JP6814082B2 - Steering drive - Google Patents

Description

The present invention relates to a device that drives the steering of a vehicle.

Conventionally, for the purpose of improving the efficiency of agricultural work, an automatic steering technique for making an agricultural work vehicle such as a tractor or a rice transplanter follow a designated traveling line has been known. Target vehicles that are subject to such automatic steering include those equipped with a mechanism that supports automatic steering and those that are equipped with only a mechanism that does not support automatic steering and manually operates the steering wheel. ..

In the manual vehicle, the steering handle for manually steering by rotating the input shaft that inputs the rotational force as the steering torque to the steering system is removable from the input shaft. Therefore, by incorporating a steering drive device that rotationally drives the input shaft between the input shaft and the steering handle and controlling the steering drive device, it is possible to make the manual vehicle compatible with automatic steering.

As a technique for controlling such a manual vehicle by a steering drive device, a receiver that receives a position instruction signal, a steering control device that generates a steering control signal based on the position instruction signal, a steering shaft, and rotation thereof. A vehicle guidance system including a drive assembly that directly drives the steering assembly in response to a steering control signal by generating torque around a drive shaft coaxial with the steering wheel to be driven is known (eg, Patent Document 1). reference).

International release 2010/139013

However, according to the vehicle guidance system described above, since the input shaft of the drive system and the drive shaft of the steering drive device are coaxial, the size of the steering drive device in the axial direction of the input shaft increases, and the steering wheel post and steering wheel Will be separated. According to this, there is a problem that the height of the steering wheel becomes an unnatural position unsuitable for the operation by the driver, which causes inconvenience in driving the vehicle when switching from automatic steering to manual steering.

An embodiment of the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a steering drive device capable of reducing the size of an input shaft of a drive system in the axial direction.

In order to solve the above-mentioned problems, the steering drive device of the present embodiment gives an deviation angle to the wheels of the vehicle to be automatically steered, and inputs a rotational force as a steering torque to the steering system for steering the vehicle. A steering drive device that drives a shaft, which has a rotating shaft that can be connected so as to rotate integrally with the input shaft, a gear is provided along the outer circumference of the rotating shaft, and a driving force is transmitted to the input shaft. The transmission shaft has a rotation shaft provided with a gear that meshes with the gear of the transmission shaft, and the rotation shaft is arranged so that the axial direction of the rotation shaft is orthogonal to the axial direction of the transmission shaft. It has a motor for driving the shaft and a rotating shaft provided with a gear that meshes with the gear of the transmission shaft, and is arranged so that the axial direction of the rotating shaft faces a direction orthogonal to the axial direction of the transmission shaft. It includes an encoder that detects the rotation of the transmission shaft.

According to the embodiment of the present invention, the size of the input shaft of the drive system in the axial direction can be reduced.

It is a schematic side view which shows the structure of the agricultural tractor which concerns on embodiment. It is a block diagram which shows the structure of the automatic steering system which concerns on embodiment. It is a perspective view which shows the steering drive device attached to the steering column. It is a top view which shows the steering drive device attached to the steering column. It is a right side view which shows the steering drive device attached to the steering column. It is a rear view which shows the steering drive device attached to the steering column. It is a top view which shows the internal structure of a steering drive device. It is sectional drawing which shows the internal structure of the steering drive device.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Structure of target vehicle and automatic steering system)
First, the automatic steering system according to the present embodiment and the target vehicle automatically steered by the automatic steering system will be described. FIG. 1 is a schematic side view showing the configuration of an agricultural tractor according to an embodiment. FIG. 2 is a block diagram showing a configuration of an automatic steering system according to an embodiment.

The vehicle to be steered by the automatic steering system according to the present embodiment is a work vehicle, and specifically, an agricultural tractor 1 as shown in FIG. The tractor 1 is a four-wheeled vehicle including a vehicle body 10, two front wheels 11, and two rear wheels 12, but any vehicle may be steerable. Further, the tractor 1 includes a seat 13 for a driver to sit on, a link mechanism 14 for connecting and connecting work machines (not shown), a steering column 30, a steering handle 40, a steering drive device 50, accelerators, brakes, and other pedals 60. Be prepared.

