DE19722254A1 - Device for transferring thermal energy from automotive brake system to passenger cabin - Google Patents

Abstract

An automotive brake system has a ribbed heat-exchanger located in close proximity to the brake linings where heat is generated. Heat emitted by the brake system is captured by fluid passing through the heat exchanger, and is passed directly or indirectly to a filter and/or a second heat exchanger, which surrenders warmth to the passenger cabin.

Description

The invention relates to a device for decoupling heat Me energy from vehicle friction brake systems, with parts of the im Service brakes arranged by a wheel or axle area Heat transfer agents are flushed or washed around.

When the outside temperature is low, motor vehicles are included Internal combustion engines use the heat for heating the Passenger cell usually from the heated engine cooling water. Nowadays the efficiency of combustion engines are constantly improving, which has the consequence that the decreasing engine heat for the passenger compartment heating decreases. The problem with modern, low-consumption die is drastic direct injection engines. With these engines only approx. 25% of the chemical energy released in the fuel delivered to the engine cooling water. In cold weather and in Stop-and-go operation, the heating output is no longer sufficient to a well-being of the occupants or fog-free vehicle ticket to ensure ben. The lack of heat must be caused by a auxiliary heating operated with fossil fuel. This makes the fuel economy advantage of combustion engine partially consumed again.  

In addition or as an alternative to conventional auxiliary heating are u. a. in Scandinavia and Canada with some vehicle types electric heaters. These devices consist of electric heating elements that u. a. in the cooling circuit the engine cooling are arranged. They warm up before starting the journey the coolant and sometimes also the passenger compartment. Since the Electricity for the heating elements is taken from stationary sockets this heat source is not available during the journey addition. In addition, primary energy consumption is excessive here average high.

Latent heat storage is used in a few vehicle types. With this system, excess thermi cal energy of the coolant in the form of heat of fusion in one thermally insulated container stored. The next cold the stored heat is returned to the coolant fed. For vehicles with low engine power, the Efficiency low, because on the one hand the memory for shorter trips only insufficiently charged and secondly the additional device importance of the relatively heavy storage tank the fuel consumption need of the vehicle increased.

Other heat suppliers are additional brakes. They are called dhows Braking preferably installed in commercial vehicles. With a we belstrombrake is the kinetic energy via electrical indu decorated eddy currents converted into partially usable thermal energy delt. With a hydrodynamic brake, it is often Be part of automatic transmission, can heat the transmission oil for Heating purposes are withdrawn. As a rule, the auxiliary brakes unsuitable as a heat supplier for heating the passenger compartment net, because they are in passenger cars because of their weight and ih res space requirements are rarely installed.  

The present invention is therefore based on the problem to create a device with which by default equipped motor vehicles in addition to the engine coolant circuit other heat sources usable for the passenger compartment heating ge be made. The change in the selected, conventional Chen heat sources should neither the installation space nor the weight of the increase the respective assemblies significantly. Also the additional energy required to harness the falling waste heat can only be a fraction of the useful energy.

The problem may a. with the features of the main claim ge solves. It gets thermal energy from the regular driving Generic brake systems decoupled. To do this, the brake disc or the brake drum a channel or a channel system on. The channel or the channel system is part of a heat Medium carrier circuit with at least one integrated Heat exchanger, or parts of the brake disc or the brake current mel are equipped with cooling fins, with the one between Cooling fins enclosing housing a heat transfer medium flows, the at least one heat exchanger and optionally passed a filter, or being the enveloping housing of Heat transfer medium is flowed through the at least one heat exchanger happens.

The brake created in conventional friction brakes heat is extracted directly at the point where heat is generated pelt and with low thermal losses to the plants and me services that need heat.  

In the first alternative, a channel is used to flow siges heat transfer medium at least through the ro while driving pumping brake body. When braking the motor vehicle The amount of heat generated in the brake body becomes a heater body transported. The radiator is part of a system for Passenger compartment heating.

