414results about How to "Improve steering stability" patented technology

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.

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.

A pneumatic tire has a unidirectional tread pattern comprising right-hand and left-hand crown circumferential grooves and a crown rib formed therebetween. The crown rib is provided with first and second V-shaped grooves arranged alternately in the tire circumferential direction. The first V-shaped grooves extend from the left-hand crown circumferential groove. The second V-shaped grooves extend from the right-hand crown circumferential groove. The first and second V-shaped grooves are terminated within the rib, and their V-shape configurations have bending points substantially positioned at the tire equator.

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 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 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.

A pneumatic tire has a tread portion provided with an asymmetrical tread pattern and comprising an inboard shoulder land portion, an inboard shoulder main groove, an inboard middle land portion, an inboard crown main groove, a center land portion, an outboard crown main groove, an outboard middle land portion, an outboard shoulder main groove, and an outboard shoulder land portion. The inboard middle land portion is provided with inboard middle axial grooves extending from the inboard shoulder main groove and each comprising a main portion and a turnback portion. The inboard shoulder land portion is provided with inboard shoulder sipes extending from the inboard shoulder main groove.

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.

A pneumatic tire has tread blocks (5) each defined by an equator-side longitudinal groove (3A), a tread-edge-side longitudinal groove (3B), a heel-side transverse groove (4A) and a toe-side transverse groove (4B). The block (5) has an equator-side longitudinal wall surface (8a) having a first radially outer edge (9a) and a first radially inner edge (10a), and a tread-edge-side longitudinal wall surface (8b) having a second radially outer edge (9b) and a second radially inner edge (10b). The angle α1U of the first radially outer edge (9a), the angle α1L of the first radially inner edge (10a), the angle α2U of the second radially outer edge (9b) and the angle α2L of the second radially inner edge (10b), each with respect to the tire circumferential direction, satisfy the following four conditional expressions: (0≦α1L<α1U≦45); (0<α2L<α2U≦45); (α1L<α2L) and (α1U<α2U).

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.

A rubber composition for tires which comprises at least one rubber component selected from natural rubber and synthetic rubbers and, based on 100 parts by mass of the rubber component, 0.1 to 45 parts by mass of (A) a terpene phenol resin and 1 to 150 parts by mass of (B) a softener comprising a process oil which comprises polycyclic aromatic compounds (PCA) in an amount such that the content of extracts with dimethyl sulfoxide (DMSO) in accordance with the method of IP346 is controlled to a value smaller than 3%. A rubber composition for tires which overcomes problems arising due to the use of a highly aromatic oil having a content of polycyclic aromatic compounds (PCA) controlled to a value smaller than 3% as the process oil in place of conventional highly aromatic oils and exhibits excellent loss property and rigidity and a tire which uses the rubber composition and exhibits excellent steering stability on dry road surfaces and excellent braking property on wet road surfaces can be provided.

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.

The invention relates to an electric automobile chassis system with a four-wheel independent steering function and a steer-by-wire mechanism of the electric automobile chassis system. The steer-by-wire mechanism comprises two steering pull rods, a steering power unit and two transmission units, the steering pull rods are arranged horizontally, the end, close to a wheel, of each steering pull rod is hinged to a steering knuckle of a suspension wheel assembly, and when the plane where wheels are located is perpendicular to the steering pull rods, the two steering pull rods are symmetrical about the vertical radial direction of the wheels; the steering power unit is electrically connected with an electronic control unit of an electric automobile and provided with two levels of power output ends which are the same in speed ratio and opposite in power output direction; the power output ends of the two transmission units are connected with the two levels of power output ends of the steering power unit respectively, and the power output end of each transmission unit is connected with one end, away from the corresponding wheel, of the corresponding steering pull rod to drive the steering pull rod to move back and forth to drive the corresponding wheel to swing. According to the electric automobile chassis system with the four-wheel independent steering function and the steer-by-wire mechanism of the electric automobile chassis system, steering stability of the wheels is good, and the electric automobile chassis system is safe, reliable and good in maneuverability in narrow space.