418results about How to "Improve steering stability" patented technology

A vehicular rear suspension system includes an upper arm, a lower arm, and a control arm, each of which is connected to a knuckle. A straight line passing through a ball joint and a rubber bushing joint intersects the road surface at an intersection point that is positioned behind a ground contact point of the rear wheel in the longitudinal direction of the vehicle body. The ball joint connects the upper arm to the knuckle, and the rubber bushing joint connects the lower arm to the knuckle. Longitudinal elastic coefficients of the three arms are set in a predetermined relationship. Therefore, the intersection point at which an elastic kingpin intersects the road surface is positioned without fail behind a point of action of a lateral force when turning in the longitudinal direction of the vehicle body to achieve a lateral force toe-in and enhanced steering stability of the vehicle.

A pneumatic tire including five land portions Q1, Q2, Q3, Q4, Q5 in a tread surface 1 by providing four main grooves G1, G2, G3, and G4 in a ground contact region R of the tread surface 1, wherein positions and groove widths of the main grooves G1, G2, G3, and G4 are specified together with only the land portion Q1 positioned outermost on a vehicle outer side when mounted on a vehicle being formed into a block row, and the other land portions Q2, Q3, Q4, and Q5 being formed into ribs, and a groove area proportion of the tread surface 1 is larger on a vehicle inner side than the vehicle outer side with a tire equator CL and center lines of the land portions Q2, Q3, Q4 as boundaries.

When a vehicle approaches a corner, a microprocessor, responsive to a determination that a detected degree of roughness of the road surface corresponds to the most moderate roughness, sets the damping force for the vehicle suspension units, on the basis of the detected degree of roughness, vehicle speed and a radius of curvature and corner information from a navigation system. In the case of a determination that the detected degree of roughness does not correspond to the most moderate roughness, a damping level is set on the basis of the detected degree of roughness, vehicle speed and radius of curvature.

The invention provides a difference active steering system of an electric wheel driving automobile and a difference active steering control method. The difference active steering system consists of a left steering electric wheel, a right steering electric wheel, a difference active steering mechanism and a difference active steering control system; the difference active steering control method uses a steering angle of the steering electric wheels and a vehicle speed dual PID (proportion integration differentiation) control arithmetic to determine target values of the torques of left and righthub electric motors in the left and right steering electric wheels. The novel steering method provided by the invention is applied to the vehicle having a steering mechanism; each steering electric wheel rotates around respective main pin to form a coordinated steering angle according to the driving force difference of the left and right steering electric wheels and the limitation of a trapezoidal steering mechanism, so that the vehicle is steered; and the active steering mechanism is simple and has steering energy consumption.

The circular ball type electric booster steering device has, except screw, nut, gear sector, steel ball and other mechanical parts, torque sensor, boosting motor, decelerating mechanism, electronic controller unit, etc. The electronic controller unit determines the target current of the motor based on the steering disc torque and the vehicle speed to complete the feedback tracking control of the motor current. The decelerating mechanism has input connected to the motor and output connected to the screw or gear sector shaft in the circular ball steering unit. The present invention has saving in energy, provides proper power force fitting different running conditions, and has less parts, light weight, compact structure and high automation.

There are provided a rubber composition having a high modulus of elasticity and a good workability, and a pneumatic tire.A rubber composition comprising at least one of natural rubber and synthetic diene rubbers as a rubber ingredient, at least one maleimide compound, and at least one nitrogen-containing compound selected from the group consisting of polyaniline, hydrazide, and amine compound is used in a tread.

The invention discloses a vehicle steer-by-wire device with a redundant mechanism, and a control method of the vehicle steer-by-wire device. The vehicle steer-by-wire device comprises a steering manipulation mechanism, a steering execution mechanism, a first clutch device and a controller; the first clutch device is arranged at the rear end of a steering coil column, and used for connecting or disconnecting the steering manipulation mechanism and the steering execution mechanism; the controller controls the steering manipulation mechanism and the steering execution mechanism; and the steeringexecution mechanism comprises a main motor, a rack assisted steering transmission mechanism connected with the main motor, an auxiliary motor, and a pinion electric assistance transmission mechanism connected with the auxiliary motor. Through mechanical disconnecting of the steering execution mechanism and the steering manipulation mechanism, and redundant design of the steering execution mechanism, the reliability of a steering system for high-grade automatic driving is improved, and high-safety design of the steer-by-wire system is achieved.

