JP2007313984A - Steering mechanism of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a steering part and reduce the size of a steering section in a steering mechanism of a vehicle, apply the mechanism to both four-wheel and three-wheel vehicles, in particular, compactly constitute the whole steering mechanism and drive the mechanism by an electric motor of the minimum output. <P>SOLUTION: The steering mechanism of the vehicle comprises a set of bevel gears comprising a large gear 11 and a small gear 12, a support shaft for supporting the large gear, a bearing for fixing the support shaft to a vehicle structure, an electric motor 31 coupled to the small gear and driving the set of the bevel gears, and an arm for a traveling wheel with one end coupled to the large gear and the other end coupled to the wheel. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a vehicle steering mechanism, and more particularly, to provide a steering mechanism that can be applied to both a four-wheel vehicle and a three-wheel vehicle by simplifying and downsizing a steering portion.

  A typical steering mechanism for a vehicle is a steering mechanism for an automobile. In a steering mechanism for an automobile, the rotational displacement of the steering handle is changed to a swing displacement, and this swing displacement is transmitted to the wheels via a link mechanism. The rotational displacement of the steering wheel is given by the driver's operation. When the vehicle is automatically operated, the rotational displacement is given by an electric motor or the like.

  Such rotational displacements can be changed to swing displacements by using the worm sector (Worm and Sector) type, using a roller to reduce the sector friction loss, screw nut type, and screw friction loss. In order to reduce this, there are a screw groove with a ball, a worm pin type, and a structure in which the pin can be rotated. Furthermore, a rack small gear type with a tie rod as a rack is also used as an independent suspension type steering mechanism.

  In addition, as a method for giving a steering force to the wheel steering mechanism, there is a system in which an electric motor and a worm gear mechanism composed of a worm and a worm gear are used in combination (see Patent Document 1).

  In the conventional wheel steering mechanism shown in FIG. 1, an electric motor 101 is mounted substantially at right angles to the shaft 110 of the traveling wheel arm, and the worm is connected to the output shaft 102 of the electric motor 101 via a coupling 103. 104 shafts are connected. A worm gear 105 is fixed to the shaft 110 of the traveling wheel arm so that the worm 104 and the worm gear 105 are engaged with each other.

  The amount of rotation of the electric motor 101 is controlled by controlling the current input to the electric motor 101, whereby the swing angle of the shaft 110 of the traveling wheel arm is determined and attached to the tip of the traveling wheel arm. Wheel steering is performed.

  However, in such a steering mechanism, the shaft of the electric motor 101 and the worm 104 and the shaft 110 of the worm gear 105 and the traveling wheel arm must be offset to each other, and the entire steering mechanism becomes large. was there.

Further, when power is transmitted through the worm gear mechanism, there is a problem that the power transmission efficiency is low, an electric motor having an output larger than necessary is required, and the entire steering mechanism is further increased.
JP 2004-183828 JP

  The present invention has been made in order to solve the above-described problems, and is intended to make the entire steering mechanism compact and to configure the steering mechanism with an electric motor having a minimum output.

In order to solve the above problems, the invention described in claim 1 has the following configuration. That is,
In a vehicle steering mechanism, a set of bevel gears composed of a large gear and a small gear, a support shaft for supporting the large gear, a bearing for fixing the support shaft to the vehicle structure, and the small gear The steering mechanism is configured to include an electric motor that is connected to drive the bevel gear, and a traveling wheel arm having one end connected to the large gear and the other end connected to the wheel.

  In this way, by using a steering mechanism that uses a set of bevel gears, the shaft of the electric motor and the axis of the arm for the traveling wheel can be arranged orthogonally without offset, and the entire steering mechanism can be made compact. Became possible.

  In addition, since the steering mechanism uses a bevel gear, the power transmission efficiency can be increased, and an electric motor having a minimum output can be used. Therefore, the entire steering mechanism can be made more compact.

Further, the invention described in claim 2 has the following configuration. That is,
In the vehicle steering mechanism according to claim 1, the steering device is configured to further include a rotation detection sensor for detecting a rotation amount of the support shaft at an end portion of the support shaft.

  As a result, the swing angle of the wheel can be detected, and the vehicle can be automatically steered in cooperation with a control device for controlling the steering mechanism.

