JP2006175948A - Steering system of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steering system of steer-by-wire type equipped with an enhanced possibility of practical application, capable of turning the applicable vehicle wheels without resorting to the operating force applied to a steering operation member. <P>SOLUTION: The steering system of a vehicle is equipped with an operational reaction force applying mechanism to give an operational reaction force by means of interlocking with the steering operation member 14, an operational reaction force applying device having a mechanism to change over between the interlocking condition and non-interlocking condition, and a coupling device 150 to couple together the operation member 14 and a wheel turning device 24 in such a way as separably, whereby the operation member 14 and the operational reaction force applying mechanism are put in interlocking in the case the operation member 14 and the wheel turning devcie 24 are separated, and in the case the operation member 14 and the wheel turning device 24 are coupled together, the operation member 14 and the operational reaction force applying mechanism are released from the interlocked condition. If the operation member 14 and the wheel turning device 24 are coupled together, a condition is established in which the operational reaction force is not applied to the operation member 14, and it is possible to make the steering operation relatively light, and on that point this assures a steering system equipped with a high practicable applicability. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a steering system provided in a vehicle, and more particularly to a steer-by-wire type steering system that enables steering of a wheel without depending on an operation force applied to a steering operation member.

Today, as a steering system provided in a vehicle, a so-called steer-by-wire type steering system as described in Patent Documents 1 to 3 below, that is, an electric power regardless of an operating force applied to a steering operation member such as a steering wheel. Under such control, a steering system in which wheels are steered in accordance with the operation of an operation member by the power of a power source provided in the steering device has been studied. In this steering system, since the steering operation member and the steered device are not normally connected so as to be able to transmit power, an operation reaction force application mechanism that applies a reaction force to the steering operation in consideration of the operational feeling of the steering operation. Has been proposed. As the operation reaction force application mechanism, for example, in the systems described in Patent Documents 1 and 2 below, a mechanism for applying an operation reaction force that makes the steering operation member move to the neutral position using the elastic force of a spring is provided. In the systems described in Patent Documents 1 and 3, a mechanism for applying an operation reaction force using the driving force of the motor is provided. On the other hand, in the steer-by-wire system, for example, in the case of an abnormality in the steering device described in Patent Documents 1 and 3, for example, the steering of the wheel by the operation force applied to the steering operation member is ensured. Therefore, it has also been proposed to provide a device for connecting the steering operation member and the steering device.
JP 2001-106111 A JP 2004-230975 A Japanese Patent Laid-Open No. 2004-224096

  In a steering system provided with a device for connecting the steering operation member and the steering device, when the steering operation member and the steering device are connected by the device, the steering device is operated from the steering device in the same manner as in a normal steering system. A reaction force to the operation can be obtained. However, in the system in which the operation reaction force applying mechanism exists, in addition to the operation reaction force from the steering device, the operation reaction force by the operation reaction force applying mechanism is also loaded, and the steering operation is considerably heavy. End up. This problem is one of the problems that steer-by-wire steering systems have, but the steer-by-wire system has enough room to improve its practicality, including dealing with such problems. It has become. The present invention has been made in view of such circumstances, and an object thereof is to provide a highly practical steering system.

  In order to solve the above-described problems, a vehicle steering system according to the present invention includes an operation reaction force application mechanism that applies an operation reaction force in cooperation with a steering operation member, and a steering operation member and a steering device that are separably connected. Steer-by-wire system including an operation member steering device coupling device that performs operation when the steering operation member and the steering device are separated from each other, in which the operation reaction force application mechanism and the steering operation member cooperate with each other In the case where the steering operation member and the steered device are connected, the operation reaction force imparting mechanism and the steering operation member are released from cooperation.

  According to the vehicle steering system of the present invention, when the wheels are steered regardless of the operation force applied to the steering operation member, the operation reaction force is applied to the steering operation member. When the wheel is steered by the operation force applied to the operation member, the operation reaction force by the operation reaction force applying mechanism is not applied to the steering operation member, so the steering operation member and the steering device are connected. Even in a state where the steering operation member is not connected, and also in a state where the steering operation member and the steered device are coupled, it is possible to make the operation feeling of the steering operation member appropriate. By having such advantages, the vehicle steering system of the present invention becomes a highly practical system.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, (1) corresponds to claim 1, (2) corresponds to claim 2, (4) corresponds to claim 3, (8) corresponds to claim 4, The (12) term corresponds to claim 5 and the (14) term corresponds to claim 6.

(1) a steering operation member;
A steering device that includes a steering actuator, and performs steering of the wheels without depending on the operation force applied to the steering operation member by the driving force of the steering actuator;
Operation member steering capable of connecting the steering operation member and the steering device to enable steering by an operation force applied to the steering operation member by its own operation and releasing the connection. A device coupling device;
(A) An operation reaction force application mechanism that applies an operation reaction force according to the operation of the steering operation member in cooperation with the steering operation member, and (B) an operation reaction force application mechanism by its own operation. And an operation reaction force imparting device having a cooperative state switching mechanism for switching between a state in which the steering operation member and the state in which the steering operation member are in cooperation with each other, and
(a) The operation member steering device connecting device releases the connection between the steering operation member and the steering device, and the cooperation reaction state switching mechanism links the operation reaction force applying mechanism and the steering operation member. And (b) the steering operation member and the steering device are connected by the operation member steering device connecting device, and the operation reaction force applying mechanism and the steering operation are connected by the cooperative state switching mechanism. A vehicle steering system comprising: a control device that controls the operation member steering device coupling device and the linkage state switching mechanism to selectively realize a second state in which the members are not linked.

  In the aspect described in this section, a steering operation member (hereinafter, simply abbreviated as “operation member”) may be provided by the operation member steering device coupling device (hereinafter may be simply abbreviated as “connection device”). When the connection with the steering device is released, the operation reaction force by the operation reaction force application mechanism is not applied to the operation member, and the operation member and the steering device are connected by the connection device In other words, the operation reaction force by the operation reaction force application mechanism is not applied to the operation member. Therefore, according to the aspect described in this section, an appropriate operation reaction force is applied to the operation member regardless of whether or not the operation member and the steering device are connected by the connection device. In other words, even when the operating member and the steering device are connected by the connecting device, the steering operation can be made relatively light. Due to such advantages, according to the vehicle steering system of the aspect described in this section, a steer-by-wire type steering system with high practicality is realized.

  The “steering operation member” in the aspect of this section is generally a steering wheel, but is not limited thereto, and various types such as a lever and a joystick can be employed. Further, the configuration of the “steering device” is not particularly limited, and various configurations that have already been studied can be adopted. For example, an electric motor can be adopted as the turning actuator, and a turning rod connected to the wheels can be moved left and right by the driving force of the motor. In that case, for example, a rack and pinion mechanism, a ball screw mechanism, or the like can be employed as a mechanism for moving the steered rod.

  The “operation member steering device coupling device” in the aspect of this section is a device for realizing the steering of the wheel by the operation force applied to the operation member regardless of the driving force of the steering actuator. As long as the operation member and the steering device can be mechanically connected by a shaft, a cable, a wire, or the like. As a mechanism for releasing the connection between the operation member and the steering device, for example, a clutch or the like can be employed. The “operation reaction force application mechanism” included in the “operation reaction force application device” may be generated based on any force, for example, a spring or the like as described later. It is possible to adopt a mechanism that relies on various forces such as the elastic force of the elastic member and the frictional resistance force caused by the viscous fluid. In addition, it is desirable that the operation reaction force application mechanism does not have an operation reaction force of 0 by control, unlike a reaction force application mechanism using a driving force such as a motor. In other words, for example, when a mechanism that applies an operation reaction force that relies on elastic force, viscous resistance force, or the like and that cannot change the magnitude of the operation reaction force that is applied depending on the control is used. The embodiment of the item is particularly suitable. In addition, the “cooperation state switching mechanism” provided in the “operation reaction force applying device” is not particularly limited in its configuration, and as long as it has a function of switching the cooperation state by being operated by control, the operation reaction switching mechanism is not limited. An appropriate one according to the configuration of the force applying mechanism can be employed. A preferred aspect of the operation reaction force applying device will be described in detail later.

  As the “control device” in the aspect of this section, for example, a configuration mainly composed of a computer can be adopted. A general steer-by-wire type steering system has a control device for controlling and operating a steering actuator so as to enable steering according to the operation of an operation member. It is possible to use the control device in the above aspect.

