JPS60515Y2 - Vehicle disc brake device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a disc brake device used in automobiles and other vehicles, particularly a brake disc; first and second friction pads whose front surfaces rub against both end faces of the disc;
a brake caliper having first and second arms spanning both friction pads and connected to a fixed bracket so as to be movable in the axial direction of the brake disc; This invention relates to an improvement in a type of friction pad in which the back surface of a first friction pad is pressed by the operation of a piston, and the second arm part is pressed against the back surface of a second friction pad by the reaction force.

In general, in such a disc brake device, the second arm is connected to a pair of arms spaced apart in the circumferential direction of the brake disc so that the piston housing cylinder can be easily cut into the first arm of the brake caliper. It is branched into two arms, and the cylinder machining tool can be inserted between the arms.

However, if the second arm is branched as described above, its rigidity will have to be sacrificed to some extent.

Furthermore, the second arm is generally covered by the wheel disc of the wheel, making it difficult to dissipate heat, and the temperature exceeds the temperature caused by braking friction heat (for example, 150°C in the case of N-alloy brake calipers).
or more), the rigidity decreases significantly,
According to this, there is a risk that the second arm portion may be bent, causing problems such as a reduction in braking performance and uneven wear of the friction pad.

The present invention was proposed in view of the above, and a ventilation passage is provided between each arm of the second arm of the brake caliper and the contact surface of the second friction pad. Each arm can be effectively cooled to prevent overheating of each arm, the manufacturing process is easy, and the first and second friction pads can be made interchangeable. The object of the present invention is to provide a disc brake device for a vehicle of the type described above, in which at least the back surface of the second friction pad has a continuous friction pad extending across each of the arm pieces. A linear ventilation groove is recessed, and both ends of the ventilation groove are opened at both end surfaces of the second friction pad in the circumferential direction of the brake disc.

Hereinafter, a description will be given of an automobile disc brake device in which the present invention is implemented with reference to the drawings.A bracket B is arranged adjacent to one side of a brake disc D that is connected to the hub of a wheel W and rotates therewith. This bracket B is fixed to a vehicle body (not shown) using the lower mounting hole 1.1.

The bracket B has two arm portions 2゜2 that are lined up at a constant interval in the rotational direction of the brake disc D, and the tips of these arms are shaped like an inverted U so that they straddle the outer circumference of the brake disc D from side to side. It is bent in a shape (Fig. 4).

Two sets of rectangular guide rails 3 are lined up on opposite sides of these arms 2, 2 with the brake disc D in between. 3; 3',
The back plate 41 of the first friction pad P1, which is provided integrally with the guide rails 3' and whose front surface faces one side of the brake disc D, is provided between the guide rails 3 and 3 of one set, and the guide rail 3 of the other set. A back plate 4° of a second friction pad P2 whose front surface faces the other side of the brake disc D is installed between ' and 3' so as to be slidable in the direction of the rotation axis of the brake disc D.

The bracket B has both friction pads P1. A brake caliper C made of N alloy and having first and second arm portions 51, 5□ spanning P2 is connected via a pair of sliding pins 6.6 parallel to the rotational axis of the brake disc D.

Both sliding pins 6.6 are fitted with bolts 8 to ears 7, 7 protruding from both front and rear ends of the first arm 51 of the brake caliper C.
, 8, and are slidably fitted into support holes 9, 9 provided in both arm portions 2, 2 of bracket B, respectively.

The first arm portion 51 of the brake caliper C is formed with a hydraulic cylinder 10 that communicates with a known brake master cylinder (not shown) operated by a brake pedal, and presses the back surface of the first friction pad P1 therein. The piston 11 is slid together.

On the other hand, the second arm portion 5□ branches into a pair of arm pieces 12, 12 spaced apart in the rotational direction of the brake disc D, and these are brought into contact with the back surface of the second friction pad P2.

When installed, the brake caliper C is housed in the inner space of the wheel W with its second arm portion 52 positioned on the wheel disk Wa side.

Then, if hydraulic pressure is applied to the hydraulic cylinder 10 from a master cylinder (not shown) by pressing the brake pedal,
The piston 11, which moves forward due to the oil pressure, presses the back surface of the first friction pad P□ and presses it against one side of the brake disc D. At the same time, the reaction force causes the brake caliper C to move the sliding pin 6.6 into the support hole. 9, 9 in the opposite direction to the piston 11, and presses the back surface of the second friction pad P2 via both arm pieces 12, 12 of the second arm portion 5□ to push it against the brake disc D. press against the other side of the

In this way, the first and second friction pads P1 and P2 rub equally against both sides of the brake disc D, thereby stopping the rotation of the brake disc D and therefore the wheel W.

At this time, friction pad P1. P2 is brake disc D
The braking torque received by the brake disc D is supported by the guide rail 3° 3' located on the exit side in the rotational direction of the brake disc D.

The above configuration is conventionally known, and the present invention provides at least one continuous straight line extending across each of the arm pieces 12, 12 on the back surface of the back plate 4□ of the second friction pad P2. The ventilation grooves 13 are recessed.

