JP2007192268A - Disk brake device and brake pad - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk brake device having a structure which actively eliminates moisture intruded between a disk rotor and a brake pad regardless of the presence or absence of braking operation. <P>SOLUTION: A disk brake device includes a ventilation pipe 36 containing a venturi part 38 in a pad back metal 26 of a brake pad 20 and a suction pipe 40 which keeps one end connected to the venturi part 38 and the other end opened toward the frictional sliding surface of a disk rotor 14. When a travel wind W received during vehicle traveling flows into the ventilation pipe 36, air flowing thereinto is accelerated in the venturi part 38. As a result, negative pressure is generated in the suction pipe 40 connected to the venturi part 38, so that moisture intruded between a disk rotor 14 and the brake pad 20 is discharged from the discharge side of the ventilation pipe 36. In other words, the moisture intruded between the disk rotor 14 and the brake pad 20 during vehicle traveling can be eliminated. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement of a disc brake device and a brake pad, and more particularly to an improvement of a disc brake device and a brake pad that can eliminate moisture or the like that has entered between the disc rotor and the brake pad.

As one of braking devices for braking a vehicle, there is a disc brake device. In this disc brake device, a braking force is generated by pressing a brake pad disposed opposite to a friction sliding surface of a disc rotor that rotates together with a wheel against the friction sliding surface. Usually, the disk rotor is exposed so as to be in contact with outside air without providing a cover or the like in order to efficiently dissipate heat generated during friction braking. For this reason, water droplets (moisture) may enter between the disc rotor and the brake pad when traveling in the rain or when passing through a water pool. In this case, a phenomenon in which the braking force is reduced due to the penetration of moisture, so-called water fade, may occur. In order to prevent this water fade, various disk brake devices having a structure for positively discharging moisture that has entered between the disk rotor and the brake pad have been proposed. For example, a pad of a disc brake disclosed in Patent Document 1 opens on the surface of a friction plate, both ends open on the side end surface of the friction plate, and the distance from the surface to the wear limit surface of the wear plate A shallower groove and at least one groove forming hole extending from the groove in a direction parallel to the surface are provided. Water that has entered between the disc rotor and the brake pad is discharged through this groove, so that water fade can be suppressed. Even when the friction plate wears and the surface groove disappears, the groove forming hole is exposed by this wear and a new groove is formed, so that the water draining action is not affected even if the friction plate wears. It is continuously performed and water fade can be continuously suppressed.
Japanese Utility Model Publication No. 62-27717

  According to the structure of Patent Document 1, it is possible to eliminate water that has entered between the disk rotor and the brake pad, thereby suppressing water fade. However, since the water is scraped off by the groove, the contact between the disc rotor and the brake pad is a drainage condition. Therefore, the braking force may be reduced in a short period of time when the braking operation is started in the braking operation, compared to when the contact surface is dry due to moisture existing between the disc rotor and the brake pad. In other words, the rising of the braking force may be delayed more than when the space between the disc rotor and the brake pad is dry, which may give the driver a sense of discomfort. Therefore, regardless of the presence or absence of braking operation and without electronic control, water that has entered between the disk rotor and brake pad is actively removed to suppress the delay in the start of braking force and reduce discomfort. The proposal of the disc brake device which can be performed is desired.

  The present invention has been made in view of such circumstances, and the object thereof is a disk having a simple mechanical structure that actively eliminates moisture that has entered between the disk rotor and the brake pad regardless of whether or not a braking operation is performed. It is to provide a brake device and a brake pad.

  In order to solve the above-described problems, in one aspect of the present invention, a brake that is disposed to face a friction sliding surface of a disk rotor that rotates together with a wheel and generates a braking force by being pressed by the friction sliding surface. A disc brake device provided with a pad, wherein the inside of the brake pad is a pipe through which a running wind received during running of the vehicle can pass, and a vent pipe including a venturi portion in the course of the running wind passing path, A suction pipe having one end connected to the venturi portion and the other end opened toward the friction sliding surface of the disk rotor is formed.

  According to this aspect, the traveling wind passing through the vent pipe is accelerated by the venturi portion, whereby a negative pressure is generated in the suction tube connected to the venturi portion and a suction force is generated. As a result, moisture that has entered between the brake pad and the friction sliding surface of the disk rotor is sucked and discharged from the friction sliding surface. This suction force is always generated while air flows in the vent pipe. Therefore, regardless of the presence or absence of the braking operation, for example, it is possible to positively discharge moisture that has entered between the disc rotor and the brake pad during vehicle travel. That is, moisture can be discharged between the disc rotor and the brake pad before the braking operation, so that the delay in the rising of the braking force during the braking operation is suppressed, and the uncomfortable feeling related to the braking force can be reduced. In addition, since the air around the frictional sliding surface heated at the time of braking is also sucked by the suction force generated in the suction pipe, the heated air can be sucked out and the heat fade can be reduced.

