JP2000118428A - Steering mechanism for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To decrease a minimum turning radius and to provide a vehicle capable of making a small sharp turn even at a limited place in a house and having excellent facility. SOLUTION: This steering mechanism for a vehicle steers a pair of steering wheels W arranged opposite to each other in the direction of a car width and at the front of a chassis 2. This steering mechanism comprises a steering rod 31 erected rotatably around own axis at the central part in the direction of the width of the chassis 2, an operation lever 34 to effect rotation operation of the steering rod 31, and a steering mechanism 4 to change the direction of a pair of steering wheels through rotation around the axis of the steering rod 31. This steering mechanism 4 increases the degree of variation of the direction of the steering wheel W on the inner wheel side to a value higher than the degree of variation of the direction of the steering wheel W on the outer wheel side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering mechanism for a vehicle mainly driven by electric power, which is suitable for running in a building or in a narrow passage.

[0002]

2. Description of the Related Art Conventionally, a vehicle steering mechanism as shown in FIGS. 9 and 10 is known. These steering mechanisms change the direction of a pair of steering wheels W (left steering wheel W1 and right steering wheel W2) disposed in front of the vehicle body B (above the plane of FIGS. 9 and 10) in the vehicle width direction. By turning the steered wheels W in a predetermined direction, the vehicle body B in progress turns around a predetermined turning center. Each steered wheel W is rotatably supported around a pair of driven shafts W3 extending in the vehicle width direction in the width direction.

A steering mechanism 100 shown in FIG. 9 rotatably supports opposite ends of the pair of driven shafts W3.
A pair of width-direction vertical shafts 101 fixed to the vehicle body B, and a pair of width-direction link arms 102 (left link arm 102a and right link arm 102b extending in the front-rear direction and extending from opposed ends of the driven shafts W3, respectively). ) And these link arms 102
a connecting rod 103 bridged between the rear ends of the a and b through a connecting pin, and a handle shaft 104 erected on a center line extending in the front-rear direction of the vehicle body B and slightly forward of the vertical shaft 101. A front link arm 105 protruding forward from the handle shaft 104; and a tie rod 106 bridged via a connecting pin between the tip of the front link arm 105 and the right link arm 102b. Consists of

The right link arm 102b is connected to the left link arm 1
The length of the left link arm 102a is the same as the length of the left link arm 102a after the vertical axis 101. Thus, a parallel link structure is formed between the left link arm 102a and the right link arm 102b. In addition, the tie rod 106
Has its right end connected to the front end of the right link arm 102b. A handle (not shown) is provided on the handle shaft 104. By operating the handle, the handle shaft 104 rotates forward and backward around the axis.

According to the steering mechanism 100 having such a structure, the steering wheel is operated while the steering wheel W shown in FIG. 9A is directed forward to rotate the handle shaft 104, for example, counterclockwise around the axis. When the tie rod 106 is moved,
Is transmitted to the right link arm 102b via the right link arm 1b.
The right steering wheel W2 turns around the vertical axis 101 and turns diagonally to the left by turning counterclockwise around the vertical axis 101 of 02b, and the rotation of the right link arm 102b turns to the connecting rod 103 and the left. The transmission is transmitted to the left steering wheel W1 via the link arm 102a, whereby the left steering wheel W1 is also turned by the same angle as the right steering wheel W2, as shown in FIG. In this state, the drive wheels W0 are driven by the drive means (not shown) to move the vehicle body B forward, so that the vehicle body B turns to the left.

A steering mechanism 200 shown in FIG. 10 has a pair of link arms 202 projecting forward from respective driven shafts W3 in the width direction. Further, instead of the front link arm 105, an inverted triangular link plate 2 is provided on the handle shaft 104.
05 is adopted. A tie rod 2 is provided between the link plate 205 and each end of the left and right link arms 202.
06 is provided. The other components are configured in the same manner as the steering mechanism 100 shown in FIG. This steering mechanism 200
Also, when the handle shaft 104 is rotated counterclockwise around the axis in the state shown in FIG.
As shown in (b) of FIG.
The vehicle body B turns around in the counterclockwise direction, whereby the vehicle body B turns to the left.

[0007]

However, in the conventional steering mechanisms 100 and 200 as described above, the angle between the tie rods 106 and 206 and the link arms 102 and 202 cannot be made so large, so that the steering The steering angle of the wheel W is about 60 ° at the maximum, and therefore, the minimum turning radius of the vehicle does not become as small as expected. FIG.
As shown in (b) of FIG. 10 and (b) of FIG.
2 and 202 are located on a straight line, that is, in a state where the direction of the steered wheels W is set to correspond to the minimum turning radius of the vehicle, the tie rod 106 and the link arms 102,
202 is located on a straight line, the handle shaft 104
When the steering wheel W is returned to the original position, there is a problem that the direction of the steered wheels W may not be returned to the original direction and may go in the opposite direction.

