Motorcycle front forks

Abstract

To provide a front fork of a motorcycle that has a simple appearance due to absence of an outstanding component about the fork, has a suspension feature, and has its trail easily adjusted.SOLUTION: A front fork 1 of a motorcycle includes a front wheel support member 3 that supports a rotation shaft of a front wheel at one end, a fork pipe 2 having an orifice 8, into which the other end of the front wheel support member 3 is inserted to pass through, formed in a lateral wall of a lower part, a support member 11 that freely rotatively supports the other end of the front wheel support member 3 which is disposed on a lateral wall of a lower part of the fork pipe 2 and which pierces the orifice 8, a rod 5 disposed above the front wheel support member 3 inside the fork pipe 2, and an upper spring 4 interposed inside the fork pipe 2 between the rod 5 and an upper part closing member that closes an upper part of the fork pipe 2.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a front fork of a motorcycle for supporting a front wheel so as to be able to rotate freely. [Background technology]

[0002] It is common for people to replace motorcycle parts with parts of their choice. For example, some people replace the front forks of their motorcycles with long forks (long front forks). With long forks, motorcycles with fewer noticeable parts are often preferred, as they look like a simple, long rod.

[0003] Suspension-related parts are attached to the front fork. There are various types of suspension, such as the telescopic type in which large and small cylinders are fitted as described in Patent Document 1, and the springer type in which the spring is attached exposed as described in Patent Document 2. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 58-93685 [Patent Document 2] Utility Model Registration No. 3145779 Summary of the Invention [Problem to be solved by the invention]

[0005] The telescopic type suspension described in Patent Document 1 and the springer type suspension described in Patent Document 2 have conspicuous suspension mechanisms, so in the case of a long fork, for example, a simpler appearance may be desired. Using a rigid type front fork, in which the front wheel is fixed to a fork without suspension, results in severe vibration.

[0006] Furthermore, when using long forks, the fork angle becomes flatter, increasing the trail. Since the amount of trail affects the handling stability and turning ability, there is a demand for adjusting the trail.

[0007] The present invention has been made to solve the above-mentioned problems, and has an object to provide a front fork for a motorcycle that has a simple appearance with no noticeable parts around the fork, yet has a suspension function and allows easy trail adjustment. [Means for solving the problem]

[0008] In order to achieve the above object, the front fork of a motorcycle described in claim 1 of the claims is a front fork of a motorcycle for supporting a front wheel so as to be freely rotatable, a front wheel support member for supporting a rotation shaft of the front wheel at one end side; a fork pipe having an opening formed in a side wall on the lower side, through which the other end of the front wheel support member is inserted; a support member provided on a side wall of a lower portion of the fork pipe, the support member rotatably supporting the other end of the front wheel support member that passes through the opening; an upper spring disposed inside the fork pipe between the front wheel support member and an upper closing member that closes an upper portion of the fork pipe; a rod disposed inside the fork pipe between the front wheel support member and the upper spring, One end of the front wheel support member is located in front of the fork pipe, The fork pipe is flexible, A gap is provided between the inner wall of the fork pipe and the rod, allowing the inner wall and the rod to come into contact with each other when the fork pipe is bent. It is characterized by:

[0009] The front fork of the motorcycle described in claim 2 is the one described in claim 1, The rod is a hollow pipe. It is characterized by the following.

[0010] The front fork of a motorcycle described in claim 3 is the one described in claim 1 or 2, and is characterized in that the upper blocking member has an upper male screw that is screwed into the upper end of the fork pipe, and the compression amount of the upper spring can be adjusted by the amount of screwing of the upper male screw.

[0011] The front fork of a motorcycle described in claim 4 is the one described in any one of claims 1 to 3, and is characterized in that it has a lower spring arranged inside the fork pipe between the front wheel support member and a lower blocking member that blocks the lower part of the fork pipe.

[0012] The front fork of a motorcycle described in claim 5 is the same as that described in claim 4, and is characterized in that the lower blocking member is provided with a lower male screw that is screwed into the lower end of the fork pipe, and the compression amount of the lower spring can be adjusted by the amount of screwing of the lower male screw.