(2) The operation reaction force applying mechanism is
The vehicle steering system according to item (1), including an elastic member and an elastic force-based reaction force applying mechanism that applies an operation reaction force that depends on an elastic force of the elastic member.

  The aspect described in this section is an aspect in which the operation reaction force applying mechanism is limited to a mechanism including an operation reaction force applying the elastic force of the elastic member. The elastic member that can be employed is not particularly limited, and for example, a spring member such as a coil spring or a spiral spring can be employed. By employing the “elastic force-based reaction force application mechanism”, for example, an operation reaction force application mechanism capable of applying an operation reaction force having a magnitude corresponding to the operation amount of the operation member can be provided. Specifically, for example, in order to facilitate the return to the neutral position of the operating member (for example, the operating position at which the turning amount at which the vehicle goes straight) is achieved, the operating position of the operating member is neutral. It is possible to apply an operation reaction force in a direction that changes toward the position. According to the aspect described in this section, in a state where the operation member and the steering device are coupled by the coupling device, the operation reaction force by the elastic force-based reaction force application mechanism is not applied to the operation member.

(3) The elastic force-based reaction force applying mechanism includes a deformation compulsory body that deforms the elastic member, and the deformation compulsory body is displaced according to an operation of the steering operation member, whereby the elastic member is moved to the steering member. It is structured to exert elastic force according to the operation of the operation member,
In the state in which the steering operation member and the operation reaction force application mechanism cooperate, the cooperation state switching mechanism realizes a displacement corresponding to the operation of the steering operation member of the deformation forcing body, and the steering operation member and the The vehicle steering system according to item (2), wherein the deformation compulsory body is configured not to realize a displacement corresponding to an operation of the steering operation member in a state where the operation reaction force application mechanism is not linked.

  The mode described in this section is a mode in which the specific structure of the operation reaction force applying device having the elastic force-based reaction force applying mechanism is limited. In the aspect of this section, the mechanism for displacing the “deformation compulsory body” in accordance with the operation of the operation member, that is, the deformation compulsory displacement mechanism is not particularly limited. For example, various mechanisms such as a screw mechanism and a gear mechanism are used. It is possible to adopt. The “cooperation state switching mechanism” can be, for example, a clutch-like structure that selectively realizes connection / disconnection between the operation member and the elastic force-based reaction force application mechanism, Further, as will be described in detail later, it is also possible to have a structure in which the deformed compulsory displacement mechanism described above is changed between a state where its function can be exhibited and a state where it cannot be exhibited. is there.

(4) The operation reaction force applying mechanism is
The vehicle according to any one of (1) to (3), wherein the vehicle includes a viscous fluid and includes a viscous resistance-based reaction force applying mechanism that applies an operation reaction force that depends on the viscous resistance of the viscous fluid. Steering system.

  The aspect described in this section is an aspect in which the operation reaction force applying mechanism is limited to a mechanism including an operation reaction force applying a viscous resistance of a viscous fluid. The viscous fluid that can be employed is not particularly limited, but it is desirable to employ a fluid having a relatively high viscosity. For example, it is also possible to employ so-called MR fluid, ER fluid or the like in which the viscous resistance changes by changing the magnitude of the magnetic field or electric field in which the viscous fluid is placed. By employing the “viscous resistance-based reaction force application mechanism”, for example, an operation reaction force according to the speed of the steering operation can be applied, and the stability of the steering operation can be improved. According to the aspect described in this section, in a state where the operation member and the steered device are connected by the connecting device, the operation reaction force by the viscous resistance-based reaction force applying mechanism is not applied to the operation member. The aspect described in this section may be an aspect in which the operation reaction force applying device includes both the elastic force-based reaction force applying mechanism and the viscous resistance-based reaction force applying mechanism described above. The operation reaction force application device may not include an elastic force-based reaction force application mechanism.

(5) The viscous resistance-based reaction force applying mechanism includes a storage container that stores the viscous fluid, and a moving body that is provided in the storage container and moves relative to the storage container. A structure in which resistance to the relative movement is generated by relative movement with the storage container according to the operation of the steering operation member,
The cooperative state switching mechanism realizes relative movement of the movable body with respect to the storage container according to the operation of the steering operation member in a state where the steering operation member and the operation reaction force application mechanism cooperate. The structure according to (4), wherein the steering operation member and the operation reaction force applying mechanism do not cooperate with each other, and the structure does not realize relative movement of the movable body with respect to the container according to the operation of the steering operation member. Vehicle steering system.

  The aspect described in this section is an aspect in which the specific structure is limited when the operation reaction force applying apparatus having the viscous resistance-based reaction force applying mechanism is employed. In the aspect of this section, the “moving body” may be linearly moved relative to the storage container, or may be relatively moved along a curve. Furthermore, you may rotate relatively. That is, the “movement” of the moving body in this section is a concept including rotational movement. Further, as a mode in which the moving body moves relative to the receiving container in accordance with the operation of the operation member, a mode in which the receiving container is fixed and the moving body moves may be used. Conversely, the moving body is fixed. The container may be moved. As a mechanism for moving the moving body and the storage container relative to each other, the operation member and the moving body or the storage container may be integrated, for example, some moving force transmission mechanism (a concept including a speed reduction mechanism or the like). The operation member and the movable body or the storage container may be connected via each other. The “cooperative state switching mechanism” can be, for example, a clutch-like structure that selectively realizes connection / disconnection between the operation member and the viscous resistance-based reaction force application mechanism, As will be described in detail later, when the moving body and the container do not move relative to each other, both are moved according to the operation of the operation member, so that the viscous resistance-based reaction force applying mechanism and the operation member are not linked. The structure may be such that is realized. In addition, when the aspect described in this section is configured to include the elastic force-based reaction force applying mechanism described above, the cooperative state switching mechanism includes a viscous resistance-based reaction force applying mechanism and an operation member. In addition to the cooperation, it may be one that switches the cooperation between the elastic force-based reaction force application mechanism and the operation member, and includes two cooperation state switching mechanisms, each of which includes a viscous resistance-based reaction force application mechanism and an operation member. It may be configured to switch between the above-described cooperation and the cooperation between the elastic force-based reaction force applying mechanism and the operation member.

  (6) The steering system according to any one of (1) to (5), wherein the steering system has a reaction force actuator and includes an actuator reaction force applying device that applies an operation reaction force that depends on a driving force of the actuator. The vehicle steering system described.

  The aspect described in this section is an aspect provided with an actuator reaction force application device as an operation reaction force application device different from the above-described operation reaction force application device. In the aspect of this section, the control device controls the actuator reaction force applying device so that the actuator reaction force is applied to the operation member in the first state and the actuator reaction force is not applied to the operation member in the second state. It is also possible.

  (7) The vehicle steering system according to (6), wherein the reaction force actuator is an electric motor.

  Since the electric motor can easily control the driving force as in this aspect, the operation reaction force can be easily controlled if the reaction force actuator is an electric motor. For example, an actuator provided with an electric motor in the case where it is desired to arbitrarily change the operation reaction force, such as when the operation reaction force is changed according to the traveling speed of the vehicle. The reaction force applying device is a particularly preferable operation reaction force changing means.

  (8) The control device is a state in which the first state is realized and the wheel is steered by the operation force applied to the steering operation member when the operation state of the vehicle is in a normal state. In the operation force steering execution state, the operation member steering device coupling device and the cooperation state switching mechanism are controlled in order to realize the second state (1) to (7). The vehicle steering system according to any one of the above.

  In the steer-by-wire type steering system, the purpose is to enable turning without using the operating force applied to the operating member. Therefore, in a normal state, it is desirable that the operating member is not connected to the steering device. On the other hand, when the state is not the normal state, for example, in the case of an abnormality of the actuator, a failure of the control system, etc., it is desirable to ensure the operation force steering execution state. The mode described in this section is a mode that satisfies such a requirement, and according to the mode of this section, in the non-normal state as described above, the operation reaction force applied by the operation reaction force applying device is applied to the operation member. It is possible to prevent this, and relatively light steering can be realized even in an abnormal state.

  (9) When the steering device is abnormal as the operation force steering execution state, the control device switches the operation member steering device coupling device and the cooperation state to realize the second state. The vehicle steering system according to item (8), which controls the mechanism.