Further, regardless of the turning angle of the handle shaft 104, the left steered wheel W1 and the right steered wheel W2 are always in a parallel state, and the extension of the driven shaft W3 of the left steered wheel W1 and the right steered wheel W2
There is no point where the left steering wheel W1 and the right steering wheel W2 travel in the same direction, and the turning center is determined only by the steering angle of the steering wheel. Without being influenced by the drive wheel W0, the actual minimum turning radius does not become small for the steering angle,
As a result, there is a problem that use in narrow places such as indoors becomes inconvenient, for example, the vehicle body B cannot be U-turned in a narrow passage.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to reduce the minimum turning radius as compared with the conventional one, and to prevent the steered wheels from returning to the original state. It is an object of the present invention to provide a vehicle steering mechanism that does not cause any inconvenience and makes it possible to make the vehicle easy to use with a small turn even in a narrow place such as indoors.

[0010]

According to a first aspect of the present invention, there is provided a steering mechanism for a vehicle which steers a pair of steering wheels provided on a vehicle body so as to face each other in a vehicle width direction, A steering rod, which is rotatably mounted on the center of the vehicle body in the width direction so as to be rotatable around its own axis, an operation rod for rotating the steering rod, and an axis of the steering rod by operating the operation rod Direction changing means for changing the direction of the pair of steered wheels by turning around; a link member fixed to the steering rod so as to protrude forward; and the left and right steered wheels. And a pair of brackets in the vehicle width direction that are rotatably supported on a frame of the vehicle body around a vertical axis,
A tie rod is provided between the link member and the brackets, the tie rods being linked in an intersecting state.

According to this vehicle steering mechanism, the steering rod is rotated in a predetermined direction by operating the operation rod, whereby the pair of steered wheels in the vehicle width direction is rotated by the operation of the direction changing means. Since the vehicle turns in the turning direction corresponding to the direction, the traveling vehicle turns in the direction.

When the steering rod is turned in the turning direction by operating the operation rod, the link member turns in the same direction, whereby each tie rod turns a pair of steered wheels in the turning direction. The vehicle turns. Since the pair of tie rods are supported by the link member in a state of intersecting each other at the front position of the steering rod, when the link member is turned in the turning direction from the neutral position facing the front, the inner ring side The tie rod can move a portion of the rotation trajectory of the link member, which has more components moving in the vehicle width direction, than the tie rod on the outer ring side.

As a result, the amount of rotation of the inner wheel side bracket that is rotated by the movement of the inner wheel side tie rod is greater than the amount of rotation of the outer wheel side bracket, and the degree of turning of the inner wheel side steering wheel in the turning direction is greater than the outer wheel amount. Since the steering wheel is larger than that of the side steering wheel, the intersection of the axis of the inner wheel side steering wheel and the axis of the outer wheel side steering wheel becomes the turning center, and the vehicle turns without slipping of each steering wheel. .

Therefore, when the directions of the steered wheels are changed so that the directions of the steered wheels are always parallel to each other, the axes of the steered wheels are not parallel and do not intersect with each other. The conventional inconvenience that the turning radius is increased by determining the turning center in relation to the non-steered wheels is not resolved by only the change of the vehicle, and the vehicle can be turned in a small turn.

Further, since the pair of tie rods intersect each other at the position in front of the steering rod, it is possible to increase the range of rotation of each steered wheel as compared with the case where they do not intersect, whereby the vehicle The turning radius of the tie rod can be made smaller, and when the operating rod is operated up to the minimum turning radius of the vehicle, the axis of the vertical axis is positioned in the direction in which the tie rod extends, so that the operating rod is in the neutral position. The conventional inconvenience that the steered wheels turn in the opposite direction when trying to return to the normal state can be avoided.

According to a second aspect of the present invention, in the vehicle steering mechanism according to the first aspect, each of the tie rods, each of the link members and each of the brackets are relatively rotated about a predetermined axis. And the tie rods have the same center distance,
The distance between the axes of the brackets is set to be the same, and the tie rods are installed so as to be symmetrical with the steered wheels facing the front.

According to the steering mechanism of this vehicle, each tie rod is rotated around the vertical axis while rotating relative to the link member by operating the operation rod, and the direction of the steered wheels is changed. . And since the center distance of the tie rods is set to be the same and the center distance of each bracket is also set to be the same, when the operation amount of the operation rod is the same for the left and right, the steering angle of each steered wheel is Same on left and right.

According to a third aspect of the present invention, there is provided a steering mechanism for a vehicle according to the second aspect, wherein the inner wheels of the steered wheels are turned to the maximum extent.
The intersection of the axis of the steered wheel on the inner wheel and the axis of the steered wheel on the outer wheel is located at the center of the non-steered wheel on the inner wheel.
The distance between the axes of the link member, the tie rod and the bracket is set.