[0013] The front fork of a motorcycle described in claim 6 is the front fork of any one of claims 1 to 5, and is characterized in that when an imaginary line is defined as a virtual line that passes through the center of the rotation axis of the front wheel support member, which is rotatably supported by the support member, and is perpendicular to the central axis of the fork pipe, the center of the rotation axis of the front wheel is always located below the imaginary line. The front fork of a motorcycle described in claim 7 is the front fork of claim 6, characterized in that the front wheel support member is formed in a mountain shape when viewed from the side.

[0014] Claim 8 The front fork of the motorcycle described in the above is the one described in any one of claims 1 to 5, and is characterized in that when an imaginary line is defined as a virtual line that passes through the center of the rotation axis of the front wheel support member, which is rotatably supported by the support member, and is perpendicular to the central axis of the fork pipe, the center of the rotation axis of the front wheel is always located above the imaginary line. The front fork of a motorcycle described in claim 9 is the one described in claim 8, characterized in that the front wheel support member is formed in a V-shape when viewed from the side. [Effects of the Invention]

[0015] In the motorcycle front fork of the present invention, the front wheel support member is provided on the inconspicuous lower side of the front fork, resulting in a simple appearance with no conspicuous parts around the fork. The front wheel support member functions as a suspension thanks to the upper spring inside the fork pipe. Furthermore, trail can be easily adjusted by replacing the front wheel support member with one of a different length.

[0016] When a rod is placed inside the fork pipe, the double structure of the fork pipe and the rod makes it possible to increase the strength of the front fork. Also, by adjusting the gap between the fork pipe and the rod (the thickness of the rod), the strength and flex of the front fork can be adjusted. For example, increasing the gap between the fork pipe and the rod increases the flex of the front fork, while decreasing the gap decreases the flex. Making the rod thicker increases the strength of the front fork.

[0017] If a lower spring is provided inside the fork pipe, vibrations can be damped more quickly than if only an upper spring is provided.

[0018] If the fork pipe has an upper male thread, the compression amount of the upper spring can be adjusted by changing the amount of threading of the upper male thread, allowing the suspension characteristics to be adjusted.If the fork pipe has a lower male thread, the compression amount of the lower spring can be adjusted, allowing the suspension characteristics to be adjusted by changing the amount of threading of the lower male thread.

[0019] If the front wheel support member is provided so that the center of the front wheel rotation axis is always located below the imaginary line, the visual effect is that the front fork appears longer.If the front wheel support member is provided so that the center of the front wheel rotation axis is always located above the imaginary line, the front fork will sink when the front wheel brake is applied, resulting in a riding feel similar to that of a telescopic front fork commonly used on motorcycles. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side view schematically showing a state in which a front fork of a motorcycle to which the present invention is applied is in use. [Figure 2] 1 is a side view showing the structure of a front fork of a motorcycle to which the present invention is applied. [Figure 3] 1 is a side view schematically showing a state in which a front fork of a motorcycle to which the present invention is applied is used, and showing characteristics during braking depending on the shape of the front wheel support member; [Figure 4] FIG. 10 is a side view showing the structure of a front fork of another motorcycle to which the present invention is applied. [Figure 5] FIG. 10 is a side view showing the structure of a front fork of another motorcycle to which the present invention is applied. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments for carrying out the present invention will be described in detail, but the scope of the present invention is not limited to these embodiments.

[0022] Fig. 1 is a side view showing a schematic representation of the use of the front fork of a motorcycle to which the present invention is applied. The figure shows a side view of the left front fork and its surroundings of the motorcycle. The figure shows only the main parts related to the present invention, and does not show other components of the motorcycle. Note that terms indicating directions such as up, down, left, right, front, and rear in the description are all expressed based on the directions as seen from a rider riding the motorcycle.

