JP3136956B2 - Water-cooled disc brake device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a water-cooled disc brake device, and more particularly to a water-cooled disc brake device for a vehicle.

[0002]

2. Description of the Related Art Disc brakes are frequently used as a braking device for a vehicle because a reliable braking force can be obtained. However, since the disk brake utilizes friction between the disk rotor and the pad, the temperature of the disk rotor tends to rise, and if braking is performed for a long time, the disk rotor and the pad become hot, resulting in a so-called fade. This may cause a phenomenon or a vapor lock phenomenon.

[0003] A water-cooled disc brake device is disclosed in Japanese Patent Application Laid-Open No. HEI 6-74271, in which cooling water is introduced into a fixed pad to reduce the temperature of the pad.

[0004]

Generally, the peripheral speed of the disk rotor increases as the peripheral speed increases, so that the outer peripheral portion of the pad facing the outer peripheral side of the disk rotor faces the inner peripheral side. It becomes hotter than the inner circumference. However, in the water-cooled disc brake device disclosed in the above-mentioned publications, the cooling water does not sufficiently and reliably reach the outer peripheral portion of the pad. Therefore, the outer peripheral portion of the pad, which is heated to a high temperature, cannot be sufficiently cooled, and the temperature distribution is not made uniform, and the friction coefficient varies between the pad portions, making it difficult to maintain stable braking.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a water-cooled disc brake device capable of always making the pad temperature distribution uniform and realizing stable braking. is there.

[0006]

In order to achieve the above object, a first aspect of the present invention is to provide a water cooling system for guiding cooling water to a pad of a disc brake and cooling the pad heated by frictional heat during braking. In the disk brake device, a disk rotor that rotates together with wheels and has friction materials fixed to both surfaces thereof, a pair of metal pads disposed on both sides of the disk rotor, and the pair of metal pads, Pressing means for pressing so as to sandwich it, and inside the metal pad, respectively, are formed along the rotation direction of the disk rotor, and the respective flow path cross-sectional areas are sequentially increased from those on the rotation center side of the disk rotor. And a plurality of cooling water passages. Therefore, frictional heat generated by friction between the friction material of the disk rotor and the pair of metal pads during braking is greater on the outer peripheral side where the peripheral speed of the disk rotor is higher, and the temperature of the outer peripheral portion of the metal pad is higher than that of the inner peripheral portion. Although the water flow becomes higher, the flow rate of the cooling water flowing in the metal pad is larger in the outer peripheral portion of the metal pad, so that the metal pad is uniformly cooled without a temperature difference, and stable braking is always realized.

Further, in the invention according to claim 2, the metal pad is directly fitted with the first member having a low thermal conductivity by directly receiving the pressing force from the pressing means, and is fitted to the first member, and It is characterized by comprising a second member having a higher thermal conductivity than the first member capable of directly contacting the friction material of the rotor. Therefore, the frictional heat generated by the friction between the disk rotor and the second member is transmitted to the second member having a high thermal conductivity, and then is well cooled by the cooling water. Further, since the first member has a low thermal conductivity, frictional heat is not transmitted to the pressing means side.

According to the third aspect of the present invention, the surface of the second member facing the friction material of the disk rotor includes:
A plurality of slits are formed perpendicular to the rotation direction of the disk rotor. Therefore,
Even if thermal distortion due to frictional heat occurs in the second member, the thermal distortion is favorably absorbed by the slit. Claim 4
In the invention, the first member has higher rigidity than at least the second member. Therefore, the metal pad does not deform significantly even if pressed strongly by the pressing means.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration diagram of a water-cooled disc brake device. As shown in the figure, reference numeral 1 denotes a disk rotor, and this disk rotor 1
It is fixed to an axle (not shown). The disk rotor 1 is formed in a disk shape, and friction members 2 and 3 made of a heat-insulating organic material are fixed to both surfaces of the outer peripheral portion over the entire circumference. The sliding friction surfaces 2a, 2a,
A pair of metal pads 4 and 5 are arranged at a front portion of the disk rotor 1 so as to face 3a.