According to the steering mechanism of this vehicle, by operating the operation rod to the maximum in the turning direction, the intersection of the axis of the steered wheels on the inner wheel side and the axis of the steered wheels on the outer wheel side is obtained. But,
Since the vehicle is located at the center of the non-steered wheels on the inner wheel side, the moving vehicle turns around the center of the non-steered wheels on the inner wheel side.
By turning the vehicle around the non-steered wheels on the inner wheel side, the turning radius of the vehicle can be made very small.

A vehicle steering mechanism according to a fourth aspect of the present invention is the vehicle steering mechanism according to the second or third aspect,
One of the pair of tie rods is linked to an upper surface of the link member and the bracket, and the other is linked to a lower surface of the bracket.

According to the steering mechanism of the vehicle, mutual interference between the pair of tie rods that cross each other is avoided.

[0022]

FIG. 1 is a perspective view showing one embodiment of a skeleton of a vehicle to which a steering mechanism according to the present invention is applied. 2 is a plan view of the vehicle shown in FIG. 1, FIG. 3 is a front view thereof, and FIG. 4 is a side view thereof. The left and right display of each member in FIG. 1 is from the driver sitting on the seat 5. As shown in these figures, the vehicle 1 has a chassis 2 as a skeleton in which a pair of steering wheels W in the width direction is provided at a front portion and the same pair of driving wheels W0 is provided at a rear portion. A handle structure 3 provided at a front portion, and a steering mechanism (direction changing means) 4 formed at a lower portion of the handle structure 3 for changing the direction of each of the steered wheels W.
A seat 5 provided as a seat on the rear of the chassis 2, a front basket 6 attached to the handle structure 3 for storing various articles, and a driving means 7 for rotating the driving wheel W0. It has a basic configuration including

The chassis 2 is formed by combining a rectangular tubular right frame 21 and a left frame 22 extending in the front-rear direction. Each frame 21,
A pair of upper and lower front connecting plates 23 are bent by welding stoppers or the like between the curved front end portions so that the front end portions of the frames 21 and 22 are connected to each other. The parts are connected to each other. The rear portion of each of the frames 21 and 22 is folded upward and then curved forward, and a pair of upper and lower rear connecting plates 24 is bridged between these forward portions by welding or the like. I have. By this bridging, the rear portions of the frames 21 and 22 are connected to each other.

A front connecting frame 25 is bridged between the frames 21 and 22 on the lower surface side of a portion slightly behind the front connecting plate 23, and an intermediate connecting frame 26 is bridged at an intermediate portion in the front-rear direction. The rigidity of the chassis 2 is ensured by the connecting frames 25 and 26.

Vertical rods 27 are respectively suspended from both sides in the width direction of the front connecting frame 25, and the steering wheel supporting frame 2 is provided between the vertical rods 27.
8 are crosslinked. A center frame 29 extending in the front-rear direction is bridged between the center portion in the width direction of the steering wheel support frame 28 and the center portion of the intermediate connection frame 26, whereby the steering wheel support frame 28 swings in the front-rear direction. Movement is regulated.

The chassis 2 has a central frame 29.
And a front floor 20 made of an iron plate supported on the front part of the left and right frames 21 and 22 from the center frame 29, and supported by the center frame 29 and the rear part of the left and right frames 21 and 22. Rear floor 2
0a is provided. The front floor 20 is for placing a driver's foot, and the rear floor 20a is
This is for supporting the driving means 7.

The handle structure 3 includes the front connecting plate 2
3 and a steering rod 31 erected on the front connecting plate 23 so as to be rotatable around its own axis.
A bifurcated handle arm 32 integrally connected to the upper end of the steering rod 31; and a pair of brackets 3 in the width direction provided at the upper end of each handle arm 32.
3 and a pair of left and right operation rods 34 (right operation rod 34a and left operation rod 34b) protruding from the respective brackets 33 in directions facing each other.

The steering rod 31 is inserted into a rod support cylinder 23a provided at the center of the front connecting plate 23 in a state of being prevented from falling off, and the lower end thereof is connected to the steering mechanism 4. Each steering wheel W (steering wheel W1 and left steering wheel W2) is turned by the forward / reverse rotation of the steering rod 31 around its own axis through the handle arm 32 by operating the operation rod 34, thereby changing the direction of the vehicle. 1 rotates in the operation direction of the operation rod 34.

Each of the handle arms 32 (the right handle arm 32a and the left handle arm 32b) has the same length, and has a distal end bent backward, and an end face of the bent portion. Is fixed to the bracket 33. Each of the brackets 33 is formed by pressing a metal plate having a predetermined shape into a U-shape, and a bottom portion of the U-shape is connected to the handle arm 32. Each of the operation rods 34 is rotatably supported around a support shaft 35 while being held by the bracket 33. Therefore,
In a state where the handlebar arm 32 is rotated forward and reverse around the steering rod 31 by operating the operation rod 34, each operation rod 34 is relatively rotated around the support shaft 35 with respect to the bracket 33. 34, the wrist torsion at the time of operation is reliably prevented.

