Power steering device for vehicles

Abstract

To enable a well transmission of information to the effect that the turning of a pair of turning wheels is restricted to a steering operation member that can be operated by a driver.SOLUTION: In this vehicular power steering device, an operating-side steering mechanism is provided with at least two stoppers each restricting the turning of each of a pair of turning wheels in the left direction and in the right direction. This enables a well transmission of information to the effect that the turning of each of the pair of turning wheels in the left direction and in the right direction is restricted to a steering operation member.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a power steering device provided in a vehicle. [Background technology]

[0002] Patent document 1 describes a power steering device for a vehicle that includes a pair of steering mechanisms that steer a pair of steering wheels of the vehicle, and a connecting mechanism that connects the pair of steering mechanisms and also connects the pair of steering wheels, one of the pair of steering mechanisms being an operating side steering mechanism having a drive shaft that is moved by the operating torque applied to a steering operating member and the driving torque of an electric assist motor, and the other of the pair of steering mechanisms being a non-operating side steering mechanism having a drive shaft that is moved by the driving torque of the electric assist motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-038383 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to effectively transmit to a steering operation member that can be operated by a driver that the steering of a pair of steered wheels has been restricted. [Means for solving the problem]

[0005] In the power steering device for a vehicle according to the present invention, the operating side steering mechanism is provided with at least two stoppers that limit the steering of the pair of steering wheels to the left and right, respectively. Therefore, it is possible to effectively transmit to the steering operation member that the steering of the pair of steering wheels to the left and right, respectively, is limited. However, Patent Document 1 does not describe the stoppers that limit the steering of the pair of steering wheels. [Brief description of the drawings]

[0006] [Figure 1] 1 is a plan view conceptually showing a basic structure of a power steering device for a vehicle. [Diagram 2] FIG. 2 is a cross-sectional view showing a main part of a basic structure of the power steering device for a vehicle. [Diagram 3] FIG. [Figure 4] FIG. 2 is a plan view conceptually showing the vehicle power steering device according to the first embodiment of the present invention. [Diagram 5] FIG. 2 is a plan view conceptually showing an operating state (leftward steering state) of the vehicle power steering device. [Figure 6] FIG. 4 is a plan view conceptually showing another operating state (rightward steering state) of the vehicle power steering device. [Figure 7] FIG. 6 is a plan view conceptually showing a vehicle power steering device according to a second embodiment of the present invention. [Figure 8] FIG. 2 is a plan view conceptually showing an operating state (leftward steering state) of the vehicle power steering device. [Figure 9] FIG. 4 is a plan view conceptually showing another operating state (rightward steering state) of the vehicle power steering device. [Figure 10] FIG. 11 is a plan view conceptually showing a vehicle power steering device according to a third embodiment of the present invention. [Figure 11] FIG. 2 is a plan view conceptually showing an operating state (leftward steering state) of the vehicle power steering device. [Figure 12] FIG. 4 is a plan view conceptually showing another operating state (rightward steering state) of the vehicle power steering device. EMBODIMENTS OF THE PRESENTINVENTION

[0007] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a power steering device for a vehicle according to an embodiment of the present invention will be described in detail below with reference to the drawings.

[0008] [Basic structure of a vehicle power steering device] First, a basic structure of a power steering device for a vehicle according to the present invention will be described. This basic structure of the power steering device for a vehicle is also a common structure of the vehicle steering devices according to the multiple embodiments described later. As shown in FIG. 1, the basic structure of a power steering device for a vehicle includes a pair of steering mechanisms 10, 12 spaced apart in the width direction (left-right direction) of the vehicle and extending generally in the fore-and-aft direction, and a connecting mechanism 16 that connects the pair of steering mechanisms 10, 12 and also connects a pair of steered wheels (e.g., left and right front wheels) 14L, 14R provided on the vehicle.

[0009] The pair of steering mechanisms 10, 12 are provided in front of the connecting mechanism 16. In this vehicle power steering device, the operating side steering mechanism 10, which is one of the pair of steering mechanisms 10, 12, is provided on the left side of the vehicle, and the non-operating side steering mechanism 12, which is the other of the pair of steering mechanisms 10, 12, is provided on the right side of the vehicle.

[0010] The operating side steering mechanism 10 includes a link mechanism 18L and a drive unit 20L. As shown in Figures 2 and 3, the drive unit 20L includes a housing 21L, a rack bar 22L as a drive shaft, a pinion gear 24L meshed with the teeth of the rack bar 22L, a steering wheel 28 attached to the pinion gear 24L via a steering shaft 26, and an electric assist device 31L.