A vehicular rear suspension system includes an upper arm, a lower arm, and a control arm, each of which is connected to a knuckle. A straight line passing through a ball joint and a rubber bushing joint intersects the road surface at an intersection point that is positioned behind a ground contact point of the rear wheel in the longitudinal direction of the vehicle body. The ball joint connects the upper arm to the knuckle, and the rubber bushing joint connects the lower arm to the knuckle. Longitudinal elastic coefficients of the three arms are set in a predetermined relationship. Therefore, the intersection point at which an elastic kingpin intersects the road surface is positioned without fail behind a point of action of a lateral force when turning in the longitudinal direction of the vehicle body to achieve a lateral force toe-in and enhanced steering stability of the vehicle.

A rubber composition containing (i) a conjugated diene-based rubber gel having a toluene swelling index of 16 to 70, (ii) a diene-based rubber such as natural rubber, polyisoprene rubber, aromatic vinyl-conjugated diene copolymer rubber and / or polybutadiene rubber, and (iii) an optional carbon black and / or silica and (a) a pneumatic tire using this composition as a high hardness reinforcing layer extending from a bead along a tire sidewalls, in which the fluidity and dimensional stability at the time of extrusion are improved, while maintaining a sufficient hardness of a high hardness reinforced rubber, (b) a pneumatic tire using this composition as two ends of a tire tread extrudate, maintaining a flex fatigue of the two ends of the tread, in which the extrudability and extrusion dimensional stability are improved and (c) a pneumatic tire using the composition as a 1.5 mm to 6 mm thick undertread, in which a high elasticity and relatively thick gauge undertread, and excellent processability and steering stability are provided.

The invention discloses a four wheel independent steering electric car steering control method and a four wheel independent steering electric car steering control system, and solves the technical problem that a four wheel independent driving and four wheel independent steering electric car is lack of a stable and affordable steering strategy in the prior art. The four wheel independent steering electric car steering control method includes: when an electric car needs to swerve, obtaining a steering wheel turning angle and car speed of the electric car; based on a car speed and car speed transmission ratio mathematic model, obtaining a variable transmission ratio between the steering wheel angle and a rear wheel turning angle of the electric car at different car speeds; obtaining a front wheel turning angle of the electric car based on the steering wheel turning angle; obtaining a car ideal condition of the electric car based on a variable transmission ratio car ideal model, the car speed and the front wheel turning angle; simultaneously, obtaining a car virtual condition of the electric car based on a four wheel steering electric car linear two freedom model, the car speed and the front wheel turning angle; obtaining the rear wheel turning angle of the electric car based on the car ideal condition and the car virtual condition of the electric car, and controlling the electric car to swerve based on the front wheel turning angle and the rear wheel turning angle of the electric car.

The invention is to permit a bushing main body of rubber elastomer to be adhered to a bar member while retaining a necessary contact pressure for adhering and after adhering, to permit a further compressive force to be imparted. The bushing main body (10) having a bore (11), through which the bar member (B) passes, and a bracket (20) holding the former are longitudinally split into two, respectively, the resulting split rubber bodies (10a)(10b) are vulcanization bonded to inner peripheral surfaces of the resulting half bracket members (20a)(20b). The inside diameter (D1) of both split rubber bodies as molded is made smaller than the outside diameter (D2) of the bar member, and inner peripheral surfaces (11a)(11b) at the bore are formed to be eccentric on mutually opposite sides. While pinching the bar member by both split rubber bodies, both half bracket members interposing a spacer (30) are locked together to compress the split rubber bodies thereby to adhere the peripheral surfaces at the bore to the outer peripheral surface of the bar member, and after the spacer is removed, both half members are locked so as to butt contact with each other thereby further compressing both split rubber bodies in mutually opposing directions.

The contact patch of the center land portion partitioned by the center side main grooves protrudes outward in the tire radial direction from the overall standard profile line of the tread portion. The maximum protruding amount is not less than 1.0% and not more than 2.5% of the tire width direction dimension of the center land portion. The contact patch of the intermediate land portion partitioned by the center side main groove and the shoulder side main groove protrudes outward in the tire radial direction from the standard profile line. The maximum protruding amount is not less than 0.7% and not more than 2.0% of the tire width direction dimension of the intermediate land portion. The maximum protruding amount of the center land portion is greater than the maximum protruding amount of the intermediate land portion.

A pneumatic tire comprises a tread portion 2 provided with two shoulder main grooves 3, a crown main grooves 4, two shoulder land zones 8, and two middle land zones 7. The shoulder land zones 8 are each provided with shoulder lateral grooves 11. The middle land zones 7 are each provided with middle narrow grooves 10. Each of the middle narrow grooves 10 comprises a sipe-like narrow portion 12 whose groove width is less than 2 mm, and a wide portion 14 whose groove width is not less than 2 mm. The wide portion 14 includes an axially outer wide portion 15 formed at the axially outer end of the middle narrow groove 10.