  The aspect described in this section is added to the operation member by connecting the operation member and the steering device, for example, when the steering of the wheel cannot be performed by the steering actuator included in the steering device. The aspect which ensures the steering by operating force is included. According to such an embodiment, a steer-by-wire type steering system that is excellent in terms of fail-safe is realized.

(10) The steering system includes an actuator reaction force applying device that includes a reaction force actuator and applies an operation reaction force that depends on a driving force of the actuator,
When the actuator reaction force application device is abnormal as the operation force steering execution state, the control device turns the operation member steering device coupling device and the cooperation state switching mechanism to realize the second state. The vehicle steering system according to item (8) or (9), wherein

  In the case of a system having an actuator reaction force applying device, it is conceivable that when the device becomes abnormal, an appropriate operation reaction force cannot be obtained and the operational feeling of the steering operation is deteriorated. In such a case, the aspect described in this section includes an aspect in which the operation member and the steering device are connected to ensure the steering by the operation force applied to the operation member.

  (11) The vehicle steering system according to any one of (1) to (10), wherein the steering system is configured to realize the second state when the vehicle is not in operation.

  In the steer-by-wire type system, the operation amount (operation angle) of the operation member and the turning amount (steering angle) of the wheel are detected, and control is performed so as to realize the turning amount according to the detected operation amount. Therefore, for example, when the vehicle is not operating (when the ignition switch is OFF), the operation amount and the turning amount are not detected, and the wheel is not steered even if the steering operation is performed. For this reason, the operation amount and the steering amount may not match each other. In view of such circumstances, for reasons such as prevention of deviation between the operation amount and the turning amount, facilitation of calibration between the operation neutral position and the turning neutral position at the start of vehicle operation, etc. Considering that the operation member and the steering device are connected. Also, from the advantage that the steering operation is possible without turning on the ignition switch, it is also considered that the operation member and the steering device are connected when the vehicle is not in operation in consideration of an emergency, a failure, etc. ing. When the connected state is established when the vehicle is not operated, it is not only wasteful that the operation reaction force applying device applies the operation reaction force, but a burden is imposed on the reaction force applying device. In particular, when the operation reaction force application mechanism is configured to include an elastic force-based reaction force application mechanism, the load on the elastic member of the mechanism is large. The aspect of this section is an especially effective aspect in such a case, and according to the aspect of this section, the advantage of reducing the burden on the operation reaction force applying device can be obtained.

(12) The steering system is
An operation range restriction device having an operation range restriction mechanism for restricting the operation range of the steering operation member and a restriction release mechanism for releasing the restriction of the operation range by the operation range restriction mechanism by its own operation (1) Or the steering system for a vehicle according to any one of (12).

  In the steer-by-wire system, when the wheels are steered by the driving force of the steerable actuator, a steering operation with a relatively small manipulation force is possible. Therefore, the range of the steering operation is set to be relatively small, and the operation is restricted within that range. On the other hand, when the operating member and the turning device are connected by the connecting device, a relatively large operating force is required to perform the turning by the operating force. In such a case, it has been studied to increase the ratio of the manipulated variable to the steered amount so that the wheel can be steered by a relatively light force. In such a case, in order to ensure an operation amount that is the maximum turning amount, it is desirable to expand the operation range of the operation member when the operation member and the steering device are connected. is there. The aspect described in this section is an aspect in view of such a situation, and according to the aspect described in this section, the operation range of the steering operation can be easily changed.

(13) When the operation range restriction mechanism is a locked body that can move by an amount corresponding to the operation amount of the steering operation member, and the locked body when the operation amount of the steering operation member becomes a set operation amount And a locking body capable of locking,
The restriction release mechanism is configured to realize a state in which the locked body is not locked by the locking body even when the steering operation member is operated to exceed the set operation amount (12). The vehicle steering system according to item.

  The mode described in this section is a mode in which the operation range regulating device is limited to a specific structure. According to the aspect described in this section, it is possible to change the range of the steering operation with a simple structure. The “locked body” referred to in this section may be displaced by moving, or may be displaced without movement such as rotating. In other words, the “movement” of the locked body referred to in this section is a concept including rotational movement. Further, the “locking body” is not particularly limited, but as a simple one, for example, a stopper for preventing the movement of the locked body by bringing the locked body or a part thereof into contact. It is possible to perform a typical function. In the aspect of this section, the restriction release mechanism may have a structure that does not lock the locked body that moves according to the operation of the operation member, for example, by displacing the locking body. Moreover, for example, the structure may be such that the locking body does not lock the locked body by prohibiting or suppressing the movement of the locked body according to the operation of the operating member. .

  (14) The control device does not operate the restriction release mechanism when realizing the first state, and executes control for operating the restriction release mechanism when realizing the second state. The vehicle steering system according to (12) or (13).

  The mode described in this section is a mode in which the operation range regulating device is controlled by the control device. According to the mode of this section, when the operating member and the steered device are connected, the operation reaction force applying device is provided. Both the state in which the operation reaction force is not applied by and the state in which the restriction of the operation range is released are realized.

  (15) Item (12) to Item (14), wherein the operation reaction force applying device functions as the operation range restriction device, and the cooperation state switching mechanism functions as the restriction release mechanism. The vehicle steering system according to any one of the above.

  The mode described in this section can be considered as a mode in which the operation reaction force applying device or the operation range regulating device is multifunctional. If the view is changed, it can be considered that the operation reaction force applying device and the operation range regulating device are integrated. According to the aspect described in this section, in the system of the aspect in which both the operation reaction force application and the operation range restriction are canceled when the operation member and the steering device are coupled, the configuration of the system Simplification will be achieved.

  Hereinafter, some embodiments of the present invention will be described in detail with reference to the drawings. In addition to the following examples, the present invention is implemented in various modes including various modes modified and improved based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. be able to.

<First embodiment>
FIG. 1 shows an overview of a steering system according to a first embodiment of the present invention. This system is a steer-by-wire type steering system in which the operation unit 10 and the steering unit 12 are mechanically separated, and the steering is performed regardless of the operation force applied to the steering wheel 14 as a steering operation member. This is a steering system that steers a steered wheel 16 (hereinafter sometimes simply referred to as “wheel 16”) by the power of a power source provided in the section 12. In this system, the operation unit 10 and the steering unit 12 are connected to each other including a mechanism for transmitting the operation force so that the wheel 16 can be steered by the operation force applied to the operation member 14 at the time of a failure. The connecting part 18 is also provided.

  The operation unit 10 is mainly composed of a steering operation device 20 (hereinafter, simply referred to as “operation device 20”). The operating device 20 includes a steering wheel 14 that is rotated by a driver, and is fixed to a vehicle body, specifically, an instrument panel reinforcement. As will be described in detail later, the operation device 20 functions as a sensor for detecting the operation amount (operation angle) of the steering wheel 14, a function for regulating the range of the steering operation, a reaction force against the rotation operation of the steering wheel 14, That is, it has a function of applying an operation reaction force. As will be described in detail later, two devices are provided as the device for applying the operation reaction force: a device having a mechanism that relies on the elastic force of the elastic member, and a device that relies on the driving force of the reaction force actuator. In this system, the former is the main device, and the latter is the device for adjusting the reaction force.

  The steered portion 12 is mainly configured by a steered device 24 that is fixed to the vehicle body and reciprocates the steered rod 22 in the axial direction. Although illustration of the inside is omitted, the steering device 24 includes a steering motor 25 (which is an electric motor) as a steering actuator provided coaxially with the steering rod 22. A ball nut that meshes with the formed ball screw is rotationally driven by the steering motor 25 so that the steered rod 22 is moved in the axial direction. Each end of the steered rod 22 is connected to a tie rod 28 via a ball joint 26, and the other end of the tie rod 28 is a steering for holding the wheel 16 rotatably via another kind of ball joint 30. It is connected to a knuckle arm 34 which is a part of the knuckle 32. With such a connection structure, the wheel 16 is steered by moving the steered rod 22 in the axial direction. The steered device 24 is provided with a steered amount sensor 36 that detects the amount of movement of the steered rod 22 (a kind of steered amount).