  In the above aspect, the brake pad includes a friction material that generates a braking force in contact with the friction sliding surface of the disk rotor, and the friction material opens toward the friction sliding surface of the disk rotor. And a groove portion connecting the outer peripheral side and the inner peripheral side, and the opening side of the friction sliding surface of the suction pipe may be connected to the groove portion. By forming the groove portion connected to the suction pipe so as to connect the outer peripheral side and the inner peripheral side of the disk rotor, the suction force can be exerted on the entire surface of the rotating disk rotor. As a result, it is possible to efficiently eliminate the suction of moisture and heated air that has entered between the disc rotor and the brake pad.

  Moreover, the said aspect WHEREIN: The said ventilation pipe | tube may have the air collection part diameter-expanded to the inflow side of the running wind. According to this aspect, a large amount of traveling wind can be efficiently sent to the venturi section, and the suction force in the suction pipe can be easily increased. In addition, a large suction force can be generated even when traveling at a low speed.

  In the above aspect, the brake pad may be moved toward the disk rotor by a negative pressure generated by air accelerated by the venturi portion. According to this aspect, the brake pad originally retracted from the disk rotor during non-braking can contact the disk rotor by the suction force. For this reason, it is possible to suppress the intrusion of moisture between the disc rotor and the brake pad, and it is possible to fundamentally prevent water fade. Since the contact force generated at this time is a weak force generated by the negative pressure generated in the venturi portion, there is very little possibility of so-called brake pad dragging or squealing due to contact between the disc rotor and the brake pad.

  In order to solve the above-described problems, in one aspect of the present invention, a brake that is disposed to face a friction sliding surface of a disk rotor that rotates together with a wheel and generates a braking force by being pressed by the friction sliding surface. A pad that penetrates in a direction substantially perpendicular to the thickness direction and has a venturi part in the middle thereof, one end connected to the venturi part, and the other end toward the friction sliding surface of the disk rotor And a suction tube that is open.

  According to this aspect, by flowing air into the vent pipe formed in the brake pad, the air flow is accelerated when passing through the venturi. For this reason, the suction pipe connected to the venturi section is set to a negative pressure. As a result, moisture that has entered between the brake pad and the friction sliding surface of the disk rotor is sucked and discharged from the friction sliding surface. Further, since the air around the frictional sliding surface heated at the time of braking is also sucked by the suction force generated in the suction pipe, the suction of the heated air can be eliminated.

  According to the disc brake device and the brake pad of the present invention, moisture that has entered between the disc rotor and the brake pad can be positively removed with a simple mechanical configuration regardless of whether or not a braking operation is performed.

  Hereinafter, an embodiment of the present invention (hereinafter referred to as an embodiment) will be described with reference to the drawings.

  In the disc brake device of the present embodiment, a vent pipe including a venturi portion is formed on a brake pad that is disposed to face a frictional sliding surface of a disc rotor that rotates with a wheel. Further, it includes a suction pipe having one end connected to the venturi portion and the other end opened toward the friction sliding surface of the disk rotor. When traveling wind received during traveling of the vehicle flows into the vent pipe, the air that flows in is accelerated at the venturi portion, so-called a venturi effect is produced. As a result, negative pressure is generated in the suction pipe connected to the venturi section, and moisture that has entered between the disk rotor and the brake pad is sucked and discharged from the discharge side of the vent pipe. In other words, moisture that has entered between the disc rotor and the brake pad while the vehicle is running is removed.

  FIG. 1 is a perspective view showing an external configuration of a disc brake device 10 of the present embodiment. Hubs 12 to which wheels are attached are provided at both ends of the axle. Further, a disk-shaped disk rotor 14 that rotates with the wheels is fixed to the hub 12. The disc rotor 14 is tightened from both sides with a brake pad to which a friction material is attached to generate a braking force. A brake pad and a piston for driving the brake pad are accommodated in the caliper 16.

