JP2016130095A - Drive mechanism of traveling device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drive mechanism of a traveling device which can use an endless member for connecting and driving a front wheel and a rear wheel as travel assistance only when necessary.SOLUTION: A drive mechanism of a traveling device (10) is provided with a pair of right and left wheels (12) mounted on a front part and a rear part of an under carriage, sprockets (16) which are integrally arranged on the right and left wheels on either one of the front or rear part and have a smaller diameter than the wheels, a belt (17) suspended around the front and rear sprockets, a pulley (21) which abuts on an inner peripheral surface of the belt and can change a position of the belt, and an actuator (22) for moving the pulley. The actuator moves the belt from a first position connecting a lower end of the sprocket to a second position which is lower than the first position by moving the pulley downward and inscribing the pulley on a lower side of the belt so as to make a belt function as an endless track.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drive mechanism of a traveling device in four-wheel drive.

  As a steering method capable of turning at the same place, a skid steer method is known in which steering is performed by a difference in rotation between left and right wheels. In particular, an autonomous traveling device using an electric motor as a power source can be steered only by rotational control of the motor by using separate electric motors for left and right driving. The autonomous traveling device preferably has a low vehicle height in order to obtain stability. On the other hand, if the vehicle height is lowered, the wheels become smaller, the minimum ground height, which is the clearance between the ground and the bottom of the vehicle body, becomes smaller, and obstacles cannot be overcome.

  Therefore, for example, in Japanese Patent Application Laid-Open No. 2008-285087, the front wheels and the rear wheels are further provided with crawlers, and the driving force is transmitted to the wheels, and the crawlers function and travel even on rough roads where the wheels are buried. A possible wheelchair has been proposed.

JP 2008-285087 A

  In such a traveling device, it is necessary to suspend the crawler with a size close to the wheel diameter. If the crawler is located far from the outer edge of the wheel, the crawler will not touch the ground or contact and will not function even if the wheel is buried in soft ground or cannot move over obstacles. Because there is. However, when the position of the crawler is close to the outer edge of the wheel, there is a problem that road surface irregularities, stones, and the like come into contact with the crawler to impair durability and cause noise.

  The present invention solves the above-mentioned problems, and provides a drive mechanism for a travel device that can use an endless member that connects and drives a front wheel and a rear wheel as a travel aid only when necessary. Objective.

The present invention includes a pair of left and right wheels attached to the front and rear of a chassis, a sprocket integrally provided on the wheels and having a smaller diameter than the wheels, an endless member suspended on the front and rear sprockets, and the endless member A pulley capable of changing the position of the endless member by abutting on the inner peripheral surface, and a moving means for moving the pulley,
The moving means moves the pulley downward so as to be inscribed in a lower side of the endless member, thereby moving the endless member from a first position connecting the lower ends of the front and rear sprockets. 2 to move the endless member to function as an endless track.
When a travel failure occurs during wheel travel, the endless member functions as an endless track, and travel continues.

  According to the present invention, when a running failure occurs, the endless member can function as an endless track, and other than that, the endless member can be driven using wheels, so that the endless member is prevented from being damaged and noise is also suppressed. Can extend the service life.

It is a side view which shows the traveling apparatus in 1st Embodiment. It is a top view which shows the traveling apparatus in 1st Embodiment. It is a side view which shows having pushed down the belt of the traveling apparatus in 1st Embodiment. It is a block diagram which shows a traveling apparatus. It is a flowchart which shows the belt position switching process in case the traveling apparatus in 1st Embodiment performs autonomous traveling. It is a side view which shows the traveling apparatus in 2nd Embodiment. It is a flowchart which shows the belt position switching process in case the traveling apparatus in 2nd Embodiment performs autonomous traveling. It is a side view which shows the traveling apparatus in 3rd Embodiment. It is a top view which shows the traveling apparatus in 3rd Embodiment.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is a side view showing a traveling device in the first embodiment, and FIG. 2 is a plan view showing the traveling device in the first embodiment.

  As shown in the figure, the traveling device 10 includes a chassis 11 and four wheels 12. In the present embodiment, of the four wheels 12, a pair of left and right front wheels 12-1 and a pair of left and right rear wheels 12-2 are provided. Although not shown, a battery is housed inside the chassis 11.

