JP2003002226A - Rear wheel steering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem that a beating sound is frequently generated at the time of switching a clutch means in a conventional rear wheel steering device. SOLUTION: The figure (a) shows the state of the steering device before operating a solenoid and when an energization is carried to the solenoid and an arm 58L shown by an imaginary line is rotated to the right, a trunk lever 60L is started to rotate to the left. The figure (b) shows a midway drawing and shows that the trunk lever 60L descends an operation element 31L along a vertical groove 72L as shown by an arrow by an action of the solenoid. The figure (c) shows the state that the solenoid completes the operation and a movement direction of the operation element 31L pushed by the trunk lever 60L is varied from a vertical direction to a lateral direction, thereafter it moves in a lateral groove 74L at a lower stage as shown by an arrow. An excess force of the solenoid is absorbed by moving the operation element in the lateral groove while swinging it. As a result, the operation element does not butt to a stopper, etc., and a generation of the beating sound can be prevented.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a rear wheel steering device suitable for a so-called 4WS vehicle. 2. Description of the Related Art In 4WS, a rear wheel turning device for turning a rear wheel is indispensable in relation to turning a front wheel. As an improved invention of this rear wheel steering device, for example, Japanese Patent Application Laid-Open No. 2000-798
There is an 81 publication “Rear wheel steering device”. The present invention is characterized in that the neutral position of the rear wheel is determined by a mechanical device. FIG. 5 of the publication is a sectional view of a clutch means which is an important element of the rear wheel steering device. This drawing is reprinted. However, the sign is 3 obtained by adding 200 to the number described in the official gazette.
Digit code was used. FIG. 22 is a reproduction of FIG. 5 of JP-A-2000-79881, wherein 203 is a casing, 213 is an arm, 214a is a circumferential portion of a guide groove, 214c is an outward axial portion of the guide groove, 215a Is an electromagnetic actuator, and 216a is a rocker arm. The figure shows a neutral state, and the electromagnetic actuator 215a is in a non-operating state.
When switching the steering direction, the electromagnetic actuator 215
By operating a, the arm 213 indicated by the solid line is quickly moved to the position indicated by the imaginary line. [0005] The electromagnetic actuator 2
Reference numeral 15a instantaneously moves the core or the spindle by electromagnetic action, and one of its features is that the moving speed is high. Therefore, when the arm 213 indicated by the solid line is moved to the imaginary line, the arm 213 violently hits the outward axial portion 214c and emits a sound. This sound is referred to as “hitting sound”, but since it is a metallic and sharp sound, the sound is likely to be unpleasant for the occupant. It is effective to attach a cushion material to the arm 213, or to attach a cushion material to the outward axial portion 214c. However, since it is necessary to consider that the cushioning material is worn and deteriorated, it is necessary to replace the cushioning material. When the cushioning material is used frequently for a long period of time, the use of the cushioning material remains a problem. [0007] Therefore, an object of the present invention is to provide a technique capable of suppressing a tapping sound without using a cushioning material on the premise that a solenoid (electromagnetic actuator) is used. [0008] In order to achieve the above object, a first aspect of the present invention is to provide a rotating member having a casing and left and right internal thread portions which are rotatably mounted on the casing and which are oppositely threaded left and right. And a male screw part which is screwed to the left and right female screw parts, the left and right slide members which are attached to the rotating member and are non-rotatable and axially movable, and are interposed between these slide members when neutral, and at a certain rotation angle An intermediate member that abuts one of the pair of slide members but whose axial movement is not restricted to the other slide member; a left and right extension member extending from the left and right ends of the intermediate member so as to penetrate the slide member; In addition, the steering shaft penetrated by the intermediate member and the outer ends of the left and right extension members are sandwiched, and the left and right slide members are prevented from moving more than a predetermined amount. Left and right flange members provided on the steering shaft for
When the left and right slide members are separated by the action of the rotating member rotated by the electric motor, the left and right slide members are brought into a neutral state when the left and right slide members are brought into contact with each other, and then the left and right slide members are brought closer to each other, so that the intermediate member is formed by the left slide member Push to the right, thereby moving the steering shaft to the right by pushing the right extension member to the right flange member, or pushing the intermediate member to the left with the right slide member, whereby the left extension member In a rear wheel steering device that can steer the rear wheel as if moving the steering shaft to the left by pushing the member, in order to rotate the intermediate member to a certain angle, to the intermediate member or the left and right extension members, An operation member is mounted so as to be swingable in the axial direction of the intermediate member, the operation member is guided by a crank groove as a guide groove provided on the casing side, and the operation member is moved by the output of the solenoid, and the crank groove The horizontal groove extending in the axial direction of the intermediate member and the vertical groove perpendicular to this horizontal groove, the connection between these horizontal grooves and the vertical groove is connected by a radius of small curvature, and the operator located in the vertical groove at the time of neutrality When moving with a solenoid,
The operation element is moved in the order of a vertical groove, a round portion, and a horizontal groove. The operator is moved in the order of a vertical groove, a round portion, and a horizontal groove. In order to make this possible, the operator is mounted so as to be swingable in the axial direction, and the connection between the horizontal groove and the vertical groove is connected by a rounded portion having a small curvature, so that the movement of the operator is smooth. That is, the remaining power of the solenoid is absorbed by moving the lateral groove while swinging the operation element.
