear shift lever device. However, there is a problem that the production efficiency decreases and the manufacturing cost increases.

The present invention has been devised under the above circumstances, solves the above-mentioned conventional problems, and can obtain a plurality of spring forces with a single return spring, and further, the above-mentioned return It is an object of the present invention to provide a bicycle derailleur that can easily adjust the spring force of a spring.

[0011]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention takes the following technical means. That is, according to the present invention, a base member fixed to a bicycle frame, a pair of parallel link members whose base ends are pivotally joined to the base member by pins, and a pair of the link members of the pair of parallel link members. A pantograph link mechanism is composed of a movable member that is swingably pin-joined to the other end and supports the chain guide, and the pantograph link mechanism is formed by a return spring provided between the two members that compose the pantograph link mechanism. In a bicycle derailleur that is elastically biased so as to be deformed in a certain direction, a spring force adjusting member that has two or more contact surfaces with different distances from the rotation center is provided on at least one end of the return spring. One part that rotatably covers the end of the return spring and that constitutes the pantograph link mechanism via the spring force adjusting member. It is characterized by being locked to the material.

[0012]

[Operation and effect of the device]

 In the bicycle derailleur according to the present invention, a spring force adjusting member is attached to at least one end of the return spring that elastically biases the pantograph link mechanism so that the spring force of the return spring can be adjusted. Is configured.

The spring force adjusting member is rotatably mounted on the end portion of the return spring, and is provided with two or more contact surfaces having different distances from the center of rotation. Then, the end portion of the return spring is locked to one member constituting the pantograph link mechanism via the spring force adjusting member. Therefore, when the spring force adjusting member is rotated, the relative position between the end portion of the return spring and the member to which the return spring is locked is changed, and the spring force for elastically urging the pantograph link mechanism is changed. can do.

Accordingly, the spring force applied to the pantograph link mechanism can be easily changed. As a result, the spring force of the return spring can be adjusted according to the derailleur, etc., and the gear shifting operability can be improved.

Moreover, even when the same derailleur is adopted for a child bicycle and an adult bicycle, one return spring can be used in common, and not only the spring force of the return spring can be easily adjusted, but also The production efficiency can be greatly improved. Further, even when using the gear shift operation lever device that employs the click mechanism, it is possible to weaken the spring force of the return spring and reduce the locking force of the click mechanism, thus improving the operability of the gear shift operation lever device. Will also be possible.

[0016]

[Explanation of Examples]

 An embodiment of a bicycle derailleur according to the present invention will be specifically described below with reference to the drawings. In this embodiment, the present invention is applied to a so-called top normal type rear derailleur in which the pantograph link mechanism is elastically biased so as to move the chain guide to the top sprocket side of the multi-stage free wheel.

As shown in FIG. 1, a rear derailleur 1 according to this embodiment includes a base member 2 attached to a vehicle body frame F and an inner link rotatably connected to the base member 2 at a base end thereof. A pantograph link mechanism 6 including a member 3 and an outer link member 4 and a movable member 5 swingably connected to the tips of the link members 3 and 4 is provided. Further, the movable member 5 is provided with a chain guide 7 which rotatably supports a guide pulley 8 and a tension pulley 9 between an outer guide plate 7a and an inner guide plate 7b in a direction to apply tension to the chain C. It is rotatably supported while being biased. By pulling the operation cable W connected to the pantograph link mechanism 6 to deform the pantograph link mechanism 6, the movable member 5 and the chain guide 7 supported by the movable member 5 are parallel to the hub axis direction. It is moved and a gear shift operation is performed.

As the shift operation cable W, a double cable composed of an inner cable w1 and an outer cable w2 inserted in the inner cable w1 is adopted. An outer receiving portion 1a having a screw hole is formed in the lower portion of the base member 2 in the vicinity of the connecting portion with the inner link member 3, and the outer receiving portion that is screwed into the outer receiving mounting portion 1a is formed. One end of the outer cable w2 is fixed to the bolt 10, while the inner cable w1 extending from the through hole of the outer receiving bolt is fixed to the inner cable connecting portion 6a provided in the intermediate portion of the outer link member 4. Has been done.

Therefore, the axial relative movement of the inner cable w1 and the outer cable w2 caused by the turning operation of the gear shift operation lever (not shown) is transmitted to the pantograph link mechanism, whereby the pantograph link mechanism 6 has its parallel four sides. It can be transformed to change the length of the diagonal of the shape. As a result, as described above, the chain guide 7 is moved to the position facing the predetermined sprocket, and the chain is changed.

Since the shift operation cable W can transmit only the force in the direction of pulling the inner cable w1 to the pantograph link mechanism 6, the pantograph link mechanism 6 operates as shown in FIG. The return spring 11 elastically biases the cable w1 in the direction opposite to the direction of deformation due to the pulling of the cable w1 (direction of arrow A in FIG. 2). Therefore, when the gear shift operation lever is operated in the direction of pulling the inner cable w1, the pantograph link mechanism 6 is forcibly deformed in the direction of storing this against the return spring 11 (direction of arrow B), while the gear shift operation is performed. When the operating lever is operated in the feeding direction of the inner cable w1, the pantograph link mechanism 6 is deformed by the elastic return force of the return spring 11.