  FIG. 2 is a cross-sectional view taken along line AA of the floating caliper 16 in FIG. The caliper 16 of the present embodiment is roughly divided into a vehicle body fixing mount 18 (see FIG. 1) for fixing the caliper 16 itself to a vehicle body side (not shown), a brake pad 20 that is pressed by the disc rotor 14 and generates a braking force. And a cylinder portion 22 for driving the brake pad 20. As shown in FIG. 2, the disk rotor 14 that rotates together with the wheels exists between the pair of brake pads 20. The side surfaces 14 a and 14 b of the disk rotor 14 constitute a frictional sliding surface, and a pair of brake pads 20 are disposed to face each other with the disk rotor 14 interposed therebetween. The brake pad 20 includes a friction material 24 that directly contacts the side surfaces 14 a and 14 b of the disk rotor 14, and a pad back metal 26 that supports the back side of the friction material 24, that is, the side that does not contact the disk rotor 14.

  The caliper 16 is attached to the vehicle body side via a vehicle body fixing mount 18 so as to be displaceable in the left-right direction. As shown in FIG. 2, a bottomed hole 28 is formed in the cylinder portion 22 of the caliper 16, and a piston 30 is slidably fitted into the hole 28. A port 32 is provided at the bottom of the hole 28 and is connected to a master cylinder (not shown) through a hydraulic pipe. When the driver operates the brake pedal, the brake oil from the master cylinder flows into the port 32 and drives the piston 30.

  When the brake oil flows into the port 32, the piston 30 slides in the arrow L direction, that is, the pressing direction of the piston 30 from the non-operating state shown in FIG. 2, and the friction material 24a is moved to the disc rotor 14 via the pad back metal 26a. Press against the side surface 14a. When the friction material 24a is pressed against the disk rotor 14, the piston 30 stops sliding. Even after the piston 30 stops sliding, if the brake oil flows into the port, the hydraulic pressure in the hole 28 further increases. As a result, the stopped piston 30 reversely presses the inner surface of the hole 28 and presses the cylinder housing 22a constituting the cylinder portion 22 in the direction of arrow R, that is, in the direction opposite to the arrow L. That is, the cylinder housing 22a is displaced in the direction of arrow R as the hydraulic pressure increases.

  In the cylinder housing 22a, a claw portion 34 is formed on the side where the cylinder portion 22 is not formed. As the cylinder housing 22a is displaced in the arrow R direction, the claw portion 34 is rubbed via the pad back metal 26b. The material 24 b is pressed against the side surface 14 b of the disk rotor 14. Thus, when the brake oil flows into the port 32, the disk rotor 14 can be pressed and clamped by the pair of friction materials 24a and 24b, and the disk rotor 14 can be braked efficiently.

  By the way, the disk rotor 14 of the disk brake device 10 cools the frictional heat generated during braking by exposing the friction sliding surface to the air. Therefore, when traveling in the rain or when traveling on a road surface with a pool of water, water droplets (moisture) are directly applied to the disk rotor 14 and between the disk rotor 14 and the brake pad 20, that is, between the disk rotor 14 and the friction material 24. Moisture invades. When moisture enters between the disk rotor 14 and the friction material 24, the frictional force when the disk rotor 14 and the friction material 24 come into contact with each other decreases, and the braking force decreases slightly compared to the observation. That is, the rising of the braking force is delayed from the time when the space between the disk rotor 14 and the friction material 24 is dry, and the driver feels uncomfortable with respect to the braking force.

  Therefore, the disc brake device 10 of the present embodiment actively discharges moisture that has entered between the disc rotor 14 and the friction material 24 from the stage before starting the braking operation, regardless of whether or not the braking operation is performed. It has a structure to do. As shown in FIG. 2 and FIG. 3 which is an enlarged view of the brake pad 20, the brake pad 20 of the disc brake device 10 of the present embodiment is provided with a ventilation pipe 36 (36a, 36a, 36b) through which the traveling wind W received by the caliper 16 passes. 36b). 2 and 3, the vent pipe 36 is formed on the pad back metal 26 and extends from the outer peripheral side of the disk rotor 14 toward the inner peripheral side. In the middle of the ventilation pipe 36, a venturi section 38 in which the width of the pipe line is narrowed is formed. Further, one end of a suction pipe 40 penetrating through the friction material 24 is connected to the venturi section 38. The other end of the suction tube 40 is connected to a suction port 42 in which the friction material 24 is opened on a surface facing the friction sliding surface of the disk rotor 14.

  By the way, as shown in FIG. 1, the cooling air (running wind W) for cooling the frictional heat generated during the braking operation of the caliper 16 is applied to the portion of the cylinder housing 22a extending from the cylinder portion 22 to the claw portion 34. An opening 44 is formed for supplying to the rotor 14. As shown in FIG. 1, the caliper 16 is often attached so that the opening 44 faces the traveling direction of the vehicle. In the present embodiment, the air inlet 46 of the ventilation pipe 36 formed in the pad back metal 26 is set in the opening 44. Therefore, when the vehicle travels, the cooling air (traveling air W) is always supplied to the ventilation pipe 36.

