Correction device in a power steering apparatus for vehicles

• US 4,047,728 A
• Filed: 06/04/1976
• Issued: 09/13/1977
• Est. Priority Date: 07/01/1975
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Takahashi, Noriyuki, Miura, Kimio
• Primary Examiner(s): Peters, Jr., Joseph F.
• Assistant Examiner(s): Schrecengost, R.
• Application Number:
  US05/693,264
• Time in Patent Office: 466 Days
• Field of Search: 180/141, 180/142, 180/143, 60/464
• US Class Current: 180/421
• CPC Class Codes: B62D 6/02 responsive only to vehicle speed

Abstract

A correction device in a vehicle power steering apparatus adapted to effectively utilize the aiding effect of a hydraulic power cylinder depending upon travelling speeds of the vehicle. A change in value of rightward or leftward acceleration resulted from the turning of the vehicle is sensed by a weight oscillatably received within a closed oil chamber of the correction device to allow the operator to perceive an adequate steering resistance, thereby avoiding his erroneous steering. The correction device includes stoppers positioned at tip surfaces of nozzle members to provide a desired clearance between an end surface of a pressure restriction plate and the nozzle member thus allowing oil in the nozzle to flow. The device further includes compression springs retained between the weight and the casing for biasing the weight towards its neutral position, the compression spring engaging an adjusting screw to predetermine a value of lateral acceleration of the vehicle.

Claims

1. A correction device in a power steering apparatus for vehicles with a flow passage connecting a pair of working oil chambers partitioned by a working piston within a steering power cylinder to a source of oil pressure such as a hydraulic pump, said flow passage including a control valve for selectively controlling and supplying pressure oil from said oil pressure source into said pair of working oil chambers in response to rotative operation of a steering handle, the improvement comprising:

a weight that may be oscillated in a lateral direction of the vehicle and is received in a closed oil chamber within a casing suitably mounted on the vehicle, a pair of left and right nozzle members with extreme nozzles thereof arranged opposite each other and disposed in said casing and leaving a desired clearance in opposite end surfaces of a pressure restriction plate formed integral with said weight, said nozzle members being internally brought into communication with said pair of working oil chambers respectively, within said power cylinder, stoppers disposed at tip surfaces of said nozzle members, said stoppers controlling the lateral oscillation of said pressure restriction plate to form a desired clearance between each of said opposite end surfaces and each of said nozzles.

2. A correction device in a power steering apparatus for vehicles with a flow passage connecting a pair of working oil chambers partitioned by a working piston within a steering power cylinder to a source of oil pressure such as a hydraulic pump, said flow passage including a control valve for selectively controlling and supplying pressure oil from said oil pressure source into said pair of working oil chambers in response to rotative operation of a steering handle, the improvement comprising:

a weight that may be oscillated in a lateral direction of the vehicle and is received in a closed oil chamber within a casing suitably mounted on the vehicle, a pair of left and right nozzle members with extreme nozzles thereof arranged opposite each other and disposed in said casing and leaving a desired clearance in opposite end surfaces of a pressure restriction plate formed integral with said weight, said nozzle members being internally brought into communication with said pair of working oil chambers respectively, within said power cylinder, compression springs adapted to bias said weight towards its neutral position and retained between said weight and said casing, and a spring pressure adjusting screw connected to one end of each compression spring so that the value of lateral acceleration of the vehicle resulting from the lateral oscillation of the weight may be predetermined.

3. A power steering apparatus for a vehicle comprising a power cylinder having a pair of working chambers defined therein by means of an output piston on the opposite sides thereof, a source of fluid pressure, a fluid reservoir, and a control valve interposed in a pair of low and high pressure fluid lines connecting said power cylinder chambers with said source of fluid pressure and said fluid reservoir, said valve being operable to selectively place said power cylinder chambers into fluid communication with said pressure source and said reservoir, respectively, and a correction device connected with said respective power cylinder chambers for correcting power cylinder output in response to lateral accelerations of the vehicle, said correction device comprising:

a casing mounted on the vehicle body and having a single closed chamber defined therein, a weight disposed centrally within said casing chamber for free movement in a lateral direction of the vehicle, a pressure restriction plate integrally formed with said weight, and a pair of nozzle members connected to said respective chambers of said power cylinder and disposed in said casing in laterally aligned opposite relation to each other, said nozzle members having their nozzle openings facing with the laterally opposite side faces of said pressure restriction plate normally at an equal spacing therefrom, whereby when the vehicle in motion is steered to turn, said weight is first moved laterally from its neutral position toward one of said nozzle members due to the pressure fluid ejecting from the nozzle opening of the other nozzle member against the associated lateral side face of said pressure restriction plate to restrict the flow of pressure fluid discharged from said casing chamber through said one nozzle member and then caused under a centrifugal force to move back in the reverse direction against the force of the pressure fluid acting thereon to a point of equilibrium, at which said centrifugal force and said force of the pressure fluid become balanced each other, thereby enlarging the spacing between said one nozzle member and the associated side face of said pressure restriction plate so that a part of the pressure fluid fed to one of said power cylinder chambers through said control valve, is bypassed therefrom to said reservoir by means of said correction device at a flow rate proportionate to the magnitude of the vehicle lateral acceleration sensed by said weight.