Motorcycle front suspension

Abstract

A motorcycle front suspension (10) comprising: - a steering arm (11) mechanically connected or adapted to be mechanically connected to a handlebar (7) of a motorcycle (1), wherein the steering arm (11) comprises a main body and a connecting arm (15) protruding from the main body; - a swingarm (12, 32) having a first connecting portion (13) and a second connecting portion (14), the first connecting portion rotatably connecting the swingarm (12, 32) to the steering arm (11) in correspondence of said connecting arm (15), the second connecting portion being adapted and configured to connect the swingarm (12, 32) with an associated front wheel (2); - a shock absorber group (20) extending from an attachment head (21) mechanically connected to the steering arm (11) to an attachment foot (22) rotatably engaged to the swingarm (12, 32); wherein the motorcycle front suspension (10) comprises a disc brake caliper (30) fixed to the swingarm (12, 32).

Description

Technical Field

[0001] This invention relates to the technical field of suspensions for transport vehicles, and particularly to front suspensions for motorcycles. Background Technology

[0002] In the motorcycle industry, it is known that swingarm suspensions are used in the front suspension of motorcycles. Swingarm suspensions, which can be single-sided or double-sided, typically include a rigid arm, also called a steering arm, on which the swingarm is hinged and terminates on the front axle. For example, a single-sided swingarm suspension is described in European Patent EP2996929B1.

[0003] In a known swingarm suspension, the steering arm is mechanically connected to the motorcycle's handlebars. Additionally, a shock absorber assembly, typically including springs and dampers, is attached to the swing arm. This shock absorber assembly then mechanically connects the steering arm to the front wheel axle.

[0004] Typically, the shock absorber assembly is rigidly engaged to the front axle: usually, the attachment foot or the lower end of the shock absorber assembly is connected to the axle via a rigid bracket. However, some solutions are known, such as those described in European Patent EP2996929B1, in which the attachment foot is non-rigidly engaged to the front axle.

[0005] In existing control arm front suspensions, it is known to fix the disc brake caliper to the attachment foot of the shock absorber assembly, such that the disc brake caliper is fixed relative to the attachment foot. To avoid interference with the control arm, the control arm and the disc brake caliper are typically arranged on opposite sides of the attachment foot of the shock absorber assembly.

[0006] The aforementioned prior art front swing arm suspension has several drawbacks.

[0007] The first drawback is that it can sink excessively during braking. In fact, during braking, due to the load transfer to the front of the vehicle caused by deceleration, the shock absorber assembly tends to compress and therefore "sink" more than the static weight of the vehicle, including the driver and any other suspension mass (such as passengers, luggage, etc.).

[0008] The drop in the front axle may be related to reaching the limit stop during compression, which directly leads to a significant change in the vehicle's attitude.

[0009] In fact, if we consider, for example, two-wheeled motorcycles, the same phenomenon applies to different types of vehicles with more wheels. During the compression phase of the shock absorber assembly, the vehicle's trail is significantly reduced. This trail alters the sensitivity and responsiveness of the handlebars as perceived by the rider. Furthermore, after poor control and / or excessive drop, there is typically an extension of the rear suspension, which in turn leads to poor control, resulting in a lighter rear axle until the rear wheel reaches its limit of separation from the ground, which can cause the rider to lose control of the trail.

[0010] It should be noted that attitude changes during the dip phase do not necessarily have a priori negative effects. In other words, while excessive dip is certainly negative because it involves dynamic attitude changes that could put the vehicle and driver in a precarious situation, controlled dip of the front suspension can even promote and improve driving performance and feel.

[0011] In fact, the driver can also perceive the vehicle's dynamic behavior due to the degree of front suspension drop, and notice in advance that the tires' grip limit has been reached. Furthermore, controlled front axle drop allows for better descent into corners to take curves, as it facilitates lowering the front axle and increases responsiveness by reducing wake, thus increasing driver sensitivity.

[0012] As can be inferred from the above, the sag of the front suspension, known as "pitch," determines the substantial modification to the vehicle's dynamic balance based on its magnitude. Controlled pitch is not only not harmful, but it also improves the vehicle's driving and handling performance.