A steering system 90 (not shown in FIG. 1) for steering the tractor 1 by giving an argument to the front wheels 11 is provided in the steering column 30, and the rotational force as steering torque by the steering handle 40 or the steering drive device 50 is steered. An input shaft 301 for inputting to the system 90 is built in. The input shaft 301 has an axial direction that is substantially vertically oriented, and a fitting portion 301a that can be fitted to a removable mounting steering handle is formed at the upper end thereof. , The fitting portion 301a is fitted to the steering drive device 50. The steering drive device 50 is a device that is not provided with a configuration for automatic steering control and is retrofitted to automatically steer the tractor 1 on the premise of manual steering, and a steering handle 40 is attached above. At the same time, the fitting portion 301a of the input shaft 301 of the steering system 90 is fitted below. The configuration of the steering drive device 50 will be described in detail later.

As shown in FIG. 2, the automatic steering system includes a steering system 90, a steering drive device 50 for driving the steering system 90, a GNSS (Global Navigation Satellite System) sensor 60, a steering control device 70, and a motor control device 80. And. The GNSS sensor 60, the steering control device 70, and the motor control device 80 are provided in the tractor 1.

The steering drive device 50 includes a transmission shaft 501 that transmits a driving force to the input shaft 301, a motor 502 that is a stepping motor that drives the transmission shaft 501, and an encoder 503 that is a rotary encoder that detects the amount of rotation and the rotation position of the transmission shaft 501. To be equipped. The motor 502 may be any kind of motor as long as it can output a sufficient torque to rotate the input shaft 301.

The GNSS sensor 60 detects the position of the tractor 1, and the steering control device 70 sets this current position as the target position based on the set target position and the current position of the tractor 1 detected by the GNSS sensor 60. The steering amount is instructed to the motor control device 80.

The motor control device 80 feedback-controls the steering drive device 50 based on the steering amount instructed by the steering control device 70. Here, the motor control device 80 controls the motor 502 so that the rotation position detected by the encoder 503 becomes a desired rotation position, and drives the transmission shaft 501.

In this way, the tractor 1 is configured to be manually steered by retrofitting the steering drive device 50, the GNSS sensor 60, the steering control device 70, and the motor control device 80 to the tractor 1. Can be realized.

(Appearance configuration of steering drive device)
Next, the appearance configuration of the steering drive device will be described. FIG. 3 is a perspective view showing a steering drive device mounted on the steering column. FIG. 4 is a plan view showing a steering drive device mounted on the steering column. FIG. 5 is a right side view showing a steering drive device mounted on the steering column. FIG. 6 is a rear view showing a steering drive device mounted on the steering column. In FIGS. 3 to 6, the z direction indicates the vertical direction facing the axial direction of the input shaft or the transmission shaft. It is assumed that the y direction is the traveling direction of the tractor and is orthogonal to the vertical direction, and the x direction is the horizontal direction orthogonal to the front-rear direction.

As shown in FIGS. 3 to 6, the steering drive device 50 rotates integrally with the input shaft 301 with respect to the fitting portion 301a formed at the upper end of the input shaft 301 protruding upward from the steering column 30. It is attached to the steering column 30 by fitting the lower end of the transmission shaft 501 (see FIG. 7). A forward / backward lever 32 is provided on the left side of the steering column 30, and a throttle lever 33 is provided on the right side.

A steering handle 40 is attached above the steering drive device 50. The steering handle 40 extends in the radial direction with a ring member 41 formed in an annular shape as a handle when the driver steers the tractor 1 and a boss member 42 formed in a substantially circular shape concentric with the ring member 41. It is provided with three spoke members 43a to 43c that are present and connect the ring member 41 and the boss member 42.

The steering drive device 50 is a housing that houses the transmission shaft 501, the motor 502, and the encoder 503 (see FIG. 7), and has a substantially triangular shape having a predetermined thickness in the vertical direction and a hollow inside. It has a formed housing 500 and is installed on the steering column 30 so that one of the vertices faces forward. The transmission shaft 501 is arranged so as to vertically penetrate the housing 500 at the apex portion located in front of the three apex portions of the housing 500 with its axial direction facing the vertical direction. Further, a mounting flange 52 protruding in the out-of-diameter direction is formed at the upper end of the transmission shaft 501 protruding upward from the housing 500, and the boss member 42 is connected to the mounting flange 52 to connect the steering handle 40. Is attached to the steering drive device 50 so that it can rotate integrally with the transmission shaft 501. As a result, when the tractor 1 is not automatically steered, the driver can manually steer the tractor 1.