The right operating rod 34a is protruded from a front surface of the right operating rod 34a so as to be freely protruded and retracted, and is urged in a projecting direction by an unillustrated urging means. And a brake lever 34c extending across
The left operating rod 34b is provided with an accelerator lever 34d protruding in the same manner as the brake lever 34c, and the driver grips the operating rods 34a and 34b and holds each lever 3 with his fingertip.
By adjusting the protrusion amounts of 4c and 34d, the brake can be applied and the traveling speed of the vehicle 1 can be changed.

The steering mechanism 4 includes a pair of link plates 41 (a lower link plate 41a and an upper link plate 41a) fixed to the lower end of the steering rod 31 corresponding to the upper and lower sides.
b) and the respective steered wheels W (right steered wheels W
1 and a pair of tie rods 42 (right tie rod 42a and left tie rod 42b) extending in the direction of the left steered wheel W2). Each of the link plates 41 is set in a triangular shape in a plan view, and is set to be symmetric with respect to a center line extending in the front-rear direction of the vehicle 1 in a state where the handle arm 32 is phase-set so that the vehicle 1 moves straight. Position is set. Each link plate 41a, 4
1b, one bottom corner portion of the triangular shape is fixed to the steering rod 31 and the other bottom corner portion is connected by a connection piece 43 extending in the vertical direction, whereby each link plate 41a, 41b is The relative positions are hard to change with each other.

The pair of tie rods 42a, 42
b are disposed so as to cross each other at a position forward of the steering rod 31. And right tie rod 4
The left end of 2a is rotatably supported around a vertically extending connection pin 44 provided at the apex of the lower link plate 41a, and the right end is connected to the right steering wheel W1. On the other hand, the right end of the left tie rod 42b is rotatably supported around a vertically extending connection pin 44 provided at the apex of the upper link plate 41b, and the left end is connected to the left steering wheel W2. Have been contacted. Each of the steered wheels W1, W is driven by the forward / reverse rotation of the link plate 41 around the steering rod 31 by the operation of the operation rod 34.
2 turns in the same direction, whereby the vehicle 1 turns in the operation direction of the operation rod 34.

The seat 5 is supported by a rear connecting plate 24 provided at the rear of the chassis 2. This sheet 5
Is composed of a seat bottom 51 as a seating portion, a seat back 52 as a backrest, and an armrest 53 as an armrest. The seat 5 has a seat support rod 54 projecting downward from the center of the bottom surface of the seat bottom 51, and the seat support rod 54 is formed in the center of the rear connecting plate 24. It is supported by the rear connecting plate 24 in a state where it can rotate around the sheet support rod 54 by being inserted into the support hole 24a. Sheet 5
Is configured to be rotatable around the seat support rod 54, so that getting on and off the seat 5 is convenient.

In the present embodiment, the front basket 6 is made of a wire mesh whose edges are reinforced with wires and has an opening on the upper surface. The front basket 6 is fixed to the handle arm 32 in a state of being fitted between the right handle arm 32a and the left handle arm 32b, so that the driver sitting on the seat 5 can reach out without getting off. To store items in the front basket 6
It is designed to be able to take out the articles stored therein.

On the other hand, a basket support arm 36 bulging rearward along the outer shape of the front basket 6 is inserted between the handle arms 32a and 32b. The front basket 6 is mounted on the handle arm 32 by a predetermined fastener with three sides surrounded by the basket support arm 36 and the handle arms 32a and 32b.

An operation panel 37 is provided on the rear side of the basket support arm 36 so as to face the driver. On the operation panel 37, a key hole for a power switch, a charge state display lamp, a forward / reverse switch, a mileage meter, a horn switch, and the like are arranged.

The driving means 7 is connected to the rear floor 20a.
And a battery 72 mounted on the rear floor 20a and supplying electric power to the electric motor 71. The drive shaft of the electric motor 71 is connected to the drive shaft W0 of the drive wheel W0 via a transmission (not shown) and a differential gear.
1 has been transmitted. Then, the accelerator lever 34
By operating d, electric power from the battery 72 is supplied to the electric motor 71, and the driving of the electric motor 71 causes the drive wheels W0 to rotate via the transmission, the differential, and the drive shaft, whereby the vehicle 1 moves forward and backward. It has become.

FIG. 5 is a perspective view showing a state in which the skeleton shown in FIG. 1 is covered. As shown in FIG.
In the finished product, a bumper 11 is provided at the front end of the chassis 2, and the steered wheels W and the drive wheels W0 are respectively covered by a pair of widthwise wheel covers 12. A front blind cover 13 is provided on the base end side of the steering rod 31 to cover the steering mechanism 4 (FIG. 1).
A rear cover 14 is provided at the lower part of the cover to prevent the drive means 7 (FIG. 1) from being exposed to the outside.