[0013] A second drawback of existing front swingarm motorcycle suspensions is the less-than-compact arrangement of components near the front wheel hub and brake disc. In fact, in this known suspension, there is a swingarm on one side, an attachment foot for the shock absorber assembly in a substantially central position, and a brake caliper on the other side. This lack of compactness results in reduced cooling efficiency of the brake disc and a lack of aesthetically pleasing cleanliness. Summary of the Invention

[0014] The general objective of this specification is to provide a front swingarm motorcycle suspension that can completely or partially solve the aforementioned drawbacks.

[0015] This objective is achieved by a motorcycle front suspension generally defined by the present invention, the motorcycle front suspension comprising: a steering arm mechanically connected to or adapted to be mechanically connected to a motorcycle handlebar, wherein the steering arm includes a body and a connecting arm extending from the body; a swing arm having a first connecting portion and a second connecting portion, the first connecting portion corresponding to the connecting arm rotatably connecting the swing arm to the steering arm, the second connecting portion being adapted and configured to connect the swing arm to an associatable front wheel; a shock absorber assembly extending from an attachment point mechanically connected to the steering arm to an attachment foot rotatably engaged with the swing arm; wherein the motorcycle front suspension includes a disc brake caliper fixed to the swing arm.

[0016] The invention will be better understood from the following detailed description of specific embodiments of the invention by way of example and in no way limiting, with reference to the accompanying drawings which are briefly described in the following paragraphs. Attached Figure Description

[0017] Figure 1 A side plan view of an exemplary and non-limiting embodiment of a motorcycle including a front suspension is shown.

[0018] Figure 2 A side view of the motorcycle's front suspension is shown.

[0019] Figure 3 A front plan view of the motorcycle's front suspension is shown.

[0020] Figure 4 A side plan view of the motorcycle's front suspension is shown, with some components shown in cross-section.

[0021] Figure 5 A perspective view of the motorcycle's front suspension is shown. Detailed Implementation

[0022] In the accompanying drawings, the same or similar elements are indicated by the same reference numerals.

[0023] The accompanying drawings illustrate embodiments of a transport vehicle, particularly an embodiment of a motorcycle 1. In the specific example shown in the drawings, the motorcycle 1 is conceived as a motorized vehicle (moped) without introducing any limitations, which includes a front wheel 2 and a rear wheel 3, a drive motor 4, a support frame 5, a seat 6, and a handlebar 7 rotatably fixed to the support frame 5 so as to be able to rotate about a steering axis.

[0024] For the purposes of this specification, the term "motorcycle" should be considered broadly, encompassing any motorcycle with at least two wheels, namely a front wheel 2 and a rear wheel 3. Therefore, this definition also includes motorcycles with three wheels, including, for example, two pairs of steering wheels on the front axle and one drive wheel on the rear axle, and further includes motorcycles with a single steering wheel on the front axle and two drive wheels on the rear axle. Finally, the definition of a motorcycle also includes so-called four-wheeled vehicles, which have two wheels on the front axle and two wheels on the rear axle.

[0025] As is well known, the motorcycle 1 also includes a steering tube 8 fixed to the steering handlebar 7 so as to rotate together with the latter about the steering axis.

[0026] The motorcycle 1 also includes a front suspension 10 adapted and configured to secure the front wheel 2 to the steering tube 8, such that the front suspension 10 is operatively positioned between the steering tube 8 and the front wheel 2.

[0027] The drive motor 4 is operatively connected directly or indirectly to the drive wheel of the motorcycle 1, in this example, to the rear wheel 3. According to a possible implementation, the drive motor 4 is an internal combustion engine. According to an alternative implementation, the drive motor 4 is an electric motor or a hybrid motor.

[0028] Although in the specific examples shown and described, the motorcycle front suspension 10 is a single-arm front suspension with an overhang extending from one side of the front wheel 2, it should be noted that the teachings of this patent application also apply to double-arm suspensions, i.e., fork suspensions.

[0029] The motorcycle front suspension 10 includes a steering arm 11, which is mechanically connected to or adapted to be mechanically connected to the handlebars 7 of the motorcycle 1. In a particular non-limiting example shown in the figure, a portion of the upper end of the steering arm 11 is connected to a steering tube 8, allowing it to rotate about the steering axis together with the steering tube. Note that the steering arm 11 and the steering tube 8 can be two separate, mechanically coupled components, but they can also form a single component between them.