  The present steering system is controlled by a steering electronic control unit 40 (steering ECU, hereinafter simply referred to as “ECU 40”) as a control device provided in the steering system. The ECU 40 includes a driver, such as a computer, various motors, various actuators, and the like. The ECU 40 obtains a signal θ related to the operation amount of the steering wheel 14 detected by an operation amount sensor, which will be described later, and a signal δ related to the movement amount of the steered rod 22 detected by the steered amount sensor 36, and receives them. Based on this, the steered motor 25 included in the steered device 24 is controlled and driven so that the steered amount of the wheel 16 becomes an amount corresponding to the operation amount of the steering wheel 14.

  This steering system is a vehicle speed sensitive steering system, and has a function of increasing an operation reaction force in accordance with the vehicle body speed in order to increase the steering operation when the vehicle body speed is high. Control for that is also performed. The vehicle is provided with a wheel speed sensor 42 that detects the wheel rotation speed for each wheel including the steered wheels 16 (only one wheel is shown in the figure, and the other wheel is not connected). The ECU 40 is configured to obtain a signal v related to the wheel rotation speed of each wheel detected by each wheel speed sensor 42 and obtain a vehicle body speed therefrom. The ECU 40 controls and drives the reaction force actuator included in the operation device 20 based on the calculated vehicle body speed. As a result, the steering wheel 14 is given an increase in the reaction force due to the vehicle speed.

  FIG. 2 is a perspective view of the steering operation device 20, showing a perspective view seen from the upper front side of the left side of the vehicle. FIG. 3 is a sectional view of the operation device 20 seen from the left side of the vehicle. FIG. 3 is a cross-sectional view taken along line AA in FIG. 2 and 3 show a state in which the steering wheel 14 is removed.

  The operating device 20 includes a housing 50, and a shaft 52 is rotatably held by the housing 50, and the steering wheel 14 is attached to one end of the shaft 52. Specifically, the housing 50 includes a tube 54 having a substantially cylindrical shape, a front end cap 56 and a rear end cap 58 that are fixedly provided at both open ends of the tube 54, and a gear on the front side of the front end cap 56. The shaft 52 includes a front casing 60 that houses a mechanism and the like, and the shaft 52 is inserted into a shaft hole 62 provided in each of the front end cap 56 and the rear end cap 58, and the bearing 64. Is held rotatably. The shaft 52 has a hollow shape except for the rear end portion 66, and a serration is formed in the rear end portion 66, and the rear end portion 66 is serrated to the boss portion 68 of the steering wheel 14. Thus, the shaft 52 and the steering wheel 14 are connected so as not to be relatively rotatable.

  A portion of the shaft 52 located inside the tube 54 is a large-diameter portion 80 having a large outer diameter, and two external thread grooves 82 on which the bearing balls roll are formed on the outer peripheral surface of the large-diameter portion 80. By being formed, the large diameter portion 80 is a ball screw. On the other hand, a slide member 84 whose inner peripheral portion is a ball nut holding a bearing ball is disposed in the tube 54 so as to be screwed with a ball screw which is a large-diameter portion 80 of the shaft 52.

  The slide member 84 has a flange portion 86 having an outer peripheral diameter slightly smaller than the inner peripheral diameter of the tube 54 at an intermediate portion in the axial direction (front-rear direction). A locked groove 88 extending in the axial direction is formed on the outer peripheral portion of the flange portion 86. On the other hand, an elongated hole 90 extending in the axial direction is formed in the upper portion of the tube 54, and a locking key 92 having a lower portion formed in an arc shape is gently fitted in the elongated hole 90. The locking key 92 is guided by the wall surface of the elongated hole 90 and is movable in the radial direction (vertical direction). When the locking key 92 is moved downward, the locking key 92 can be fitted into the locked groove 88.

  A mounting seat 94 is formed at the upper center in the axial direction of the outer peripheral portion of the tube 54, and a solenoid device 96 is mounted on the mounting seat 94. The solenoid device 96 has a structure in which a plunger 102, an electromagnetic coil 104, and a compression coil spring 106 are incorporated in a casing composed of a base plate 98 and a cover 100, and the distal end portion of the plunger 102 is attached to a locking key 92. It is inserted into the provided mounting hole and fixedly attached to the locking key 92. FIG. 3 shows a state in which the electromagnetic coil 104 is excited. In this state, the plunger 102 moves forward and the locking key 92 can be engaged with the locked groove 88 provided in the slide member 84. Is done. On the contrary, if the electromagnetic coil 104 is demagnetized, the plunger 102 is retracted by the elastic force of the spring 106, and the locking key 92 and the locked groove 88 are not engaged.

  In a state where the locking key 92 and the locked groove 88 are engaged, rotation of the slide member 84 around the central axis of the shaft 52 is prohibited, and according to the rotation of the shaft 52, that is, the steering wheel 14. The slide member 84 is moved in the axial direction according to the operation amount. The position of the slide member 84 shown in FIG. 3 is a position in which the steering wheel 14 is not operated, that is, a neutral position. When the steering operation is started, the slide member 84 is moved from the neutral position to the position of the steering wheel 14. Move forward or backward according to the direction of operation. Incidentally, in the case of a right turn operation, it moves forward, and in the case of a left turn operation, it moves backward. When the steering operation proceeds, the end surface of the slide member 84 comes into contact with the annular convex portion 110 formed on the front end cap 56 and the rear end cap 58 constituting the housing 50, and the slide member 84 is prohibited from further movement. Is done. Accordingly, the steering wheel 14 cannot be operated any further. In other words, the slide member 84 functions as a locked body that can move by an amount corresponding to the operation amount of the steering wheel 14, and the annular convex portion 110 is a slide member when the operation amount of the steering wheel 14 becomes the set operation amount. 84, which functions as a locking body capable of locking, and includes an operating range regulating mechanism that regulates the operating range of the steering wheel 14 including the slide member 84 and the annular convex portion 110. It is. Incidentally, in the present steering system, the set operation amount is approximately 3/4 rotation from the neutral state to the right turn direction and the left turn direction, respectively.

  Further, two compression coil springs 120 as elastic members are disposed between the front end cap 56 and the slide member 84 and between the rear end cap 58 and the slide member 84, respectively. Specifically, the two springs 120 have the same structure and spring characteristics, and one end portion of each spring 120 is supported by the opposite end surfaces of the front end cap 56 or the rear end cap 58 and the other end. The portion is supported on the surface of the flange portion 86 of the slide member 84 facing the front end cap 56 or the rear end cap 58 via a thrust bearing 122. The two springs 120 are configured to urge the slide member 84 in opposite directions by the respective compression reaction forces, and are compressed in a state where the slide member 84 is located at the neutral position. It is said that the elastic force in that state is balanced. When the slide member 84 moves in the axial direction from the neutral position, the two springs 120 lose their balance of elastic force, and the difference between the elastic forces is an elastic force in a direction to prevent the movement of the slide member 84. Act on. The difference between the elastic forces of the two springs 120 is a force corresponding to the amount of movement of the slide member 84, that is, a force corresponding to the amount of operation of the steering wheel 14, and this force is applied as a reaction force to the steering operation. It will be. That is, the operation reaction force application device of the present steering system includes an operation reaction force application mechanism, specifically, an elastic force-based reaction force application mechanism that applies an operation reaction force that depends on an elastic force. The slide member 84 functions as a deformation compulsory body that deforms the spring 120, and includes a ball screw provided on the shaft 52, a ball nut provided on the slide member 84, and a locked groove 88 that prohibits rotation of the nut. A ball screw mechanism constituted by a locking key 92 engaged therewith functions as a deformation compelling body displacement mechanism that displaces the slide member 84 by an amount corresponding to the operation amount of the steering wheel 14, and these slides An elastic force-based reaction force application mechanism is configured including the member 84, the ball screw mechanism, and the two springs 120.

  On the other hand, when the locking key 92 and the locked groove 88 are not engaged, the rotation of the slide member 84 is allowed, and the slide member 84 does not move according to the operation amount of the steering wheel 14. It becomes. When the steering wheel 14 is operated in that state, the slide member 84 rotates integrally with the shaft 52 while maintaining the neutral position by the action of the two springs 120. That is, the operation reaction force depending on the elastic force described above is not generated, and the operation reaction force by the elastic force dependency reaction force application mechanism is not applied to the steering wheel 14. As described above, the configuration including the locked groove 88, the locking key 92, and the solenoid device 96 realizes a state in which the displacement corresponding to the operation amount of the steering wheel 14 of the slide member 84 is realized, and does not realize it. It has a function of switching between states, and functions as a cooperative state switching mechanism that switches between a state in which the steering wheel 14 and the elastic force-based reaction force application mechanism cooperate and a state in which the steering wheel 14 does not cooperate. The operation reaction force applying device includes the cooperation state switching mechanism and the elastic force-based reaction force applying mechanism.