As a result, the operator did not have to worry about hitting the stopper or the like, and it was possible to prevent occurrence of a tapping sound. Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings should be viewed in the direction of reference numerals. The cross-sectional structure of the rear wheel steering device will be described later with reference to FIG. 2 and thereafter, but for ease of understanding, an exploded perspective view will be described first. FIG. 1 is an exploded perspective view of a main part of a rear wheel steering device according to the present invention.
And wheels 13 provided on the outer periphery of the tube portion 12 and left and right female screw portions 14L, 14R (L
Indicates left and R indicates right. The same shall apply hereinafter). Reference numeral 15L denotes a left slide member,
The left external thread 17L and the rotation stopper 18 are provided on the outer periphery of the 6L.
L, 19L, and a left female spline 20L on the inner periphery of the cylindrical portion 16L. 21L is a window. Reference numeral 15R denotes a right slide member,
The right external thread 17R and the rotation stopper 18 on the outer periphery of the 6R
R, 19R, and a right female spline 20R on the inner periphery of the cylindrical portion 16R. 21R is a window. Reference numeral 22 denotes a second stroke sensor, which is linked to the rotation stopper 18R via levers 23 and 24. Reference numeral 26 denotes an intermediate member.
A male spline 29 made up of ridges 28... 30L is the intermediate member 26
The left extension member extends from the left side, and includes a left operation element 31L at a left end portion. 32L is a left large-diameter torsion spring. Similarly, 30R is a right extension member extending from the intermediate member 26, and has a right operation element 31R at the right end. 3
2R is a right large-diameter torsion spring. The winding direction and the number of turns of the large-diameter torsion springs 32L and 32R are not accurate. Reference numeral 34L denotes a left flange member provided with rotation stoppers 35 and 36 on the outer periphery. 37L is left retaining ring, 38L
Is the swage ring on the left. Reference numeral 41 denotes a first stroke sensor, which is linked to the rotation stopper 35 via levers 42 and 43. 34R is a right flange member (detailed structure will be described later), 37R is a right retaining ring, and 38R is a right swaging ring. Reference numeral 44 denotes a steering shaft, a key 45, and two circumferential grooves 46L and 47L on the left, and two circumferential grooves 46R and 46R on the right.
47R, the key 45 suppresses rotation of the left flange member 34L with respect to the steering shaft 44, and the left retaining ring 37L hung on the circumferential groove 46L suppresses the left flange member 34L from moving to the left. The caulking ring 38L is hung on the left flange member 34L, the diameter of which is reduced, and then fitted into the circumferential groove 47L, whereby the left flange member 34L is fitted.