A caliper 6 is arranged on the outer periphery of the disk rotor 1 so as to sandwich the disk rotor 1 via metal pads 4 and 5. The caliper 6 has a piston housing 8 for housing a piston (pressing means) 7 for pressing the back of the metal pad 5 toward the disk rotor 1, and a caliper claw (pressing means) 9 for supporting the back of the metal pad 5. Are integrally formed. The caliper 6 is slidably supported by a caliper support (not shown) in a direction parallel to the rotation axis of the disk rotor 1.

The piston 7 is formed in a hollow cylindrical shape, and is slidably fitted in the piston housing 8. A hydraulic chamber 7a is formed on the back surface of the piston 7, and the hydraulic chamber 7a
Is connected to an oil passage 8a provided in the piston storage section 8. The metal pads 4 and 5 are formed by fitting outer members (for example, cast iron) 10 and 11 having low thermal conductivity with inner members (for example, copper or copper alloy) 12 and 13 having high thermal conductivity. Specifically, the outer peripheral portions 12a, 13a of the inner members (second members) 12, 13 are attached to the inner surfaces of the flanges 10a, 11a formed on the outer periphery of the outer members (first members) 10, 11, respectively. The distal end and the inner surfaces 10b, 11b of the outer members 10, 11 are press-fitted and adhered so as to be in contact with each other. And the outer member 1
Chambers 14 and 1 surrounded by 0 and 11 and inner members 12 and 13
5 are formed.

The inner members 12 and 13 are formed so as to be convex toward the outer members 10 and 11, respectively.
c, 12d, 12e and partition walls 13b, 13c, 13d,
13e are formed. These partitions 12b, 12
c, 12d, 12e and partition walls 13b, 13c, 13d,
The tip of 13e is also in contact with the inner surfaces 10b, 11b of the outer members 10, 11 in the same manner as the outer peripheral portions 12a, 13a. Therefore, the chambers 14 and 15 are provided with these partition walls 12b and 12b.
c, 12d, 12e and partition walls 13b, 13c, 13d,
13e, the outer peripheral portion 12a and the partition 12
cooling water passages 14a, 14b, 14c, 14d, 14e surrounded by b, 12c, 12d, 12e and the inner surface 10b.
But also an outer peripheral portion 13a and partition walls 13b, 13c, 13
d, 13e and the inner surface 11b.
a, 15b, 15c, 15d, and 15e are formed.

On the surfaces of the inner members 12 and 13,
A plurality of groove-shaped slits 12g and 13g are provided in a direction perpendicular to the rotation direction of the disk rotor 1 (see FIG. 3). FIG. 2 shows a metal pad 4 along the line AA in FIG.
Is shown, and the metal pad 4 will be described in more detail below. Since the same applies to the metal pad 5, the description of the metal pad 5 is omitted here.

As shown in FIG. 1, the partition walls 12b, 12c, 12d, and 12e of the inner member 12 are concentric with the outer peripheral portions 12a and 13a along the rotation direction of the disk rotor 1 indicated by an arrow X in the figure. It has an interval and is arranged with a predetermined interval between the partition walls. The predetermined intervals are indicated by symbols a, b, c, d, and e in the figure, and the relationship between these intervals is a <b <c <d <e.
It has become. That is, the cooling water passages 14a, 14b, 1
4c, 14d, and 14e, the passage width is wider and the passage cross-sectional area is larger on the outer peripheral side farther from the rotation center of the disk rotor 1.

Further, as shown in FIG.
A water supply hole 16 for cooling water is formed in one lower end portion of the first through hole of the outer member 10. On the other hand, the outer member 10
A drain hole 17 for cooling water is formed in the other lower end in the same manner. Thereby, the cooling water flows into the metal pad 4 from the water supply hole 16, and the cooling water flows into the cooling water passage 1.
After being diverted to 4a, 14b, 14c, 14d, and 14e and flowing as indicated by arrows, the water is drained from the drain hole 17.