Further, as shown in FIGS. 5 and 6, in the vicinity of the rear side of the bottom surface of the housing 500, the steering drive device 50 abuts on the steering column 30 and the steering drive device 50 is around the axis of the transmission shaft 501 with respect to the steering column 30. Two regulating members 50a and 50b are provided to regulate the rotation. Further, as shown in FIGS. 3, 5, and 6, the horn switch 51 is located on the rear side surface of the housing 500, that is, the side surface that does not form the apex on which the transmission shaft 501 is arranged, in the substantially central portion in the left-right direction. Is provided. Further, as shown in FIGS. 4 and 5, the transmission shaft 501 is supplied with lubricating oil to the front side surface of the housing 500, that is, the front apex of the housing 500 formed in a substantially triangular shape. The grease nipple 53 is provided. The grease nipple 53 will be described in detail later.

(Internal configuration of steering drive)
Next, the internal configuration of the steering drive device will be described. FIG. 7 is a plan view showing the internal configuration of the steering drive device. FIG. 8 is a cross-sectional view showing the internal configuration of the steering drive device. Note that FIG. 7 shows a steering drive device in a state where the upper part of the housing and the mounting flange are transmitted through the mounting flange for explanation, and FIG. 8 shows the axis of the transmission shaft which is parallel in the front-rear direction and the up-down direction. The cross section of the cut surface by the plane through which it passes is shown from the right side.

As shown in FIGS. 7 and 8, the transmission shaft 501 is a substantially cylindrical member whose axial direction is oriented in the vertical direction, and tooth streaks are outside the diameter of a plane orthogonal to the vertical direction on the outer periphery thereof. A bevel gear 501a is formed which is inclined downward by a predetermined angle along the direction. A mounting flange 52 is integrally rotatably connected to the upper end of the transmission shaft 501, and the boss member 42 of the steering handle 40 is mounted on the mounting flange 52 as described above. Further, the mounting flange 52 is formed to have a diameter larger than the through hole of the housing 500 through which the transmission shaft 501 is inserted, whereby the transmission shaft 501 is restricted by the mounting flange 52 so as not to move downward.

Further, a first attachment 54a and a second attachment 54b corresponding to the spline shape of the fitting portion 301a of the input shaft 301 are attached to the lower end of the transmission shaft 501, whereby the input in the tractor 1 to be automatically steered is provided. Regardless of the spline shape of the fitting portion 301a of the shaft 301, the steering drive device 50 can be made to correspond to the tractor 1 only by preparing an attachment having a shape that matches the spline shape.

The first attachment 54a is connected to the transmission shaft 501 so as to rotate integrally, and the fitting portion 301a fitted to the first attachment 54a is integrally rotatably fixed to the first attachment 54a by the hard lock nut 54a1. Further, at the lower end of the first attachment 54a, a flange formed having a diameter larger than that of the through hole of the housing 500 is formed, and the second attachment 54b is formed having a diameter larger than this flange. The transmission shaft 501 is restricted from moving upward by such a first attachment 54a and a second attachment 54b.

As shown in FIG. 7, the motor 502 has a rotary shaft 502a that is rotationally driven and a bevel gear 502b attached to the tip of the rotary shaft 502a. In the housing 500, the motor 502 is arranged so that at least the axial direction of the rotation shaft 502a faces the direction orthogonal to the axial direction of the transmission shaft 501, and further, the motor 502 is arranged behind the transmission shaft 501. It is located and is arranged so that the axial direction of the rotation shaft 502a faces between the front-rear direction F and the left-right direction L. In the present embodiment, the motor 502 is arranged so that the axial direction of the rotation shaft 502a is inclined by 30 ° to the left from the front-rear direction F.

The encoder 503 has a rotary shaft 503a for inputting a rotational displacement, and a bevel gear 503b attached to the tip of the rotary shaft 503a. In the housing 500, the encoder 503 is arranged so that the axial direction of the rotation shaft 503a is perpendicular to the axial direction of the transmission shaft 501, and further, the transmission shaft 501 is arranged so as to be oriented in the axial direction of the rotation shaft 503a. It is arranged so as to be located rearward and the axial direction of the rotation shaft 503a faces from the front-rear direction F to the opposite side of the left-right direction L. In the present embodiment, the encoder 503 is arranged so that the axial direction of the rotation shaft 503a is inclined by 30 ° from the front-rear direction F to the right side.

As described above, with respect to the reference line (the line facing the front-rear direction F) that passes through the axis of the transmission shaft 501 and is orthogonal to the axial direction, the axial direction of the rotation axis 502a of the motor 502 is the reference line from the reference line. It is arranged at an angle with respect to the reference line so as to be located between the line and the orthogonal line (the line facing the left-right direction L) orthogonal to the axial direction of the transmission shaft 501. Further, the encoder 503 is inclined in the direction opposite to the motor 502 with respect to the reference line so that the axial direction of the rotation axis 503a is located between the reference line and the orthogonal line. Be placed.