The drive portion of the vehicle 1 is protected by attaching the bumper 11, the wheel cover 12, the front blind cover 13 and the rear blind cover 14 to the chassis 2 to cover the frame and various mechanisms as a whole. As a result, inconveniences such as failure due to foreign matter can be avoided, and the appearance is improved in design, and the commercial value increases.

FIG. 6 is a partially cutaway perspective view showing details of the steering mechanism 4, and FIG. 7 is a plan view thereof. As shown in these figures, the steering mechanism 4 includes the link plate 41 (lower link plate 41a and upper link plate 41b) fixed to the lower end of the steering rod 31 and the link plate 4
1 (the right tie rod 4)
2a and a left tie rod 42b), and a steering wheel support bracket 45 (right support bracket 45a and left support bracket 45b) to which the tip side of the tie rod 42 is linked via a link protruding piece 46.

The steering wheel support bracket 45 has a U-shape in a front view. The steering wheel support bracket 45 sandwiches the end of the steering wheel support frame 28 from above and below via a link projecting piece 46 protruding forward (downward in FIG. 7) to support a king pin 47 made of a bolt. Through the bracket 45 and the steering wheel support frame 28,
The distal end of the king pin 47 projecting outward from the steering wheel support bracket 45 is fastened with a nut, so that the steering wheel support bracket 45 is attached to the distal end of the steering wheel support frame 28 so as to be rotatable around the king pin 47. .

The link projection 46 and the steering wheel support bracket 45 are integrated by welding or the like. By rotating the link projection 46 around the king pin 47, the steering wheel support bracket 45 is linked. The protruding piece 46 rotates together with the protruding piece 46. A steering wheel shaft W4 that supports the steering wheel W is fixed to an end surface of the steering wheel support bracket 45 in the vehicle width direction, and the steering wheel W is mounted to be rotatable around the steering wheel axis W4. Therefore, by rotating the link projecting piece 46 forward and backward around the king pin 47, the steering wheel support bracket 45 rotates forward and backward, thereby changing the direction of the steering wheel W.

As for the link projection 46, the right one (right link projection 46a) is attached to the lower surface of the right support bracket 45a, and the left one (left link projection 46b) is left supported. A pair of tie rods 42 attached between the link plate 41 and the steering wheel support bracket 45 in an intersecting state are provided so as not to interfere with each other.

The right link protruding piece 46a has a connecting pin 48 protruding downward from the lower surface of the front end thereof, and the left link protruding piece 46b has a connecting pin 48 provided on the upper surface of the front end thereof. It protrudes upward. One end of the pair of tie rods 42 is connected to these connection pins 48, and the other end is connected to the connection pin 44 of the link plate 41 in a state where the pair of tie rods 42 intersect. The tie rod 42 is mounted between the link plate 41 and the link projection 46.

The tie rod 42 has a connection fitting 421 attached to both ends and having an internal cavity with a hemispherical appearance and a narrowed opening, while being connected to both ends.
Reference numeral 48 has a connection sphere closer to a sphere than a hemisphere at an end, and the tie rod 42 can be three-dimensionally rotated around the connection sphere by press-fitting the connection sphere into the connection fitting 421. The connection pins 44 and 48 are connected to each other in a retaining state.

In this embodiment, the steering rod 31 is positioned on a center line L extending in the front-rear direction of the vehicle 1.
The layout is set such that the axis of the column-shaped connecting piece 43 is also located on the center line L in a state where the respective steered wheels W face the front. Further, the steering wheel support frame 28 and the steering wheel axis W4 are formed symmetrically with respect to the center line L, and the left and right steering wheel support brackets 45, the left and right link plates 41, and the left and right tie rods 42 form the steering wheels. The dimensions are set such that W is symmetrical left and right when facing the front.

The axis of the steering rod 31 and the axis of each connection pin 48 of the left and right link projections 46 are aligned with a straight line L1 orthogonal to the center line L when the left and right steered wheels W face front. They are positioned relative to each other so as to be located above.

When the left and right steering wheels W face forward, the angle formed by the right link projection 46a and the right tie rod 42a is set to approximately 90 °, and the left link projection 46b is The angle formed by the left tie rod 42b is also set to approximately 90 °.

Further, with the left and right steering wheels W facing the front as a starting point and the steering rod 31 fully rotated in a predetermined direction, as shown in FIG. The intersection O between the center line L2 of the left steered wheel W2 in the example shown in FIG. 8 and the center line L3 of the steered wheel W on the outer wheel side (right steered wheel W1 in the example shown in FIG. 8) is determined as the inner wheel drive. Wheel W0
(In the example shown in FIG. 8, the left driving wheel W02), the steering wheel support frame 28 and each link projection 4
6. The effective length (inter-axis distance) of each link plate 41 and each tie rod 42 is set.

