JP2009040301A - Connection structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To direct a connection structure to utilization when a front fork is laid/attached to a front wheel side of a motorcycle. <P>SOLUTION: A lower half side of an upper end part 11 formed on the front fork F penetrated to a mounting hole of a fork bracket B in a cylindrical shape is made to an inclination part 11a having an outer diameter gradually contracted as it upwardly advances, an upper half side of the upper end part 11 continued to the inclination part 11a is made to a straight part 11b having the same outer diameter. A lower half side of the mounting hole 4 in the fork bracket B is made to a cone-like hole 4a having an inner diameter gradually increased toward a lower side, and an upper half side of the mounting hole 4 in the fork bracket B is made to a straight hole 4b having an inner diameter not varied toward an upper side. By fastening of a cap member 2 thread-engaged with an inner periphery of the straight part 11b penetrated to the straight hole 4b, the inclination part 11a is pulled up by the cone-like hole 4a. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a connection structure, and more particularly to an improvement in a connection structure suitable for use when connecting an upper end portion of a front fork for suspending a front wheel of a two-wheeled vehicle to a fork bracket on a handle side.

  As a connection structure suitable for use when connecting the upper end of a front fork for suspending a front wheel of a two-wheeled vehicle to a fork bracket on the handle side, there have been various proposals so far. Patent Document 2 has a proposal of disclosure.

  That is, in the connection structure disclosed in Patent Document 1, the fork bracket has a split in the mounting hole for conducting the upper end portion of the front fork, and the conduction of the upper end portion of the front fork to the mounting hole is easy. I have to.

  In this connection structure, the mounting hole has an inner flange portion at the upper end, the upper end of the front fork is brought into contact with the lower end of the inner flange portion, and the upper end portion of the front fork penetrates the mounting hole. Is blocking.

  Therefore, in the connection structure disclosed in Patent Document 1, the split of the mounting hole is eliminated by tightening the bolt while the upper end of the front fork is in contact with the lower end of the inner flange portion of the mounting hole. In this way, the upper end portion of the front fork can be connected to a state of being gripped by the fork bracket.

  On the other hand, in the place disclosed in Patent Document 2, the attachment hole in the fork bracket is a tapered hole having a cross-sectional widening, and the upper end portion of the front fork is also formed in a cone shape corresponding to the tapered hole.

Therefore, in the proposal of the coupling structure disclosed in Patent Document 2, the upper end of the front fork is pulled up by the mounting hole by tightening a bolt screwed to the upper end of the front fork, and the wedge at that time As a result, the front fork is integrally connected to the fork bracket.
Japanese Utility Model Publication No. 57-60893 (see FIGS. 1 and 2) Japanese Utility Model Publication No. 57-98991 (see FIG. 2)

  However, in the connection structures disclosed in Patent Document 1 and Patent Document 2 described above, there is no problem in the basic point of connecting the upper end of the front fork to the fork bracket. It may be pointed out that there is a minor defect.

  That is, in the connection structure of Patent Document 1, the tightening force between the inner periphery of the mounting hole and the outer periphery of the front fork is not uniform in the circumferential direction, and thus complete tightening in which the tightening force is uniform in the circumferential direction. There is a problem that cannot be realized.

  In that respect, in the connection structure of Patent Document 2, since the mounting hole does not have a split, it is easy to achieve uniform tightening force from the fork bracket side toward the outer periphery side of the front fork.

  However, in the connection structure of Patent Document 2, considering that the upper end portion of the front fork and the attachment hole of the fork bracket are integrally connected by the wedge effect, for example, the wall thickness of the fork bracket is thick. Therefore, when the taper hole becomes deeper, the so-called inclination angle of the wedge becomes looser as the taper hole becomes deeper. As a result, it is difficult to obtain an effective wedge effect for the amount of stroke between the two. Invoke a bug.

  The present invention was devised in view of such a current situation, and the object of the present invention is suitable for use when a front fork is mounted on the front wheel side of a two-wheeled vehicle and is expected to improve its versatility. It is to provide a connecting structure that is optimal for the purpose.

  In order to achieve the above-described object, the structure of the connecting structure according to the present invention is basically configured such that the upper end of the front fork that suspends the front wheel of the two-wheeled vehicle is connected to the mounting hole of the fork bracket on the handle side and the front fork In the connection structure in which the upper end of the front fork is connected to the fork bracket by screwing the cap member to the upper end, the upper end of the front fork that is connected to the mounting hole of the fork bracket is formed in a cylindrical shape. The lower half side of the part is an inclined part that gradually reduces the outer diameter as it goes upward, and the upper half side of the upper end part that continues to the inclined part is a straight part that has the same outer diameter. The lower half of the hole is a cone-shaped hole that gradually increases in diameter toward the bottom. The upper half of the mounting hole is a straight hole that does not change its inner diameter upward, and a cap member is screwed onto the inner periphery of the straight portion at the upper end of the front fork that is connected to the straight hole. It is assumed that the inclined portion at the upper end portion of the front fork is pulled up by the cone-shaped hole in the mounting hole of the fork bracket by tightening the member.