A steering control method for a trailer includes firstly, controlling steering of front wheels of a tractor and acquiring deflection angles theta 1 of inner steering front wheels of front wheels of the tractor and an included angle alpha between a longitudinal central vertical plane of the tractor and a longitudinal central vertical plane of the trailer; and secondly, controlling steering of other pairs of steering wheels of the trailer, so that deflection angles of various other inner steering wheels on the tractor meet an inequality of arctan [(Li / L1)Xtan(theta 1)-3 degrees]< / =theta i< / ={arctan[(Li / L1)Xtan(theta 1)]+3 degrees, and deflection angles of various inner steering wheels on the trailer meet an inequality of [alpha-arctan(Z / P)-3 degrees]< / =theta j< / =[alpha-arctan(Z / P)+3 degrees]. The invention further provides a controller, the trailer and a steering system of the same. The steering control method, the controller, the trailer and the steering system have the advantages that the various wheels of the trailer can at least rotate around the same steering central area, abnormal abrasion to tires is obviously relieved, and the steering stability and the passing ability of the trailer are improved.

A pneumatic tire for a two-wheeled motor vehicle in which a belt layer 26 includes a spiral belt (26A) where the direction of its cords is substantially a circumferential direction of the tire, and at least one angled belt (26B) that is provided on at least an outer layer of the spiral belt (26A) and whose cords have an angle with respect to an equatorial plane of the tire. On a tread surface portion of a tread (22) of the tire, there is provided, at least in a tread center region, a main groove component having an angle in the range of 0° or more to less than 20° with respect to the circumferential direction. Thus, a pneumatic tire for a two-wheeled motor vehicle is provided that is applicable to a front or rear wheel, and that possesses improved kinematical performance including the turning capability at a corner, grip limit, overall settling of vibrations of a vehicle body, slip-control performance, capability of absorbing unevenness of a road surface, and enhanced steering stability, which are realized by making use of respective advantageous characteristics of the respective belts.

An inverted pendulum type omnidirectional vehicle includes: a pair of wheels; a drive mechanism; a control apparatus; an auxiliary wheel; and a vehicle body. Each of the wheels includes: a rotation member capable of rotating about the wheel axis; a plurality of free rollers which are disposed all around an outer circumference of the rotation member, and each of which is brought into contact with a road surface at a lowest position of the rotation member and is rotatable about a rotation axis diagonal with respect to the wheel axis. The free rollers on both sides in contact with the road surface at ground contact portions each have the rotation axis extending in parallel with the road surface, and are arranged in an orientation in which a distance between the rotation axes of the free rollers is shorter toward a side of the auxiliary wheel.

On the surface of a tread portion (1), one central main groove (2) extends in a tire circumferential direction (C) at a pattern center, and a pair of outer main grooves (4a, 4b) extend in the tire circumferential direction (C) each at a position between the central main groove (2) and a respective one of two tread ends (3a, 3b). The central main groove (2) and the outer main grooves (4a, 4b) define central land portions (5a, 5b), and the outer main grooves (4a, 4b) and the tread ends (3a, 3b) define outer land portions (6a, 6b). Among the central land portions (5a, 5b) and the outer land portions (6a, 6b), first circumferential narrow grooves (7a, 7b) are provided only in the central land portions (5a, 5b), extend in the tire circumferential direction (C), have a narrower opening width and a shallower depth than those of the central main groove (2), and have a first groove wall (8) on the side of the outer main groove (4a, 4b) and a second groove wall (9) on the side of the central main groove (2) such that an intersection angle (θ1) between a tread surface (10) and the first groove wall (8) is larger than an intersection angle (θ2) between the tread surface (10) and the second groove wall (9).

A steering apparatus for a vehicle is set to a steer-by-wire mode with an electromagnetic clutch being in a disconnected state. In response to steering operation applied to a steering wheel, first and second electric motors turn left and right front wheels. When a failure arises in one of first and second turning control systems including the first and second motors, the turning characteristic of the left and right front wheels is gradually changed from a turning characteristic for steer-by-wire to that for steer-by-mechanical connection. When a failure arises in the first and second turning control systems or after the turning characteristic is changed, the electromagnetic clutch is brought into a connected state, whereby the steering apparatus is switched to a steer-by-mechanical connection mode. Even when the steer-by-wire mode is switched to the steer-by-mechanical connection mode, a driver is not given an unnatural sensation, and excellent steering stability is maintained.