In brake systems that at least each time the Be can flow through the drive brake with heat transfer medium Brake body, for example the brake disc, through the raised reduction of the maximum temperature from a light weight valley alloy. The material-related Ge weight savings equal the additional weight of the heating circuit partially off again.

If the heat transfer medium circuit flowing through the brake system run with the cooling circuit of the internal combustion engine ther mixed coupled, for example in long-haul or Uphill the brake body as a heat sink for the engine or Gear oil can be used. The prerequisite for this is that the Brake body at least during its cooling function from the wind be washed around.

The second alternative to using the brake waste heat is the convectional heat dissipation in air is proposed. To do this the brake body with holes, air blades and / or cooling fins equipped and with a thermally insulated, air passage poured encapsulation surrounded. For this are inside Schei ben or drum brakes particularly suitable. For example right next to the corresponding axle differential Brakes can be encapsulated together with the differential. Through the encapsulation u. a. the wind. The through that  Braking heated air is when a heat is required over a Air / water heat exchanger directed.

The third alternative is the hot brake body radiated heat energy by means of special heat exchangers added.

The fourth alternative to using the brake waste heat is one Brake system proposed in which the caliper from heat Carrier is flowed through. In this brake system are the Brake pads on both sides on a ro with the wheel to be braked driving plate and are arranged by the Bremssat tel at least partially. Work in the caliper the brake piston or pistons via a pressure block on the brake coverings. The brake caliper coming into contact with the brake pad area and the pressure block contain a channel or a Ka nalsystem, the part of a heat transfer medium circuit with min is an integrated heat exchanger.

In this solution, the internal brake fluid is circuit stationary with respect to the wheel carrier. Through a thermi The brake pads are insulated from the drive plate can the latter from a light metal alloy or a Ver are made of composite material, which accelerates the can significantly reduce the wheel mass.

Further details of the invention do not emerge from the or only partially cited sub-claims and the following the description of several schematically shown Ausfüh forms:  

Fig. 1 brake disc with integrated heat pipe;

Fig. 2 brake disc with direct cooling by the engine cooling medium.

Fig. 3 brake disc with radiant heat dissipation;

Fig. 4 caliper with direct cooling.

Fig. 1 shows part of the circuit of a liquid heat carrier. At least one disc brake is arranged in this circuit.

The disc brake ( 3 ), the brake caliper ( 1 ) and the brake pads ( 2 ) are shown here. The one-piece brake disc ( 3 ) consists of a friction ring ( 11 ) and the disc cup ( 21 ). The friction ring ( 11 ) and part of the disc pot ( 21 ) are hollow. The coherent cavity forms a heat pipe ( 12 ). In the disc pot ( 21 ) is adjacent to the heat pipe ( 12 ), a heat exchanger channel ( 22 ). The separating web ( 23 ) between the heat pipe ( 12 ) and the heat exchanger channel ( 22 ) has the heat pipe ( 12 ) towards a heating zone ( 15 ) and the heat exchanger channel ( 22 ) towards a cooling zone ( 26 ).

On the disc pot ( 21 ) in the area of the Wärmetauscherka channel ( 22 ) a two-channel mechanical seal ( 31 ) is arranged. The latter comprises an end ring ( 33 ), three bellows ( 34 , 35 , 36 ) with sliding seals ( 37 , 38 , 39 ) and a torsionally rigidly mounted on the ring or caliper carrier (not shown) on the connecting ring ( 32 ). The end ring ( 33 ) is ausgebil det three stages. The connecting ring ( 32 ), which is also stepped three times, lies opposite in the axial direction. The steps of the two rings ( 32 , 33 ) are approximately complementary to each other. Between the gradations, the bellows ( 34 , 35 , 36 ) are arranged concentrically. They are each on their right side from the end ring ( 33 ) attached. At their left, free ends they carry the sliding seals ( 37 , 38 , 39 ), for example inner sealing seals.