FIG. 3 shows the connection relationship between the metal pads 4 and 5 and the respective water supply / drainage pipes. In the figure, the vertical direction in the figure is the vehicle vertical direction. As shown in the figure, water supply pipes 20 and 21 are connected to the water absorption holes 16 at the lower ends of the metal pads 4 and 5, respectively. Water supply pipe 2
0 is connected to the connection port 22 a of the connection joint 22. On the other hand, the other end of the water supply pipe 21 is connected to the connection port 23 a of the connection joint 23. And the connection joint 22
The connection port 22b of the connection joint 23 and the connection port 23b of the connection joint 23 are connected to each other by a connection pipe 25 having a bellows 24. A water supply pipe 26 is connected to the connection portion 23c of the connection joint 23, and the water supply pipe 26 is connected to a heat exchanger 41 described later.

Each drain hole 17 at the upper end of the metal pads 4 and 5
Are connected to drain pipes 30 and 31, respectively. The drainage pipes 30 and 31 are connected to each other by connection pipes 35 having bellows 34 via connection joints 32 and 33, similarly to the water supply pipes 20 and 21, and the drainage pipe 36 is also connected to the heat exchanger 41. ing. FIG. 4 shows a cooling water circuit 40 for cooling the metal pads 4 and 5. As shown in the figure, a cooling water circuit 40 is provided with a heat exchanger 41 for cooling the high-temperature cooling water, and supplies the cooling water from the heat exchanger 41 to metal pads 4 and 5 provided on each wheel. Water supply path 42 and a drain path 4 for returning the cooling water, which has been heated by the metal pads 4 and 5, to the heat exchanger 41.
3 and a pump 44 for circulating cooling water through the cooling water circuit 40
It is composed of The pump 44 is provided in the middle of the water supply path 42.

Hereinafter, the cooling operation of the metal pads 4 and 5 when the vehicle is braked in the water-cooled disc brake device configured as described above will be described. When a brake pedal (not shown) is depressed, brake oil flows from a hydraulic circuit (not shown) via an oil passage 8a, and hydraulic pressure is applied to the hydraulic chamber 7a. Then, the piston 7 slides toward the disk rotor 1, and presses the metal pad 5 against the sliding friction surface 3a. At the same time, the caliper 6 is slid by the reaction force of the piston 7 in the direction opposite to the direction in which the piston 7 moves, and the caliper claw 9 presses the metal pad 4 against the sliding friction surface 2a.

As a result, the metal pads 4 and 5 press the disk rotor 1 so as to sandwich the disk rotor 1 from both sides, and a frictional force acts on the disk rotor 1 to perform braking. When this braking is repeatedly performed, frictional heat is generated due to friction between the friction members 2 and 3 and the metal pads 4 and 5. This frictional heat is hardly transmitted to the disk rotor 1 but is transmitted to the metal pads 4 and 5 having high thermal conductivity because the friction members 2 and 3 are formed of a heat insulating organic material. The temperature of the cooling water flowing through the passages 14a, 14b, 14c, 14d, 14e and the cooling water passages 15a, 15b, 15c, 15d, 15e is increased.

At this time, as shown in FIG.
Is running simultaneously with the start of the engine (not shown),
The cooling water circulates in the cooling water circuit 40 in the direction indicated by the arrow in the figure. When the cooling water is circulated in this manner, the cooling water heated by the metal pads 4 and 5 is returned from the metal pads 4 and 5 to the heat exchanger 41 through the drainage path 43, and this heat exchanger It is cooled at 41. Then, the water passes through the water supply path 42 and is circulated again to the metal pads 4 and 5.

In the metal pads 4 and 5, as described above, the cooling water flows through the respective cooling water passages 14a, 14b, 14c, 14d and 14e and the respective cooling water passages 15a and 15a, as indicated by arrows in FIG. 15b, 15c, 15d, and 15e. At this time, as described above, since the passage width of each cooling water passage becomes wider toward the outer peripheral side away from the center of the disk rotor 1, the flow rate of the cooling water per unit time is the smallest in the cooling water passages 14a and 15a. On the other hand, it is the largest in the cooling water passages 14e and 15e.
As a result, the peripheral speed of the disk rotor 1 is generally higher on the outer peripheral side of the disk rotor 1, and the generated frictional heat is larger,
Correspondingly, the temperature of the outer peripheral portions of the metal pads 4 and 5 becomes particularly high. By increasing the cooling water flow rate of the outer peripheral portion where the temperature becomes high, the metal pads 4 and 5 are sufficiently cooled, By making the temperature distribution of the metal pads 4 and 5 and thus the friction coefficient uniform, stable braking can be maintained.