[0030] The motorcycle front suspension 10 also includes control arms 12, 32, having a first connecting portion 13 rotatably connecting the control arms 12, 32 to a steering arm 11 and a second connecting portion 14 adapted and configured to connect the control arms 12, 32 to an associated front wheel 2. Furthermore, the motorcycle front suspension 10 includes a shock absorber assembly 20 extending from an attachment 21 mechanically connected to the steering arm 11 to attachment feet 22 rotatably engaged with the control arms 12, 32. Additionally, the motorcycle front suspension 10 includes disc brake calipers 30 fixed to the control arms 12, 32. For example, the disc brake caliper 30 is part of the braking system 29, 30 of the motorcycle 1, which, in addition to the brake caliper 30, includes a disc assembly 29 for a brake disc fixed to the front wheel 2 such that it can rotate with the front wheel. The attachment of the brake caliper 30 to the swing arms 12, 32 advantageously reduces the drop of the motorcycle front suspension 10 during braking and makes the suspension 10 particularly neat and compact near the hub of the front wheel 2.

[0031] According to one embodiment, a first connecting portion 13 is a first end of the swing arms 12, 32, and a second connecting portion 14 is a second end of the swing arms 12, 32 opposite to the first end. The first connecting portion 13 is rotatably engaged to the steering arm 11, for example, rotatably hinged to the steering arm 11, and the second connecting portion 14 carries a rotating pin 16 associated with the front wheel 2. This rotating pin 16 defines the axis of rotation XX of the front wheel 2. Preferably, the rotating pin 16 of the front wheel 2 has an end that is forcibly engaged and interference-locked in a locking seat defined within the second end of the swing arms 12, 32. More preferably, the rotating pin 16 is tensioned within the aforementioned locking seat to prevent relative rotation between the rotating pin 16 and the swing arms 12, 32.

[0032] According to a particularly advantageous embodiment, the disc brake caliper 30 is a floating brake caliper and includes a caliper body 31 and a support frame 32, the caliper body 31 being slidably constrained to the support frame, and the swing arms 12, 32 being or including the support frame 32. This convenient approach further increases the compactness of the proposed solution. The overall structure of a floating brake caliper is well known to those skilled in the art and will therefore not be described in further detail in this specification. For example, it is known to those skilled in the art that a floating brake caliper includes a structural element referred to as the support frame 12, which slidably supports the caliper body 31 such that the caliper body 31 can slide in a direction perpendicular to or substantially perpendicular to the support frame 12 when the braking device 15 is activated and deactivated.

[0033] According to possible implementations, the control arms 12, 32 include a first half-arm 12 and a second half-arm 32 arranged side-by-side, wherein one of the half-arms 12, 32 is a support frame 32 for the floating brake caliper 30. For the purposes of this specification, "side-by-side" means that the two half-arms 12, 32 are arranged side-by-side, and does not necessarily mean that the two half-arms must be in contact with each other, as the two half-arms may also be spaced apart, or even simultaneously partially in contact with each other and partially spaced apart. The above-described specific solution allows for a significant simplification of the mechanical coupling of the control arms 12, 32 with the steering arm 11 of the shock absorber assembly 20. For example, according to a particular and non-limiting embodiment, the half-arms 12, 32 are configured and arranged such that the attachment feet 22 of the shock absorber assembly 20 are arranged between the half-arms. For example, the two half-arms 12, 32 are arranged and shaped to be relatively closer together, for example, adjacent to each other, at the swivel pin 16 of the front wheel 2, and relatively further apart at the attachment feet 22 of the shock absorber assembly 20. For example, the two half-arms 12, 32 gradually separate from the rotating pin 16 of the front wheel 2 toward the attachment foot 22 of the shock absorber assembly 20, such that at the attachment foot 22, the two half-arms are spaced apart so that the attachment foot 22 can be inserted between the two half-arms. Therefore, preferably, the attachment foot 22 is located between the two half-arms 12, 32 and is rotatably hinged to the two half-arms, for example, by a cylindrical hinge. In the example shown in the figures, without introducing any limitations, the aforementioned cylindrical hinge has a hinge axis defined by a pin 18 that penetrates and / or engages in three aligned openings respectively defined in half-arm 12, attachment foot 22, and half-arm 32.