The connecting ring ( 32 ) has an inlet ( 41 ) and a return connection ( 42 ) for the heat transfer medium. The inlet connection ( 41 ) is hydraulically connected via a shut-off valve ( 55 ) to the pressure side of a heat transfer medium pump ( 51 ). Between the heat transfer medium pump ( 51 ) and the shut-off valve ( 55 ), a heat transfer medium store ( 52 ) is arranged. The Rücklaufan circuit ( 42 ) leads via a condenser ( 53 ) into a heating circuit ( 57 ), the end of which on the suction side of the heat transfer medium pump ( 51 ) ends. After the capacitor ( 53 ) is a fe der loaded check valve ( 56 ) is arranged, which blocks in the direction of the capacitor ( 53 ). In the flow direction before the suction side of the heat transfer medium pump ( 51 ) and after the return check valve ( 56 ), a short-circuit line ( 58 ) is installed, which is guided through the condenser ( 53 ). The condenser ( 53 ) is intended to condense any evaporated heat transfer medium so that the pressure in the heating circuit ( 57 ) does not increase too much. Via the short-circuit line ( 58 ) the condenser ( 53 ) receives the heat transfer medium required for the condensation, not overheated.

The heat pipe ( 12 ) in the brake disc ( 3 ) serves as an effective heat exchanger for large heat flows. The frictional heat generated by working the vehicle service brake is transported from the heating zone ( 15 ) - predominantly in the form of heat of vaporization - to the cooling zone ( 26 ). From there it is transferred to a liquid heat transfer medium, for example coolant, engine and / or gear oil or the like. If necessary, the heat is also given directly to the useful air to be heated.

With increasing vehicle speed, the heat dissipation of the heat pipe ( 12 ) increases, since the increasing centrifugal force supports the circulation of the heat transfer medium. The at least partially evaporating at the Kühlzo ne ( 26 ) evaporating heat transfer medium is returned in a condenser ( 53 ) in the liquid phase. The heat transfer medium storage ( 52 ) connected downstream of the pump ( 51 ) serves to buffer the pressure and volume changes of the heat transfer medium. In addition, the heat transfer medium storage ( 52 ) ensures a sufficient supply of heat transfer medium to the brake body when large amounts of heat occur in short periods.

To make better use of the frictional heat in cold weather, the brake system can be provided with a windproof capsule ( 45 ) in the area of the brake disc ( 3 ) or brake drum. The capsule ( 45 ) can consist of a thermally insulating material, or be coated with such a material.

In order to enable conventional cooling of the braking system by wind during the warmer seasons, the capsule ( 45 ) can be provided with at least one closable opening, for example.

If the brake is only cooled by the airstream and the heat transfer medium pump ( 51 ) in the heating circuit is switched off, the brake disc must withstand the vapor pressure generated during braking at maximum nominal temperature. If the steam pressure is too high, the evaporated heat transfer medium escapes via the check valve ( 56 ) when the shut-off valve ( 55 ) is closed. Of course, the mechanical seals ( 37 , 38 , 39 ) are temperature-resistant. In addition, the seals ( 37 , 38 , 39 ) via special bellows ( 34 , 35 , 36 ) thermally decoupled from the closing ring ( 33 ).

Fig. 2 shows a comparable heating circuit. However, the heat transfer medium is passed directly through a channel system ( 13 ) arranged in the friction ring ( 11 ) of the brake disc ( 3 ). Due to the direct contact of the heat transfer medium with the friction ring ( 11 ) and the omission of a heat transfer point, a greater cooling of the brake body compared to the solution presented in Fig. 1 can be achieved.

Optionally, the brake disc ( 3 ) can be used as a pump by a special design of the channel system ( 13 ), so that the pump ( 51 ) can be dispensed with.