[0023] The front forks 1 of the motorcycle to which the present invention is applied are, for example, used in a pair, one on the left and one on the right, to rotatably support the front wheel 90. While the left front fork 1 is shown in the figure, a symmetrical front fork is also provided on the right side of the motorcycle. The front wheel 90 is supported by a front wheel support member 3. The front fork 1 is connected to a frame 93 by a steering stem 92 when in use. A steering axis A, indicated by a dashed line in the figure, is the axis of rotation about which the front wheel 90 turns.

[0024] Figure 2 is a side view showing the structure of a front fork 1 of a motorcycle to which the present invention is applied. The front fork 1 of a motorcycle to which the present invention is applied is characterized by comprising a front wheel support member 3 for supporting one end of a rotating shaft 91 (see Figure 1) of a front wheel 90, a fork pipe 2 having an opening 8 formed in its lower side wall through which the other end of the front wheel support member 3 is inserted, a support member 11 provided in the lower side wall of the fork pipe 2 for rotatably supporting the other end of the front wheel support member 3 that passes through opening 8, and an upper spring 4 arranged inside the fork pipe 2 between the front wheel support member 3 and an upper closing member (an upper male screw 21) that closes the upper part of the fork pipe 2.

[0025] Moreover, the front fork 1 of the motorcycle preferably includes a rod 5 disposed inside the fork pipe 2 between the front wheel support member 3 and the upper spring 4.

[0026] Furthermore, it is preferable that the front fork 1 of the motorcycle is provided with a lower spring 6 arranged inside the fork pipe 2 between the front wheel support member 3 and a lower closing member (lower side male thread 22) that closes the lower part of the fork pipe 2.

[0027] It is also preferable that the upper blocking member has an upper male screw 21 that screws into the upper end of the fork pipe 2, and that the amount of compression of the upper spring 4 can be adjusted by the amount of threading of the upper male screw 21. It is also preferable that the lower blocking member has a lower male screw 22 that screws into the lower end of the fork pipe 2, and that the amount of compression of the lower spring 6 can be adjusted by the amount of threading of the lower male screw 22. This will be explained in detail below.

[0028] As shown in FIG. 2, the fork pipe 2 is a rod-shaped tube formed hollow. One example of the fork pipe 2 is a round pipe. A round pipe is preferable because it has high strength. The fork pipe 2 may have any shape depending on design requirements. For example, the fork pipe 2 may be a square pipe, a hexagonal pipe, or an elliptical pipe. Alternatively, the fork pipe 2 may have any appearance, such as a spirally twisted pipe, and the hollow hole of the pipe may be a round or square hole.

[0029] The opening 8 opening at the lower side of the fork pipe 2 is formed to penetrate the side wall of the fork pipe 2 in the front-to-rear direction. As an example, the opening 8 penetrates the fork pipe 2 perpendicular to the axis of the fork pipe 2. As shown by the two-dot chain arrow in the figure, the opening 8 is formed in the fork pipe 2 so as to open with a vertical width (vertical width) that allows the front wheel support member 3 to rotate back and forth in the up-and-down direction.

[0030] The support member 11 is made up of, for example, a pair of plates that sandwich the other end (rear side) of the front wheel support member 3. The support member 11 is fixed to the rear side of the fork pipe 2, for example by welding. The support member 11 is formed with a shaft hole 14 through which a rotating shaft 15 that supports the front wheel support member 3 passes.

[0031] A shaft hole 12 through which a rotating shaft 15 passes is formed on the other end side of the front wheel support member 3. The rotating shaft 15 passes through the shaft hole 14 of the support member 11 and the shaft hole 12 of the front wheel support member 3, and the front wheel support member 3 is rotatably supported by the support member 11. The front wheel support member 3 rotates in the vertical direction (top-bottom direction). The rotating shaft 15 is attached to the support member 11 and is prevented from coming off by a fixing member such as a nut (not shown).

[0032] An axle hole 13 through which a rotation axle 91 (see FIG. 1) of a front wheel 90 passes is formed at one end (front side) of the front wheel support member 3. The front wheel support member 3 is formed of a plate material, for example. The shape of the front wheel support member 3 is arbitrary, and may be formed in a mountain shape as shown in the same figure, a straight plate shape, a V shape, or a complex shape rich in design.