[0011] The electric assist device 31L includes an electric assist motor (hereinafter simply referred to as an assist motor) 32L, a worm gear 30L attached to the output shaft of the assist motor 32L so as to be integrally rotatable, and a reduction gear 34L that is provided on the pinion gear 24L so as to be integrally rotatable with the pinion gear 24L and has a larger diameter than the pinion gear 24L. The worm gear 30L is engaged with the reduction gear 34L.

[0012] The rack bar 22L extends in the axial direction (parallel to the axis h in FIG. 2) in the front-rear direction of the vehicle, and is held in the housing 21L so as to be non-rotatable relative to the housing 21L and movable relative to the housing 21L in the axial direction. A front contact portion 36L is provided at the front end of the rack bar 22L, and a ball joint 38L functioning as a rear end contact portion is provided at the rear end. Meanwhile, the housing 21L is provided with a front stopper 40L that can contact the front contact portion 36L, and a rear stopper 42L that can contact the ball joint 38L.

[0013] The link mechanism 18L includes a first link member 50L having a generally L-shape and a second link member 54L extending generally linearly. The first link member 50L includes a first arm portion 51L and a second arm portion 52L extending in directions intersecting each other (directions substantially perpendicular to each other). One end portion (end portion of the first arm portion 51L) of the first link member 50L is connected to one end portion of the connecting mechanism 16 so as to be rotatable relative to each other, and the other end portion (end portion of the second arm portion 52L) of the first link member 50L is connected to one end portion of the second link member 54L so as to be rotatable relative to each other. The other end portion of the second link member 54L is connected to the rack bar 22L via a ball joint 38L so as to be rotatable relative to each other. Reference numerals 56L and 56R denote adjustment portions for adjusting the lengths of the second link members 54L and 54R.

[0014] In the basic structure of the vehicle steering device, the non-operating side turning mechanism 12 does not include the steering shaft 26 and steering wheel 28 included in the operating side turning mechanism 10. However, other components and structures are the same between the non-operating side turning mechanism 12 and the operating side turning mechanism 10. Therefore, in the drawings, the same components are given the suffix R instead of the suffix L, and the explanation will be omitted.

[0015] The connecting mechanism 16 includes a pair of tie rods 60L, 60R connected to the knuckle arms of the left and right front wheels 14L, 14R, and a connecting rod 62 connecting the pair of tie rods 60L, 60R. One ends of the pair of first link members 50L, 50R (ends of the first arm portions 51L, 51R) are respectively connected to both ends of the connecting rod 62 so as to be rotatable relative to each other.

[0016] Alternatively, the connecting rod 62 may be connected to the knuckle arms of the left and right front wheels 14L, 14R, and one end of the pair of first link members 50L, 50R may be connected to tie rods 60L, 60R, respectively.

[0017] The motor ECUs 70 and 72, each of which is a computer, are connected to the assist motors 32L and 32R via a drive circuit (not shown). The motor ECUs 70 and 72 are connected to a torque sensor 74 that detects the operation torque applied to the steering wheel 28 by the driver. The motor ECUs 70 and 72 control the assist motors 32L and 32R based on the operation torque detected by the torque sensor 74. For example, the motor ECUs 70 and 72 obtain a target assist force based on the operation torque detected by the torque sensor 74, detect a current flowing through the assist motors 32L and 32R, obtain a load applied to the assist motors 32L and 32R based on the detected current, and obtain an actually output assist force. The assist motors 32L and 32R can be controlled so that the actually output assist force approaches the target assist force.

[0018] The assist motor 32L provided in the steering side turning mechanism 10 and the assist motor 32R provided in the non-steering side turning mechanism 12 may be controlled in the same manner or in different manners.

[0019] A plurality of stoppers are provided in the vehicle steering device having the basic structure configured as described above. The plurality of stoppers limit the left and right steering of the left and right front wheels 14L, 14R. The plurality of stoppers will be described below in each of the embodiments. Example 1

[0020] The vehicle steering device according to the first embodiment is shown in Fig. 4. This vehicle steering device includes two stopper members 80, 82 that limit the rotation limit of the link mechanism 18L of the operating side steering mechanism 10X, and one stopper member 84 that limits the rotation limit of the link mechanism 18R of the non-operating side steering mechanism 12X.

[0021] The stopper members 80, 82 are attached to the vehicle body side member at positions facing the first link member 50L of the link mechanism 18L. As shown in Fig. 4, the stopper members 80, 82 are attached to both sides (front and rear sides) of the second arm portion 52L.