By the way, as described above, the metal pads 4 and 5 are made of inner members (for example, copper or copper alloy) 12 and 13 having high thermal conductivity on the side in contact with the disk rotor 1, and are provided on the piston 7 side or the caliper claw. Outer members (for example, cast iron) 10 and 11 having low thermal conductivity are provided on the part 9 side. Here, outer members (for example, cast iron) 10, 11
Has a thermal conductivity of, for example, about 1/5 of the inner members (for example, copper or copper alloy) 12 and 13. Therefore, although frictional heat is easily transmitted to the inner members 12 and 13, it is difficult for the frictional heat to be transmitted to the outer members 10 and 11 via the inner members 12 and 13.

From this, the frictional heat is generated by the inner member 1
In addition to being cooled well by the cooling water via the pistons 2 and 13, there is almost no transmission to the piston 7 side.
Thus, it is possible to prevent the temperature of the brake oil in the hydraulic chamber 7a that presses the pressure from rising, and to appropriately suppress the vapor lock phenomenon.
Also, since the metal tends to expand due to a rise in temperature as the thermal conductivity increases, the inner member 1
2 and 13 expand and try to deform like a bimetal. However, since the inner members 12 and 13 are press-fitted and adhered to the outer members 10 and 11,
The deformation of the inner members 12, 13 is suppressed by the outer members 10, 11. At this time, thermal strain is generated in the inner members 12 and 13.
Good absorption is achieved by the slits 12g described above. Therefore, the inner members 12 and 13 do not expand and come into contact with the friction members 2 and 3 of the disk rotor 1, thereby preventing a decrease in friction coefficient and uneven wear of the inner members 12 and 13 and the friction members 2 and 3. In addition, generation of abnormal noise and vibration can be suppressed.

Note that, due to the difference in thermal conductivity, the inner member 1
The outer members 2 and 13 expand due to an increase in temperature and are outer members 10 and 11.
Are pressed against the flanges 10a and 11a. Therefore, when the temperature of the metal pads 4 and 5 rises, the joining between the inner members 12 and 13 and the outer members 10 and 11 is further strengthened, and the outer members 10 and 11 and the inner member 1 are joined together.
Even if the metal pads 2 and 13 are not joined by welding or the like, the cost is reduced and the reliability of the metal pads 4 and 5 is secured.

The outer member (for example, cast iron) 10,
11 is an inner member (eg, copper or copper alloy) 1
Since the rigidity is higher than the rigidities 2 and 13, the contact between the piston 7 and the caliper claw 9 and the caliper support (not shown)
The deformation of the metal pads 4 and 5 due to the reaction force can be minimized. As described above in detail, according to the cooling type disc brake device of the present invention, the metal pads 4
5 is made of two kinds of metals, outer members 10 and 11 having a low thermal conductivity and inner members 12 and 13 having a high thermal conductivity. The outer members 10 and 11 are provided on the piston 7 side or the caliper claw 9 side. On the other hand, the inner members 12 and 13 are disposed on the friction members 2 and 3 sides of the disk rotor 1, and the cooling water is passed between the outer members 10 and 11 and the inner members 12 and 13. , 3 and inner member 12,
The frictional heat generated by friction with the member 13 can be efficiently and suitably transmitted to the inner members 12 and 13 to be cooled by the cooling water, and the frictional heat is not transmitted to the piston 7 side or the caliper claw portion 9 side. In this manner, the occurrence of the vapor lock phenomenon can be more reliably suppressed.

The cooling water passage 1 in the metal pads 4 and 5
4a, 14b, 14c, 14d, 14e and the cooling water passages 15a, 15b, 15c, 15d, 15e have larger passage cross-sectional areas as the distance from the center of the disk rotor 1 increases. By cooling the metal pads 4 and 5 by increasing the amount of cooling water flowing through the outer peripheral portions of the metal pads 4 and 5 opposed to the outer peripheral side of the disk rotor 1 having a large number, the temperature distribution of the metal pads 4 and 5 is preferably uniform. It is possible to realize stable braking at all times by suppressing variations in the coefficient of friction and thermal strain.