[0033] The rod 5 is disposed inside the fork pipe 2 and above the front wheel support member 3. The rod 5 abuts against the upper side of the front wheel support member 3. The rod 5 may abut directly against the upper side of the front wheel support member 3, or may abut indirectly via a height adjustment member such as a collar or washer.

[0034] The rod 5 is formed with a thickness that allows it to move axially inside the fork pipe 2. In other words, the rod 5 is formed with a thickness that leaves a gap between the rod 5 and the inner wall of the fork pipe 2. There are no limitations on the cross-sectional shape of the rod 5. As an example, it is preferable that the cross-sectional shape of the rod 5 and the cross-sectional shape of the inner wall of the fork pipe 2 are similar. For example, if the fork pipe 2 is a round pipe, it is preferable that the rod 5 is a round bar. If the fork pipe 2 is a hexagonal pipe, it is preferable that the rod 5 is a hexagonal bar. The rod 5 may be a bar material or a hollow pipe.

[0035] If the rod 5 is present inside the fork pipe 2, the fork pipe 2 and the rod 5 form a double structure, which makes the strength higher than that of the fork pipe 2 alone. Changing the length of the gap between the inner wall of the fork pipe 2 and the rod 5, i.e., changing the thickness of the rod 5, changes the way the fork pipe 2 contacts the rod 5 when it bends, and therefore makes it possible to change the degree of flex and strength of the front fork 1. The smaller the gap between the inner wall of the fork pipe 2 and the rod 5, i.e., the thicker the rod 5, the higher the strength of the front fork 1 and the lower the degree of flex. Conversely, the larger the gap between the inner wall of the fork pipe 2 and the rod 5, i.e., the thinner the rod 5, the greater the degree of flex of the front fork 1. Furthermore, increasing the length of the rod 5 increases the length of the double structure between the fork pipe 2 and the rod 5, thereby increasing the strength of the front fork 1.

[0036] The upper spring 4 is disposed inside the fork pipe 2, above the rod 5. In this example, an upper male screw 21 is disposed at the upper end of the fork pipe 2 as an upper closing member, and therefore the upper spring 4 is disposed between the rod 5 and the male screw 21. The lower end of the upper spring 4 abuts against the upper part of the rod 5. The upper end of the upper spring 4 abuts against the lower part (tip) of the male screw 21. In any position in which the front wheel support member 3 rotates up and down as a suspension, the upper spring 4 expands and contracts, so that the upper spring 4 is always abutting against the upper side of the rod 5 and also against the male screw 21, which is the upper closing member.

[0037] The upper spring 4 may be in direct contact with the upper side of the rod 5, or indirect contact via a height adjustment member such as a collar or washer. The upper spring 4 may be in direct contact with the upper closing member (male thread 21) on the upper end side of the fork pipe 2, or indirect contact via a height adjustment member such as a collar or washer.

[0038] The upper spring 4 is preferably a compression coil spring. In this example, the male screw 21 is a bolt. By screwing in the male screw 21, the upper spring 4 is compressed. By changing the amount of screwing in the male screw 21, the amount of compression of the upper spring 4 can be changed, allowing the suspension characteristics to be adjusted.

[0039] The upper spring 4 may be a plurality of springs (for example, two) arranged in series. The plurality of springs may have different characteristics. It is preferable that the upper closing member be configured so that the amount of threading of the male screw 21 can be variably adjusted, but it may also be configured to simply close the upper end of the fork pipe 2, depending on the need.

[0040] By having the upper spring 4, the front fork 1 functions as a suspension, but as shown in the figure, it is more preferable to have a lower spring 6 inside the fork pipe 2. Note that the lower spring 6 can be omitted if not necessary.