[0022] The stopper member 84 is attached to the rear side of the second arm portion 52L of the link mechanism 18R which is a vehicle body side member. The stopper member 84 can be attached to a position substantially symmetrical to the stopper member 82. The vehicle body side member refers to a member that is attached to the body or the body and does not rotate in conjunction with the rotation of the link mechanisms 18L, 18R or move in conjunction with the movement of the rack bars 22L, 22R.

[0023] As shown in FIG. 5, when the steering wheel 28 is steered so that the left and right front wheels 14L, 14R are steered to the left, in the operating side steering mechanism 10X, the pinion gear 24L is subjected to an operating torque applied via the steering wheel 28 and an assist torque applied by the assist motor 32L. As a result, the rack bar 22L is moved in a direction approaching the connecting mechanism 16 (hereinafter, sometimes referred to as rearward), and the link mechanism 18L is rotated to the right. In the non-operating side steering mechanism 12X, the pinion gear 24L is rotated by the assist torque applied by the assist motor 32R, the rack bar 22R is moved in a direction away from the connecting mechanism 16 (hereinafter, sometimes referred to as forward), and the link mechanism 18R is rotated to the right. As a result, the connecting rod 62 is moved to the left, and the left and right front wheels 14L, 14R are steered to the left.

[0024] In the operating side steering mechanism 10X, when the first link member 50L abuts against the stopper member 82, the rightward rotation of the link mechanism 18L is restricted, and the rearward movement of the rack bar 22L is restricted. The leftward movement of the connecting rod 62 is restricted, and the leftward steering of the left and right front wheels 14L, 14R is restricted. The left and right front wheels 14L, 14R will not be steered further to the left. The limit of leftward steering of the left and right front wheels 14L, 14R is determined, and the maximum leftward steering angle is determined.

[0025] In this way, in the operating side steering mechanism 10X equipped with the steering wheel 28, the first link member 50L abuts against the stopper member 82. Therefore, this is smoothly transmitted to the steering wheel 28 via the second link member 54L, the rack bar 22L, the pinion 24L, and the steering shaft 26. The driver can clearly recognize that the steering of the left and right front wheels 14L, 14R has been restricted. It is considered that the driver will end any further steering operation of the steering wheel 28. This can suppress unnecessary energy consumption in the assist motors 32L, 32R.

[0026] As shown in Fig. 6, when the steering wheel 28 is steered so that the left and right front wheels 14L, 14R are steered to the right, in the operating side steering mechanism 10X, the pinion gear 24L is rotated by the operating torque by the driver and the assist torque by the assist motor 32L, the rack bar 22L is moved forward, and the link mechanism 18L is rotated to the left. In the non-operating side steering mechanism 12X, the rack bar 22R is moved rearward by the assist motor 32R, thereby rotating the link mechanism 18R to the left. As a result, the connecting rod 62 is moved to the right, and the left and right front wheels 14L, 14R are steered to the right.

[0027] In addition, when the first link member 50L abuts against the stopper member 80 in the operating side steering mechanism 10X, and the first link member 50R abuts against the stopper member 84 in the non-operating side steering mechanism 12X, the leftward rotation of the link mechanisms 18L, 18R is restricted, and the forward movement of the rack bar 22L and the rearward movement of the rack bar 24R are restricted. The rightward movement of the connecting rod 62 is restricted, and the rightward steering of the left and right front wheels 14L, 14R is restricted. The left and right front wheels 14L, 14R will not be steered any further to the right. The rightward steering limit of the left and right front wheels 14L, 14R is determined, and the maximum rightward steering angle is restricted.

[0028] In the operating side steering mechanism 10X, the first link member 50L abuts against the stopper member 80, and this is transmitted well to the steering wheel 28, allowing the driver to clearly recognize that the rightward steering of the left and right front wheels 14L, 14R has been restricted. It is considered that the driver will end any further steering operation of the steering wheel 28. This makes it possible to reduce the energy consumed by the assist motors 32L, 32R.

[0029] Furthermore, in the non-operating side steering mechanism 12X, the first link member 50R comes into contact with the stopper member 84, thereby restricting the rearward movement of the rack bar 22R. If the stopper member 84 is not provided, and the steering wheel 28 is steered even after the rightward steering of the left and right front wheels 14L, 14R is restricted, the assist motors 32L, 32R continue to be controlled based on the operation torque. On the other hand, since the rack bar 22R is connected to the link mechanism 18R, the rack bar 22R is moved rearward by the assist motor 32R, and the second link member 54R and the first link member 50R are bent, and the link mechanism 18R may be forcibly rotated. In addition, a large load is applied to the rack bar 22R, the second link member 54R, the first link member 50R, etc.