  Further, since the slide member 84 that also functions as the locked body described above remains in the neutral position, the end portion of the slide member 84 serves as a locking body for the front end cap 56 and the rear end cap 58. The operation beyond the restricted operation range is possible without contacting the functioning annular projection 110. In other words, the configuration including the locked groove 88, the locking key 92, and the solenoid device 96 realizes a state in which the slide member 84 is not locked by the annular convex portion 110, and the steering wheel 14 by the operation range restriction mechanism is realized. In this steering system, the operation range of the steering wheel 14 is expanded by the function of the restriction release mechanism. The operation range restriction device is configured including the operation range restriction mechanism and the restriction release mechanism.

  In the state where the locking key 92 and the locked groove 88 are not engaged, as described above, the slide member 84 and the shaft 52 remain while the slide member 84 is positioned at the neutral position in the axial direction. And rotate together. That is, in a state where the locking key 92 and the locked groove 88 are not engaged, the slide member 84 and the steering wheel 14 rotate integrally. On the other hand, the locked groove 88 is provided on the outer periphery of the slide member 84 at a rotation angle position where the locking key 92 is fitted in a state where the steering wheel 14 is in the neutral position. Accordingly, when the locking key 92 and the locked groove 88 are shifted from the non-engaged state to the engageable state, the locking key 92 and the engaged key are engaged at a rotation angle at which the steering wheel 14 is in the neutral position. The stop groove 88 is engaged. That is, even if the lock key 92 and the locked groove 88 are once brought into a non-engaged state and then brought into an engageable state, the neutral position of the steering wheel 14 and the elasticity The neutral state of the operation reaction force by the force-based reaction force applying mechanism, that is, the state in which the elastic force by the two springs 120 is balanced and the operation reaction force is not applied to the steering wheel 14 is matched.

  From the structure as described above, in this steering system, the cooperative state switching mechanism provided in the operation reaction force application device functions as a restriction release mechanism provided in the operation range restriction device. The operation range regulating device is integrated. As a result, the present steering system is compact.

  In the operating device 20, in the space defined by the front end cap 56 and the front casing 60, the output pulley 130 and the large-diameter gear 132 can relatively rotate at the front end portion of the shaft 52 extending into the space. Is provided. On the output pulley 130, a belt 134 that ties the input pulley (which will be described later) included in the operation member steering device coupling device existing in the coupling portion 18 and the self pulley is strung. Further, a motor seat 136 is formed on the front end upper portion of the front casing 60, and a reaction force motor 138 (which is an electric motor) as a reaction force actuator is attached to the motor seat 136. The motor shaft 140 of the reaction force motor 138 is rotatably held by the bearing 142 in a state of extending into the front casing 60. A small-diameter gear 144 is provided at the tip of the motor shaft 140 so as not to rotate relative to the motor shaft 140, and the small-diameter gear 144 is meshed with the large-diameter gear 132 described above. A structure in which the shaft 52 is rotated by the rotation of the reaction force motor 138, in other words, a structure in which a rotational torque is applied to the shaft 52 by a driving force of the reaction force motor 138, and the reaction force motor 138 operates the steering wheel 14. An operation reaction force is applied to the steering wheel 14 by generating a driving force that resists the above. That is, this steering system is provided with an actuator reaction force applying device that applies an operation reaction force that depends on the driving force of the reaction force actuator, which mainly includes the reaction force motor 138. As described above, this actuator reaction force application device is an auxiliary operation reaction force application when the operation reaction force application device provided with the elastic force-based reaction force application mechanism using the two springs 120 is the main device. It is a device and is used to adjust the operation reaction force. An operation amount sensor 146 for detecting the operation amount (operation angle) of the steering wheel 14 is provided at the front end of the reaction force motor 138. The operation amount sensor 146 is a rotation angle sensor that detects the rotation angle of the motor shaft 140, and detects the operation amount of the steering wheel 14 by detecting the rotation angle of the motor shaft 140.

  Next, the structure of the connection part 18 is demonstrated, referring FIG. The connecting portion 18 connects the steering wheel 14 and the steering device 24 so as to enable steering by an operating force applied to the steering wheel 14, and can also release the connection of the steering member steering device. The apparatus 150 is mainly configured. Generally speaking, the operating member steering device coupling device 150 includes an input pulley 152 to which an operating force is input, an output roller 154 for outputting the rotational force of the input pulley 152 to the steering device 24, an output roller 154, and the steering. A transmission cable 158 strung over an input roller 156 included in the device 24, a guide tube 160 that guides the transmission cable 158, and an electromagnetic clutch 162 that selectively switches between a connection state and a connection release state between the input pulley 152 and the output roller 154. Etc. are included. The electromagnetic clutch 162 connects the input pulley 152 and the output roller 154 in the demagnetized state, and releases the connection in the excited state. In addition, while the rack is formed in the steering rod 22, and the pinion is provided in the input roller 156, the steered device 24 has a rack and pinion mechanism, and the input roller 156 is rotated. Thus, the wheel 16 is steered. Incidentally, the transmission ratio of the force by the operating member steering device coupling device 150 is such a value that the wheel 16 can be steered with a relatively small operational force, and the steering wheel 14 and the steering device 24 are coupled. In order to ensure the same amount of steering as in the non-operating state, a larger operating range of the steering wheel 14 is required than in that state.

  Control of the operation of the cooperative state release mechanism of the operation member steering device coupling device 150 and the operation reaction force applying device (hereinafter, also referred to as “steering state switching control”), in detail, the electromagnetic clutch 162 and the solenoid device 96 This control is performed by the suspension ECU 40. After the ignition switch 164 (see FIG. 1) of the vehicle is turned on, the ECU 40 energizes both the electromagnetic clutch 162 and the solenoid device 96 in the normal state to bring it into an excited state. As a result, the wheel 16 can be steered without depending on the operation force applied to the steering wheel 14, the slide member 84 is allowed to move in the axial direction, and an operation reaction force is applied to the steering wheel 14. It becomes a state. That is, the ECU 40 is in a state in which the steering wheel 14 and the steering device 24 are disconnected by the operation member steering device connecting device 150 and the operation reaction force applying mechanism and the steering wheel 14 are linked by the cooperative state releasing mechanism. The first state is realized.

  In the present steering system, when an abnormality of the steering device 24, for example, an abnormality or failure of the steering motor 25 occurs, the wheel 16 cannot be steered by the steering motor 25. . Further, even when the actuator reaction force applying device becomes abnormal, it becomes a state where an appropriate operation reaction force cannot be obtained. In such a case, it is necessary to set a state in which steering is performed by the operation force applied to the steering wheel 14, that is, an operation force steering execution state. More specifically, the ECU 40 puts the electromagnetic clutch 162 in a demagnetized state, and releases the connection between the steering wheel 14 and the steering device 24 to enter the operating force steering execution state. In addition, the ECU 40 also demagnetizes the solenoid device 96 so that no operation reaction force is applied to the steering wheel 14. That is, the ECU 40 connects the steering wheel 14 and the steering device 24 by the operation member steering device connecting device 150, and the second state is a state in which the operation reaction force applying mechanism and the steering wheel 14 are not linked by the cooperation state release mechanism. Realize the state. In this steering system, both the electromagnetic clutch 162 and the solenoid device 96 are de-energized when the vehicle is inoperative when the ignition switch 164 of the vehicle is OFF, so that the second state is realized. It is comprised and the burden to the spring 120 which is an elastic member which comprises an elastic force dependence reaction force provision mechanism is reduced.

  In the present steering system, as described above, the cooperation state switching mechanism functions as a restriction release mechanism of the operation range restriction device. That is, in the normal state, the first state is realized, and the operation range of the steering wheel 14 is restricted by the operation range restriction mechanism. In the case of an abnormality in the steering device 24, the second state is realized, but the operation of the cooperative state switching mechanism at that time is also the operation of the restriction release mechanism, and the restriction of the operation range restriction mechanism is released. Thus, the operation range of the steering wheel 14 is expanded, and relatively light steering is realized.