[0041] The lower spring 6 is disposed inside the fork pipe 2 and below the front wheel support member 3. In this example, a lower male screw 22 is disposed at the lower end of the fork pipe 2 as a lower closing member, and therefore the lower spring 6 is disposed between the front wheel support member 3 and the male screw 22. The upper end of the lower spring 6 abuts against the lower side of the front wheel support member 3. The lower end of the lower spring 6 abuts against the upper part (tip) of the male screw 22. In any position in which the front wheel support member 3 rotates up and down as a suspension, the lower spring 6 expands and contracts, so that the lower spring 6 is always abutting against the lower side of the front wheel support member 3 and against the male screw 22 as a lower closing member, preferably.

[0042] The lower spring 6 may be in direct contact with the lower side of the front wheel support member 3, or indirect contact via a height adjustment member such as a collar or washer. The lower spring 6 may be in direct contact with the lower blocking member on the lower end side of the fork pipe 2, or indirect contact via a height adjustment member such as a collar or washer.

[0043] The lower spring 6 is preferably a compression coil spring. In this example, the male screw 22 is a bolt. The lower spring 6 is compressed by screwing in the male screw 22. By changing the amount of screwing in the male screw 22, the amount of compression of the lower spring 6 can be changed, allowing the suspension characteristics to be adjusted.

[0044] The lower spring 6 may be a plurality of springs (for example, two) arranged in series. The plurality of springs may have different characteristics. It is preferable that the lower closing member be configured so that the amount of threading of the male screw 22 can be variably adjusted, but it may also be configured to simply close the lower end of the fork pipe 2, depending on the need.

[0045] Providing the lower springs 6 can damp vibrations of the front wheels 90 more quickly than providing only the upper springs 4. When providing both the upper springs 4 and the lower springs 6, the upper springs 4 may be used as the main suspension and the lower springs 6 as the sub-suspension (for vibration damping), or the upper springs 4 may be used as the sub-suspension (for vibration damping) and the lower springs 6 as the main suspension. The characteristics of the upper springs 4 and lower springs 6 may be set appropriately according to need.

[0046] As explained above, the front fork of the motorcycle of the present invention has a suspension function, as shown by the two-dot chain arrow in Figure 2, in which the front wheel support member 3 can rotate back and forth in the up and down direction, and the movement of the front wheel support member 3 is cushioned by the upper spring 4 and the lower spring 6.

[0047] In the front fork of the motorcycle of the present invention, the trail amount can be easily adjusted by replacing the front wheel support member 3.

[0048] As shown in Figure 1, trail is the distance T between the "intersection of the steering axis A and the ground" and the "ground contact point G of the front wheel 90." Replacing the front wheel support member 3 with one that is shorter in the fore-and-aft direction can increase the trail, and conversely, replacing the front wheel support member 3 with one that is longer in the fore-and-aft direction can decrease the trail.

[0049] FIG. 3 shows the front wheel braking characteristics depending on the shape of the front wheel support member. Imaginary line S is an imaginary line that passes through the center (axial center) 41 of the pivot shaft 15 (shaft hole 12) of the front wheel support member 3 and is perpendicular to the central axis F of the fork pipe 2. FIG. 3(a) schematically shows the front fork 1 having the mountain-shaped front wheel support member 3 described above in use. FIG. 3(b) schematically shows the front fork 1a having the V-shaped front wheel support member 3a in use. The configuration of the front fork 1a other than the front wheel support member 3a is the same as that of the front fork 1. Note that the front wheel brake is not shown. The front wheel brake is a conventional drum brake or disc brake. The front wheel brake's detent is fixed, for example, to the front wheel support member 3, 3a.

[0050] As shown in Figure 3(a), the front wheel support member 3 of the front fork 1 is formed in a mountain shape, for example, so that the center (axial center) 42 of the rotation shaft 91 (shaft hole 13) of the front wheel 90 is located below the imaginary line S. For this reason, when the front wheel 90 is braked, the fork pipes 2 of the front fork 1 are raised upward as shown by the two-dot chain arrow U. From a design perspective, the front wheel support member 3 has a visual effect of emphasizing the length of the fork pipes 2.