  When the traveling wind W flows into the ventilation pipe 36, the flow velocity is accelerated by the venturi section 38. That is, a venturi effect occurs. As a result, the inside of the suction pipe 40 connected to the venturi section 38 has a negative pressure, and the air between the friction material 24 and the disk rotor 14 can be sucked from the suction port 42. At this time, if moisture exists between the friction material 24 and the disk rotor 14, the moisture is sucked together with air from the suction port 42. That is, water that causes water fade can be excluded from the space between the disk rotor 14 and the friction material 24. This suction operation is always performed as long as the traveling wind W passes through the ventilation pipe 36 while the vehicle is traveling. Therefore, when a braking operation is performed, moisture (water droplets) is excluded from between the disk rotor 14 and the friction material 24, and sufficient control is achieved by contact between the disk rotor 14 and the friction material 24 from the initial stage of the braking operation. It becomes possible to generate motive power, and it is possible to eliminate or reduce the uncomfortable feeling related to the braking force of the driver. When water is discharged from the outlet 48, the water is atomized by the venturi effect, so that the water discharged from the outlet 48 is easily evaporated and prevented from collecting again as water droplets around the axle. Is done.

  Further, as described above, since the suction pipe 40 sucks air existing between the disk rotor 14 and the friction material 24, the suction air heated by the braking friction is sucked and discharged from the outlet 48. As a result, the heating of the disk rotor 14 and the friction material 24 can be suppressed. That is, it can also contribute to suppression of heat fade.

  FIG. 4 shows a front view of the friction material 24 in contact with the friction sliding surface of the disk rotor 14. As shown in FIG. 4, the suction port 42 is formed substantially at the center of the friction material 24, and the suction port 42 is connected to a groove portion 50 that connects the outer periphery side Out and the inner periphery side In of the friction material 24. By connecting the suction port 42 to the groove portion 50 that connects the outer periphery side Out and the inner periphery side In of the friction material 24, the entire groove portion 50 can be influenced by the negative pressure generated by the venturi effect. At this time, the portion of the rotating disk rotor 14 that comes into contact with the friction material 24 always faces the groove 50 extending from the outer periphery side Out to the inner periphery side In, so that it enters between the disk rotor 14 and the friction material 24. It is possible to efficiently remove the sucked moisture and heated air. In addition, although the suction efficiency of moisture and heated air can be improved by providing a plurality of groove portions 50, if the number of grooves 50 is increased too much, the strength of the friction material 24 or the friction area decreases. It is desirable to design appropriately considering the area. In the case of FIG. 4, the groove portion 50 is formed in parallel with the ventilation pipe 36, but the same effect as in the present embodiment can be obtained even if it is formed obliquely.

  FIG. 5 shows an example in which the air collecting portion 52 having an enlarged diameter is attached to the air inlet 46 of the vent pipe 36. By attaching the air collecting part 52 to the air inlet 46, a large amount of traveling wind W can be efficiently sent to the venturi part 38. As a result, the suction force in the suction tube 40 can be easily increased. In addition, since a large amount of traveling wind W can be guided to the ventilation pipe 36 even when traveling at a low speed, a large suction force can be generated. Since the venturi portion 38 of the ventilation pipe 36 has a small diameter, it is also preferable to arrange a filter in the air collecting portion 52 or the air inlet 46 in order to avoid clogging due to foreign matters such as dust.

  By the way, the brake pad 20 is pressed against the side surfaces 14a and 14b of the disk rotor 14 by the piston 30 and the claw portion 34. However, the brake pad 20 is not fixed to the piston 30 or the claw portion 34 but guided by a separately provided guide member or the like. Can be made floating. In this case, the brake pad 20 moves so as to be attracted to the disk rotor 14 by the negative pressure generated in the suction pipe 40. As a result, as shown in FIG. 6, the brake pad 20 originally retracted from the disk rotor 14 during non-braking can contact the disk rotor 14. For this reason, the clearance formed between the disk rotor 14 and the friction material 24 is filled, and it is possible to suppress the intrusion of moisture itself. That is, it is possible to fundamentally prevent water fade. Note that the contact force generated at this time is a weak force generated by the negative pressure generated in the venturi portion 38, and the friction material 24 only touches the disk rotor 14, and no pressing force is generated on the disk rotor 14. . As a result, there is very little possibility of causing so-called dragging and squeaking of the brake pad 20. Further, even when a water film is formed on the surface of the disc rotor 14 in a state where the brake pad 20 and the disc rotor 14 are in contact with each other due to negative pressure, the suction is caused by the negative pressure generated in the suction pipe 40 as described above. And eliminated.