  Therefore, in the present invention, the upper end portion of the front fork is in a state where the lower half inclined portion of the upper end portion of the front fork is fitted into the lower cone portion of the fork bracket mounting hole. By tightening the cap member that is screwed into the inside of the straight portion, the inclined portion at the upper end portion of the front fork is pulled up by the cone-shaped hole in the mounting hole of the fork bracket and closely contacts.

  At this time, since the upper half straight portion at the upper end portion of the front fork is fitted into the upper half straight hole in the mounting hole of the fork bracket, the centering action is expressed between the two, and therefore the inclined portion and the cone The wedge effect between the holes is obtained as set.

  In addition to forming the inclined portion and the cone-shaped hole as described above, it is not formed over the entire length of the mounting hole in the fork bracket and in the thickness direction of the upper end portion of the front fork. This is not formed over the entire length, but is formed on the lower half side, so that the inclination angle in the inclined portion and the cone-shaped hole can be set to a steep angle that is advantageous for exerting the wedge effect, and with a short movement stroke The wedge effect can be effectively exhibited, and in the integration of both, the adhesion between the two is improved.

  In the following, the present invention will be described based on the illustrated embodiment. As shown in FIG. 1 and FIG. 2, the connection structure according to the present invention has an upper end portion of a front fork F for suspending a front wheel of a two-wheeled vehicle. It is embodied when connecting to the fork bracket B.

  The front fork F has a front wheel connected to the lower end side and suspends the front wheel. On the other hand, the upper end 11 of the cylinder 1 that is the upper end of the front fork F is integrally connected to the fork bracket B.

  At this time, the cylinder 1 is an inner tube when the front fork F is set upright, and is an outer tube when the front fork F is set upside down.

  In the front fork F, the upper end opening of the cylindrical body 1 is closed by screwing the cap member 2, and the shaft core portion of the cap member 2 has a damper in which the front fork F is built. The upper end of the rod body 3 is screwed under the presence of the lock nut 3a.

  By the way, as will be described later, in the connection structure of the present invention, the upper end portion of the front fork F is in a state where the upper end portion 11 of the front fork F is electrically connected to the mounting hole 4 of the fork bracket B on the handle side. The upper end of the front fork is connected to the fork bracket by tightening the cap member 2 screwed into the fork 11.

  At this time, the cap member 2 has the outer peripheral flange portion 2a at the upper end, and the lower end of the outer peripheral flange portion 2a is brought into contact with the upper end of the boss portion 11c forming the attachment hole 4 in the fork bracket B. A gap A appears between the lower end of the portion 2a and the upper end of the upper end portion 11 of the front fork F.

  Therefore, in the cap member 2, the mounting hole in the fork bracket B of the upper end portion 11 in the front fork F is operated by screwing the flange portion 2 a in a state where the flange portion 2 a is in contact with the boss portion 11 c. Can be raised by 4.

  At this time, since the gap A appears between the lower end of the outer peripheral flange portion 2a and the upper end of the upper end portion 11 of the front fork F, the upper end portion 11 of the front fork F is engaged by the screwing operation of the cap member 2. The raising is not hindered.

  Further, the fork bracket B is composed of a single bracket having a front fork F on the left and right and a steering shaft S at the center as shown in FIG. .

  And this fork bracket B is in the fork bracket disclosed in the above-mentioned Patent Document 1 and is set to a structure that does not have a split in the mounting hole 4 in view of the inconvenience caused by the split in the mounting hole. Has been.

  In addition, in the fork bracket B according to the present invention, the gap A described above is formed instead of having an inner flange portion at the upper end of the mounting hole as in the fork bracket disclosed in Patent Document 1 described above. In some cases, the inner flange portion is not provided at the upper end of the mounting hole 4.

  Therefore, in view of the fact that the upper end of the mounting hole 4 does not have an inner flange portion, the fork bracket B is formed when the above-mentioned inner flange portion is formed, particularly when machining a cast prototype. There is no need to form, and there is an advantage that labor can be saved in parts processing.

  When connecting the upper end 11 of the front fork F formed as described above to the fork bracket B formed as described above, the connection structure of the present invention is used.

  Therefore, in the following, this connection structure will be described. The connection structure according to the present invention gradually reduces the outer diameter as the lower half side of the upper end portion 11 of the front fork F formed in a cylindrical shape goes upward. That is, the inclined portion 11a is formed to gradually reduce the thickness on the outer peripheral side without changing the inner diameter.

  The upper half of the upper end 11, that is, the upper half of the upper end 11 connected to the inclined portion 11 a goes upward, and the outer diameter is made the same, that is, the inner diameter is not changed. The straight portion 11b has the same thickness, and the screw portion 2b of the cap member 2 is screwed to the inner periphery of the straight portion 11b.

  And in the attachment hole 4 in the fork bracket B that accepts the upper end portion 11 formed as described above, the lower half side is a cone-shaped hole 4a that gradually increases the inner diameter downward, and the upper half side is The straight hole 4b does not change the inner diameter upward.