In the present embodiment, regarding the plane size of the vehicle 1, the distance S1 between the left and right king pins 47 is 40
0 mm, each steering wheel W with the steering wheel W facing front
1, the distance S2 between the centers of W2 is 540 mm,
The distance S3 between the centers of 0 is also set to 540 mm, and the distance S4 in the front-rear direction between the axis of the king pin 47 and the axis connecting the centers of the pair of drive wheels W0 is set to 800 mm. In addition, the left and right king pins 47 are all set inside the vehicle body by the same dimension from the center position of the left and right drive wheels W0. The distance S5 between the king pin 47 and the center point of the left steering wheel W2 is 70
mm ((S2-S1) / 2).

Therefore, each of the steered wheels W1 and W2 facing the front shown by two-dot chain lines in FIG.
In the state shown by a solid line in FIG. 7, the total steering angle α of the right steered wheel W1 is tan α = S4 / (S1 + S5) = 800/470 = 1.702.

Further, the steering angle β of the left steered wheel W2 is tan β = S4 / S5 = 800/70 = 11.429.

That is, in the present embodiment, with the direction of the steered wheels W being changed to the maximum, the total steering angle α of the steered wheels W on the outer wheel side becomes 60 ° and the steered wheels W on the inner wheel side are changed. The link plate 41, the tie rod 42, and the steering wheel support bracket 4 in the steering mechanism 4 are set so that the total steering angle β is 85 °.
5 and the link protruding pieces 46 are set in size, and the installation positions of the connection pins 44 and 48 and the king pin 47 are set.

By operating the operating rod 34 and operating the handle arm 32 to the maximum, the running vehicle 1 turns around the ground contact portion of the inner wheel side drive wheel W0. The vehicle 1 has a very small turn, and the vehicle 1 can travel freely indoors or in a narrow passage.

As described in detail above, the present invention is a steering mechanism for a vehicle that steers a pair of steering wheels W provided at the front of the chassis 2 so as to face each other in the vehicle width direction. A steering rod 31 erected at the center in the direction of rotation about its own axis;
And a steering mechanism 4 that turns the pair of steered wheels W by rotating the steering rod 31 around the axis by operating the operation rod 34. 4 is configured such that the degree of change in the direction of the steered wheels W on the inner wheel side is made larger than the degree of change in the direction of the steered wheels W on the outer wheel side. By turning the vehicle in the turning direction of the vehicle, the pair of steered wheels W in the vehicle width direction is turned by the operation of the steering mechanism 4 into the steering rod 3.
The vehicle 1 is turned in a turning direction corresponding to the turning direction of the vehicle 1, whereby the running vehicle 1 can be turned in that direction.

The degree of change in the direction of the steered wheels W on the inner wheel side can be made larger than the degree of the change in the direction of the steered wheels W on the outer wheel side by the action of the steering mechanism 4. The intersection of the axis and the axis of the steered wheel W on the outer wheel side can be set as the turning center, whereby the vehicle 1 can be moved in a state where the turning radius of the steered wheel W on the inner wheel side is smaller than that of the outer wheel side. Can be turned.

Therefore, in contrast to the conventional steering device in which the steered wheels W are steered so that the directions of the steered wheels W are always parallel, this steering wheel W does not intersect with the axes of the steered wheels W being parallel. Therefore, the turning center cannot be determined only by changing the direction of the steered wheels, and there is no inconvenience that the turning radius is increased by determining the turning center in relation to the non-steered wheels. Can work.

Then, the link plate 41 fixed to the steering rod 31 with the steering mechanism 4 protruding forward.
And the left and right steered wheels W have their axes fixed, and the chassis 2
A pair of steering wheel support brackets 45 in the vehicle width direction, which are rotatably supported around the king pin 47 on the steering wheel support frame 28, and intersect between the link plate 41 and the respective steering wheel support brackets 45. A pair of tie rods 42 are provided so as to be linked, and the tie rods 42 and the link plate 41 and the steering wheel support brackets 45 are relatively positioned around predetermined axes (connection pins 44, 48, king pin 47). When the steering rod 31 is turned in the turning direction by operating the operation rod 34 by rotatably connecting, the link plate 41 is turned in the same direction, whereby each tie rod 42 is connected to the pair of steering wheels W. In the turning direction, and the running vehicle 1 can be turned.