In the pantograph link mechanism 6 according to this embodiment, as shown in FIG. 2, the coil-shaped return spring 11 is inserted into the pin 12 that connects the movable member 5 and the inner link member 3. At the same time, the end of the return spring 11 is locked to the inner surfaces of the movable member 5 and the inner link member 3.

The return spring 11 includes a winding portion 13 inserted into the pin 12, and locking portions 14 a and 14 b extending outward in the radial direction from both sides of the winding portion 13. As shown in FIG. 3, the end portion of the locking portion 14a that is locked to the inner link member 3 is bent in the axial direction of the winding portion 13. A spring force adjusting member 16 for adjusting the spring force of the return spring 11 is inserted into the bent portion 15.

As shown in FIGS. 2 to 4, the spring force adjusting member 16 has a shape in which the outer peripheral surface of a cylinder is cut out by two parallel planes parallel to the center axis and different in distance from the center axis. The contact surfaces 18a and 18b are formed on the inner surface of the inner link member 3 by the cutout surfaces. The spring force adjusting member 16 is attached to the return spring 11 by inserting the support hole 17 provided along the axis into the bent portion 15 of the return spring 11. Then, one locking piece 14b is locked to the inner side surface of the movable member 5, while the other locking piece 14a is fixed to the inner side surface of the inner link member 3 via the spring force adjusting member 16. It is locked.

Further, as shown in FIG. 3, the spring force adjusting member 16 has a side surface opposite to the side of the return spring 11 which is inserted into the bent portion 15 in the direction perpendicular to the axis. Engagement grooves 19 are formed. When the driver is engaged with the tool engaging groove 19 and the spring force adjusting member 16 is rotated, as shown in FIG. 4, the other contact surface of the contact surfaces 18a and 18b is brought into contact with the inner link. It is brought into contact with the inner surface of the member 3.

The contact surfaces 18a and 18b are formed so that the distance from the central axis of the support hole 17 supported by the bent portion 15 of the return spring 11 is different, and thus the spring force adjusting member is formed. By rotating 16 the distance between the locking portion 14a of the return spring 11 and the inner surface of the inner link member 3 at which the locking portion 14a is locked is changed. As a result, the elastic force applied to the inner link member 3 is changed.

In the rear derailleur 1 having the above structure, the spring force of the return spring 11 can be changed extremely easily by rotating the spring force adjusting member 16 described above. Therefore, with one return spring 11, it is possible to adjust the spring force that elastically biases the pantograph link mechanism 6 in two steps. As a result, even when different gear shift operation levers are adopted, it is possible to deal with the single return spring 11.

Moreover, since the spring force of the return spring 11 of the pantograph link mechanism 6 can be adjusted, one derailleur can be applied to both a child bicycle and an adult bicycle. Therefore, it is not necessary to prepare two types of springs, and the production efficiency can be significantly improved. Further, even when the variable speed operation lever device adopting the click mechanism is used, the spring force of the return spring is weakened to weaken the locking force of the click mechanism, and the gear shift operability can be improved.

The scope of the present invention is not limited to the above embodiments. Although the present invention is applied to the rear derailleur for bicycles in the embodiment, it can also be applied to the front derailleur for bicycles. Further, in the present embodiment, the two contact surfaces 18a and 18b are provided on the spring force adjusting member, but three or more contact surfaces may be provided. Further, the position at which the return spring 11 is provided and the member for contacting the spring force adjusting member 16 are not limited to those in the embodiment, and can be set between desired members constituting the pantograph link mechanism.

[Brief description of drawings]

FIG. 1 is a side view of a rear derailleur to which the present invention is applied.

FIG. 2 is a sectional view of a pantograph link mechanism of the rear derailleur according to FIG.

FIG. 3 is a perspective view showing a main part of the present invention.

FIG. 4 is a sectional view of an essential part for explaining the operation of the present invention.

[Explanation of symbols]

 1 Derailleur 2 Base member 3,4 Link member 5 Movable member 6 Pantograph link mechanism 7 Chain guide 11 Return spring 16 Spring force adjusting member 18a, 18b Contact surface

Claims (1)

[Scope of utility model registration request] 1. A base member fixed to a bicycle frame, a pair of parallel link members whose base end portions are rotatably pin-joined to the base member, and the other ends of the pair of link members. A pantograph link mechanism is configured by a movable member that is swingably pin-jointed to support the chain guide, and the pantograph link mechanism is deformed in a certain direction by a return spring provided between the two members that configure the pantograph link mechanism. In a bicycle derailleur that is elastically urged, a spring force adjusting member having two or more contact surfaces having different distances from the rotation center is rotatably mounted on at least one end of the return spring. In addition, the end portion of the return spring is locked to one member constituting the pantograph link mechanism via the spring force adjusting member. And wherein the bicycle derailleur.