Further, the invention described in claim 3 has the following configuration. That is,
In the vehicle steering mechanism according to claim 1, the set of bevel gears is selected from either a bevel gear or a spiral bevel gear.

Furthermore, the invention described in claim 4 has the following configuration. That is,
In the vehicle steering mechanism according to claim 1, the wheel is provided with an electric motor for driving the vehicle.

The invention described in claim 5 has the following configuration. That is,
5. The vehicle steering mechanism according to claim 4, wherein a harness for driving and controlling the electric motor passes through the inside of the traveling wheel arm and is wired inside the vehicle structure in which a set of bevel gears are housed. The configuration.

  By adopting such a configuration, the harness can be reliably protected and the appearance can be made clear.

The invention described in claim 6 has the following configuration. That is,
The vehicle steering mechanism according to claim 1, wherein the support shaft for supporting the large gear and the large gear of the bevel gear are integrated.

  By adopting such a configuration, it is possible to reduce the number of parts, increase the rigidity of the steering mechanism, and make the steering mechanism compact.

Furthermore, the invention described in claim 7 has the following configuration. That is,
The vehicle steering mechanism according to claim 6, wherein the large gear of the bevel gear and the arm for the traveling wheel are mechanically coupled on the lower surface of the large gear.

  As described above, according to the present invention, by using a steering mechanism that uses a set of bevel gears, the axis of the electric motor and the axis of the arm for the traveling wheel can be arranged orthogonally without being offset, and the steering It has the effect that the whole mechanism can be made compact.

  In addition, since the steering mechanism uses a bevel gear, the power transmission efficiency can be increased, and the steering mechanism can be configured by an electric motor having a minimum output, so that the entire steering mechanism can be made more compact. Has the effect of being able to.

  Hereinafter, the present invention will be described based on embodiments shown in the drawings.

  FIG. 2 shows a side view of the steering mechanism according to the present invention. FIG. 3 is a front view of the steering mechanism according to the present invention. The steering mechanism according to the present invention includes a pair of bevel gears 10 including a large gear 11 and a small gear 12 and a support shaft 13 for supporting the large gear 11. The support shaft 13 is rotatably fixed to the vehicle structure (or chassis) 20 via a plurality of ball bearings 21. The large gear 11 is mechanically fixed so as to be coaxial with the support shaft 13. The large gear 11 and the support shaft 13 can be integrally formed. By integrating the large gear 11 and the support shaft 13, the number of components can be reduced and the rigidity of the large gear 11 and the support shaft 13 can be increased.

  Further, the steering mechanism according to the present invention is provided with an electric motor 31 for driving the steering mechanism. The small gear 12 of the bevel gear 10 is coaxially attached to the output shaft of the electric motor 31, and the output shaft of the electric motor 31 and the shaft of the small gear 12, the shaft of the large gear 11, and the shaft of the support shaft 13 are They are assembled so that they intersect in the same plane. The small gear 12 side axis and the large gear 11 side axis intersect at an angle of 90 degrees.

  The electric motor 31 is mechanically fixed inside the vehicle structure (or chassis) 20 using a fixing bracket (not shown).

  Here, in order to make the steering mechanism more compact, the angle formed by the shaft on the small gear 12 side and the shaft on the large gear 11 side has been described as 90 degrees, but this angle is not limited to 90 degrees. Alternatively, they may intersect at an arbitrary angle. In this case, the angle obtained by adding the half apex angle of the large gear 11 and the half apex angle of the small gear 12 is an axial angle, and this axial angle corresponds to the angle formed by the small gear 12 side axis and the large gear 11 side axis. To do. Therefore, when the angle formed between the shaft on the small gear 12 side and the shaft on the large gear 11 side is set to 90 degrees, it is necessary to select a bevel gear whose shaft angle is 90 degrees.

  Furthermore, the steering mechanism according to the present invention includes a traveling wheel arm 41 and a wheel 42. The upper end of the traveling wheel arm 41 is mechanically coupled to the lower surface of the large gear 11. The traveling wheel arm 41 is temporarily offset from the axis X of the large gear 11 and the support shaft 13, and the center position in the thickness direction of the wheel 42 attached to the lower end side of the traveling wheel arm 41 coincides with the axis X. Thus, the traveling wheel arm 41 has a curved shape (see FIG. 3).