Since the pair of tie rods 42 are pivotally supported by the link plate 41 in a state of intersecting each other at a position in front of the steering rod 31, the link plate 41 is turned from the neutral position facing the front toward the turning direction. When the tie rod 42 is turned, the tie rod 42 on the inner race moves a portion of the rotation trajectory of the link plate 41 in which the component moving in the vehicle width direction is larger than the tie rod 42 on the outer race. Accordingly, the amount of rotation of the inner-wheel-side steering wheel support bracket 45 that is rotated by the movement of the inner-wheel-side tie rod 42 is greater than the amount of rotation of the outer-wheel-side steering wheel support bracket 45. The degree of the direction in the turning direction can be made larger than the degree of the direction of the steering wheel W on the outer wheel side in the turning direction.

In the state where the inner wheel side of the steered wheels W is turned to the maximum, the intersection of the center line of the inner wheel side steered wheels W and the center line of the outer wheel side steered wheels W is determined. Since the center distance between the link plate 41, the tie rods 42, and the steering wheel support bracket 45 is set so as to be located at the center of the drive wheel W0 on the inner wheel side, the operating rod 34 is maximally operated in the turning direction. By doing so, the intersection of the axis of the steered wheel W on the inner wheel side and the axis of the steered wheel W on the outer wheel side is located at the center of the drive wheel W0 on the inner wheel side. Of the vehicle 1 can be turned around the center of the inner wheel side drive wheel W0, and the turning radius of the vehicle 1 is very small.
It can be a small turn.

Further, one of the pair of tie rods 42 is connected to the link plate 41 and the steering wheel support bracket 45.
By linking the tie rods to the upper surface side and the other to the lower surface side, it is possible to easily avoid mutual interference between the pair of crossed tie rods 42, and to make the steering mechanism 4 a simple structure. It is valid.

The present invention is not limited to the above embodiment, but includes the following contents.

(1) In the above embodiment, two drive wheels W0 are provided. However, the present invention is not limited to two drive wheels, and one drive wheel W0 is provided. May be applied to a so-called tricycle.

(2) In the above embodiment, the steering mechanism 4 is applied to the front wheel side. However, the present invention is not limited to the application of the steering mechanism 4 to the front wheel side. It may be applied to the wheel side. However, in order to apply the steering mechanism 4 to the rear wheel side, the steering rod 31 is provided on the rear wheel side, and the turning operation of the operation rod 34 is transmitted to the rear wheel side steering rod by a predetermined link mechanism. Installation of a transmission structure is required.

(3) In the above embodiment, the link plate 41 fixed to the steering rod 31 and the pair of link projections 46 provided on each of the steering wheel support brackets 45 project forward. However, the present invention is not limited to the configuration in which the link plate 41 and the link projection 46 protrude forward, and both may protrude rearward. In this way, the left and right tie rods 42 can be linked to the link plate 41 without crossing each other, and as a result, as in the above-described embodiment,
Is divided into a lower link plate 41a and an upper link plate 41b, and the right tie rod 42a is linked to the lower link plate 41a, and the left tie rod 42b is connected to the upper link plate 41b.
Therefore, it is not necessary to adopt a complicated structure such that the steering mechanism 4 is linked, and the structure of the steering mechanism 4 can be simplified accordingly.

(4) In the above embodiment, the chassis 2 is formed by a square pipe. However, the present invention is not limited to the case where the chassis 2 is formed of a square pipe. It may be.

[0067]

According to the steering mechanism for a vehicle according to the first aspect of the present invention, a steering rod is provided upright at the center in the width direction of the vehicle body so as to be rotatable around its own axis. An operation rod for performing a turning operation, and a direction changing means for changing the direction of the pair of steered wheels by turning the steering rod around the axis by operating the operation rod; Since the degree of change is configured to be greater than the degree of change in the direction of the outer-wheel-side steered wheels, the axis of the inner-wheel-side steered wheels and the axis of the outer-wheel-side steered wheels are maintained while the operating rod is operated in the turning direction. The intersection point with the core wire becomes the turning center, whereby the vehicle can be turned with the turning radius of the steered wheels on the inner wheel side smaller than that on the outer wheel side. Therefore, when steering is performed such that the directions of the steered wheels are always parallel as in the related art, the axes of the steered wheels are not parallel and do not intersect with each other. The inconvenience that the turning radius becomes large due to the turning center being determined in relation to the non-steered wheels can be solved without being determined only by the change, and the vehicle can be made to turn very slightly.

Further, since the pair of tie rods intersect each other at the position in front of the steering rod, it is possible to increase the range of rotation of each steered wheel as compared with the case where they do not intersect, so that the vehicle The turning radius can be made smaller, and when the operating rod is operated up to the minimum turning radius of the vehicle, the axis of the vertical axis is located in the direction in which the tie rod extends, and thereby the operating rod is in the neutral position. The conventional disadvantage that the steered wheels turn in the opposite direction when trying to return can be avoided.