  Steering state switching control, that is, switching control between the first state and the second state is performed by executing a steering state switching control program shown in the flowchart of FIG. The control program is stored in a computer included in the ECU 40. Specifically, after the vehicle is in an activated state, specifically, after the ignition switch 164 is turned on, a short time interval (for example, ten to several tens of times). msec) is repeatedly executed. Hereinafter, the contents of the control in this steering system will be described with reference to the flowchart of FIG.

  In the steering state switching control, in step 1 (hereinafter abbreviated as “S1”, the same applies to other steps) to S4, determination for switching from the first state to the second state is made. Will be described later, and S5 to S8 will be described first. The process after S6 is a process that is performed only once when the vehicle is brought into an operating state. The calibration flag is a flag that is turned on when the calibration in S7 is performed, and in S5, when the calibration flag is turned off, the first execution of the program. Is determined, and the processing after S6 is executed. As will be described later, the processes after S6 are executed only when the vehicle is in a normal state (for example, a state that is not an abnormal state). In S6, in order to implement | achieve the 1st state mentioned above, the electromagnetic clutch 162 of the operation member steering apparatus connection apparatus 150 and the solenoid apparatus 96 of a cooperation state cancellation | release mechanism are made into an excitation state. That is, when the ignition switch 154 is turned on in the normal state, first, the first state is realized.

  Next, in S7, calibration is performed. In the calibration, the neutral position of the steering device 24, the neutral position of the steering wheel 14, and the neutral position of the elastic force-based reaction force applying mechanism described above, that is, the neutral position of the slide member 84 are aligned. It is a process to make. The steered amount sensor 36 is an absolute type sensor, but calibration is necessary because the operation amount sensor 146 is an incremental type sensor. The calibration is executed in parallel with the processing by the steering state switching control program by a program different from the steering state switching control program. Specifically, first, the steering motor 25 is rotationally driven in the steering device 24, and the steering rod 22 is moved to the neutral position. Next, the steering wheel 14, that is, the shaft 52 is rotated by the reaction force motor 138, and the locking key 92 is engaged with the locked groove 88 provided in the slide member 84. When the steering wheel 14 is not in the neutral position, the locking key 92 is not fitted into the locked groove 88 even when the solenoid device 96 is in the excited state, but as described above. When the shaft 52 is rotated, the slide member 84 is rotated integrally therewith, and the locking key 92 is fitted into the locked groove 88 when the steering wheel 14 is positioned at the neutral position. The solenoid device 96 is provided with a position sensor (not shown) for detecting the position of the plunger 102, and the plunger 102 is moved downward, that is, the locking key 92 is fitted in the locked groove 88. The detected state is detected. Based on this detection, the rotation of the reaction force motor 138 is stopped and the steering wheel 14 is maintained at the neutral position. In this state, the detection value of the operation amount sensor 146 is set to 0, and matching processing with the detection value of the steering amount sensor 36 is performed. Incidentally, during the calibration, the driver is alerted with a buzzer or the like in consideration of the possibility that the steering wheel 14 automatically rotates.

  After calibration is executed in S7, the calibration flag is set to ON in S8. By setting this flag, S6 to S8 are skipped by the determination of S5 when the program is executed next time. The calibration flag is set in a non-volatile memory so that the set contents are not erased even when the ignition switch 164 is turned off.

  Next, S1 to S4 reserved in the above description will be described. Whether the vehicle is in a normal state is determined in S2 and S3. In S <b> 2, it is determined whether there is an abnormality in the steering motor 25 as an abnormality of the steering device 24. The abnormality of the steering motor 25 is, for example, a case where the wheel cannot be steered due to disconnection or a short circuit. In S3, it is determined whether or not there is an abnormality in the reaction force motor 138 as an abnormality in the actuator reaction force application device. If either of the steered motor 25 or the reaction force motor 138 is abnormal, it is determined that the system is in a non-normal state that is not a normal state. Specifically, it is determined that the system is in a failure state. Is set to ON, and in S10, the electromagnetic clutch 162 and the solenoid device 96 are demagnetized. By the process of S10, the above-described second state is realized. If no abnormality of the steering motor 25 is detected in S2, and no abnormality of the reaction force motor 138 is detected in S3, it is determined that the system is in the normal state, and the second state is not realized. When the failure flag is set to ON, an indication that an abnormality has occurred in the system is displayed on the instrument panel.

  The failure flag is set in a nonvolatile memory like the calibration flag, and the set contents are not erased even when the ignition switch 164 is turned off. Therefore, when the system is already in an abnormal state at the time of starting the vehicle, S2 and subsequent steps are skipped by the determination of the failure flag in S1, and switching to the first state is not performed. Similarly, when an abnormality occurs in the system while the vehicle is operating, not from when the vehicle is started, S2 and the subsequent steps are skipped, and switching to the first state is not performed.

  In S4, it is detected whether or not the vehicle is in an inoperative state by determining whether or not the ignition switch 164 is in an OFF state. In the non-operating state of the vehicle, the steering system is configured to realize the second state, as described above, S11 is executed, the calibration flag is turned off, In the described S10, the electromagnetic clutch 162 and the solenoid device 96 are demagnetized.

<Second embodiment>
FIG. 6 is a cross-sectional view of the steering operation device 200 provided in the steering system of the second embodiment as seen from the left side of the vehicle. The steering system of the present embodiment has substantially the same configuration as the system of the first embodiment except for the steering operation device 200, and therefore, in the description of the present embodiment, the same configuration as the system of the first embodiment. About an element, it shows that it respond | corresponds using the same code | symbol, Those description shall be abbreviate | omitted or simplified.

  The operating device 200 has two housings 202 and 204. The first housing 202, which is one of the housings, includes a tube 206 having a cylindrical shape, a front end cap 208 and a rear end cap 210 that are fixedly provided at both open ends of the tube 206, and a front of the front end cap 208. And a casing 212 fixed to the side. The shaft 52 is provided between each of the front end cap 208 and the rear end cap 210 in a state where the shaft hole 214 provided in each of the front end cap 208, the rear end cap 210 and the casing 212 is inserted. The first housing 202 and the shaft 52 are supported via a bearing 216 so that they can rotate relative to each other. As in the first embodiment, the shaft 52 holds the steering wheel 14 at the rear end portion 66 in a relatively non-rotatable manner (FIG. 6 shows a state in which the steering wheel 14 is removed).

  The shaft 52 is substantially the same as that of the first embodiment, and the large-diameter portion 80 located inside the tube 206 is a ball screw in which a male screw groove 82 is formed. On the other hand, in the tube 206, a nut member 220 whose inner peripheral portion is a ball nut holding a bearing ball is disposed in a state of being screwed with a ball screw which is the large diameter portion 80 of the shaft 52, The nut member 220 has a shape having a flange portion 222 at an intermediate portion in the axial direction (front-rear direction). In the tube 206, two annular slide members 224 and 226 are disposed so as to be movable in the axial direction. The figure shows a state in which the nut member 220 is located at a neutral position. In this state, the portions of the nut member 220 that protrude from the flange portion 222 toward the front side and the rear side of the vehicle are the slide members 224 and 226, respectively. The front side slide member 224 and the rear side surface of the rear side slide member 226 are respectively connected to the front side surface and the rear side surface of the flange portion 222, respectively. It is in a state of contact. A pair of guide rods 228 are provided in the tube 206 so as to pass through the two slide members 224 and 226 and the flange portion 222 of the nut member 220. The nut member 220 and the slide members 224 and 226 are provided. Is not rotatable with respect to the first housing 202.

  Further, two compression coil springs 230 having the same structure and spring characteristics are arranged between the front side slide member 224 and the front end cap 208 and between the rear side slide member 226 and the rear end cap 210, respectively. It is installed. The two springs 230 function as elastic members and urge each of the slide members 224 and 226 by their respective compression reaction forces. Each of the slide members 224 and 226 is prohibited from moving from the neutral position to the vehicle rear side and the vehicle front side by a stopper 232 provided on the inner periphery of the tube 206, as shown in the figure. In addition, in a state where the nut member 220 is located at the neutral position, both the slide members 224 and 226 are locked by the stopper 232. In this state, the flange member 222 of the nut member 220 is just sandwiched between the slide members 224 and 226.