  The traveling wheel arm 41 and the wheel 42 are coupled via a pair of ball bearings 44, and the wheel 42 is coupled to the traveling wheel arm 41 so as to be rotatable.

  Further, a rotation detection sensor 52 can be provided at the upper end position of the support shaft 13 of the large gear 11 in order to detect the rotation angle of the support shaft 13. A potentiometer can be used as such a rotation detection sensor.

  By using the signal of the rotation detection sensor 52 such as a potentiometer, the steering mechanism can be automatically operated.

  Also, as the bevel gear used here, either a bevel gear or a spiral bevel gear can be used immediately, but it is necessary to select it in consideration of the size of transmission load, silence, cost, etc. is there.

  Furthermore, an electric motor 43 for driving the vehicle can be arranged between the arm 41 for traveling wheels and the wheel 42. In this way, not only the steering of the driven wheel but also the steering of the driving wheel is possible.

  When the vehicle driving electric motor 43 is arranged between the traveling wheel arm 41 and the wheel 42, a harness 51 for driving and controlling the electric motor 43 is arranged along the traveling wheel arm 41. However, such a harness 51 can be collectively disposed inside the traveling wheel arm 41. In this case, the harness 51 can be wired without being exposed to the outside by providing the cover 45 at the lower position of the portion of the vehicle structure (or chassis) 20 to which the large gear 11 is attached.

  Next, the operation of the steering mechanism according to the present invention will be described. When the steering mechanism is automatically operated, the electric motor 31 is rotationally controlled based on the steering angle information sent from the control device, and the small gear 12 of the bevel gear 10 rotates according to the rotation of the motor 31. . When the small gear 12 rotates, the large gear 13 that meshes with it rotates, and the traveling wheel arm 41 and the wheel 42 are integrated (if the vehicle driving electric motor 43 is disposed, the vehicle The electric motor 43 for driving is also integrated (rotated around the X axis), and steering is performed.

  When this steering mechanism is applied to a three-wheeled vehicle, it is possible to steer the vehicle by providing the above-described steering mechanism for only one wheel. However, when this steering mechanism is applied to a four-wheeled vehicle, It is necessary to provide the steering mechanism described here for two wheels. And in order to steer a four-wheel vehicle, it is necessary to synchronize and control each steering mechanism provided in two wheels.

  The steering mechanism according to the present invention can be used as a steering mechanism for a cargo transportation vehicle, a wheel movement type robot, and the like, and can be used not only in a three-wheeled vehicle but also in a four-wheeled vehicle. .

FIG. 1 shows a conventional wheel steering mechanism. FIG. 2 shows a side view of the steering mechanism according to the present invention. FIG. 3 is a front view of the steering mechanism according to the present invention.

Explanation of symbols

10 Bevel gear
11 Large gear
12 large gears
13 Support shaft
20 Vehicle structure (or chassis)
21 Ball bearing
31 Electric motor
41 Traveling wheel arm
42 wheels
43 Electric motor
44 Ball bearing
45 Cover
51 Harness
52 Rotation detection sensor

Claims (7)

In the vehicle steering mechanism,
A set of bevel gears consisting of a large gear and a small gear;
A support shaft for supporting the large gear;
A bearing for fixing the support shaft to the vehicle structure;
An electric motor connected to the small gear and driving the bevel gear;
A steering mechanism comprising: a traveling wheel arm having one end connected to the large gear and the other end connected to a wheel.   2. The steering apparatus according to claim 1, further comprising a rotation detection sensor for detecting a rotation amount of the support shaft at the end of the support shaft.   2. The steering apparatus according to claim 1, wherein the set of bevel gears is either a bevel gear or a spiral bevel gear.   2. The steering mechanism according to claim 1, wherein the wheel is provided with an electric motor for driving the vehicle.   5. The vehicle steering mechanism according to claim 4, wherein a harness for driving and controlling the electric motor passes through the inside of the traveling wheel arm, and is inside the vehicle structure in which the pair of bevel gears are housed. A steering mechanism that is wired.   2. The steering mechanism for a vehicle according to claim 1, wherein a support shaft for supporting the large gear and the large gear of the bevel gear are integrated. 7. The steering mechanism according to claim 6, wherein the large gear of the bevel gear and the arm for the traveling wheel are mechanically coupled to each other on the lower surface of the large gear.

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