Fig. 3 shows a disc brake with two heat exchangers ( 61 , 62 ), which partially absorb and dissipate the heat radiation emitted by the brake disc ( 3 ). For this purpose, the brake disc ( 3 ) is ribbed, for example in the inner region of the friction ring ( 11 ). This area forms the cooling zone. The friction ring ribs ( 63 ) are concentric rings which are arranged on both sides of the friction ring ( 11 ). Annular heat exchanger fins ( 64 ) also protrude into the annular cavities between the friction ring fins ( 63 ). The heat exchanger ribs ( 64 ) arranged on the wheel carrier or the brake caliper carrier do not touch the friction ring ribs. To increase the heat transfer capacity, the friction ring ( 63 ) and heat exchanger fins ( 64 ) can be provided with a structured surface. The structure can e.g. B. tooth-shaped or wave-shaped to verbes to the portion of the convective heat dissipation by an increased shear flow between the ribs.

In addition, the brake disc ( 3 ) is equipped with a heat pipe ( 12 ). The heat pipe ( 12 ) increases the heat transport within the friction ring ( 11 ) from the hot braking zone into the cooling zone.

In this embodiment, the heat is transferred contact-free from the rotating brake body ( 3 ) to the stationary heat exchanger ( 61 , 62 ). Due to the heat extraction there are no leakage problems and hardly any friction losses.

In Fig. 4, a construction is shown in which the heat transfer medium flows through the non-rotating brake caliper. In this construction, a driver plate ( 71 ) with insulating sleeves ( 72 ) and a brake pad carrier ( 81 ) with driver pins ( 82 ) form a functional unit, which is called the brake disc below. The two brake pad carriers ( 81 ) are flat rings which are connected to one another via driving pins ( 82 ). You sit cross-slidably in the Isolierhül sen ( 72 ) to compensate for the movement of the brake piston or brake ( 93 ) and lining wear. If necessary, the brake pad carrier ( 81 ), for. B. by mechanical springs or friction clamps, mechanically centered with respect to the drive plate ( 71 ) and vibration-damped.

A slight play between the driver pins ( 82 ) and the insulating sleeves ( 72 ) supporting them also enables radial movement of the brake lining carrier ( 81 ) relative to the driver disk ( 71 ), so that the thermal expansions occurring during braking do not lead to tension.

The brake pad carriers ( 81 ) have a low thermal conductivity and a low heat storage capacity. They are thermally separated from the drive plate ( 71 ) by the pins ( 82 ) and the insulating sleeves ( 72 ). The latter can be made of a light metal alloy or of a material, for example a composite material, with low temperature resistance.

The non-rotating part of the wheel brake system includes a brake caliper ( 91 ), a pressure block ( 92 ) and a Bremskol ben ( 93 ). At least the caliper area, which comes into contact with the brake pad during braking, and the pressure block ( 92 ) consist of a material with high thermal conductivity, high strength and low cold friction properties. The material may also have a low specific weight. Channels ( 96 , 97 ) are embedded in the corresponding brake caliper area and the pressure block ( 92 ) and are flushed through by a heat transfer medium at least during the braking process. The channels ( 96 , 97 ) are connected in series, for example.

The brake caliper ( 91 ) and the pressure block ( 92 ) can also be ring-shaped, so that the friction surfaces abut the entire brake pad surface when braking. This variant results in a large heat transfer area, good heat dissipation, symmetrical brake disc loading and a reduction in braking forces.

The pressure block ( 92 ) is stored in the brake caliper ( 91 ) against rotation. He is for example by pins, not shown, or a profile in the brake caliper ( 91 ) prevented from rotating. In addition, it is mechanically coupled with the brake piston (s) ( 93 ) in such a way that it follows the return stroke of the brake piston ( 93 ) in order to produce the necessary clearance.

Reference list

1

Brake caliper

2nd

Brake pads

3rd

Brake disc, brake body

11

Friction ring

12th

Heat pipe

13

Channel system (

Fig.

