JPH0326067Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial application field) This invention is a seal structure for bicycle parts such as a bicycle derailleur, and more specifically, a seal structure for a bicycle part such as a bicycle derailleur. a second member having an insertion portion, the insertion portion of the second member is relatively rotatably mounted between each mounting wall of the first member via a pivot shaft, and the first member is mounted. The present invention relates to a sealing structure for a bicycle component, in which the circumference of the pivot shaft is sealed via an annular sealing member between opposing surfaces of a wall and an insertion portion of the second member.

(Prior art) Conventionally, seal structures for bicycle parts, for example, seal structures for bicycle derailleurs, were developed in the 1980s.
The seal structure described in the -188691 publication is known, and the seal structure described in this publication is based on a base member (first
a link member (second member) having an insertion portion inserted between the mounting walls of the base member, and a link member (second member) having an insertion portion inserted between the mounting walls of the base member. The link member is supported relatively rotatably by a support shaft, and an annular seal member is interposed around the pivot shaft between opposing surfaces of the mounting wall of the base member and the insertion portion of the link member. A gap formed between the mounting wall and the insertion portion is sealed by the sealing member.

(Problem to be Solved by the Invention) By the way, since the first member used in a bicycle derailleur etc. is mainly molded using a mold, there is a A tapered surface for mold cutting is formed whose diameter gradually increases toward the opening side. Therefore, when the insertion portion of the second member is inserted and supported between the respective mounting walls, the insertion portion and the mounting wall are The surfaces facing the wall are not spaced at the same distance and are non-parallel, so
A generally wedge-shaped gap is formed between the insertion portion and the mounting wall. Therefore, when the annular seal member is interposed between the mounting wall and the insertion portion, a gap is formed on the opening side of the mounting wall, and rainwater or the like may enter the interior through the gap.
Alternatively, on the inside of the mounting wall, the surface pressure of the sealing member against the insertion portion becomes large, causing problems such as impairing smooth relative rotation of the first and second members.

That is, the sealing member is set to have the same thickness as the gap formed on the inner side of the mounting wall and on the surface facing the insertion part, and is interposed between the mounting wall and the insertion part. If so, the relative rotatability of the first and second members will be good, but since the gap on the opening side of the mounting wall is larger than the gap on the inside side of the mounting wall, the A gap is formed between the sealing member and the mounting wall, and problems such as rainwater entering the interior through the gap occur. Further, the sealing member is set to have the same thickness as the gap formed on the opening side of the mounting wall on the surface facing the insertion portion, and is interposed between the mounting wall and the insertion portion. For example, the above-mentioned gap is not formed, and the problems such as the above-mentioned rainwater intrusion can be solved, but since the gap on the inside side of the mounting wall is smaller than the gap on the opening side of the mounting wall, On this inside side, the surface pressure of the sealing member against the mounting wall and the insertion portion increases, causing problems such as impairing the smooth relative rotation of the first and second members.

The present invention was devised in view of the above-mentioned problems, and its purpose is to solve the various conventional problems mentioned above at once by making a simple design change to the insertion part of the second member. The purpose of the present invention is to provide a sealing structure for bicycle parts.

(Means for Solving the Problems) The present invention provides a pivot shaft 10 between the mounting walls 1a, 1a of the first member 1 having the mounting walls 1a, 1a facing each other, and , a second member 2 having an insertion portion 2a to be inserted between the mounting walls 1a, 1a via the pivot shaft 10 so as to be relatively rotatable between the mounting walls 1a, 1a. A sealing structure in which a gap between the opposing surfaces of the mounting walls 1a, 1a and the insertion part 2a and around the pivot shaft 10 is sealed with an annular sealing member 11, Support shaft 1
0, an inner circumferential surface 12a having a larger diameter than the seal member 11, and a conical bottom surface 1 continuous to the inner circumferential surface 12a.
2b, an annular recess 12 is formed around the pivot shaft 10, and the seal member 11 is movably housed in the annular recess 12.

(Function) If the facing surfaces of the mounting wall 1a and the insertion portion 2a are non-parallel, the mounting wall 1a of the first member 1,
1a, when the insertion portion 2a of the second member 2 is inserted and supported, the seal member 11 housed in the annular recess 12 of the insertion portion 2a receives contact pressure, for example, on the inner wall surface of the mounting wall 1a. As a result, while moving on the conical bottom surface 12b of the recess 12, it is inserted into the gap between the mounting wall 1a and the insertion portion 2a in a uniform state of contact.