[0034] According to one embodiment, the steering arm 11 includes a body and a connecting arm 15 extending from the body. A first connecting portion 13 of the swing arms 12, 32 rotatably connects the swing arms 12, 32 to the steering arm 11 corresponding to the connecting arm 15. For example, the connecting arm 15 has a free end, and the first connecting portion 13 of the swing arms 12, 32 is rotatably engaged (e.g., rotatably hinged) to said free end of the connecting arm 15. Preferably, the connecting arm 15 extends from one end of the body of the steering arm 11. According to a particularly preferred embodiment, the connecting arm 15 is a curved arm. The body of the steering arm is preferably tubular, for example having a circular or more preferably quadrilateral cross section, and even more preferably rectangular.

[0035] In cases where the swing arms 12, 32 as described above comprise two half-arms 12, 32, it is advantageous that the half-arms 12, 32 are configured and arranged such that the free end of the connecting arm 15 is placed therebetween. For example, the free end of the connecting arm 15 may be provided so as to be rotatably hinged between the two half-arms 12, 32 by, for example, a hinge pin 150 inserted through the connecting arm and, for example, through the two half-arms 12, 32 and / or engaged in the two half-arms.

[0036] According to a particularly advantageous embodiment, the swing arms 12, 32 are curved or non-linear arms. This makes it easier to attach the attachment foot 22 to the swing arms 12, 32, because, for example, the length of the attachment foot 22 can be reduced. Additionally, the swing arms 12, 32 may comprise a main arm 26 and a reinforcing arm 27 rigidly joined together, for example, as a single component. In this case, preferably, a through-hole is defined between the main arm 26 and the reinforcing arm 27, which allows for a reduction in the mass of the swing arms 12, 32. The above conditions preferably apply to each of the two half-arms 12, 32 of the swing arms.

[0037] According to an advantageous embodiment, the swing arms 12, 32 include a third connecting portion 19, which, in the stationary state of the shock absorber assembly 20, is positioned at a height higher than the first connecting portion 13 and the second connecting portion 14 of the swing arms 12, 32. The attachment foot 22 of the shock absorber assembly 20 engages with the third connecting portion 19 of the swing arms 12, 32. This also makes it easier to attach the attachment foot 22 to the swing arms 12, 32, as the length of the attachment foot 22 can be reduced in this way, for example. It should be noted that the third connecting portion 19 is radially positioned between the first connecting portion 13 and the second connecting portion 14. The term "radially" means along one or more directions perpendicular to the rotation axis XX of the front wheel 2.

[0038] According to an advantageous embodiment, the steering arm 11 is hollow internally, for example tubular, and houses at least a portion of the shock absorber assembly 20 therein. This arrangement has the advantage of reducing the exposure of the shock absorber assembly 20 to dust and weather.

[0039] According to an advantageous embodiment, the shock absorber assembly includes a muffler block 41 operably disposed between the attachment 21 and the steering arm 11. In this way, the shock absorber assembly 20 can rotate within the shock absorber assembly 20 to allow and follow the rotation of the swing arms 12, 32 relative to the steering arm 11. For example, the muffler block engages in a through-hole defined in the steering arm 11 and passes through the attachment 21.

[0040] According to a preferred embodiment, in the motorcycle front suspension 10, the shock absorber assembly 20 includes a spring 23 and dampers 24, 25, with the spring 23 fully housed within the steering arm 11. The spring 23 is, for example, a coil spring, positioned between the attachment joint 21 and the attachment foot 22 of the shock absorber assembly 20 to apply an elastic thrust tending to separate the attachment joint 21 and the attachment foot 22. The spring 23 preferably surrounds the damper 24.

[0041] Preferably, the damper includes a rod 24 and a sleeve 25, wherein the rod 24 is adapted and configured to slide within the sleeve 25 and be received in the steering arm 11. This also has the advantage of reducing the exposure of the shock absorber assembly 20 (particularly the rod 24) to dust and weather.

[0042] Based on the explanations above, it becomes clear how the aforementioned type of motorcycle front suspension achieves the objectives mentioned in the prior art. In fact, as stated above, this suspension is able to counteract excessive sinking during braking, is particularly compact, features low aesthetic impact, exposes a large portion of the brake disc components, and ensures greater cleanliness and protection for the shock absorber assembly.