  As described above, the first housing 202 is provided with the casing 212 fixed to the front side of the front end cap 208, and the shaft 52 projects to the vehicle front outer side of the casing 212, that is, to the vehicle front outer side of the first housing 202. It is structured. A donut-shaped disk member 240 is fixed to the shaft 52 in a space defined by the casing 212 and the front end cap 208, and the space is filled with a viscous fluid 242. The casing 212 and the shaft hole 214 of the front end cap 208 are provided with a seal 244, and the seal 244 prevents the viscous fluid 242 from leaking out of the space.

  The second housing 204, which is the other housing, is operated on the bottomed cylindrical tube 250, a cap 252 fixed to the opening end of the tube 250 on the vehicle rear side, and the front side of the bottom of the tube 250. And a casing 254 that houses a part of the member steering device coupling device 150. The first housing 202 is accommodated in the tube 250, and the shaft 52 is rotatable via the bearing 258 in a state where the shaft hole 256 provided in each of the bottom portion of the tube 250 and the cap 252 is inserted. Is held in. The operation device 200 is fixed to the vehicle body by fixing the second housing 204 to the reinforcement of the instrument panel that is a part of the vehicle body.

  Between the first housing 202 and the second housing 204, specifically, between the rear side end surface of the rear end cap 210 constituting the first housing 202 and the front side surface of the cap 252 of the second housing 204, there is no electromagnetic wave. A clutch 270 is provided. The electromagnetic clutch 270 includes annular clutch plates 272 and 274 fixed to the rear end cap 210 and the cap 252 respectively, and a clutch plate mover 276 that moves the clutch plate 274 in the axial direction mainly using an electromagnet. It consists of The electromagnetic clutch 270 is in a state of being separated from the clutch plates 272 and 274 by demagnetizing the electromagnet of the clutch plate mover 276 (this state is shown in the figure, and hereinafter referred to as “demagnetized state” of the electromagnetic clutch 270). In some cases, the clutch plates 272 and 274 are pressed against each other and come into contact with each other (hereinafter sometimes referred to as “excited state” of the electromagnetic clutch 270).

  When the clutch plates 272 and 274 are in contact with each other, that is, when the electromagnetic clutch 270 is in an excited state, the rotation of the first housing 202 is prohibited. Therefore, if the steering wheel 14 is operated in this state, the nut member 220 moves forward or backward from the neutral position shown in the drawing according to the operation direction of the steering wheel 14. With the movement of the nut member 220, the sliding member 224 (226) on the moving direction side is moved, whereby the spring 230 is contracted to the nut member 220 via the slide member 224 (226). An elastic force acting in a direction to prevent the movement of the film acts. The elastic force of the spring 230 is a force corresponding to the movement amount of the slide member 224 (226) and the nut member 220, that is, a force corresponding to the operation amount of the steering wheel 14, and the force is a reaction force against the steering operation. Will be granted. That is, the operation reaction force applying device of the present steering system includes an elastic force-based reaction force applying mechanism that applies an operation reaction force that depends on the elastic force of the elastic member. Note that the nut member 220 and the slide members 224 and 226 function as a deformation compulsory body that deforms the spring 230, and are constituted by a ball screw provided on the shaft 52 and a ball nut provided on the nut member 220. The mechanism functions as a deformation compulsory displacement mechanism that displaces the deformation compulsory by an amount corresponding to the operation amount of the steering wheel 14, and includes a nut member 220, slide members 224, 226, a ball screw mechanism, and 2 An elastic force-based reaction force application mechanism (a kind of operation reaction force application mechanism) is configured including the two springs 230.

  When the electromagnetic clutch 270 is in an excited state and the steering operation proceeds, the end surface of the nut member 220 has an annular convex portion 280 formed on each of the front end cap 208 and the rear end cap 210 constituting the first housing 202. The nut member 220 and the slide members 224 and 226 are prohibited from further movement. Accordingly, the steering wheel 14 cannot be operated any further. That is, in the operation device 200, the nut member 220 functions as a locked body that can move by an amount corresponding to the operation amount of the steering wheel 14, and the annular protrusion 280 has the operation amount of the steering wheel 14 set operation amount. In this case, the nut member 220 functions as a latching body that can be latched, and includes the nut member 220 and the annular convex portion 280, and an operation range that restricts the operation range of the steering wheel 14. A regulation mechanism is configured.

  In addition, when the electromagnetic clutch 270 is in an excited state, the first housing 202 is prohibited from rotating. Therefore, if the disk member 240 rotates with the rotation of the shaft 52 by the steering operation, the first housing 202 and the disk member 240 are rotated. The first housing 202 rotates relative to the first housing 202. When they rotate relative to each other, the viscous resistance of the viscous fluid 242 filled in the space defined by the casing 212 and the front end cap 208 acts on the disk member 240. The force depending on the viscous resistance is a force corresponding to the rotation speed of the disk member 240, that is, a force corresponding to the operation speed of the steering wheel 14, and the force is a reaction force against the steering operation. Will be granted. In other words, in addition to the elastic force-based reaction force applying mechanism, the steering reaction force applying device of the present steering system includes a viscous resistance-based reaction force applying mechanism (an operation reaction force applying mechanism) that applies an operation reaction force that depends on viscous resistance. Is a kind). A portion of the first housing 202 including the casing 212 and the front end cap 208 that accommodates the viscous fluid 242 functions as a storage container, and the disk member 240 functions as a moving body that moves relative to the storage container. The viscous resistance-based reaction force application mechanism is configured including the casing 212, the front end cap 208, and the disk member 240.

  On the other hand, in the demagnetized state of the electromagnetic clutch 270 shown in FIG. 5, the clutch plates 272 and 274 are separated from each other, and if the steering wheel 14 is operated in this state, the rotation of the first housing 202 is allowed. Thus, the first housing 202 and the shaft 52 rotate as if they were integrated. In such a state, the nut member 220 is not moved in the front-rear direction as described above, and remains in the neutral position. Even when the electromagnetic clutch 270 is demagnetized while the steering wheel 14 is rotated, the nut member 220 moves to the neutral position with the rotation of the first housing 202 by the elastic force of the spring 230. The neutral position is maintained. That is, since the elastic force of the spring 230 is not generated with respect to the steering operation, the operation reaction force by the elastic force-based reaction force application mechanism is not applied to the steering wheel 14. As described above, the configuration including the two housings 202 and 204 and the electromagnetic clutch 270 realizes the displacement corresponding to the operation amount of the steering wheel 14 of the nut member 220 and the slide members 224 and 226, and It has a function of switching between a state in which it is not realized, and functions as a cooperative state switching mechanism that switches between a state in which the steering wheel 14 and the elastic force-based reaction force applying mechanism cooperate and a state in which the steering wheel 14 does not cooperate. Yes.

  Further, in the demagnetized state of the electromagnetic clutch 270, the nut member 220 that also functions as the above-described locked body remains in the neutral position, so that the end portion of the nut member 220 has the front end cap 208 and The operation beyond the restricted operation range is possible without coming into contact with the annular convex portion 280 that functions as a locking body of the rear end cap 210. That is, the configuration including the two housings 202, 204 and the electromagnetic clutch 270 realizes a state in which the nut member 220 is not locked by the annular convex portion 280, and the operation of the steering wheel 14 by the operation range restriction mechanism. It functions as a restriction release mechanism for releasing the restriction of the range. In this steering system, the operation range of the steering wheel 14 is expanded by the function of the restriction release mechanism. An operation range restriction device is configured including the operation range restriction mechanism and the restriction release mechanism.

  Further, in the demagnetized state of the electromagnetic clutch 270, the disk member 240 is rotated with the rotation of the shaft 52 by the steering operation. However, since the first housing 202 is also rotated, the casing 212 and the front end cap 208 are included. It will be in the state which does not move relatively with respect to the storage container comprised. That is, since the viscous resistance of the viscous fluid 242 is not generated, the operation reaction force by the viscous resistance-based reaction force application mechanism is not applied to the steering wheel 14. As described above, the configuration including the two housings 202 and 204 and the electromagnetic clutch 270 realizes the relative movement of the disk member 240 with respect to the storage container according to the operation speed of the steering wheel 14, and Has a function of switching between a state in which the steering wheel 14 and the viscous resistance-based reaction force applying mechanism are linked, and functions as a linked state switching mechanism that switches between a state in which the steering wheel 14 and the viscous resistance-based reaction force applying mechanism are linked. . Strictly speaking, when the shaft 52 is rotated by the steering operation, the shaft 52 and the first housing 202 are slightly rotated relative to each other due to the influence of the inertia of the first housing 202. This relative rotation gives an uncomfortable feeling to the steering operation. In the operating device 200, the viscous resistance of the fluid 242 acts on the relative rotation between the shaft 52 and the first housing 202 so as to suppress the relative rotation. .