According to the steering mechanism for a vehicle according to the second aspect of the present invention, each tie rod is connected to the link member and each bracket so as to be relatively rotatable about a predetermined axis. Accordingly, each bracket is rotated around a vertical axis while being relatively rotated around the axis with respect to the link member, whereby the direction of the steered wheels can be changed. And since the center distance between the tie rods is set to be the same and the center distance between the brackets is also set to be the same, when the operation amount of the operation rod is the same on the left and right, the steering angle of each steered wheel is changed. Left and right can be the same.

According to the steering mechanism for a vehicle according to the third aspect of the present invention, when the inner wheels of the steered wheels are turned to the maximum extent, the axial center line of the inner wheels and the outer wheels are adjusted. The distance between the link members, the tie rods and the brackets is set so that the intersection of the steered wheels on the side with the axis of the inner wheel is located at the center of the non-steered wheels on the inner wheel side. The steered wheels can be turned around the center. By turning the vehicle around the non-steered wheels on the inner wheel side, the turning radius of the vehicle can be made very small.

According to the steering mechanism for a vehicle according to the fourth aspect of the present invention, one of the pair of tie rods is linked to the upper surface of the link member and the bracket, and the other is linked to the lower surface, so that the tie rods intersect. Mutual interference between the pair of tie rods can be reliably avoided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a skeleton of a vehicle to which a steering mechanism according to the present invention is applied.

FIG. 2 is a plan view of the vehicle shown in FIG.

FIG. 3 is a front view of the vehicle shown in FIG.

FIG. 4 is a side view of the vehicle shown in FIG.

FIG. 5 is a perspective view showing the vehicle in a state where a cover is applied to the skeleton shown in FIG. 1;

FIG. 6 is a partially cutaway perspective view showing details of a steering mechanism.

FIG. 7 is a plan view of the steering mechanism shown in FIG. 6;

FIG. 8 is a plan view illustrating the maximum steering angle of a steered wheel.

FIG. 9 is a plan view illustrating an example of a conventional steering mechanism.

FIG. 10 is an explanatory plan view showing another example of a conventional steering mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Vehicle 11 Bumper 12 Wheel cover 13 Front blind cover 14 Rear blind cover 2 Chassis 21 Right frame 22 Left frame 23 Front connecting plate 23a Rod support tube 24 Rear connecting plate 24a Support hole 25 Front connecting frame 26 Intermediate connecting frame 27 Vertical rod 28 Steering wheel support frame 29 Central frame 3 Handle structure 31 Steering rod 32 Handle arm 32a Right handle arm 32b Left handle arm 33 Bracket 34 Operation rod 34a Right operation rod 34b Left operation rod 35 Support shaft 36 Basket support arm 37 Operation panel 4 Steering mechanism (Direction changing means) 41 link plate 41a lower link plate 41b upper link plate 42 tie rod 42a right tie rod 42b left tie rod 43 connecting piece 44 connection pin 45 operation Wheel support bracket 45a Right support bracket 45b Left support bracket 46 Link projection 46a Right link projection 46b Left link projection 47 King pin 48 Connection pin 5 Seat 51 Seat bottom 52 Seat back 53 Armrest 54 Seat support rod 6 Front basket 7 Drive means 71 Electric motor 72 Battery W Steering wheel W1 Right steering wheel W2 Left steering wheel W3 Driven shaft W0 Driving wheel

Claims (4)

[Claims] 1. A steering mechanism for a vehicle that steers a pair of steering wheels provided on a vehicle body facing each other in a vehicle width direction, wherein the steering mechanism is rotatable around its own axis at a central portion in the width direction of the vehicle body. An upright steering rod, an operation rod for rotating the steering rod, and direction changing means for changing the direction of the pair of steered wheels by rotation of the steering rod around the axis by operation of the operation rod. The direction changing means is provided with a link member fixed to the steering rod in a state of protruding forward, a shaft of the left and right steering wheels being supported, and rotating around a vertical axis to a frame of the vehicle body. A steering mechanism for a vehicle, comprising: a pair of brackets freely supported in a vehicle width direction; and a pair of tie rods interlinked between the link member and the brackets. . 2. The tie rods, the link member, and the brackets are connected to each other so as to be relatively rotatable about a predetermined axis, and the tie rods are set to have the same inter-axis distance. 2. The vehicle steering mechanism according to claim 1, wherein the distance between the shafts is set to be the same, and each tie rod is installed so as to be left-right symmetrical with the steered wheels facing the front. 3. An intersection between the axis of the inner-wheel steered wheels and the axis of the outer-wheel steered wheels in a state in which the inner wheels of the steered wheels are maximally turned, 3. The vehicle steering system according to claim 2, wherein the center distance between the link member, the tie rod, and the bracket is set so as to be located at the center of the non-steered wheel on the inner wheel side. 4. The method according to claim 2, wherein one of the pair of tie rods is linked to an upper surface of the link member and the bracket, and the other is linked to a lower surface of the bracket. Vehicle steering mechanism.