[0027]

As described above, according to the water-cooled disc brake device of the first aspect, the water-cooled disc that guides the cooling water to the pad of the disc brake and cools the pad heated by frictional heat during braking. In the brake device,
Rotating with the wheels, a disk rotor having friction materials fixed to both surfaces thereof, a pair of metal pads disposed on both sides of the disk rotor, and a pressing means for pressing the pair of metal pads so as to sandwich the disk rotor, Inside the metal pad, a plurality of cooling water passages are formed along the rotation direction of the disk rotor, and each of the flow path cross-sectional areas is sequentially increased from the rotation center side of the disk rotor. As a result, the frictional heat that is generated more on the outer peripheral side where the peripheral speed of the disk rotor is large due to braking and raises the temperature of the outer peripheral portion of the metal pad than the inner peripheral portion can be cooled well, and the temperature distribution of the metal pad can be reduced It is possible to realize stable braking at all times by keeping it uniform.

Further, according to the water-cooled disc brake device of the second aspect, the metal pad is directly fitted with the pressing force from the pressing means and fitted to the first member having a low thermal conductivity and the first member. , The first that can directly contact the friction material of the disk rotor
Since it is composed of the second member having a higher thermal conductivity than the member of
Friction heat generated by friction between the disk rotor and the second member is preferably transmitted to the second member having a high thermal conductivity, and can be favorably cooled by the cooling water. In addition, since the first member has a low thermal conductivity, frictional heat can be prevented from being transmitted to the pressing means, and when the pressing means uses a fluid, the vapor lock phenomenon can be suitably prevented.

Further, according to the water-cooled disk brake device of the third aspect, the second member opposed to the friction material of the disk rotor.
Since a plurality of slits are formed on the surface of the member perpendicular to the rotation direction of the disk rotor, thermal distortion of the second member caused by frictional heat can be favorably absorbed by the slit, and Deformation can be suitably prevented. Also,
According to the water-cooled disc brake device of the fourth aspect, the first
Since the member of is higher in rigidity than at least the second member,
The metal pad can be prevented from being greatly deformed even by the pressing by the pressing means.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a water-cooled disc brake device of the present invention.

FIG. 2 is a longitudinal sectional view of the metal pad taken along line AA in FIG.

FIG. 3 is a diagram showing a connection relationship between a metal pad and a water supply / drainage pipe.

FIG. 4 is a diagram showing a schematic configuration of a cooling water circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Disc rotor 2, 3 Friction member 4, 5 Metal pad 6 Caliper 7 Piston (pressing means) 9 Caliper claw part (pressing means) 10, 11 Outer member (first member) 12, 13 Inner member (second member) 12g, 13g Slits 14a, 14b, 14c, 14d, 14e Cooling water passage 15a, 15b, 15c, 15d, 15e Cooling water passage 16 Water supply hole 17 Drainage hole 40 Cooling water circuit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-8-170669 (JP, A) JP-A-2-159431 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 49/00-71/04

Claims (4)

(57) [Claims] 1. A water-cooled disc brake device for guiding cooling water to a pad of a disc brake and cooling the pad heated by frictional heat during braking, wherein the disc rotates with wheels and has friction materials fixed to both surfaces. A rotor; a pair of metal pads disposed on both sides of the disk rotor; pressing means for pressing the pair of metal pads so as to sandwich the disk rotor; and a disk rotor inside the metal pad. A plurality of cooling water passages formed along the rotation direction of the disk rotor, and each of the passage cross-sectional areas of the cooling water passages is gradually increased from the one on the rotation center side of the disk rotor. apparatus. 2. The metal pad directly receives a pressing force from the pressing means and is fitted to the first member having a low thermal conductivity and the first member, and directly contacts a friction material of the disk rotor. The water-cooled disc brake device according to claim 1, further comprising a second member having a higher thermal conductivity than the first member. 3. A plurality of slits are formed on a surface of the second member facing a friction material of the disk rotor, the slits being perpendicular to a rotation direction of the disk rotor. 2. The water-cooled disc brake device according to 2. 4. The first member is at least the second member .
The water-cooled disc brake device according to claim 2 or 3, wherein the rigidity is higher than that of the member .