JPH0712236Y2 - Mounting structure for brake caliper for front wheel of motorcycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to an improvement in a mounting structure of a brake caliper for braking a front wheel of a two-wheeled vehicle.

(Prior Art) The number of motorcycles using a disc brake as a front wheel brake is increasing in recent years. In that case, a brake caliper for braking a brake disc is attached as shown in FIG. 3, for example. In this figure, 1 is a front fork interposed between a front wheel axle 3 and a vehicle body (not shown), 16 is a brake disc that rotates integrally with the front wheel, and a brake caliper 14 is an outer tube 1A of the front fork 1. Is fixed to the caliper mounting portion 20 formed on the lower part of the. The brake caliper 14 accommodates a brake cylinder 15 therein, and brakes rotation of the front wheels by pressing a brake pad (not shown) mounted on the tip of the brake cylinder 15 against the rotating brake disk 16 during braking.

(Problems to be solved by the invention) By the way, during braking, the brake disc 16 may cause high frequency vibration due to friction with the brake pad.
In this disc brake, since the brake caliper 14 is rigidly supported by the front fork 1 via the caliper mounting portion 20, the natural frequency is extremely large, and when the high frequency vibration of the brake disc 16 approaches this natural frequency, resonance occurs. There is a problem that a phenomenon is caused to cause annoying noise. In order to prevent this abnormal noise, it is sufficient to devise the structure of the brake pad so that the brake disc 16 does not generate high-frequency vibration, but the structure of the brake pad becomes complicated and the cost increases and the worn brake It was difficult to implement because there were some difficulties such as replacement of pads.

The present invention has been made in view of the above problems, and an object thereof is to prevent the generation of abnormal noise during use of the brake by improving the mounting structure of the brake caliper.

(Means for Solving the Problems) In order to achieve the above object, the present invention supports a link around a lower end of a front fork via a bracket so as to freely rotate about a pin parallel to a front wheel axle. , The axle at the end of the link extending forward of the pin,
Similarly, a cushion that supports brake calipers at the ends extending rearward and above the pin, and that always elastically regulates rotational displacement about the pin of the link between the link and the front fork. Sandwiched.

(Function) Since the cushion is interposed between the link for attaching the brake caliper and the front fork, the cushion prevents vibration transmission from the link to the front fork, and the link and the brake caliper elastically supported by the cushion are The natural frequency becomes extremely small, and it is difficult for it to resonate with the high-frequency vibration generated when the brake is actuated.

(Embodiment) FIG. 1 shows an embodiment of the present invention.

Reference numeral 1 denotes a front fork composed of an outer tube 1A supported by a front wheel axle 3 via a link 2 and a vehicle-body-side inner tube 1B slidably inserted into the outer tube 1A from above. The link 2 has one end attached to the axle 3 and extends obliquely upward so as to wrap around the rear of the outer tube 1A from the axle 3, and is connected via a bracket 4 and a pin 5 protruding rearward from the lower end of the outer tube 1A on the way. To do. The link 2 is formed with a projecting portion 2A which projects further forward from the node with the axle 3, and the projecting portion 2A and another bracket 6 formed on the outer tube 1A opposite to this projecting portion 2A are elastic cushions. The compression rubber 7 and the bump rubber 8 are used to connect the bolts 9. That is, the compression rubber 7 is sandwiched between the bracket 6 and the projecting portion 2A, the bump rubber 8 and the washer 10 for restraining the compression rubber 7 are arranged on the back side of the projecting portion 2A, and the bolt 9 is passed through these to provide the nut at the penetrating end. 11 is screwed together, and the compression rubber 7 and the bump rubber 8 absorb vibrations in both directions of expansion. In this way, the outer tube 1A attached to the link 2 via the brackets 4 and 6 is held above the axle 3.

The upper part of the link 2 extends further obliquely upward from the pin 5 to form a caliper mounting portion 2B. A brake caliper 14 is fixedly mounted on the caliper mounting portion 2B via two caliper mounting holes 12. The brake caliper 14 has a brake cylinder.
15 is accommodated, and a brake pad (not shown) is attached to the tip of the brake cylinder 15. Then, at the time of braking, the brake pad is pressed against the brake disc 16 that rotates integrally with the wheels by driving the brake cylinder 15.
The brake disc 16 is braked by friction. A stop rubber 13 is attached to the caliper attaching portion 2B at a position facing the outer tube 1A. When the link 2 rotates, the stop rubber 13 contacts the outer tube 1A to prevent the link 2 from rotating more than a certain amount.