This invention relates to a tire suitable in a passenger car, particularly a tire being high in the resistance to hydroplaning on a wet road surface and low in the tire noise and having an asymmetric tread pattern. In such a tread pattern that at least two circumferential grooves extending along an equatorial plane of the tire are formed in a region of a tread surface at an axially inner side with respect to the equatorial plane in the mounting on the vehicle and at least one circumferential groove is formed in a region at an axially outer side thereof, a circumferential groove nearest to the equatorial plane of the tire among the circumferential grooves arranged in the axially inner side region has a width wider by 20% or more than an average groove width of the tire and a circumferential groove arranged toward a side of a tread end at the axially inner side region has a width corresponding to 90-110% of the average groove width, and the circumferential groove nearest to the equatorial plane of the tire at the axially outer side region has a width narrower by 10% or more than the average groove width, whereby the resistance to hydroplaning and the controllability of tire noise, which have a conflicting relation in the prior art, are established in a higher level.

An exhaust system for a motorcycle provides enhanced steering stability and improved function for purifying exhaust gas. Front exhaust pipes connected with front cylinders of a V-type engine are joined to a front part of an exhaust chamber. Rear exhaust pipes connected with rear cylinders of the engine are joined to an upper part of the exhaust chamber. Exhaust gases discharged from both the front and rear exhaust pipes are unified within the exhaust chamber, and a catalyst is disposed in the vicinity of the unifying section. The length of the rear exhaust pipes is shorter than the length of the front exhaust pipes. High-temperature exhaust gas is introduced to the catalyst contained within the exhaust chamber via the rear exhaust pipes.

A suspension control system and a suspension control method for a vehicle control the suspension based on the condition of the road surface traveled by the vehicle in addition to information pertaining to a corner obtained from a navigation device when the vehicle approaches the corner. A microprocessor controls damping forces of suspension devices on the basis of a degree of irregularity of the road surface detected immediately preceding entry of the automobile into a turn around the corner, and corner information from the navigation device.

The invention relates to a pulse impact producing mechanism and a center differential pressure drill comprising the same. The pulse impact producing mechanism comprises a righting element, a driving element, a rotating element and a throttling element which are placed sequentially, the righting element, the driving element and the rotating element are connected sequentially, the throttling element and the rotating element are in clearance fit, overcurrent channels which are used for flowing of a drilling fluid are arranged on the righting element and the throttling element, the driving element drives the rotating element to rotate, and the overcurrent channels on the rotating element and the throttling element move relatively. The center differential pressure drill comprises a reaming bit, the pulse impact producing mechanism, a pressure regulating element, a transmission mechanism and a pilot bit, and the pressure regulating element, the transmission mechanism and the pilot bit are connected sequentially. Compared with the prior art, the cuttings hold-down effect of the pilot bit and the reaming bit is reduced while rotary impact drilling of the pilot bit can be realized, further the purposes of protecting the bits, prolonging the service lives and improving the drilling speed are realized, and the drilling effect is further improved.

Electric power steering system has steering mechanism; input and output shaft side rotation angle sensors detecting rotation angles of input and output shafts; operation circuit calculating command current for an electric motor; rotation direction judging circuit judging whether rotation directions of the input and output shafts are identical; advanced-phase judging circuit judging which phase of input and output shaft side rotation angle signals (S1, S2) is advanced; normal / reverse input judging circuit judging that (i) when both rotation directions are identical and S1 is advanced, input is normal input and (ii) when both rotation directions are identical and S2 is advanced, input is reverse input; and command current correcting circuit. The command current correcting circuit corrects the command current so that when the normal input is judged, torque in the same direction as input shaft rotation direction generated by the electric motor is greater than a case of reverse input judgment.

The reduction of noise in the rotation of the tire and the improvement of resistance to hydroplaning are established and also the resistance to uneven wear is improved, in which four circumferential main grooves 2-5 are formed asymmetrically, and a sum of groove volume in a circumferential direction in lateral grooves formed in a shoulder land part row 7 as a portion of an axially inner side per unit width is made smaller than a sum of groove volume in the circumferential direction in lateral grooves 11 formed in a shoulder land part row 9 as a portion of an axially outer side and a land part row 6 in a central region is rendered into a rib, and slant grooves 13 extending at an average inclination angle of not less than 45° with respect to a widthwise direction of the tread are arranged in a second inner land part row 8 located at a side of an equatorial line adjacent to the shoulder land part row 7 at the axially inner side and these slant grooves 13 are opened to the circumferential main groove located adjacent to the second inner land part row 8 of the axially inner side.