We claim:
1. A hydraulic braking apparatus intended for a motor vehicle and comprising, for the actuation of the wheel brakes:
a service braking system (A), supplied with a pressure brake fluid by a central hydraulic unit (3), using an external energy source;
an emergency braking system (B), controlled by muscular energy;
a hand-control member (D, 16), the forward travel of which actuates the service braking system or, in the case of a failure of the latter, the emergency braking system;
a master cylinder (17) having at least one primary piston (18), the stroke of which is controlled by the hand-control member at least one safety valve (26, 28), capable either of separating the master cylinder (17) from the wheel brakes (2a, 2b) when the service braking system operates properly or, should the service braking system fail to operate correctly, of connecting the master cylinder with at least one wheel brake;
a feeling simulator (M), intended to resist the forward motion of the hand-control member (D, 16) with a reaction corresponding to the progress of a braking operation, such simulator comprising a cylinder (30) in which a simulator piston (31) may slide while being subjected, in one direction, to a fluid pressure coming from the master cylinder (17) and, in the opposite direction, to a counterforce dependent on the travel of the hand-control member;
pressure-fluid admission solenoid valves (9a-9d) and exhaust solenoid valves (14a-14d), connected to the wheel brakes;
sensors (8, 13a-13d, 24, 29) for the detection of various braking parameters, in particular the travel of the hand-control member, and the pressures at various spots of the apparatus;
and a computer (C), connected to the various sensors and capable of controlling the solenoid valves so as to obtain the desired pressures in the wheel brakes,
characterised in that the counterforce within the simulator (M) results from the action, on a surface (S3) of the simulator piston (31), of a modulated pressure (Pehb), which comes from the fluid pressure supplied by the central hydraulic unit (3) and is controlled by the computer (C) in accordance with a determined law (L1), alterable ad lib as a function of the pedal travel.
2. The apparatus according to claim 1, characterised in that the surface (S3) of the simulator piston, which is under the modulated pressure (Pehb), defines a variable-capacity chamber (34) connected in parallel to an admission solenoid valve (36), for the pressure fluid supplied by the central hydraulic unit (3), and to an exhaust solenoid valve (37), connected to the feed tank (9), the opening and closing of said solenoid valves (36, 37) being controlled by the computer (C) so that the pressure (Pehb) inside the simulator chamber (34) may follow the desired law.
3. The apparatus according to claim 2, characterised in that the solenoid valves (36, 37), connected to the chamber (34) of the simulator, are of the onoff type.
4. The apparatus according to claim 3, characterised in that the pressure drop between the inlets and the outlets of the solenoid valves (36, 37) is linear dependently on the control current strength.
5. The apparatus according to claim 4, characterised in that the cylinder (30) of the simulator comprises two intercommunicating coaxial bores (30a, 30b) with different diameters, and a stepped piston (31) including a small-diameter portion (31a) sliding in a leakproof manner inside the small-diameter bore (30a), and a greater-diameter portion (31b) sliding in a leakproof manner in the large-diameter bore (30b), the end wall (30c) of the small-diameter bore comprising a port (32) connected to the master cylinder for the fluid pressure from the master cylinder to be applied to the small cross-section (S2) of the stepped piston, whereas an annular chamber (34) is defined between the transition wall (30d) of the bore and the large cross-section of the stepped piston, such annular chamber being connected in parallel to the respective admission and exhaust solenoid valves (36, 37).
6. The apparatus according to claim 5, characterised in that, in the simulator (M), the counterforce is the resultant of a resilient force acting upon the simulator piston (31) in the opposite direction to the fluid pressure coming from the master cylinder (17), and of a variable force resisting the resilient force, such variable force being generated by the modulated pressure (Pehb) acting on a surface (S3) of the simulator piston.
7. The apparatus according to claim 6, characterised in that the resilient force is produced by at least one resilient return means.
8. The apparatus according to claim 7, characterised in that the resilient return means comprises an air spring (42, 43).
9. The apparatus according to claim 6, characterised in that the end wall (30e) of the simulator cylinder, which closes the large cross-section bore in the opposite direction to the small cross-section bore, comprises an opening (40) for the passage of a rod (41) resting on the large cross-section (31b) of the stepped piston (31) and exerting the resilient force on said piston.
10. The apparatus according to claim 9, characterised in that said rod (41) may be integral with a pneumatic piston (42) sliding inside a pneumatic cylinder (43), for its part integral with the simulator cylinder (30), said pneumatic cylinder being connected to an external air-pressure source (49) intended, more particularly, for a pneumatic suspension.
11. The apparatus according to claim 10, characterised in that a nonreturn valve (50) is provided on a pressure-air line (48) connected to the pneumatic cylinder, said valve allowing the inflow of the pressure air into the cylinder and opposing its outflow.
12. The apparatus according to claim 11, characterised in that a mechanical compression spring (51) is arranged inside the pneumatic cylinder to as to act upon the pneumatic piston in the same direction as the air pressure.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A cooling apparatus for an electric motor control unit comprising a heat sink (H) contacting a module (Um, Ug) of an electric motor control unit (U), a concave portion (20b) continuously formed in the heat sink, and a wall member (22) mounted on an opening face side of the concave portion so as to be fixed to the heat sink, which defines a coolant passage in the heat sink together with the concave portion of the heat sink, characterized in that
the heat sink includes a projection (20e) projecting from a mounting surface with respect to the wall member;
the wall member includes a hole (22a) fitted into the projection; and
the wall member is fixed to the heat sink by caulking the projection of the heat sink.
2. The cooling apparatus for the electric motor control unit according to claim 1, wherein the concave portion is a race that winds so as to extend over an entire practical area of the heat sink.
3. The cooling apparatus for the electric motor control unit according to claim 2, wherein a dividing wall (20s), the height of which from a bottom of the race is shorter than a depth of the race, is provided along the race.
4. The cooling apparatus for the electric motor control unit according to claim 1, wherein the concave portion is structured from a space between a plurality of pin-like fins (20f) rising from a bottom portion of the heat sink.
5. The cooling apparatus for the electric motor control unit according to claim 4, wherein the plurality of pin-like fins are evenly arranged over an entire practical surface of the heat sink.
6. The cooling apparatus for the electric motor control unit according to claim 4 or 5, wherein a part of the plurality of pin-like fins have the projections at tips thereof.
7. The cooling apparatus for the electric motor control unit according to any one of claims 1 to 6, wherein a contact surface of the heat sink with the module is a surface to which finish machining is applied.
8. The cooling apparatus for the electric motor control unit according to any one of claims 1 to 7, wherein the heat sink is fixed on a driving device case (10) of a driving device for a vehicle including an electric motor (M) at a predetermined distance to define a return passage of a coolant between the driving device case and the wall member of the heat sink.