[0043] Without altering the principles of the invention or departing from its scope, the implementation methods and details may vary extensively from those described and illustrated only by way of non-limiting examples.

Claims

1. A motorcycle front suspension (10), comprising: A steering arm (11) is mechanically connected to or adapted to be mechanically connected to a steering handlebar (7) of a motorcycle (1), wherein the steering arm (11) includes a body and a connecting arm (15) extending from the body. The swing arm (12, 32) has a first connecting portion (13) and a second connecting portion (14), the first connecting portion corresponding to the connecting arm (15) rotatably connecting the swing arm (12, 32) to the steering arm (11), and the second connecting portion being adapted and configured to connect the swing arm (12, 32) to an associatable front wheel (2); The shock absorber assembly (20) extends from the attachment (21) mechanically connected to the steering arm (11) to the attachment foot (22) rotatably engaged with the swing arm (12, 32). The motorcycle front suspension (10) includes a disc brake caliper (30), which is fixed to the swing arms (12, 32) between the first connecting portion (13) and the second connecting portion (14). The disc brake caliper (30) is a floating brake caliper and includes a caliper body (31) and a support frame (32), wherein the caliper body (31) is slidably constrained to the support frame; the swing arms (12, 32) are the support frame (32) or include the support frame. The swing arms (12, 32) include a first half-arm (12) and a second half-arm (32) arranged side by side, wherein one of the first half-arm and the second half-arm is the support frame (32). The swing arms (12, 32) are arranged and configured such that the attachment feet (22) of the shock absorber assembly (20) are arranged between the swing arms.

2. The motorcycle front suspension (10) according to claim 1, wherein, The first connecting portion (13) is the first end of the swing arm (12, 32), and the second connecting portion (14) is the second end of the swing arm opposite to the first end, wherein the first connecting portion (13) is rotatably engaged to the steering arm (11), and the second connecting portion (14) carries the swivel pin (16) of the associated front wheel (2).

3. The motorcycle front suspension (10) according to claim 1, wherein, The connecting arm (15) has a free end, and wherein the first connecting portion (13) of the swing arm (12, 32) is rotatably engaged with the free end of the connecting arm (15).

4. The motorcycle front suspension (10) according to claim 3, wherein, The swing arms (12, 32) are arranged such that the free end of the connecting arm (15) is located between the swing arms.

5. The motorcycle front suspension (10) according to claim 3, wherein, The connecting arm (15) extends from the end of the body of the steering arm (11).

6. The motorcycle front suspension (10) according to claim 3, wherein, The connecting arm (15) is a curved arm.

7. The motorcycle front suspension (10) according to claim 1, wherein, The swing arms (12, 32) are curved or non-linear arms.

8. The motorcycle front suspension (10) according to claim 7, wherein, The swing arms (12, 32) include a main arm (26) and a reinforcing arm (27) that are rigidly connected to each other.

9. The motorcycle front suspension (10) according to claim 8, wherein, A through hole is defined between the main arm (26) and the reinforcing arm (27).

10. The motorcycle front suspension (10) according to claim 1, wherein, The swing arms (12, 32) include a third connecting portion (19) which, in the static state of the shock absorber assembly (20), is arranged at a height higher than the first connecting portion (13) and the second connecting portion (14) of the swing arms (12, 32), and wherein the attachment foot (22) is connected to the third connecting portion (19) of the swing arms (12, 32).

11. The motorcycle front suspension (10) according to claim 1, wherein, The steering arm (11) is hollow inside and houses at least a portion of the shock absorber assembly (20).

12. The motorcycle front suspension (10) according to claim 1, wherein, The shock absorber assembly (20) includes a muffler block (41) operably located between the attachment (21) and the steering arm (11).

13. The motorcycle front suspension (10) according to claim 11, wherein, The shock absorber assembly (20) includes a spring (23) and dampers (24, 25), wherein the spring (23) is fully housed in the steering arm (11).

14. The motorcycle front suspension (10) according to claim 13, wherein, The damper includes a rod (24) and a sleeve (25), wherein the rod is adapted and configured to slide within the sleeve (25) and be received in the steering arm (11).

15. A motorcycle (1) comprising at least a motorcycle front suspension (10) according to any one of the preceding claims.

16. The motorcycle (1) according to claim 15, wherein, The motorcycle (1) is a moped.

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