To the right. The same applies to the right retaining ring 37R and the swaging ring 38R. The results obtained by appropriately combining the above elements are shown below. FIG. 2 is a cross-sectional view of the rear wheel steering device according to the present invention. The rear wheel steering device 10 includes a casing 48, a rotating member 11 mounted on the casing 48 with a pair of bearings 49L and 49R, and a rotating member. An electric motor 50 for rotating the rotating member 11 forward and backward, left and right sliding members 15L and 15R screwed into the rotating member 11, and these sliding members 15
L, 15R, and left and right extension members 30L, 30R extending from both ends of the intermediate member 26.
And these extension members 30L, 30R and the intermediate member 2
The steering shaft 44 penetrates through the steering shaft 6, and left and right flange members 34L and 34R attached to the steering shaft 44. 41 is a first stroke sensor, and 22 is a second stroke sensor. The sections of FIG. 2 will be described with reference to FIGS.
FIG. 3 is a sectional view taken along line 3-3 of FIG.
Are fitted in the grooves 51, 52 provided on the casing 48 side, so that the flange member 34L can move in the front and back direction of the drawing without rotating. The amount of movement of the flange member 34L is detected by the first stroke sensor 41 via the levers 42 and 43. 53L is a wall lowered to one side of the flange member 34L, and this wall 53L forms a part of the casing 48. FIG. 4 is a sectional view taken along the line 4-4 in FIG. 2, and is a configuration diagram of the left switching means 55L for rotating the left operator 31L around the steering shaft 44. That is, the left switching means 55L is connected to the left rotary solenoid 57L attached to the wall 53L by the bracket 56L, the arm 58L of the solenoid 57L, the arm 58L via the pin 59L, and the drawing to the wall 53L. The relay lever 60L is attached so as to be swingable in the front and back directions. The left operating element 31L penetrates a crank groove 61L (a crank shape will be described later) provided in the wall 53L, and a pin 62L and a pin 62L are attached to the left extending member 30L so as to be able to swing in the front and back directions in the drawing. Overhang portions 63L, 6
Install with 4L. A left small-diameter torsion spring 65L urges the operation element 31L toward the front side of the drawing. FIG. 5 is a sectional view taken along line 5-5 of FIG. 2, and shows the relationship between the male spline 29 formed on the intermediate member 26 and the female spline 20L formed on the rear slide member 15L. In the figure, the phases do not match. Therefore, when the intermediate member 26 is moved to the back of the drawing, the intermediate member 26 hits the slide member 15L and is prevented from moving. However, the slide member 15L is non-rotating, and the intermediate member 26 on the near side is rotated clockwise or counterclockwise by a predetermined angle so that the phases of the two members coincide with each other. FIG. 6 is a sectional view taken along the line 6-6 in FIG. 2, and is a configuration diagram of the right switching means 55R for rotating the right operator 31R around the steering shaft 44. That is, the right switching means 55R is connected to the right rotary solenoid 57R mounted on the wall 53R with the bracket 56R, the arm 58R of the solenoid 57R, and the arm 58R via the pin 59R and is connected to the wall 53R. The relay lever 60R is attached so as to be swingable in the front and back directions. The right operator 31R penetrates a crank groove 61R (a crank shape will be described later) provided in the wall 53R, and a pin 62R and a pin 62R are attached to the right extension member 30R so as to be able to swing in the front and rear directions in the drawing. Overhang 63R, 6
Install with 4R. 65R is a right small-diameter torsion spring that urges the operating element 31R toward the front of the drawing. FIG. 7 is a sectional view taken along the line 7-7 in FIG. 2, and the rotation stoppers 18R and 19R of the right slide member 15R are fitted into the grooves 66 and 67 provided on the casing 48 side. Indicates that it can move in the front and back direction of the drawing without rotating. The amount of movement of the slide member 15R is detected by the second stroke sensor 22 via the levers 23 and 24. FIG. 8 is a cross-sectional view of the flange member employed in the present invention.