  Due to the above structure, in this steering system, the cooperative state switching mechanism of the elastic force-based reaction force applying mechanism also functions as the cooperative state switching mechanism of the viscous resistance-based reaction force applying mechanism. The operation reaction force application device is configured to include a force-based reaction force application mechanism, a viscous resistance-based reaction force application mechanism, and a common state switching mechanism. Moreover, the cooperation state switching mechanism of the operation reaction force imparting device also functions as a restriction release mechanism provided in the operation range restriction device, and the present steering system has a compact structure.

  In the operating device 200, in the space defined by the bottom of the tube 250 of the second housing 204 and the casing 254, the operating member steering device coupling device 150 is provided at the front end portion of the shaft 52 extending into the space. An output pulley 130 and a large-diameter gear 132 are provided so as to be relatively rotatable. The operating member steering device coupling device 150 has the same configuration as that of the first embodiment. When the electromagnetic clutch 162 is demagnetized, the steering wheel 14 and the steering device 24 are coupled to bring the electromagnetic clutch 162 into an excited state. Is to release the connection. In addition, a reaction force motor 138 as a reaction force actuator is attached to the casing 254, and an actuator reaction force applying device having the same structure as that of the first embodiment is provided. That is, in this steering system as well, an operation reaction force is applied to the steering wheel 14 by the driving force of the reaction force motor 138.

  Also in the steering system of the present embodiment, as in the case of the first embodiment, the operation member steering device coupling mechanism 150, the cooperation state switching mechanism of the operation reaction force applying device, and the restriction release mechanism of the operation range restriction device are: Specifically, the electromagnetic clutch 162 of the operating member steering device coupling mechanism 150 and the electromagnetic clutch 270 of the cooperation state switching mechanism and the regulation release mechanism are operated by the ECU 40 that is a control device. Specifically, in a normal state, both the electromagnetic clutches 162 and 270 are in an excited state, thereby releasing the connection between the steering wheel 14 and the steering device 24, and the steering wheel 14 and the operation reaction force applying mechanism. Is realized, and the operation range of the steering wheel 14 is restricted. When an abnormality or the like of the steering device 24 occurs, the steering wheel 14 and the steering device 24 are connected by demagnetizing both the electromagnetic clutches 162 and 270, and the steering wheel 14 and the operation reaction force While realizing the 2nd state which is a state which does not cooperate with a grant mechanism, the restriction | limiting of an operation range is cancelled | released, the operation range of the steering wheel 14 is expanded, and a relatively light steering is implement | achieved.

  Further, the switching control between the first state and the second state is performed by executing a program substantially similar to the steering switching control program of the first embodiment. However, the steering system according to the first embodiment is capable of cooperating with the steering wheel 14 only when the elastic force-based reaction force applying mechanism, that is, the slide member 84 is in the neutral position. In this steering system, the elastic force-based reaction force applying mechanism, that is, the position of the nut member 220 can be linked to the steering wheel 14 by the electromagnetic clutch 270 of the linkage state switching mechanism. This calibration is different from that of the first embodiment. Specifically, the calibration of the present steering system is started when the electromagnetic clutch 270 is demagnetized. First, the steering wheel 14, that is, the shaft 52 is rotated by the reaction force motor 138. The steering wheel 14 is provided with a neutral position sensor (not shown), and a state where the steering wheel 14 is in the neutral position is detected. Based on this detection, the rotation of the reaction force motor 138 is stopped and the steering wheel 14 is maintained at the neutral position. Then, by setting the electromagnetic clutch 270 in an excited state, the neutral position between the steering wheel 14 and the elastic force-based reaction force applying mechanism, that is, the nut member 220 is aligned. Further, in this state, the detection value of the operation amount sensor 146 is set to 0, and matching processing with the detection value of the turning amount sensor 36 of the turning device 24 in the neutral position is performed.

1 is a schematic diagram illustrating a steering system according to a first embodiment of the present invention. It is a perspective view which shows the steering operation apparatus shown in FIG. FIG. 2 is a cross-sectional view of the steering operation device shown in FIG. 1 with the vehicle left side as a viewpoint. It is sectional drawing of the AA view in FIG. 3 of the steering operation apparatus shown in FIG. It is a flowchart showing the steering state switching control program executed by the steering electronic control unit shown in FIG. It is sectional drawing which makes a vehicle left side the viewpoint of the steering operation apparatus with which the steering system of 2nd Example is provided.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10: Operation part 12: Steering part 14: Steering wheel (steering operation member) 18: Connection part 24: Steering device 25: Steering motor (steering actuator) 36: Steering amount sensor 40: Steering electronic control unit ( Control device) 52: Shaft 84: Slide member (deformation compulsory body, locking body) 88: Locked groove 92: Locking key 96: Solenoid device (cooperation state switching mechanism, restriction release mechanism) 110: Annular protrusion ( 120: compression coil spring (elastic member) 138: reaction force motor (reaction force actuator) 146: operation amount sensor 150: operation member steering device coupling device 162: electromagnetic clutch 164: ignition switch 202: first Housing 204: Second housing 220: Nut member (deformation forced body, locking body) 224: Front side slur 226: Back side slide member (deformation forced body) 230: Compression coil spring (elastic member) 240: Disk member (moving body) 242: Viscous fluid 270: Electromagnetic clutch (cooperative state switching mechanism, regulation) Release mechanism) 280: annular projection (locked body)

Claims (6)

A steering operation member;
A steering device that includes a steering actuator, and performs steering of the wheels without depending on the operation force applied to the steering operation member by the driving force of the steering actuator;
Operation member steering capable of connecting the steering operation member and the steering device to enable steering by an operation force applied to the steering operation member by its own operation and releasing the connection. A device coupling device;
(A) An operation reaction force application mechanism that applies an operation reaction force according to the operation of the steering operation member in cooperation with the steering operation member, and (B) an operation reaction force application mechanism by its own operation. And an operation reaction force imparting device having a cooperative state switching mechanism for switching between a state in which the steering operation member cooperates and a state in which they do not cooperate,
(a) The operation member turning device connecting device releases the connection between the steering operation member and the steering device, and the cooperation reaction state switching mechanism links the operation reaction force applying mechanism and the steering operation member. And (b) the steering operation member and the steering device are connected by the operation member steering device connecting device, and the operation reaction force applying mechanism and the steering operation are connected by the cooperative state switching mechanism. A vehicle steering system comprising: a control device that controls the operation member steering device coupling device and the linkage state switching mechanism to selectively realize a second state in which the members are not linked. The operation reaction force application mechanism is
The vehicle steering system according to claim 1, further comprising an elastic force-based reaction force applying mechanism that includes an elastic member and applies an operation reaction force that depends on an elastic force of the elastic member. The operation reaction force application mechanism is
3. The vehicle steering system according to claim 1, further comprising a viscous resistance-based reaction force applying mechanism that has a viscous fluid and applies an operation reaction force that depends on the viscous resistance of the viscous fluid.   When the operation state of the vehicle is in a normal state, the control device realizes the first state, and is an operation force change state in which the wheel should be steered by the operation force applied to the steering operation member. 4. The control device according to claim 1, wherein the operation member turning device coupling device and the linkage state switching mechanism are controlled to realize the second state when the steering execution state is reached. 5. Vehicle steering system. The steering system
The operation range restriction device having an operation range restriction mechanism for restricting an operation range of the steering operation member and a restriction release mechanism for releasing the restriction of the operation range by the operation range restriction mechanism by its own operation. The vehicle steering system according to claim 4. The said control apparatus shall perform control which does not operate the said regulation cancellation | release mechanism when implement | achieving a said 1st state, but operates the said regulation cancellation | release mechanism when implement | achieving the said 2nd state. A vehicle steering system according to claim 1.

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