  At this time, the inner diameter of the straight hole 4b is set to a dimension that allows the straight portion 11b to be inserted, and the inclination angle of the cone-shaped hole 4a is set to an angle that allows the inclined portion 11a to be closely contacted. Of course.

  As described above, in the fork bracket B according to the present invention, the attachment hole 4 is formed by the lower half cone-shaped hole 4a and the upper half straight hole 4b. This is advantageous as compared with the fork bracket disclosed in Patent Document 1.

  That is, in the fork bracket disclosed in Patent Document 1, since the mounting hole is composed of only a straight hole, there is an advantage that this can be formed by using only one drill, but it is possible to make it for a long time. The use of a book drill is disadvantageous in terms of the durability of the drill.

  On the other hand, in the fork bracket B of the present invention, the cone-shaped hole 4a is once formed by one drill, and then the straight hole 4b is formed by using another drill. Although it is disadvantageous to use, the use time of each drill can be shortened, and therefore, it is advantageous in ensuring the durability of each drill.

  Since the upper end portion 11 of the front fork F and the mounting hole 4 in the fork bracket B on the handle side for conducting the same are formed as described above, the upper end portion 11 of the front fork F is formed in the connecting structure of the present invention. The upper end portion 11 of the front fork F can be integrally connected to the fork bracket B by tightening the cap member 2 screwed into the upper end portion 11 in a state where it is conducted to the mounting hole 4 of the fork bracket B. .

  That is, the upper end portion 11 of the front fork F is in a state where the lower half inclined portion 11a of the upper end portion 11 of the front fork F is fitted into the lower half cone-shaped hole 4a of the attachment hole 4 of the fork bracket B. By tightening the cap member 2 screwed inside the straight portion 11b, the inclined portion 11a at the upper end portion 11 of the front fork F is pulled up by the cone-shaped hole 4a in the attachment hole 4 of the fork bracket B and is brought into close contact therewith.

  At this time, since the upper half straight portion 11b of the upper end portion 11 of the front fork F is fitted and inserted into the upper half straight hole 4b of the attachment hole 4 of the fork bracket B, a centering action is expressed between the two. Therefore, the wedge effect between the inclined portion 11a and the cone-shaped hole 4a is obtained as set.

  In addition, the inclined portion 11a and the cone-shaped hole 4a are formed over the entire length of the mounting hole 4 in the fork bracket B in the thickness direction, and the upper end of the front fork F is not formed. This is not formed over the entire length of the portion 11 in the thickness direction, but is formed on the lower half side, so that the inclination angle in the inclined portion 11a and the cone-shaped hole 4a is advantageous for exerting the wedge effect. The wedge effect can be effectively exhibited with a short movement stroke, and the adhesion between the two is improved in the integration of the two.

  In the above description, the fork bracket B is made of a so-called single piece. However, according to the intention of the present invention, even if the fork bracket B is made of two pieces of an upper bracket and an under bracket, Of course, the present invention can be realized.

It is a top view which shows the fork bracket with which the front fork and steering shaft which embody the connection structure by this invention were connected. FIG. 2 is a partial cross-sectional front view showing a state in which an upper end portion of a front fork is connected to a fork bracket at a position along line XX in FIG. 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Cylindrical body which comprises a front fork 2 Cap member 2a Outer flange part 2b Screw part 3 Rod body 3a Lock nut 4 Mounting hole 4a Cone-shaped hole 4b Straight hole 11 Upper end part 11a Inclined part 11b Straight part 11c Boss part A Crevice B Fork bracket F Front fork

Claims (3)

The upper end of the front fork that suspends the front wheel of the motorcycle is connected to the mounting hole of the fork bracket on the handle side, and the upper end of the front fork is connected to the fork bracket by screwing the cap member to the upper end of the front fork. In the connection structure, the upper end portion of the front fork that is conducted to the mounting hole of the fork bracket is formed in a cylindrical shape, and the lower half side of the upper end portion is an inclined portion that gradually reduces the outer diameter as it goes upward. The upper half of the upper end connected to the inclined part is a straight part having the same outer diameter, and the lower half of the mounting hole in the fork bracket is a cone-shaped hole that gradually increases in inner diameter downward. The upper half side of the mounting hole in is a straight hole that does not change the inner diameter upward, The cap member is screwed onto the inner periphery of the straight portion at the upper end portion of the front fork that is conducted to the straight hole of the front fork, and when the cap member is tightened, the inclined portion at the upper end portion of the front fork becomes the cone in the mounting hole of the fork bracket. A connecting structure characterized by being pulled up by a hole. The cap member has an outer peripheral flange portion at the upper end, and the lower end of the outer peripheral flange portion is brought into contact with the upper end of the boss portion that forms the mounting hole in the fork bracket, and the lower end of the flange portion and the upper end of the upper end portion of the front fork The connection structure according to claim 1, wherein a gap appears between them. The connecting structure according to claim 1 or 2, wherein the front fork has a damper built in the shaft core portion, and an upper end portion of a rod body forming the damper is screwed to the shaft core portion of the cap member.

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