A retaining ring 37R is attached to 6R, and a sleeve 68 having a step therein is moved from left to right in the figure, and the step is brought into contact with the retaining ring 37R. The sleeve 68 will no longer move to the right. The right collar member 34R is screwed into such a sleeve 68. The reason will be described below. In FIG. 1, the left flange member 34L and the right flange member 34R sandwich an integrated shaft composed of the extension members 30L and 30R and the intermediate member 26. The length of the integrated shaft is a certain error. including. Therefore, the left flange member 34L is immovably attached to the steering shaft 44, and the right flange member 34R is movable in the axial direction. Returning to FIG. 8, when the position of the flange member 34R is determined, the locking is performed with the lock nut 69. The caulking wheel 38R may be attached at an appropriate time. FIG. 9 is a perspective view of the switching means according to the present invention. For convenience of drawing, walls forming the crank grooves 61L and 61R (see reference numeral 53L in FIG. 4 and reference numeral 53R in FIG. 6).
Is not shown. The left operation member 3 provided on the left extension member 30L
1L protrudes through the crank groove 61L, the relay lever 60L of the left switching means 55L faces the protruding portion, and the relay lever 60L is driven by the arm 58L of the left rotary solenoid 57L, and the operator 31L is turned on. It is moved along the crank groove 61L as indicated by the arrow. The same applies to the right switching means 55R. FIG. 10 is a diagram showing the correlation among the arm, the relay lever, and the crank groove of the solenoid according to the present invention. (A) is a view on arrow 10a of FIG.
Is connected to a relay lever 60L via a pin 59L, and by rotating the arm 58L clockwise, the relay lever 60L is rotated.
Indicates that L can be rotated left. FIG. 9B is a view taken in the direction of arrow 10b in FIG. 9. The crank groove 61L includes an upper horizontal groove 71L, a vertical groove 72L, and a lower horizontal groove 73L, and in particular, the vertical groove 72L and the lower horizontal groove 73L.
Is characterized by being connected by a round portion 74L having a small curvature (large radius). In this figure, since the operator 31L does not interfere with the relay lever 60L indicated by the solid line, the operator 31
L is movable over the entire area of the crank groove 61L. When the relay lever 60L is rotated counterclockwise, the relay lever 60L is engaged with the operator 31L, and thereafter, the operator 31L can be forcibly moved to a position indicated by an imaginary line. The operation of the switching means described above will now be described.
The operation of the torsion spring will be described with reference to FIG.
(A) and (a), (b) and (b), and (c) and (c) in both figures were matched in time. FIGS. 11A to 11C are diagrams for explaining the movement of the operation element according to the present invention. (A) is the same as FIG.
It is the figure which combined (b), and shows before a solenoid operation.
When the solenoid is energized and the arm 58L indicated by the imaginary line is rotated clockwise, the relay lever 60L starts rotating counterclockwise.
(B) shows an intermediate view, and shows that the relay lever 60L has lowered the operation element 31L along the vertical groove 72L as indicated by the arrow by the action of the solenoid. (C) shows a state in which the operation of the solenoid has been completed, and the operator 31L pushed by the relay lever 60L is
The moving direction changes from vertical to horizontal at the round part 74L, and then
The lower horizontal groove 73L is moved as indicated by the arrow. FIGS. 12 (a) to 12 (c) are diagrams for explaining the operation of the large diameter torsion spring and the small diameter torsion spring according to the present invention. (A) shows that the operation element 31L is at the neutral position by the action of the large-diameter torsion spring 32L. In FIG. 9, the left large-diameter torsion spring 32L and the right large-diameter torsion spring 32R extend in the opposite direction to each other.
In order to twist the L and 30R, the intermediate member 26 includes the two springs 32.
The rotation stops when L and 32R are suspended. This is the neutral position. Returning to FIG. 12, if the operator 31L is lowered as shown by the arrow in (b), the intermediate member 26 will rotate rightward.
At this point, spring energy is accumulated in the large-diameter torsion spring 32L. In (c), the pin 62L is used as the center of rotation,
This shows that the operation element 31L has been rotated horizontally toward the front of the figure. At this point, spring energy is accumulated in the small-diameter torsion spring 65L. FIGS. 13 (a) and 13 (b) are explanatory views of the hitting noise suppression technique according to the present invention. In the graph, Fa is the reaction force of the large diameter torsion spring, and FIG. 11 (a) → ( b) is the reaction force generated in the large-diameter torsion spring 32L in FIG. Fb is a reaction force of the small-diameter torsion spring, and is a reaction force generated in the small-diameter torsion spring 65L of FIG. 12C from (b) to (c) of FIG. The solenoid is, literally, an electric component that converts electromagnetic force into mechanical force. The output torque changes depending on the ambient temperature and the like. In addition, the solenoid itself deteriorates due to aging and the output decreases. Therefore, the output of the solenoid is considerably large in order to anticipate deterioration and to consider the influence of temperature. (A) shows an output S where the output of the solenoid is large.