  FIG. 1 shows an example in which the caliper 16 is disposed in such a manner that the opening 44 is directed in the vehicle traveling direction and receives the traveling wind W efficiently. However, if an air guide plate or a duct for guiding the traveling wind W is provided in the opening 44, the same effect as that of the present embodiment can be obtained while improving the degree of freedom of the caliper 16 placement posture.

  Further, in the present embodiment, the example in which the vent pipe 36 is formed on the pad back metal 26 is shown, but even if the vent pipe 36 is formed on the friction material 24, the same effect as in the present embodiment can be obtained. In this case, it is desirable to form the vent pipe 36 at a position deeper than the wear limit of the friction material 24. Further, in the present embodiment, an example in which the vent pipe 36 is formed from the outer peripheral side to the inner peripheral side of the pad back metal 26 has been shown. However, if an air flow such as traveling wind is provided to the venturi portion, the vent pipe The formation direction of 36 is arbitrary, and it only has to penetrate in a direction substantially orthogonal to the thickness direction of the brake pad. For example, even if it is formed in the circumferential direction of the brake pad, the same effect as in the present embodiment can be obtained.

  The structure of the disc brake device shown in the present embodiment is an example, and has a vent pipe having a venturi portion on a brake pad, and a suction tube that connects one end to the venturi portion and opens the other end toward the disc rotor. If it is a structure, other structures can be changed suitably. For example, in this embodiment, a one-piston type floating caliper is shown. However, in the case of a two-piston type floating caliper or a fixed caliper type, as in this embodiment, moisture or water that has entered between the disc rotor and the brake pad Heated air can be eliminated without performing a braking operation.

1 is an external perspective view illustrating a configuration of a disc brake device according to an embodiment of the present invention. It is sectional drawing of the caliper of the disc brake apparatus which concerns on embodiment of this invention. It is sectional drawing explaining the structure of the brake pad of the disc brake apparatus which concerns on embodiment of this invention. It is explanatory drawing explaining the groove part formed in the friction material of the disc brake apparatus which concerns on embodiment of this invention. It is sectional drawing explaining the state which attached the air collection part to the vent pipe of the disc brake apparatus which concerns on embodiment of this invention. It is explanatory drawing explaining the state by which the brake pad of the disc brake apparatus which concerns on embodiment of this invention is attracted | sucked by the disc rotor.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Disc brake device, 12 Hub, 14 Disc rotor, 16 Caliper, 18 Car body fixed mount, 20 Brake pad, 22 Cylinder part, 22a Cylinder housing, 24 Friction material, 26 Pad back metal, 28 holes, 30 Piston, 32 port, 34 Claw part, 36 vent pipe, 38 venturi part, 40 suction pipe, 42 suction port, 44 opening part, 46 air inlet, 48 outlet, 50 groove part, 52 air collecting part, W running air.

Claims (5)

A disk brake device provided with a brake pad that is disposed opposite to a friction sliding surface of a disk rotor that rotates with a wheel and generates a braking force by being pressed by the friction sliding surface,
Inside the brake pad,
A pipe through which a running wind received when the vehicle travels can pass, and a vent pipe including a venturi portion in the course of the running wind;
A suction pipe having one end connected to the venturi portion and the other end opened toward the friction sliding surface of the disk rotor;
A disc brake device in which is formed. The brake pad includes a friction material that generates a braking force in contact with the friction sliding surface of the disk rotor,
The friction material has an opening facing the friction sliding surface of the disk rotor, and has a groove portion connecting the outer peripheral side and the inner peripheral side,
2. The disc brake device according to claim 1, wherein an opening side of the friction sliding surface of the suction pipe is connected to the groove portion.   3. The disc brake device according to claim 1, wherein the ventilation pipe has an air collecting portion having an enlarged diameter on the inflow side of the traveling wind.   4. The disc brake device according to claim 1, wherein the brake pad moves toward the disc rotor by a negative pressure generated by air accelerated by the venturi portion. 5. . A brake pad that is disposed opposite to a friction sliding surface of a disk rotor that rotates with a wheel and generates a braking force by being pressed against the friction sliding surface,
A vent pipe that penetrates in a direction substantially perpendicular to the thickness direction and has a venturi portion in the middle thereof;
A suction pipe having one end connected to the venturi portion and the other end opened toward the friction sliding surface of the disk rotor;
A brake pad comprising:

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