2nd

)

15

Heating zone

21

Disc pot

22

Heat exchanger duct

23

Separator

26

Cooling zone

31

Mechanical seal

32

Connecting ring

33

End ring

34

,

35

,

36

Pipes, bellows

37

,

38

,

39

Sliding seals

41

Inlet connection

42

Return connection

45

capsule

51

Heat transfer medium pump

52

Heat transfer medium storage

53

capacitor

55

Shut-off valve

56

check valve

57

Heating circuit

58

Short-circuit line

61

,

62

Heat exchanger

63

Friction ring ribs

64

Heat exchanger fins

71

Drive plate

72

Insulating sleeves

81

Brake pad carrier

82

Driving pins

83

Brake pads

91

Brake caliper

92

Contact block

93

Brake piston

94

Pressure line

96

Channel system in (

91

)

97

Channel system in (

92

)

Claims (8)

1. Apparatus for decoupling thermal energy from vehicle brake brake systems, parts of which in the wheel or axle area are flushed through or around by a cooling medium on service brakes, characterized in that

• - That the brake disc ( 3 ) or the brake drum has a channel or a channel system ( 13 , 22 ), the channel or the channel system being part of a heat transfer medium circuit with at least one integrated heat exchanger ( 53 , 61 , 62 ), or
• - That parts of the brake disc ( 3 ) or the brake drum are equipped with cooling fins ( 63 ), a heat transfer medium flowing between a housing enclosing the cooling fin zones, which passes at least one, or wherein the enveloping housing is flowed through by heat transfer medium, the at least one heat exchanger ( 61 , 62 ) happens.

2. Device according to claim 1, characterized in that a heat pipe ( 12 ) is integrated in the brake disc ( 3 ) or in the brake drum. 3. Apparatus according to claim 1, characterized in that in the brake disc ( 3 ) or in the brake drum, the heat pipe ( 12 ) is adjacent to a heat transfer medium leading heat exchanger channel ( 22 ). 4. The device according to claim 1, characterized in that in the case of a brake disk ( 3 ) through which liquid heat transfer medium flows, a three-stage adapter ( 33 ) is seated in the area of the brake disk chamber ( 21 ), on which three concentrically arranged at least partially corrugated tubes ( 34 - 36 ) are attached, the free ends of which abut against the seals ( 37 - 39 ) on a ring ( 32 ) which is also arranged in three stages and is arranged on the wheel or brake caliper carrier, the coolant being added or removed between the outer and middle stages is dissipated while it is discharged or supplied accordingly between the middle and inner stage. 5. Apparatus for decoupling thermal energy from vehicle braking brake systems, wherein non-rotating parts of the service brakes arranged in the wheel or axle area are flushed out by a cooling medium, characterized in that

• - That the brake pads ( 83 ) are arranged on both sides on a drive plate ( 71 ) rotating with the wheel to be braked and are at least partially encompassed by a brake caliper ( 91 ),
• - That in the brake caliper ( 91 ) or the brake pistons ( 93 ) via a pressure block ( 92 ) act on the brake pads ( 83 ) and
• - That with the brake pad ( 83 ) coming into contact Bremssat telbereich and the pressure block ( 92 ) include a channel ( 96 , 97 ) or a channel system, the channel ( 96 , 97 ) or the channel system part of a heat transfer medium circuit with at least one integrated heat exchanger.

6. The device according to claim 5, characterized in that the brake pads ( 83 ) with respect to the drive plate ( 71 ) are arranged ther mixed insulated. 7. The device according to claim 5, characterized in that the brake pads ( 83 ) sit on a brake pad carrier ( 81 ) which is mounted with the aid of driver pins ( 82 ) displaceably in the driver plate ( 71 ). 8. The device according to claim 1 or 5, characterized in that that the heat transfer medium circuit with the cooling circuit Internal combustion engine can be coupled.