FIG. 8 is an explanatory diagram when the time is t1, and a large output St1
Until the balance is achieved, first, the large-diameter torsion spring bends, and then the small-diameter torsion spring bends, resulting in a relationship of St1 = Fa + Fb. In the process until this relationship is established, FIG.
The operator 31L shown in (a) to (c) does not hit a stopper or the like. Therefore, according to the present invention, the hitting sound which has been unavoidably generated for the purpose of stopping the operation element 31L is not generated according to the present invention. (B) is an explanatory diagram when the output of the solenoid becomes a small output St2 due to deterioration or the like. The relationship of St1 = Fa + Fb does not change, only Fb becomes small. According to the present invention, the hitting sound which has conventionally been inevitably generated for the purpose of stopping the operation element 31L is not generated. That is, one of the features of the present invention is that the output fluctuation accompanying the output of the solenoid is absorbed by Fb. Next, the operation of the rear wheel steering device 10 of the present invention will be described. 14 (a) is a schematic view of a sectional view, FIG. 14 (b) is a sectional view taken along the line bb of FIG. 14 (a), and FIG. 14 (c) is a sectional view of the rear wheel steering device of the present invention (neutral state). FIG. 3A is a cross-sectional view taken along line c-c. However, the solenoids 57L and 57R are simplified. The figure shows a neutral state, and in (a), the left and right slide members 15L and 15R are connected to the left and right flange members 34.
Since the lateral movement of the steering shaft 44 is disabled via L and 34R, the neutral position of the steering shaft 44 is determined. In (b) and (c), the solenoid 57
L, 57R are in a non-operating state, and the relay levers 60L, 60R
0R is at the standby position. Large diameter torsion spring 32L, 3
By the return action of 2R, the male spline 29 overlaps the female splines 20L, 20R. For this purpose, in (a), the intermediate member 26 is mechanically
Since it is sandwiched between L and 15R, lateral movement is almost impossible. FIGS. 15A and 15B are explanatory diagrams of the operation of the rear wheel steering device of the present invention (operation of the right switching means). FIG. 15A is a schematic diagram of a sectional view, FIG. 15B is a sectional view taken along line bb of FIG. (C) is (a)
2 shows a cross-sectional view taken along line cc of FIG. In (c), the right solenoid 57R is operated, the right relay lever 60R is rotated left, and the right operator 31R is swung. Then
The male spline 29 moves clockwise and the female spline 20
R is disengaged (the phase is matched). This will be described in detail with reference to the following drawings. FIG. 16 is a view taken in the direction of arrow 16 in FIG. 15 (a), and a female spline 20R of the right slide member 15R and
The relative relationship between the intermediate member 26 and the male spline 29 is shown,
The male spline 29 can enter the female spline 20R. This state is referred to as "the phases match." Returning to FIG. 15, in FIG. 15B, the male spline 29 is necessarily rotated counterclockwise, and as a result, the female spline 20 is rotated.
L overlaps the front and back of the drawing. FIG. 17 is a view taken in the direction of arrow 17 in FIG. 15 (a), in which a female spline 20L of the left slide member 15L and
The relative relationship between the intermediate member 26 and the male spline 29 is shown,
The male spline 29 hits the female spline 20L and cannot enter any further (movement in the axial direction). This state is called “out of phase”. Returning to FIG. 15, in (a), it can be said that the intermediate member 44 can be moved only to the right. FIG. 18 is a view for explaining the operation of the rear wheel steering device of the present invention (while the steering shaft is moving to the right), in which the electric motor 50 is started and the rotating member 11 is turned to rotate the right and left sliding members 15.