[0051] On the other hand, the front wheel support member 3a of the front fork 1a shown in Figure 3(b) is formed in a V-shape, for example, so that the center (axial center) 42 of the rotation shaft 91 (shaft hole 13) of the front wheel 90 is located above the imaginary line S. As a result, in the front fork 1a, when the front wheel 90 is braked, the fork pipe 2 sinks downward as shown by the two-dot chain arrow D. In terms of riding feel during braking, the front wheel support member 3a is closer to a telescopic type because the front fork 1a sinks.

[0052] It is possible to use a front wheel support member shaped such that the center (axial center) 42 of the rotation shaft 91 (axial hole 13) of the front wheel 90 is located below the imaginary line S, such as the front wheel support member 3, or it is possible to use a front wheel support member shaped such that the center (axial center) 42 of the rotation shaft 91 (axial hole 13) of the front wheel 90 is located above the imaginary line S, such as the front wheel support member 3a. The choice can be made based on preferences such as design and riding feel.

[0053] The front wheel support member 3 (3a) functions as a suspension and rotates in response to road conditions, vibrations, load changes, and the like while the motorcycle is traveling. The shape of the front wheel support member 3 (3a) may be determined taking into consideration that the positional relationship (whether it is above or below) of the center 42 of the front wheel 90 with respect to the imaginary line S does not change when the front wheel support member 3 (3a) rotates. In other words, the front wheel support member may be shaped so that the center 42 of the front wheel 90 is always located below the imaginary line S when the front wheel support member rotates, or the front wheel support member may be shaped so that the center 42 of the front wheel 90 is always located above the imaginary line S. Furthermore, for example, the lower spring 6 may be made stronger so that the front wheel support member 3 (3a) is less likely to rotate downward, thereby preventing the positional relationship of the center 42 of the front wheel 90 with respect to the imaginary line S from changing. In addition, when the front wheel support member 3 (3a) rotates due to road conditions, vibrations, load changes, etc. while the two-wheeled vehicle is traveling, the center 42 of the front wheel 90 may move above or below the imaginary line S.

[0054] It should be noted that a configuration like the front fork 1b shown in FIG. 4 may also be used. The front fork 1b is an example in which a middle spring 7 is arranged inside the fork pipe 2, between the front wheel support member 3 and the rod 5. Other configurations of the front fork 1b are the same as those of the front fork 1. The lower end of the middle spring 7 abuts against the upper part of the front wheel support member 3. The upper end of the middle spring 7 abuts against the lower part of the rod 5. The middle spring 7 may abut directly against the upper side of the front wheel support member 3, or may abut indirectly via a height adjustment member such as a collar or washer. The middle spring 7 may abut directly against the rod 5, or may abut indirectly via a height adjustment member such as a collar or washer. The middle spring 7 may be configured by arranging multiple springs (for example, two) in series. The multiple springs may have different characteristics.

[0055] In this front fork 1 b, the movement of the front wheel support member 3 is buffered by the upper spring 4 , the middle spring 7 and the lower spring 6 .

[0056] Furthermore, although not shown, the rod 5 of the front fork 1 or the front fork 1b may be configured by arranging a plurality of short rods in series, with springs provided between each rod.

[0057] Alternatively, a front fork 1c as shown in FIG. 5 may be used. The front fork 1c is an example in which an upper spring 4 is disposed inside the fork pipe 2 between the front wheel support member 3 and the upper closing member (the upper external thread 21) without including a rod 5. The other configurations of the front fork 1c are the same as those of the front fork 1. The lower end of the upper spring 4 abuts against the upper part of the front wheel support member 3. The upper end of the upper spring 4 abuts against the lower part (tip) of the external thread 21. The upper spring 4 may abut directly against the upper side of the front wheel support member 3, or may abut indirectly via a height adjustment member such as a collar or washer. The upper spring 4 may abut directly against the upper closing member (the external thread 21) on the upper end side of the fork pipe 2, or may abut indirectly via a height adjustment member such as a collar or washer.

[0058] This front fork 1c has a simple structure without a rod 5. The movement of the front wheel support member 3 is buffered by an upper spring 4 and a lower spring 6.