Next, the operation will be described.

In normal traveling, a load corresponding to the traveling weight acts on the axle 3, the front fork 1 contracts appropriately, and the compression rubber 7 is slightly deformed between the bracket 6 and the protruding portion 2A of the link 2. Are balanced.

When the brake pad driven by the brake cylinder 15 is pressed against the brake disc 16 during braking, a reaction force corresponding to this braking torque acts on the caliper mounting portion 2B via the brake caliper 14, so that the link 2 has a bump rubber 8a. While being compressed and deformed, the pin 5 is rotationally displaced in the clockwise direction in the figure. At this time, high-frequency vibration is generated in the brake disc 16 due to friction with the brake pad. This vibration is applied to the front fork 1 by the vibration isolation effect of the bump rubber 8 interposed between the link 2 and the outer tube 1A. I can't get it. The natural frequency f ₀ of the vibration system composed of the link 2 supported by the bump rubber 8 and the brake caliper 14 fixedly mounted on the link 2 is the link 2 centered on the pin 5.
If the moment of inertia of the brake caliper 14 is It and the spring constant of the bump rubber 8 is Kt, then f ₀ = {1 / (2π)} × ▲ √ ▼, but since the stop rubber 8 is an elastic material, The value of the constant Kt is small, and therefore the natural frequency f ₀ is also small, for example, in the range of 20 to 100 Hz as shown in FIG. On the other hand, since the resonance phenomenon of the brake disc 16 with respect to the high frequency vibration occurs at a frequency of 1000 Hz or higher as shown in the shaded area in the figure, the vibration system including the brake caliper 14 and the link 2 is extremely high against the high frequency vibration of the brake disc 16. It does not resonate easily, so there is no fear of producing annoying noises during braking. When the link 2 largely rotates due to sudden braking or the like, the stop rubber 13 comes into contact with the after tube 1A and restricts further rotation of the link 2, thereby over-compressing the bump rubber 8 and increasing the bending stress of the link 2. However, even in this state, the resonance phenomenon does not occur because the link 2 is elastically supported by the stop rubber 13.

By the way, at the time of braking, the front fork 1 is compressed by the movement of the load on the front side of the vehicle body, and the intersection of the handle shaft and the ground moves rearward. As a result, the distance between the intersection and the contact point of the wheel, that is, the trail, changes, which adversely affects the operability of the steering wheel.
Under the mounting structure of 14, the link 2 is pin 5 due to braking.
1 is rotated in the clockwise direction and the axle 3 is retracted, whereby the trail change is corrected and stable steering wheel operability is obtained.

(Effect of the Invention) As described above, according to the present invention, the cushion is sandwiched between the link having the brake caliper and the front fork so that the relative rotation of the link is always elastically regulated. Vibration propagation from the link to the front fork is prevented, and the natural frequency of the link and the brake caliper supported by the cushion becomes extremely small, which makes it difficult for resonance to occur with respect to the high frequency vibration generated by the braking operation. Therefore, it is possible to prevent the generation of annoying noise due to use of the brake.

Further, the vibration transmitted from the axle to the front fork is also absorbed by the cushion, which improves the riding comfort. further,
The braking reaction force causes the link to rotationally displace around the bracket mounting portion to retract the axle, so that the trail change due to braking is corrected and the maneuverability is also improved.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a front wheel portion of a motorcycle showing an embodiment of the present invention, FIG. 2 is a graph showing vibration characteristics of a brake caliper and a link in the same example, and FIG. 3 is a brake caliper mounting structure. FIG. 7 is a side view of a main part of a front wheel portion of a two-wheeled vehicle showing the conventional example of FIG. 1 ... Front fork, 2 ... Link, 2B ... Caliper mounting part, 3 ... Axle, 4 ... Bracket, 7 ... Compression rubber, 8 ... Bump rubber, 14 ... Brake caliper, 16 ... Brake disk.

Claims (1)

[Scope of utility model registration request] 1. A link is supported near a lower end portion of a front fork via a bracket so as to be rotatable about a pin parallel to a front wheel axle, and the link is provided at an end portion extending forward of the pin. Similarly, the brake calipers are supported on the ends of the axle, which also extend to the rear upper side of the pin,
A mounting structure for a front wheel brake caliper of a two-wheeled vehicle, wherein a cushion that constantly elastically restricts rotational displacement of the link about the pin is sandwiched between the link and the front fork.