[0030] In contrast, according to the stopper member 84, the first link member 50R comes into contact with the stopper member 84, and the rearward movement of the rack bar 22R is restricted. This makes it possible to effectively prevent the first link member 50R and the second link member 54R from being rotated while being bent. In addition, the stopper member 84 limits the rotation of the first link member 50R at a position close to the pinion 24R. As a result, the load applied to the assist motor 32R increases suddenly, and the actual assist force of the assist motor 32R may exceed the target assist force. This makes it possible to stop the assist motor 32R or reduce the assist force, and in this case, the load (e.g., bending stress, etc.) applied to the rack bar 22R, the second link member 54R, etc. can be effectively suppressed.

[0031] In addition, as described above, the fact that the steering of the left and right front wheels 14L, 14R to the right is restricted is conveyed to the driver by the first link member 50L abutting against the stopper member 80, so it is considered that the driver will end the steering operation of the steering wheel 28 in the direction in which the left and right front wheels 14L, 14R are steered to the right. In this sense, too, the bending stress applied to the rack bar 22R, etc. can be suppressed, and the lifespan can be extended.

[0032] On the other hand, the positions of the stopper members 80, 82, 84 that limit the rotation of the first link members 50L, 50R are easy to adjust. Therefore, it is possible to adjust the positions of the stopper members 80, 84 so that the first link member 50L abuts against the stopper member 80 and the first link member 50R abuts against the stopper member 84 at the same time.

[0033] In this embodiment, the first link member 50L abuts against the stopper member 82 before the front contact portion 36L abuts against the front stopper 40L in the operating side turning mechanism 10X, and before the ball joint 38R abuts against the rear stopper 42R in the non-operating side turning mechanism 12X. Also, before the front contact portion 36L abuts against the front stopper 40L in the non-operating side turning mechanism 12X, and before the ball joint 38L abuts against the rear stopper 42 in the operating side turning mechanism 10X, the first link member 50L abuts against the stopper member 80 in the operating side turning mechanism 10X, and the first link member 50R abuts against the stopper member 84 in the non-operating side turning mechanism 12X. Therefore, the front stoppers 40L, 40R and the rear stoppers 42L, 42R do not substantially function as stoppers. Therefore, the front stoppers 40L, 40R and the rear stoppers 42L, 42R are not essential, but can be considered to function to prevent dislodging.

[0034] From the above, in this embodiment, the stopper members 80, 82 correspond to an operating side stopper and an operating side rotation stopper, and the stopper member 84 corresponds to a non-operating side stopper and a non-operating side rotation stopper. Example 2

[0035] In the vehicle power steering device according to the second embodiment, the movement of the rack bar 22L of the operating side steering mechanism 10Y is restricted, and the rotation of the link mechanism 18R is restricted.

[0036] In the power steering apparatus for a vehicle, as shown in FIG. 7, when the left and right front wheels 14L and 14R are in the neutral position, in other words, when the vehicle is in a straight-ahead state, the state of the left and right front wheels 14L and 14R (it can be considered that the steering angle is 0), the distance L1a between the front stopper 40L and the front contact portion 36L in the operating-side steering mechanism 10Y is smaller than the distance L2b between the rear stopper 42R and the ball joint 38R in the non-operating-side steering mechanism 12Y (L1a < L2b), and the distance L1b between the rear stopper 42L and the ball joint 38L in the operating-side steering mechanism 10Y is smaller than the distance L2a between the front stopper 42R and the front contact portion 36R in the non-operating-side steering mechanism 12Y (L1b < L2a). Therefore, in the non-operating-side steering mechanism 12Y, the front contact portion 36R and the ball joint 38R do not contact the front stopper 40R and the rear stopper 42R.

[0037] Also, in the non-operating-side steering mechanism 12Y, a stopper member 98 is provided at a position of the vehicle body member facing the first link member 50R of the link mechanism 18R, and the rotation of the link mechanism 18R is restricted. In the present embodiment, the stopper member 98 is attached behind the second arm portion 52R, that is, at a position where the ball joint 38L of the rack bar 22L contacts the rear stopper 42L in the operating-side steering mechanism 10Y and at the same time the first link member 50R contacts in the non-operating-side steering mechanism 12Y.