L and 15R are brought closer to each other. Then, the left slide member 15L pushes the intermediate member 26 to the right at the mark P1, whereby the right extension member 30R pushes the right flange member 34R to the right at the mark P2, and consequently the steering shaft 44 to the right. Move. This movement amount is the first stroke sensor 4
Detect at 1. The second stroke sensor 22 backs up the first stroke sensor 41. FIG. 19 is a diagram for explaining the operation of the rear wheel steering device of the present invention (steering shaft right maximum movement), and shows a state in which the steering shaft 44 has moved most to the right. Although not described so far, when a moving force (external force) acts on the steering shaft 44 with a force acting from the wheel side, an external force is received by the left slide member 15L at the mark P3 or P4. Therefore, there is no fear that the steering shaft 44 moves due to the external force from the wheel side. FIG. 20 is a view for explaining the operation of the rear wheel steering device of the present invention (reversing from the maximum rightward movement of the steering shaft).
0, and the rotation direction of the rotating member 11 is changed. Then, the left and right slide members 15L and 15R begin to move in directions away from each other. Then, the left slide member 15L pushes the left flange member 34L at the mark P3,
As a result, the steering shaft 44 starts moving to the left. Thereafter, by returning to the neutral state of FIG. 14 through FIG.
From the neutral position to rightward movement and return to the neutral position. The leftward movement and the return of the neutral position from the neutral position of the steering shaft 44 and the return of the neutral position may be performed by reversing the left and right sides, and thus the description thereof is omitted. FIG. 21 is a view for explaining the assembling procedure of the intermediate member and the extension member according to the present invention, and a comparative explanatory diagram of the comparative example. (A) is an exploded view, in which an intermediate member 26 in which a male spline 29 is formed in a cylinder 27 and a left and right extension member 30 in the form of a simple pipe.
Prepare L, 30R. (B) is an assembling drawing of the cylinder 27;
The ends of the left and right extension members 30L and 30R are joined by friction joining (a kind of joining method in which the metal on the joining surface is melted by frictional heat and welded together) to both ends of the joint. (C) shows a comparative example, in which the conventional cylindrical member 103 described with reference to FIG.
Since the b and the clutch inners 76a and 76b are integrally provided, the machining cost is increased regardless of whether the machining is performed from a thick cylinder or welding to the cylinder and finishing. On the other hand, the integrated shaft of the intermediate member 26 and the extension members 30L and 30R of the present invention manufactured in the manner of (a) and (b) can be manufactured at extremely low cost. 18 and 19, marks P1 to P4
As shown by, only the force from the center to the outside acts on the flange member of the present invention. Therefore, the retaining ring 37R shown in FIG.
Is established, and the swaging wheel 38R is not always necessary. As a result, the screw portion 102 described with reference to FIG. 22 becomes unnecessary, and the steering shaft 44 of the present invention can be a simple shaft having the circumferential grooves 46L, 46R, 47L, 47R as shown in FIG. . The number of male and female splines is arbitrary, and the spline teeth are also arbitrary. Further, although a rotary solenoid is employed as the solenoid, a linear solenoid may be used. Further, the solenoid may be a pneumatic actuator, a hydraulic actuator, or an electric actuator. According to the present invention, the following effects can be obtained by the above-described structure. In the rear wheel steering device according to the first aspect, the operation element is moved in the order of the vertical groove, the round portion, and the horizontal groove. In order to make this possible, the operator is mounted so as to be swingable in the axial direction, and the connecting portion between the horizontal groove and the vertical groove is connected by a rounded portion having a small curvature to facilitate the movement of the operator. That is, the remaining power of the solenoid is absorbed by moving the lateral groove while swinging the operation element. As a result, the operator does not have to worry about hitting the stopper or the like, and it is possible to prevent occurrence of a tapping sound.