Furthermore, when the second member 2 supported as described above is rotated relative to the first member 1, the insertion portion 2a of the second member 2 and the mounting wall 1a of the first member 1 are connected to each other.
For example, the gap formed on the opposing surface of the mounting wall 1a is different between the inner side and the opening side of the mounting wall 1a, that is, the contact pressure against the seal member 11 on the inner side and the opening side of the mounting wall 1a is different. , the sealing member 11 moves on the conical bottom surface 12b of the annular recess 12 from the direction of high contact pressure to the direction of low contact pressure, while always maintaining uniform contact between the mounting wall 1a and the insertion portion 2a. Therefore, the first and second members 1,
2 is ensured, and the entire gap between the first member 1 and the second member 2 is kept closed by the seal member 11, so that sufficient sealing is achieved. .

(Example) The seal structure of a bicycle component according to the present invention will be described below with reference to an example shown in the drawings.

Fig. 6 shows a rear derailleur of a bicycle as an example of bicycle parts.
The member will be described as a base member, and the second member will be referred to as a link member.

The rear derailleur basically includes a base member 1 and two link members 2 extending in parallel.
and a movable member 3.

The base member 1 has a pair of opposing mounting walls 1a, 1a with open side ends on one side in the length direction, and is attached to a stationary member such as a bicycle backhawk on the other side in the length direction. A bracket 4 is supported via a horizontal shaft 5 so as to be freely swingable.

The base member 1 is molded by a mold, and the mounting walls 1a, 1a have a tapered surface 1b on the inner surface thereof, which gradually increases in diameter from the inner side toward the opening side. , 1b are formed.

Further, the movable member 3 has a pair of mounting walls 3a, 3a formed on one side in the length direction, similar to the base member 1, and the horizontal shaft 5 on the other side in the length direction.
A chain guide 8 having pulleys 7, 7 is swingably supported via a horizontal shaft 6 extending in the same direction.

Furthermore, each of the link members 2 has mounting walls 1a, 1a of the base member 1 on both ends in the length direction,
Insert portions 2a to be inserted between the mounting walls 3a, 3a of the movable member 3 are respectively formed, and insertion holes 9 are formed through each of the insertion portions 2a, so that each of the insertion portions 2a is inserted into the base. the mounting walls 1a, 1a formed on the member 1 and the movable member 3;
and 3a, 3a, and the respective mounting walls 1a,
By inserting the pivot shaft 10 into each of the insertion holes 9 through 1a, 3a, and 3a, each link member 2 is supported by the base member 1 and the movable member 3 so as to be able to swing freely.

In the bicycle rear derailleur as described above, the gap between each mounting wall 1a provided on the base member 1 and the insertion portion 2a of the link member 2 inserted and supported between the respective mounting walls 1a is defined as a cross-sectional circle. The ring-shaped sealing member 11 is used to perform sealing with the following sealing structure.

That is, as is clear from FIGS. 1 to 3, the pivot shaft 10 of the insertion portion 2a in the link member 2
each mounting wall 1 provided on the base member 1 around the
an inner circumferential surface 12a having a diameter larger than the outer diameter of the sealing member 11, and an inner circumferential surface 12a on a surface opposite to a;
An annular recess 1 having a conical bottom surface 12b continuous to
2, and the seal member 11 is movably housed in the annular recess 12.

Specifically, an annular recess 1 having a predetermined depth is formed on both upper and lower sides of the insertion portion 2a of the link member 2.
2, the bottom surface of each annular recess 12 is a conical bottom surface 12b whose depth gradually increases from the outer circumferential side to the center side, and between the bottom surface 12b and the mounting wall 1a of the base member 1, The ring-shaped seal member 11 is movably interposed.

By doing so, when inserting and supporting the insertion portion 2a of the link member 2 between the mounting walls 1a of the base member 1, as shown by the solid line in FIG. The sealed seal member 11 receives contact pressure from the tapered surface 1b of the mounting wall 1a and closes in the annular recess 1.
While moving toward the center on the conical bottom surface 12b of No. 2,
As shown by the imaginary line in the figure, the insertion portion is moved to a position where it receives uniform contact pressure in the gap between the tapered surface 1b of the mounting wall 1a and the insertion portion 2a, and the insertion portion is placed in a uniform contact state at this position. It will be equipped.