[0038] For example, when the steering wheel 28 is steered so that the left and right front wheels 14L and 14R are steered to the left, as shown in FIG. 8, in the operating-side steering mechanism 10Y, the pinion gear 24L is rotated by the operating torque and the assist torque by the assist motor 32L, and the rack bar 22L is moved rearward. In the non-operating-side steering mechanism 12Y, the pinion gear 24R is rotated by the assist torque, and the rack bar 22R is moved forward. The link mechanisms 18L and 18R are both rotated to the right, the connecting rod 62 is moved to the left, and the left and right front wheels 14L and 14R are steered to the left.

[0039] In the operating side steering mechanism 10Y, when the front contact portion 36L contacts the front stopper 40L, the rearward movement of the rack bar 22L is restricted, and the rotation of the link mechanism 18L is restricted. The leftward movement of the connecting rod 62 is restricted, and the steering of the left and right front wheels 14L, 14R is restricted. The left and right front wheels 14L, 14R will not be steered any further to the left. In this way, in the operating side steering mechanism 10Y, since the front contact portion 36L contacts the front stopper 40L, the fact that the leftward steering of the left and right front wheels 14L, 14R has been restricted can be properly transmitted to the steering wheel 28.

[0040] Also, when the steering wheel 28 is steered so that the left and right front wheels 14L, 14R are steered to the right, in the operating side steering mechanism 10Y, the pinion gear 24L is rotated by the steering torque and the assist torque by the assist motor 32L, and the rack bar 22L is moved forward, as shown in Fig. 9. In the non-operating side steering mechanism 12Y, the pinion gear 24R is rotated by the assist motor 32R, and the rack bar 22R is moved rearward. The link mechanisms 18L, 18R are rotated to the left, the connecting rod 62 is moved to the right, and the left and right front wheels 14L, 14R are steered to the right.

[0041] In the operating side steering mechanism 10Y, the ball joint 38L abuts against the rear stopper 42L, and in the non-operating side steering mechanism 12Y, the first link member 50R abuts against the stopper member 98. This limits the rightward steering of the left and right front wheels 14L, 14R. In the operating side steering mechanism 10Y, because the ball joint 38L abuts against the rear stopper 42L, the fact that the rightward steering of the left and right front wheels 14L, 14R has been limited can be transmitted to the steering wheel 28 in an excellent manner.

[0042] In the non-operating side steering mechanism 12Y, the first link member 50R abuts against the stopper member 58R, so that the rearward movement of the rack bar 22R is restricted, the bending of the first link member 50R and the second link member 54R is restricted, and the forced rotation of the link mechanism 18R can be restricted. Also, the load applied to the rack bar 22R, etc. can be suppressed.

[0043] On the other hand, it is difficult due to variations in the rack bars 22L, 22R to determine the positions of the front stoppers 40L, 40R and the rear stoppers 42L, 42R so that, at the same time that the front abutment portion 36L abuts against the front stopper 40L in the operating side turning mechanism 10Y, the ball joint 38R abuts against the rear stopper 40R in the non-operating side turning mechanism 12Y, and at the same time that the ball joint 38L abuts against the rear stopper 42L in the operating side turning mechanism 10Y, the front abutment portion 36R abuts against the front stopper 40R in the non-operating side turning mechanism 12Y. Therefore, even if the ball joint 38R in the non-operating side turning mechanism 12Y abuts against the rear stopper 40R at the same time that the front contact portion 36L abuts against the front stopper 40L, and the ball joint 38L in the operating side turning mechanism 10Y abuts against the rear stopper 42L at the same time that the front contact portion 36R in the non-operating side turning mechanism 12Y abuts against the front stopper 40R, a misalignment occurs between them, making it difficult to properly determine the turning angle when the left and right steering of the left and right front wheels 14L, 14R is restricted. On the other hand, if there is a single stopper that restricts the steering of the left and right front wheels 14L, 14R, the turning angle when the steering is restricted can be properly determined.

[0044] In this embodiment, the front stopper 40L and the rear stopper 42L correspond to an operating side stopper and an operating side movement stopper, respectively, and the stopper member 98 corresponds to a non-operating side stopper and a rotation stopper. Example 3

[0045] In the vehicle power steering apparatus according to Embodiment 3, the movement of the rack bars 22L and 22R of the operation-side steering mechanism 10Z and the non-operation-side steering mechanism 12Z is restricted, and the rotation of the link mechanism 18L is restricted.

[0046] As shown in FIG. 10, when the left and right front wheels 14L and 14R are in the neutral position, the distance L1c between the front contact portion 36L and the front stopper 40L in the operation-side steering mechanism 10Z is smaller than the distance L2d between the ball joint 38R and the rear stopper 42R in the non-operation-side steering mechanism 12Z (L1c < L2d), and the distance L2c between the front contact portion 36R and the front stopper 40R in the non-operation-side steering mechanism 12Z is smaller than the distance L1d between the ball joint 38L and the rear stopper 42L in the operation-side steering mechanism 10Z (L2c < L1d).