That is, according to claim 1, on the assumption that a solenoid (electromagnetic actuator) is used, the hitting sound can be eliminated without using a cushion material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded perspective view of a main part of a rear wheel steering device according to the present invention. FIG. 2 is a sectional view of a rear wheel steering device according to the present invention. FIG. FIG. 4 is a sectional view taken along line 4-4 of FIG. 2. FIG. 5 is a sectional view taken along line 5-5 of FIG. 2. FIG. 6 is a sectional view taken along line 6-6 of FIG. FIG. 8 is a sectional view of a flange member employed in the present invention. FIG. 9 is a perspective view of a switching means according to the present invention. FIG. 10 is an arm, relay lever, and crank groove of a solenoid according to the present invention. FIG. 11 is an explanatory view of the movement of the operation element according to the present invention. FIG. 12 is an operational explanatory view of a large-diameter torsion spring and a small-diameter torsion spring according to the present invention. FIG. 14 is an explanatory diagram of the operation of the rear wheel steering device of the present invention (neutral state). FIG. 15 is an operational diagram of the rear wheel steering device of the present invention (neutral state). FIG. 16 is a view as seen in the direction of arrow 16 in FIG. 15 (a). FIG. 17 is a view as seen in the direction of arrow 17 in FIG. 15 (a). FIG. 19 is an explanatory diagram of the operation of the rear wheel steering device of the present invention (steering shaft right maximum movement). FIG. 20 is an operational explanatory diagram of the rear wheel steering device of the present invention (reversed from the steering shaft right maximum movement). FIG. 21 is an assembling procedure diagram of an intermediate member and an extension member according to the present invention and a comparative explanatory diagram of a comparative example. FIG. 22 is a reprint of FIG. 5 of JP-A-2000-79881. Rudder device, 11 ... rotating member, 14L, 14R
... left and right female screw parts, 15L, 15R ... left and right slide members, 17L, 17R ... left and right male screw parts, 20 ... left and right female splines, 26 ... intermediate members, 29 ... male splines, 3
0L, 30R: left and right extension members, 31L, 31R: left and right operators, 34L, 34R: left and right flange members, 44: steering shaft, 48: casing, 50: electric motor, 55L, 5
5R: left and right switching means, 57L, 57R: left and right rotary solenoids, 60L, 60R: left and right relay levers, 6
1L, 61R: left and right crank grooves, 72L, 72R: vertical grooves, 73L, 73R: horizontal grooves (lower horizontal grooves), 74L, 74
R ... R section.

   ────────────────────────────────────────────────── ─── Continuation of front page    (72) Inventor Hiroshi Furumi             1-4-1 Chuo, Wako-shi, Saitama Stock Association             Inside the Honda Research Laboratory F term (reference) 3D034 CA05 CC09 CC12 CD12 CE03                       CE13

Claims (1)

Claims: 1. A casing, a rotating member rotatably mounted on the casing and having left and right female threads which are oppositely threaded to each other on the left and right sides, and a male threaded part screwed to the left and right female threads. A left and right slide member attached to the rotating member and axially movable without rotation.
An intermediate member which is interposed between these slide members at the time of neutrality and which comes into contact with one of the pair of slide members at a certain rotation angle but whose axial movement is not restricted to the other slide member; The left and right extension members extending from the left and right ends of the member, the steering shaft penetrated by these extension members and the intermediate member, and the outside ends of the left and right extension members are sandwiched and the left and right slide members are suppressed from moving more than a predetermined amount. The left and right slide members are separated by the action of a rotating member that is turned by an electric motor while the left and right slide members are separated from each other. By approaching the members, the left slide member pushes the intermediate member to the right, whereby the right extension member pushes the right flange member to move the steering shaft to the right, or A rear wheel steering device that can steer the rear wheels such that the intermediate member is pushed to the left by the right slide member, and the left extension member pushes the left flange member to move the steering shaft to the left. In the above, in order to rotate the intermediate member to a certain angle, an operator is attached to the intermediate member or the left and right extension members so as to be able to swing in the axial direction of the intermediate member, and the operator is provided as a guide groove provided on the casing side. The guide is guided by a crank groove, and the operation member is moved by the output of the solenoid. The crank groove includes a lateral groove extending in the axial direction of the intermediate member and a vertical groove perpendicular to the lateral groove. When the operator located in the vertical groove is moved by the solenoid at the time of neutral, the operator is moved in the order of the vertical groove, the radius part, and the horizontal groove. To Wheel steering apparatus after the butterflies.