Further, in the case of switching the rear derailleur, when rotating the link member 2 with respect to the base member 1, since the tapered surface 1b is formed on the mounting wall 1a of the base member 1, The gap formed between the insertion portion 2a of the link member 2 and the facing surface of the mounting wall 1a of the base member 1 is different between the inside side and the opening side of the mounting wall 1a, that is, the gap formed inside the mounting wall 1a is different. The contact pressure against the sealing member 11 on the side and the opening side is different, but in this case, the sealing member 11 is pressed against the conical bottom surface 12b of the annular recess 12, as shown from the solid line state to the imaginary line state in FIG. In this case, while moving from the direction of high contact pressure to the direction of low contact pressure, it is inserted in the gap between the tapered surface 1b of the mounting wall 1a and the insertion portion 2a in a constant state of uniform contact.

Therefore, the link member 2 is connected to the base member 1.
The rotation operation is smooth and good,
Further, the entire gap between the base member 1 and the link member 2 is always kept uniformly closed by the seal member 11, and a sufficient seal is achieved.

In the above embodiment, the annular recess 12 was provided with a conical bottom surface 12b whose depth gradually increased from the outer periphery to the center. Conical bottom surface 12 whose depth gradually becomes shallower from the side to the center
It may also have a shape with b. In this case as well, the seal member 11 moves from the direction of high contact pressure to the direction of low contact pressure due to the rotation of the link member 2.

Further, the inner surface of the mounting wall 1a may be formed by cutting instead of being formed by a template of a molding die.

In the embodiment, only the connecting portion between the base member 1 and the link member 2 has been described, but the present invention can also be applied to the connecting portion between the link member 2 and the movable member 3.

Further, in the above embodiments, the rear derailleur of a bicycle has been described, but the present invention can also be applied to parts such as a brake lever of a bicycle.

(Effect of the invention) As explained above, in the seal structure for bicycle parts according to the invention, the mounting walls 1a, 1
A pivot shaft 10 is provided between the mounting walls 1a, 1a of the first member 1 having a
a second member 2 having an insertion portion 2a inserted between 1a;
Between the facing surfaces of the mounting walls 1a, 1a and the insertion portion 2a in a bicycle component in which the insertion portion 2a is relatively rotatably mounted between the mounting walls 1a, 1a via the pivot shaft 10. And, in the seal structure in which a gap around the pivot shaft 10 is sealed with an annular seal member 11, the seal member 1 is arranged around the pivot shaft 10 of the insertion portion 2a.
An annular recess 12 having an inner circumferential surface 12a having a diameter larger than 1 and a conical bottom surface 12b continuous with the inner circumferential surface 12a and centered on the pivot shaft 10 is formed, and the seal is placed in the annular recess 12. Since the member 11 is movably housed, even if the facing surfaces of the mounting wall 1a and the insertion portion 2a are non-parallel, the first
Smooth and good relative rotation between the second members 1 and 2 can be obtained, and the entire gap between the first member 1 and the second member 2 can be kept closed by the seal member 11, so that a sufficient degree of rotation can be obtained. This made it possible to perform sealing.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a main part showing the seal structure of a bicycle component according to the present invention, Fig. 2 is a plan view of the second member, Fig. 3 is a longitudinal sectional view of a part thereof, Figs. 5 is an explanatory view showing the operating state, FIG. 6 is a side view showing the overall structure of a rear derailleur as an example of bicycle parts, and FIG. 7 is a sectional view showing another embodiment. DESCRIPTION OF SYMBOLS 1... First member (base member), 1a... Mounting wall, 2... Second member (link member), 2a... Insertion part, 10... Pivoting shaft, 11... Seal member, 1
2... Annular recess, 12a... Inner peripheral surface, 12b...
Cone base.

Claims (1)

[Scope of utility model registration request] A first member 1 having opposing mounting walls 1a, 1a has a pivot shaft 10 between the mounting walls 1a, 1a, and a second member 1 having an insertion portion 2a inserted between the mounting walls 1a, 1a. The insertion portion 2a of the member 2
, the mounting walls 1a, 1 via the pivot shaft 10.
A ring-shaped sealing member 11 seals a gap between the opposing surfaces of the mounting walls 1a, 1a and the insertion portion 2a and around the pivot shaft 10 in a bicycle component mounted so as to be relatively rotatable between the parts a. The insertion portion 2a has an inner circumferential surface 12a having a larger diameter than the seal member 11 around the pivot shaft 10.
and a conical bottom surface 12b continuous with the inner circumferential surface 12a, and an annular recess 12 centered on the pivot shaft 10, and the seal member 11 is movably housed in the annular recess 12. A seal structure for bicycle parts featuring: