JP3156059B2 - Disc brake cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling system for a disk brake used as an emergency brake of a magnetic levitation type railway vehicle, and more particularly to a cooling means for a multi-plate type disk brake wheel for high speed stopping.

[0002]

2. Description of the Related Art Generally, a magnetic levitation type railway vehicle floats on a track by a magnetic repulsion and is controlled by a linear motor.

FIGS. 3 (a) and 3 (b) are schematic diagrams of a magnetic levitation type railway vehicle. As shown in the drawing, a magnetically levitated railway vehicle usually includes a plurality of vehicle bodies 1 and a bogie 2 arranged at a connection portion between them. The cart 2 is provided with an auxiliary wheel 4 that rotates in contact with the track 3. The auxiliary wheels 4 are mainly used when the vehicle stops and runs at low speed.

FIG. 4 is a sectional view of a main part of the carriage 2. The auxiliary wheel 4 is fixed to the bogie main body 6 by a support device 5, and is stored in the tire house 7 during normal running.
The lower part of the carriage 2 is closed by an underfloor cover 8 to reduce air resistance and noise.

Incidentally, a magnetic brake by a linear motor is generally used for braking a magnetically levitated railway vehicle. However, if the magnetic brake fails during high-speed running, the auxiliary wheels 4
Is brought into contact with the track 3, and a disc brake provided inside the auxiliary wheel 4 is used.

FIG. 5 is a diagram showing a main part of a conventional auxiliary wheel 4 provided with such a disk brake. That is, a rotating shaft 21 of a metal wheel 20 is rotatably mounted around a bearing fixed to a support device (not shown). A tire 22 is fitted around the outer periphery of the wheel 20, and is fixed by a wheel inboard 23 and a retainer ring 24. A wheel key 25 is formed on the inner peripheral surface of the wheel 20, and three annular disk rotors 26 concentrically arranged on the wheel 20 are fixed by the wheel key 25. Further, the heat shield 27 is connected to the disk rotor 26.
Is disposed between the circumference of the wheel 20 and the wheel 20.

On the other hand, a hydraulically operated brake piston 28 is provided in the support device. In addition, four annular disk stators 29 provided concentrically with the disk rotor 26 and sandwiched from the axial direction are fixed to a torque tube 30 provided in parallel with the rotation shaft 21 of the wheel 20. Have been. A backing plate 31 is fixed to the right end of the torque tube 30 in the drawing, and a brake piston 28 is fixed to the left end in the drawing. In the drawing, reference numeral 32 denotes a pipe for hydraulic oil, and reference numeral 33 denotes a housing for a brake piston.

As described above, the auxiliary wheels 4 are housed in the tire house 7 by the support device 5 when the magnetic levitation type railway vehicle is traveling normally. Further, the brake piston 28 does not operate, and a state is maintained in which there is a slight gap between the disk rotor 26 and the disk stator 29. Then, when sudden braking is applied, the auxiliary wheel 4 is taken out of the tire house 7 by the support device 5, and
The tire 22 contacts the track 3 and rotates. Subsequently, the brake piston 28 operates to apply a force toward the right side in the figure to the torque tube 30. Backing plate 3
Since 1 is stationary, the disk rotor 26 and the disk stator 29 come into contact with each other and cause friction. The rotation of the wheel 20 is stopped by this frictional force, and the magnetic levitation type railway vehicle is decelerated.

Here, in order to effectively operate the disk brake, the contact area between the disk rotor 26 and the disk stator 29 may be increased. What is necessary is just to increase the diameter of a wheel and a tire. However, in the limited space of the tire house 7, the size of the disc brake has its own limit. Therefore, in this conventional disk brake, a plurality of disk rotors 26 and disk stators 29 having a small area are provided concentrically on one another to increase the contact area between the disk rotor 26 and the disk stator 29. Disc brakes are employed.

[0010]

In such a multi-disc brake, the frictional heat generated by the friction between the disk rotor 26 and the disk stator 29 hardly escapes and tends to be high in temperature. Wheel key 2
The metal fitting of No. 5 melts, and re-rotation becomes impossible due to thermal deterioration of the strength of the wheel 20, or the internal pressure of the tire 22 decreases due to the melting of the thermal fuse 34 of the wheel 20,
When the vehicle is towed, there is a possibility that the tire 22 generates heat due to rotation, and it becomes difficult to move the vehicle. Therefore, in the auxiliary wheel 4 having the conventional disk brake, one or two heat shields 27 are provided between the disk rotor 26 and the wheel 20 to protect the wheel 20 and the tire 22 from heat. However, this only has the function of preventing radiant heat from the disk rotor 26 and the disk stator 29. The wheel 20 is provided with an intake port 35 for taking in air from the outside by convection and exchanging heat with the disk rotor 26 and the disk stator 29. However, when the underfloor cover 8 and the tire house 7 of the truck are provided, natural cooling of the disc brake is difficult, and natural convection from the clearance between the side wall, the vehicle body and the truck is limited, so that considerable time is required for cooling. did.

Therefore, a method for rapidly cooling the disc brake is required. For example, even if an air intake such as an air scoop is provided, the disc brake has the most heat at the time of stopping after absorbing kinetic energy or immediately after the stop, so the inside of the tire house by the scoop is Semi-forced cooling cannot be expected.

Therefore, a method of cooling a multi-disc disc brake wheel by forced cooling has been proposed.
Examples of forced cooling include a method of cooling using a fan (Japanese Patent Publication No. 58-500705) and a method of cooling by partially using a multi-plate disk rotor and a disk stator (Japanese Patent Application Laid-Open No. 62-279165). is there. There is also a method of injecting a coolant such as water or a fire extinguishing liquid into the disc brake.

However, mounting a fan on a disc brake is disadvantageous in terms of space and weight. In the method of spraying a coolant, water and a fire extinguishing solution promote corrosion of a supporting device and a tire house, and a fire extinguishing solution is sprayed. There has been a problem that it requires labor for subsequent cleaning. Therefore, an object of the present invention is to provide a disk brake cooling device that does not require additional equipment that causes an increase in weight.

[0014]

Means for Solving the Problems In order to solve the above problems and achieve the object, the present invention takes the following means.
That is, a wheel rotatably provided on a support shaft and having an intake port, a disk rotor fixed to the inside of a rim of the wheel, a disk stator fixed to the support shaft, A heat shield having two layers provided outside the disk rotor, and an injection mechanism for blowing a cooling gas into the gap between the two layers of heat shield from the side where the air inlet is provided is provided.

[0015]

The following effects are obtained as a result of taking the above measures.

Since a large amount of the secondary flow is sucked from the inlet of the wheel by the ejector effect of the primary flow, the primary flow and the secondary flow are mixed and flow into the gap between the two layers of the heat shield, and The brake will be cooled efficiently.

[0017]

1 and 2 are sectional views of a main part of a cooling device for a disk brake according to an embodiment of the present invention. In these figures, the same parts as those in FIG. 5 are denoted by the same reference numerals. Therefore, a detailed description of the overlapping part will be omitted.

The main difference between the disk brake cooling device according to the present embodiment and the conventional disk brake cooling device is a structure for cooling the heat generated by the disk brake.

That is, in this embodiment, the housing 3
3. Air passages 41, 42, 43 are provided in the torque tube 30, the backing plate 31a via the joint portion 40, and the end of the air passage 41 is connected to an air circuit of a bogie (not shown). The end of the air passage 43 is the nozzle hole 4
It is 4. In order to close the through-hole, a detour is made possible by utilizing the lead plug 45 in manufacturing.

A two-layer heat shield 2 is provided inside the wheel.
7a and 27b are provided, the nozzle hole 44 is brought close to the heat shields 27a and 27b, and the cross sections of the ends of the heat shields 27a and 27b are bent so as to form a bell mouth. The outer bent end of the heat shield 27 is provided with a slight gap from the wheel 20.

The backing plate 31a is
A star-shaped serration is provided so that the air flow passing through the zero inlet port 35 is naturally sucked, and the secondary flow B passes through the concave portion 46.

In this embodiment constructed as above, the compressed air introduced from the air circuit of the bogie is supplied to the air passage 4.
1, 42, and 43, as a primary flow A from the nozzle hole 44 of the backing plate 31a as the heat shield 27a,
It is sprayed toward the bell mouth part of 27b. At this time,
The air outside the wheel 20 is sucked as the secondary flow B from the intake port 35 by the ejector effect. As a result, the two airflows become a mixed flow and become heat shields 27a and 27b.
Flows into the gap.

Since the mixed flow has a momentum, a part of the mixed flow is forcibly discharged to the outside of the tire house 7 near the opening of the tire house 7 and the tire house 7 on the opposite side of the discharge direction is discharged.
The outside low-temperature air is drawn in, and the rise in the air temperature in the tire house 7 is suppressed. Wheel 2 without forced cooling
The heat flow is concentrated at the top, but the forced air flow is
Since heat insulation and cooling can be performed on the entire inner circumference, uniform cooling is possible, and a local temperature rise can be avoided.

The temperature of the mixed flow in the tire house 7 also rises with time, but the tire house 7 itself and the supporting device 5
Since heat exchange is performed through a mixed flow with a wide range of members such as the above, heat can be absorbed in the entirety of the tire house 7 up to the allowable temperature of the component having the lowest heat resistance.

Further, the primary flow A exchanges heat while passing through the air passages of the housing 33, the torque tube 30, and the backing plate 31a. Further, the temperature rise of the primary flow A to some extent is caused by the housing 33, the torque tube 30,
It also serves to cool the backing plate 31a, and also has the effect of suppressing the thermal deterioration of the axle and the temperature rise of the ABS detector in the axle.

As described above, in this embodiment, the small primary flow A
, The secondary flow B several times the amount of the primary flow A can be sucked by the ejector effect, and a large amount of the cooling mixed flow can be sent between the two layers of the heat shield.

Therefore, the disk rotor 2 as a heat source
6 and the disk stator 29 are blocked by a flowing air layer and at the same time, the heat shields 27a and 27b are cooled by a mixed flow, so that the wheels 2
0 and the tire 22 can be protected from heat.

On the other hand, since the primary flow A injected from the backing plate 31a utilizes a part or all of an air source (with a compressor) such as an air spring of a bogie or a compressor, a special gas (helium, helium, etc.) is used. There is no need to mount N ₂ , CO _2, etc.) or liquids (water, fire extinguisher, etc.), and the increase in weight due to additional equipment can be minimized. Where 1
The injection control of the next flow A will be described.

The size of the nozzle hole 44 depends on the kinetic energy of the vehicle, the disk capacity, the amount of air available from the bogie, the gap between the two layers of the heat shield, the amount of air in the tire house, the size of the intake port 35, and the primary flow discharge. The most efficient size is determined from time and the like.

The position and direction of the nozzle hole 44 are relative to the two-layer heat shields 27a and 27b and the nozzle hole 44, the position of the intake port 35 stopping at an arbitrary position, and the star-shaped serration provided on the backing plate 31a. The number of holes and the angle of the holes at which the ejector efficiency is maximized are set in consideration of the allowable dimensions of the holes. When the disk rotor 26 and the disk stator 29 are made of carbon, the bell mouth portion of the inner heat shield 27 is bent inward so as not to promote oxidation.

The injection timing of the primary flow A does not need to be the same as the start of braking. A temperature sensor or the like is provided on the housing so that the injection starts when the disk rotor 26 and the disk stator 29 reach a certain temperature or higher. Provided with a solenoid valve opening / closing function via a provided controller. Further, the joint portion 40 may be provided with a function of a thermal relief (a shape memory alloy-like material for closing and reusable after cooling).

The injection amount and discharge time of the primary flow are determined as follows. That is, the mixed flow discharged into the tire house fills the tire house, but the inside of the tire house is disturbed by the mixed flow, and the inflow of the primary flow is discharged outside the tire house. In particular, since the lower part of the disc brake goes to the side wall, the air in the tire house replaces the air under the floor, and eventually the tire house and the whole support device rise in temperature, but reach a steady state at a certain temperature, and in that steady state, the wheel Is determined so that the temperature becomes equal to or lower than the specified temperature. Next, the cleaning of the nozzle hole 44 and detection of an abnormality will be described.

Since the disk brake is used only in an emergency, the frequency of injecting air from the nozzle holes 44 is low.
However, the nozzle hole 44 is easily blocked and solidified by dust or the like. Further, in the case of a carbon disk (adopted from the viewpoint of reducing the weight and suppressing the progress of abrasion), there is a possibility that carbon abrasion powder adheres and also closes and solidifies the nozzle hole 44. For this reason, during traveling, the air discharged from the air spring, the entrance door, etc. is constantly drawn into the backing plate, and the primary flow is jetted at a low pressure to prevent the nozzle holes 44 from being clogged. Detect. If there is any abnormality, inspection and replacement are possible in advance. It should be noted that the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0034]

According to the present invention, the disc brake wheel can be efficiently cooled by a small amount of airflow, which can contribute to a reduction in equipment weight of the vehicle.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an auxiliary wheel showing a disk brake forced cooling unit according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the embodiment taken along line 2A-2A in FIG. 1 and viewed in the direction of the arrow;

FIG. 3 is a schematic view of a magnetic levitation type railway vehicle shown for explaining a conventional example.

FIG. 4 is an essential part cross-sectional view of a bogie shown for explaining a conventional example.

FIG. 5 is a sectional view of a main part showing a cooling means of a conventional disc brake.

[Explanation of symbols]

4, 4 ': auxiliary wheel, 20: wheel, 21: support shaft, 22: tire, 26: disk rotor, 27a, 2
7b: heat shield, 28: brake piston,
29: disk stator, 31, 31a: backing plate, 35: intake port, A: primary flow,
B: Secondary flow.

──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Minoru Okano 10 Oecho, Minato-ku, Nagoya, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Address: Mitsubishi Heavy Industries, Ltd. Nagoya Aerospace Systems Works (56) Reference: Shokai Sho 57-73435 (JP, U) JP44-19492 (JP, B1) JP58-500705 (JP, A) Table 61-502343 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F16D 49/00-69/04 B60T 5/00 B61H 1/00-13/38

Claims (3)

(57) [Claims] 1. A wheel rotatably provided on a support shaft and having an intake port, a disk rotor fixed inside a rim of the wheel, a disk stator fixed to the support shaft, and a And a two-layer heat shield provided outside the disk rotor, and an injection mechanism for blowing a cooling gas into a gap between the two-layer heat shield from the side where the air inlet is provided. Disc brake cooling device. Wherein the injection mechanism injects cooling gas at low pressure, prior to
Monitoring the air circuit pressure to supply the cooling gas
2. The cooling device for a disk brake according to claim 1, further comprising an injection inspection means for detecting a normal state . 3. The disk brake cooling device according to claim 1, wherein the cooling gas is air.