Both ends of this ventilation groove 13 are open to both end surfaces of the second friction pad P2 in the zero circumferential direction of the brake disc.

With the above configuration, the cooling effect on each arm piece 12 and the second friction pad P2 is improved, and the cooling effect on each arm piece 12 and the second friction pad P2 is improved, and these 12. It has been experimentally confirmed that this can contribute to preventing overheating of P2.

(For example, an experiment in which the temperature rise of the arm piece 12 was suppressed to about 115°C by recessing the ventilation groove 13 of the present invention in the arm piece 12 whose temperature rose to about 140°C under certain braking conditions) There are consequences.

). The reason why the cooling effect on each arm piece 12 and the second friction pad P2 is improved by the above structure is considered to be due to the following reason.

That is, while the vehicle is running, (1) air turbulence is generated around the wheels W and brake disc D due to each rotation of the wheels W and brake disc D; Wind pressure of the passing wind, ■Brake caliper C and friction pad P1 whose temperature rises during braking. Due to natural convection of air generated near the surface of brake caliper P2, air turbulence and eddies occur around the brake caliper C1, especially around each arm piece 12. When a pressure difference (this pressure difference constantly changes) occurs between each end of the ventilation passage formed between the piece 12, the air flow immediately moves through the ventilation groove 13, as shown by the arrow a in FIG. 1, for example. passing through, and at that time each arm piece 12 and the second
This effectively cools the friction pad P2.

In addition, in this embodiment, the back metal 41 of the first friction pad P□
A ventilation groove 13 is also formed on the back surface, similar to the second friction pad P2, and both pads P1. P2 is compatible.

Therefore, when the vehicle is running, the first friction pad P
Since the airflow flows through the ventilation groove 13 of No. 1, for example, as shown by the arrow in FIG. It's something you get.

As described above, according to the present invention, the second brake caliper
In a disc brake device for a vehicle, the arm part is branched into a pair of arm pieces that are spaced apart in the circumferential direction of the brake disc and can press the back surface of the second friction pad by the action reaction force of the piston, wherein at least the second friction pad A ventilation groove extending across each arm is recessed on the back of the vehicle, so it prevents the air from swirling around the wheels and brake discs as they rotate each time the vehicle is running, and from the air on both sides of the wheels. In particular, air turbulence and eddy currents occur around each arm due to the wind pressure of the traveling wind that passes forcefully near the brake caliper, and as a result, air turbulence and vortices are formed between the ventilation groove and each arm. When a pressure difference occurs between both ends of the ventilation passage, the air flow immediately passes through the ventilation passage and effectively cools each arm piece and the contact surface of the second friction pad with each arm piece. As a result, it is possible to contribute to preventing overheating of each arm piece and the second friction pad due to braking friction heat, and to prevent a decrease in rigidity of each arm piece due to overheating. This is advantageous in preventing the fading phenomenon of the two friction pads due to overheating.

In particular, the ventilation groove extending across each arm has a continuous straight line, and both ends of the groove are open to both end surfaces of the second friction pad in the circumferential direction of the brake disc, so that friction The ventilation grooves can be formed by simply cutting out a straight line in one direction on the back surface of the pad, making the manufacturing process extremely easy and reducing costs.

Moreover, even though the ventilation grooves are formed in a continuous straight line, the ventilation passages defined between the groove and each arm piece can be separated from each other independently. It is possible to constantly circulate fresh outside air independently to each area, and the cooling effect of the ventilation grooves can be enhanced.

Furthermore, when the second friction pad is also used as the first friction pad, the center portion of the ventilation groove crosses the front surface of the piston, so that it effectively functions as a cooling ventilation path for the piston. Therefore, the first
and the second friction pad can be made compatible,
Mass productivity of pads can be improved.

[Brief explanation of drawings]

Fig. 1 is a partially vertical plan view of an embodiment of the device of the present invention;
, 3 and 4 are the n-n, ■-■ and IV-
The sectional view taken along line IV and FIG. 5 are rear views of the second friction pad in this embodiment, showing the relationship between the ventilation passage and the second arm of the brake caliper. B... Bracket, C... Brake caliper, D... Brake disc, Pl...
...First friction pad, P2...Second friction pad, 51...First arm, 5□...Second
Arm part, 11... Zeston, 13... Ventilation groove.

Claims (1)

[Scope of utility model registration request] a brake disc; first and second friction pads whose front surfaces respectively slide on both sides of the brake disc; first and second arm parts that straddle both of the friction pads;
a brake caliper connected to a fixed bracket so as to be movable in the axial direction of the brake disc; a first arm of the brake caliper having a piston capable of pressing a back surface of the first friction pad; In a disc brake device for a vehicle, the second arm part is branched into a pair of arm pieces that are spaced apart in the circumferential direction of the brake disc and can press the back surface of the second friction pad by the reaction force of the operation of the piston. A continuous linear ventilation groove extending across each of the arm pieces is recessed on the back surface of the second friction pad, and both ends of the ventilation groove are connected to the second friction pad.
A disc brake device for a vehicle, characterized in that openings are provided at both end surfaces in the circumferential direction of the brake disc.