[0047] Further, in the operation-side steering mechanism 10Z, a stopper member 108 is provided at a position facing the first link member 50L of the vehicle body side member.

[0048] As shown in FIG. 11, when the steering wheel 28 is steered so that the left and right front wheels 14L and 14R are steered to the left, the assist motors 32L and 32R are actuated, the rack bar 22L is moved rearward, and the rack bar 22R is moved forward. The link mechanisms 18L and 18R are rotated to the right, the connecting rod 62 is moved to the left, and the left and right front wheels 14L and 14R are steered to the left. The leftward steering of the left and right front wheels 14L and 14R is restricted by the front contact portion 36L abutting against the front stopper 40L in the operation-side steering mechanism 10Z. Further, the fact that the steering of the left and right front wheels 14L and 14R is restricted can be favorably transmitted to the steering wheel 28.

[0049] When the steering wheel 28 is steered so that the left and right front wheels 14L, 14R are steered to the right, the assist motors 32L, 32R are operated, the rack bar 22L is moved forward, and the rack bar 22R is moved rearward, as shown in Fig. 12. The link mechanisms 18L, 18R are rotated to the left, the connecting rod 62 is moved to the right, and the left and right front wheels 14L, 14R are steered to the right. The rightward steering of the left and right front wheels 14L, 14R is restricted by the front abutment portion 36R abutting against the front stopper 40R in the non-operating side steering mechanism 12Z and the first link member 50L abutting against the first stopper member 108 in the operating side steering mechanism 10Z.

[0050] In the operating side steering mechanism 10Z, the first link member 50L abuts against the first stopper member 108, so that the fact that the turning of the left and right front wheels 14L, 14R in the right direction is restricted can be transmitted smoothly to the steering wheel 28.

[0051] Furthermore, whether the steering wheel 28 is steered leftward or rightward, the front contact portions 36L, 36R come into contact with the front stoppers 40L, 40R. As a result, even if the assist motors 32L, 32R are operated after the turning of the left and right front wheels 14L, 14R is restricted, the rack bars 22L, 22R are prevented from moving rearward, and the load applied to the rack bars 22L, 22R, etc. can be suppressed.

[0052] In this embodiment, the front stopper 40L corresponds to the operating side stopper and the operating side movement stopper, the stopper member 108 corresponds to the operating side stopper and the operating side rotation stopper, and the front stopper 40R corresponds to the non-operating side stopper and the non-operating side movement stopper.

[0053] The operating side turning mechanism 10 may be provided on the right side, and the non-operating side turning mechanism 12 may be provided on the left side.

[0054] Furthermore, in the operating side steering mechanism 10, it is not essential to provide the electric assist device 31L. Further, the motor ECUs 70, 72 may be provided in common to the assist motor 32L and the assist motor 32R, or the assist motors 32L, 32R may be controlled taking into consideration the vehicle running speed in addition to the operating torque. In addition to the above-described embodiment, the present invention may be embodied in various forms that include various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0055] 10: Operating side steering mechanism 12: Non-operating side steering mechanism 16: Connection mechanism 18L, 18R: Link mechanism 20R, 20L: Drive unit 22L, 22R: Rack bar 24L, 24R: Pinion gear 28: Steering wheel 31L, 31R: Electric assist device 32L, 32R: Assist motor 36L, 36R: Front contact portion 40L, 40R: Front stopper 38L, 38R: Ball joint 42L, 42R: Rear stopper 50L, 50R: First link member 60L, 60R: Tie rod 62: Connection rod 80, 82, 84, 98, 108: Stopper member Patentable invention

[0056] (1) A pair of steering mechanisms for steering a pair of steering wheels of a vehicle; a connecting mechanism that connects the pair of steering wheels and also connects the pair of steering mechanisms; Including, The pair of steering mechanisms are an operating side steering mechanism including a drive shaft connected to one end of the connecting mechanism and extending in an axial direction, and a steering operation member engaged with the drive shaft; a non-operated side steering mechanism including a drive shaft that is connected to the other end of the connecting mechanism and extends in an axial direction, and an electric assist device that is engaged with the drive shaft; A power steering device for a vehicle, comprising: A power steering device for a vehicle, wherein the operating side steering mechanism includes at least two operating side stoppers that respectively limit the leftward and rightward steering of the pair of steered wheels.