[0059] Furthermore, although an example has been described in which the front forks 1 to 1c are used in a pair on the left and right to rotatably support the front wheel 90, the front fork of the motorcycle of the present invention can also be applied to a so-called cantilever type front fork in which a single front fork 1 to 1c supports the front wheel 90 in a rotatable manner.

[0060] The front fork of the motorcycle of the present invention is not limited to a long fork, but can be applied to a front fork of any length. For example, the front fork of the motorcycle of the present invention can be applied to a front fork of a normal length. [Explanation of symbols]

[0061] Reference numerals 1, 1a, 1b, and 1c indicate the front fork of a motorcycle, 2 is a fork pipe, 3 and 3a are front wheel support members, 4 is an upper spring, 5 is a rod, 6 is a lower spring, 7 is a middle spring, 8 is an opening hole, 11 is a support member, 12 is an axle hole, 13 is an axle hole, 14 is an axle hole, 15 is a rotating shaft, 21 is an upper male screw, 22 is a lower male screw, 41 is the center (axis) of the rotating shaft of the front wheel support member, 42 is the center (axis) of the rotating shaft of the front wheel, 90 is the front wheel, 91 is the rotating shaft, 92 is the steering stem, 93 is the frame, A is the steering axis (steer axis), D is a two-dot chain arrow, F is the central axis (axis) of the fork pipe, G is the contact point of the front wheel, S is an imaginary line, T is the trail, and U is a two-dot chain arrow.

Claims

1. A front fork of a motorcycle for rotatably supporting a front wheel, a front wheel support member for supporting a rotation shaft of the front wheel at one end side; a fork pipe having an opening formed in a side wall on the lower side, through which the other end of the front wheel support member is inserted; a support member provided on a side wall of a lower portion of the fork pipe, the support member rotatably supporting the other end of the front wheel support member that passes through the opening; an upper spring disposed inside the fork pipe between the front wheel support member and an upper closing member that closes an upper portion of the fork pipe; a rod disposed inside the fork pipe between the front wheel support member and the upper spring, One end of the front wheel support member is located in front of the fork pipe, The fork pipe is flexible, A front fork for a motorcycle, wherein a gap is provided between an inner wall of the fork pipe and the rod, allowing the inner wall and the rod to come into contact with each other when the fork pipe is bent.

2. A front fork of a motorcycle as described in Claim 1, characterized in that the rod is a hollow pipe.

3. 3. The front fork of a motorcycle according to claim 1, wherein the upper blocking member comprises an upper male screw that is screwed into the upper end of the fork pipe, and the compression amount of the upper spring can be adjusted by the amount of screwing of the upper male screw.

4. 4. The front fork of a motorcycle according to claim 1, further comprising a lower spring disposed inside the fork pipe between the front wheel support member and a lower closing member that closes a lower portion of the fork pipe.

5. 5. The front fork of a motorcycle according to claim 4, wherein the lower blocking member comprises a lower male screw that is screwed into a lower end of the fork pipe, and the compression amount of the lower spring can be adjusted by the amount of screwing of the lower male screw.

6. 6. The front fork of a motorcycle according to claim 1, further comprising: a front wheel support member rotatably supported by the support member, the front wheel support member being provided with a front fork such that, when an imaginary line is defined as a line that passes through the center of a rotation axis of the front wheel support member, the front wheel support member being rotatably supported by the support member, and that is perpendicular to a central axis of a fork pipe, the center of the rotation axis of the front wheel is always located below the imaginary line.

7. A front fork of a motorcycle as described in Claim 6, characterized in that the front wheel support member is formed in a mountain shape when viewed from the side.

8. 6. The front fork of a motorcycle according to claim 1, further comprising: a front wheel support member rotatably supported by the support member, the front wheel support member being provided with a front fork such that, when an imaginary line is defined as a line that passes through the center of a rotation axis of the front wheel support member, the front wheel support member being rotatably supported by the support member, and that is perpendicular to a central axis of a fork pipe, the center of the rotation axis of the front wheel is always located above the imaginary line.

9. A front fork of a motorcycle as described in Claim 8, characterized in that the front wheel support member is formed in a V-shape when viewed from the side.

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