By arranging the transmission shaft 501, the motor 502, and the encoder 503 in this way, the size of the steering drive device 50 in the vertical direction can be reduced, and by making the housing 500 substantially triangular, the vehicle moves forward and backward. It does not prevent the driver from operating the operating parts such as the lever 32 and the throttle lever 33 that project in the left-right direction. Further, since the motor 502 and the encoder 503 are inclined in opposite directions in the left-right direction, an operation unit such as a horn switch 51 to be arranged near the steering handle 40 should be arranged between the motor 502 and the encoder 503. Can be done.

The housing 500 that houses the transmission shaft 501, the motor 502, and the encoder 503 is composed of an upper member 500a and a lower member 500b as two vertically divided members. A rubber packing 500c as a sealing member is arranged between the upper member 500a and the lower member 500b. Further, in the through hole through which the transmission shaft 501 of the upper member 500a is passed, the oil seal 501b seals between the upper member 500a and the transmission shaft 501. Further, in the through hole through which the transmission shaft 501 of the lower member 500b is penetrated, a bearing 501c with a contact seal seals between the lower member 500b and the transmission shaft 501. By sealing the gap generated in the housing 500 in this way, it is possible to prevent earth and sand or water from entering the steering drive device 50 mounted on the tractor 1 used in the agricultural land.

The upper member 500a is provided with a grease nipple 53 in the front-rear direction, that is, on the side where the transmission shaft 501 is arranged, and a horn button on the rear side, that is, on the side opposite to the side where the transmission shaft 501 is arranged. 51 is provided. The grease nipple 53 is provided to supply grease to the bevel gear 501a of the transmission shaft 501 from the outside of the housing 500, and has a nipple portion 531 that protrudes to the outside of the housing 500 and can supply grease to the inside of the housing 500. It has a guide portion 532 that guides the grease supplied to the inside of the housing 500 by the nipple portion 531 onto the bevel gear 501a.

The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

50 Steering drive 501 Transmission shaft 501a Bevel gear 502 Motor 502a Rotating shaft 502b Bevel gear 503 Encoder 503a Rotating shaft 503b Bevel gear

Claims (6)

It is a steering drive device that inputs a driving force to the input shaft of the steering system configured so that the driver can give a declination to the wheels in a vehicle that is the target of automatic steering.
A transmission shaft formed so as to rotate integrally with the input shaft, a gear is provided along the rotation axis center of the input shaft, and a driving force is transmitted to the input shaft.
A motor that has a rotating shaft provided with a gear that meshes with the gear of the transmission shaft, and is arranged so that the axial direction of the rotating shaft faces a direction orthogonal to the axial direction of the transmission shaft to drive the transmission shaft. When,
It has a rotating shaft provided with a gear that meshes with the gear of the transmission shaft, and is arranged so that the axial direction of the rotating shaft faces a direction orthogonal to the axial direction of the transmission shaft to detect the rotation of the transmission shaft. Steering drive with an encoder. In the motor, the axial direction of the rotation axis of the motor is from the reference line to the reference line and the transmission shaft with respect to a reference line that passes through the axis of the transmission shaft and is orthogonal to the axial direction of the transmission shaft. It is arranged so as to incline in one of the rotation directions of the transmission axis so as to face between the orthogonal lines orthogonal to the axial direction.
The encoder is arranged so that the axial direction of the rotation axis of the encoder is inclined in the direction opposite to the rotation direction of the transmission axis with respect to the reference line so as to face between the reference line and the orthogonal line. The steering drive device according to claim 1, wherein the steering drive device is provided. The steering drive device according to claim 1 or 2, wherein the gear of the transmission shaft, the gear of the motor, and the gear of the encoder are bevel gears, respectively. 2. A claim 2 or claim, further comprising a housing for accommodating the transmission shaft, the motor, and the encoder, and the housing is formed in a substantially triangular shape when viewed from the axial direction of the transmission shaft. The steering drive device according to 3. The transmission shaft is located near one of the vertices of the housing.
The steering drive device according to claim 4, further comprising a grease nipple for supplying grease from the outside of the housing to the gear of the transmission shaft. Wherein the housing, the steering drive according to請Motomeko 5 you further comprising a horn button provided on a side surface portion which does not form a vertex in which the transmission shaft is arranged.

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