[0057] The operating side steering mechanism is provided with at least two operating side stoppers, but may be provided with three or more operating side stoppers.

[0058] The operating side turning mechanism and the non-operating side turning mechanism are provided separately in the left-right direction of the vehicle. The operating side turning mechanism may be provided on the left side and the non-operating side turning mechanism on the right side, or the operating side turning mechanism may be provided on the right side and the non-operating side turning mechanism on the left side.

[0059] (2) The operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, The vehicle power steering device described in item (1), wherein the at least two operating side stoppers each include two operating side rotation stoppers that are capable of abutting against a link member constituting the link mechanism and limit the rotation of the link member associated with the movement of the drive shaft.

[0060] (3) The operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, The vehicle power steering device described in item (1), wherein the at least two operating side stoppers include an operating side movement stopper that is capable of contacting the drive shaft and limits the movement of the drive shaft in a direction toward the connecting mechanism, and an operating side rotation stopper that is capable of contacting a link member that constitutes the link mechanism and limits the rotation of the link member associated with the movement of the drive shaft in a direction away from the connecting mechanism.

[0061] (4) The vehicle power steering device according to (1), wherein the at least two operating side stoppers include two operating side movement stoppers that are capable of contacting the drive shaft and limiting movement of the drive shaft.

[0062] (5) A power steering device for a vehicle described in any one of (1) to (4), wherein the non-operating side steering mechanism is provided with at least one non-operating side stopper that limits steering of the pair of steered wheels in either the left direction or the right direction.

[0063] The non-operation side turning mechanism is provided with at least one non-operation side stopper, but may be provided with two or more non-operation side stoppers. The present vehicle steering device is provided with at least three stoppers.

[0064] The non-operating side stopper, together with one of the two operating side stoppers, limits the steering of a pair of steering wheels, and in addition to the function of limiting steering, can also have the function of suppressing movement of the drive shaft.

[0065] (6) The non-operated side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, The vehicle power steering device described in (5) above, wherein the at least one non-operating side stopper includes a non-operating side rotation stopper that is capable of abutting against a link member constituting the link mechanism and limits the rotation of the link member associated with the movement of the drive shaft in a direction approaching the connecting mechanism.

[0066] In the first to third embodiments, the first link members 50L and 50R correspond to the link members.

[0067] (7) A power steering device for a vehicle as described in (5), wherein the at least one non-operating side stopper includes a non-operating side movement stopper that is capable of contacting the drive shaft and limits the movement of the drive shaft in a direction approaching the connecting mechanism.

[0068] (8) The operating side steering mechanism is provided on either the right side or the left side of the vehicle, the non-operated side steering mechanism is provided on the other of the right side and the left side of the vehicle, The vehicle power steering device according to any one of (5) to (7), wherein the at least one non-operating side stopper limits steering of the pair of steered wheels to the other side.

[0069] (9) The vehicle power steering device according to any one of (1) to (8), wherein the operating side steering mechanism further includes an electric assist device engaged with the drive shaft.

[0070] (10) A power steering device for a vehicle as described in any one of (1) to (9), wherein the connecting mechanism includes a pair of tie rods connected to each of the pair of steering wheels, and a connecting rod connecting the pair of tie rods.

[0071] The pair of steering mechanisms may be connected to each of the pair of tie rods, or may be connected to a connecting rod.

[0072] (11) A pair of steering mechanisms provided at intervals in the left-right direction of the vehicle and configured to steer a pair of steering wheels; a connecting mechanism that connects the pair of steering wheels and also connects the pair of steering mechanisms; Including, The pair of steering mechanisms are an operating side steering mechanism provided on one side in the left-right direction of the vehicle and connected to one end of the connecting mechanism, the operating side steering mechanism including a drive shaft extending in an axial direction and a steering operation member engaged with the drive shaft; a non-operated side steering mechanism provided on the other side in the left-right direction of the vehicle and connected to the other end of the connecting mechanism, the non-operated side steering mechanism including a drive shaft extending in an axial direction and an electric assist device engaged with the drive shaft; A power steering device for a vehicle, comprising: At least one first stopper that limits the steering of the pair of steering wheels when the pair of steering wheels are steered to one side in the left-right direction; At least two second stoppers that limit the steering of the pair of steering wheels when the pair of steering wheels is steered to the other side in the left-right direction; A power steering device for a vehicle comprising:

[0073] The power steering device according to the present invention may employ any one of the features described in (1) to (10).

[0074] One of the at least one first stopper is an operating side stopper provided in the operating side steering mechanism, and two of the at least two second stoppers are an operating side stopper provided in the operating side steering mechanism and a non-operating side stopper provided in the non-operating side steering mechanism.

