Fluid handling – With indicator – register – recorder – alarm or inspection means – Fluid pressure responsive indicator – recorder or alarm
Reexamination Certificate
1999-12-10
2001-05-22
Rivell, John (Department: 3753)
Fluid handling
With indicator, register, recorder, alarm or inspection means
Fluid pressure responsive indicator, recorder or alarm
C137S884000, C303S119300
Reexamination Certificate
active
06234199
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a hydraulic pressure control unit, and more particularly to the hydraulic pressure control unit which is applicable to a hydraulic pressure control system of an automobile for performing a steering control by braking and the like.
2. Description of the Related Arts
In a conventional hydraulic pressure control system of an automobile, electromagnetic valves have been employed for controlling the hydraulic pressure. As an embodiment, employed is a hydraulic pressure control unit having a housing with hydraulic passages defined therein, and a plurality of electromagnetic valves communicated with the hydraulic passages. One such hydraulic pressure control unit is disclosed in Japanese Patent Laid-open Publication No.7-248068, which corresponds to U.S. Pat. No. 5,474,108. In that unit, valve mechanisms of electromagnetic valves are accommodated in a housing, and solenoid coil portions are mounted on one wall of the housing, in parallel with each other.
Such hydraulic pressure control unit is used for various hydraulic pressure control systems, including a conventional system with a traction control system as shown in
FIG. 7
, for example.
FIG. 7
illustrates a front-rear hydraulic braking system for use in a front drive vehicle with front wheels FR, FL driven. Wheel brake cylinders Wfr, Wfl, Wrr, Wrl are operatively mounted on the wheels including rear wheels RR, RL, respectively. Between these wheel brake cylinders and a master cylinder MC are disposed electromagnetic valves PC
1
-PC
8
for controlling the hydraulic pressure, and electromagnetic valves TC
1
, TC
2
, TI
1
, TI
2
for changing control modes. In
FIG. 7
, DP
1
, DP
2
designate dampers, PV
1
, PV
2
designate proportioning valves, RS
1
, RS
2
designate reservoirs, and ECU designates an electronic controller.
In the above hydraulic pressure control system, is used a hydraulic pressure control unit similar to the one as disclosed in the Publication No. 7-248068, while each solenoid coil portion is formed in a cylindrical configuration, without being received in a rectangular case as shown in that Publication. For instance, twelve electromagnetic valves in total are mounted on the housing HP to form the hydraulic pressure control unit, as shown in FIG.
8
. More precisely, the valve mechanism of each electromagnetic valve is accommodated in the housing HP, while its cylindrical solenoid coil portion is mounted on one wall of the housing HP to extend therefrom. In this case, provided that the outer diameters of all of the solenoid coil portions are equal, the twelve valves can be located with the neighboring valves being in contact with each other, as shown in FIG.
8
.
In such a hydraulic pressure control system that performs a steering control by braking operation (i.e., an excessive oversteer restraining control and an excessive understeer restraining control), however, it is necessary to control the brake fluid pressurized at a relatively high pressure, with a brake pedal depressed. Therefore, in lieu of the electromagnetic valves TC
1
, TC
2
, TI
1
, TI
2
for the traction control system as shown in
FIG. 8
, are employed such electromagnetic valves SC
1
, SC
2
, SI
1
, SI
2
having solenoid coil portions of relatively large outer diameters as shown in FIG.
9
. Supposing that the electromagnetic valves SC
1
, SC
2
, SI
1
, SI
2
as shown in
FIG. 9
are substituted for the electromagnetic valves TC
1
, TC
2
, TI
1
, TI
2
as shown in
FIG. 8
, the housing HL in
FIG. 9
is to be made larger than the housing HP in
FIG. 8
, which will result in increase in size of the hydraulic pressure control unit as a whole. That is, comparing with the housing HR as shown in
FIG. 8
, the housing HL is to be enlarged in the horizontal direction in
FIG. 9
, by a difference between the outer diameter of the valve SC
1
or the like and that of the valve TC
1
or the like, and in the vertical direction in
FIG. 9
, by a total of the difference between the outer diameter of the valve SC
1
and the like, and that of the valve TC
1
and the like (i.e., L
1
+L
2
in total as shown in FIG.
9
).
In the case where the pressure sensor PS is to be provided for detecting a condition for use in the steering control by braking system or the like, the unit will be necessarily enlarged further in the horizontal direction in FIG.
9
.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a hydraulic pressure control unit, which is provided with a plurality of electromagnetic valves having solenoid coil portions of different sizes, and which can be made small in size as a whole, by locating the electromagnetic valves appropriately.
In accomplish the above and other objects, a hydraulic pressure control unit includes a housing having hydraulic passages defined therein, and a plurality of electromagnetic valves having valve mechanisms disposed in the hydraulic passages and solenoid coil portions mounted on one wall of the housing for actuating the valve mechanisms. The electromagnetic valves include four large electromagnetic valves provided with cylindrical solenoid coil portions, each having a relatively large diameter, and eight small electromagnetic valves provided with cylindrical solenoid coil portions, each having a relatively small diameter. And, two rows of four small electromagnetic valves aligned in a row are located in parallel with each other on the wall of the housing, and two rows of two large electromagnetic valves aligned in a row are located in parallel with the two rows of the four small electromagnetic valves.
The hydraulic pressure control unit may further include a hydraulic pressure sensor which is provided for detecting the hydraulic pressure in the hydraulic passages defined in the housing, and which is located between the two large electromagnetic valves aligned in a row.
Preferably, each of the four large electromagnetic valves is located in substantial contact with two neighboring small electromagnetic valves in each row of the four small electromagnetic valves.
REFERENCES:
patent: 4932728 (1990-06-01), Schenk et al.
patent: 5474108 (1995-12-01), Inden et al.
patent: 5482362 (1996-01-01), Robinson
patent: 5820228 (1998-10-01), Schneider et al.
patent: 5937898 (1999-08-01), Gluf, Jr. et al.
patent: 6007162 (1999-12-01), Hinz et al.
patent: 6086041 (2000-07-01), Gattuso et al.
patent: 7-248068 (1995-09-01), None
patent: 8-80827 (1998-03-01), None
Aisin Seiki Kabushiki Kaisha
Burns Doane , Swecker, Mathis LLP
Rivell John
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