Claims

1. A pair of steering mechanisms for steering a pair of steering wheels of a vehicle; a connecting mechanism that connects the pair of steering wheels and connects the pair of steering mechanisms, The pair of steering mechanisms are an operating side steering mechanism including a drive shaft connected to one end of the connecting mechanism and extending in an axial direction, and a steering operation member engaged with the drive shaft; A power steering device for a vehicle including a non-operated side steering mechanism including a drive shaft that is connected to the other end of the connecting mechanism and extends in an axial direction, and an electric assist device that is engaged with the drive shaft, the operating side steering mechanism includes at least two operating side stoppers that respectively limit the leftward steering and the rightward steering of the pair of steering wheels, the non-operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, and includes at least one non-operating side stopper that limits steering of the pair of steering wheels in either the left direction or the right direction, the pair of steering wheels are steered in one direction, either the left direction or the right direction, when the drive shaft is moved in a direction approaching the connecting mechanism in the non-operated side steering mechanism, and are steered in the other direction, either the left direction or the right direction, when the drive shaft is moved in a direction away from the connecting mechanism, the link mechanism includes a link member that is deflected when the drive shaft is moved in a direction approaching the connecting mechanism, A power steering device for a vehicle, wherein the at least one non-operating side stopper is capable of abutting the link member and does not include a stopper that limits the rotation of the link member associated with movement of the drive shaft in a direction away from the connecting mechanism, but includes a non-operating side rotation stopper that limits the rotation of the link member associated with movement of the drive shaft in a direction toward the connecting mechanism and suppresses bending of the link member.

2. The link mechanism includes a first link member which is the link member, and a second link member which is connected to the first link member at one end and is connected to the drive shaft at the other end, 2. The power steering device for a vehicle as described in claim 1, wherein the first link member is generally L-shaped, connected at one end to the connecting mechanism, connected at the other end to the one end of the second link member, and the intermediate portion is left free.

3. The operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, 3. The power steering device for a vehicle according to claim 1, wherein the at least two operating side stoppers include two operating side rotation stoppers that are capable of abutting against link members constituting the link mechanism and limit the rotation of the link members associated with the movement of the drive shaft.

4. The operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, 3. The power steering device for a vehicle according to claim 1, wherein the at least two operating side stoppers include an operating side movement stopper that is capable of contacting the drive shaft and limits the movement of the drive shaft in a direction toward the connecting mechanism, and an operating side rotation stopper that is capable of contacting a link member constituting the link mechanism and limits the rotation of the link member associated with the movement of the drive shaft in a direction away from the connecting mechanism.

5. 3. The power steering device for a vehicle according to claim 1, wherein the at least two operation side stoppers include two operation side movement stoppers that are capable of coming into contact with the drive shaft and limit movement of the drive shaft.

6. 6. The power steering device for a vehicle according to claim 1, wherein the operating side steering mechanism further comprises an electric assist device engaged with the drive shaft.

7. A pair of steering mechanisms for steering a pair of steering wheels of a vehicle; a connecting mechanism that connects the pair of steering wheels and connects the pair of steering mechanisms, The pair of steering mechanisms are an operating side steering mechanism including a drive shaft connected to one end of the connecting mechanism and extending in an axial direction, and a steering operation member engaged with the drive shaft; A power steering device for a vehicle including a non-operated side steering mechanism including a drive shaft that is connected to the other end of the connecting mechanism and extends in an axial direction, and an electric assist device that is engaged with the drive shaft, the operating side steering mechanism includes at least two operating side stoppers that respectively limit the leftward steering and the rightward steering of the pair of steering wheels, the non-operating side steering mechanism includes a link mechanism that connects the connecting mechanism and the drive shaft, and includes at least one non-operating side stopper that limits steering of the pair of steering wheels in either the left direction or the right direction, the pair of steering wheels are steered in one direction, either the left direction or the right direction, when the drive shaft is moved in a direction approaching the connecting mechanism in the non-operated side steering mechanism, and are steered in the other direction, either the left direction or the right direction, when the drive shaft is moved in a direction away from the connecting mechanism, the link mechanism includes a link member that is deflected when the drive shaft is moved in a direction approaching the connecting mechanism, A power steering device for a vehicle, wherein the at least one non-operating side stopper is capable of abutting against the drive shaft, does not include a stopper that limits movement of the drive shaft in a direction away from the connecting mechanism, and includes a non-operating side movement stopper that suppresses movement of the drive shaft in a direction toward the connecting mechanism.

Images