  Each of the left and right front wheel shafts 15-1 has one end connected to the left and right front wheels 12-1, and the other end connected to the left and right front wheel sprockets 16-1 and the transmission 14. The front wheel 12-1, the front wheel shaft 15-1, and the front wheel sprocket 16-1 are integrally configured to operate. The left and right transmissions 14 are respectively connected to the left and right electric motors 13. The left and right electric motors 13 are controlled by a travel control unit 31 (see FIG. 4) described later.

  Each of the left and right rear wheel shafts 15-2 has one end connected to the left and right rear wheels 12-2 and the other end connected to the left and right rear wheel sprockets 16-2 and the bearing 18. Yes. The rear wheel 12-2, the rear wheel shaft 15-2, and the rear wheel sprocket 16-2 are integrally configured to operate.

  A belt 17, which is an endless member, is suspended around the outer periphery of the front wheel sprocket 16-1 and the rear wheel sprocket 16-2, and the front wheel 12-1 and the rear wheel 12-2 are connected by the belt 17. . The belt 17 has a structure in which protrusions are formed at regular intervals on the inner surface in contact with the sprocket 16 and meshed with the sprocket 16.

  The front wheel 12-1 receives the power of the electric motor 13 via the transmission 14, and rotates together with the front wheel shaft 15-1 and the front wheel sprocket 16-1 based on the power. The rear wheel 12-2 receives the rotational motion of the front wheel 12-1 by the belt 17, and rotates together with the rear wheel shaft 15-2 and the left rear wheel sprocket 16-2 based on the rotational motion.

  The transmission 14 includes, for example, a clutch and a gear box. The gear box is composed of a shaft whose one end is connected to the electric motor 13 and a gear (not shown) provided on the outer periphery of the shaft, and the power of the power source (electric motor 13) is converted into torque, rotation speed, and rotation. Change direction and communicate. Therefore, the transmission 14, the front wheel shaft 15-1, the rear wheel shaft 15-2, the front wheel sprocket 16-1, the rear wheel sprocket 16-2, and the belt 17 are configured as a power transmission member.

  The left and right electric motors 13 drive and stop the chassis 11 by driving the four wheels 12 by transmitting power to the left and right power transmission members, respectively.

  Here, the transmission 14 may not be included as a power transmission member. In this case, the electric motor 13 and the left and right front wheel shafts 15-1 are coupled with a gear (fixed ratio) to control the rotation speed and rotation direction of the electric motor 13.

  The left and right pulleys 21-1 are arranged in the vicinity of the front wheel 12-1 and are connected to left and right actuators 22-1 that move the pulley 21-1 up and down. The left and right pulleys 21-2 are disposed in the vicinity of the rear wheel 12-2, and are connected to left and right actuators (moving means) 22-2 that move the pulley 21-2 up and down. The actuators 22-1 and 22-2 move the pulley 21 by hydraulic or electric drive. The pulleys 21-1 and 21-2 are inscribed in the upper and lower sides of the belt 17 and can change the position of the belt 17.

The position of the belt 17 is the position of the lower side of the belt 17.
As shown in FIG. 1, the first position 26 of the belt 17 is a position connecting both the front and rear sprockets 16-1 and the lower end of the sprocket 16-2, and is located above the bottom surface of the chassis 11. Is accommodated in the chassis 11. At this time, the pulleys 21-1 and 21-2 are moved to a position inscribed in the upper side of the belt 17 by the actuators 22-1 and 22-2, and the upper side of the suspended belt 17 is pushed vertically upward. Is held at the first position 26.

  As shown in FIG. 3, the second position 27 of the belt 17 is below the first position 26, further below the bottom surface of the chassis 11, and a part of the belt 17 protrudes below the chassis 11. To do. At this time, the pulleys 21-1 and 21-2 are moved to a position inscribed in the lower side of the belt 17 by the actuators 22-1 and 22-2 and push down the lower side of the belt 17 vertically downward.

  Thus, when the belt 17 is in the first position 26, the belt 17 is accommodated in the chassis 11, and when it is in the second position 27, the belt 17 is pushed out below the chassis bottom. When in the first position 26, since the belt 17 is accommodated in the chassis 11, the traveling device 10 is driven by the wheels 12 and the belt 17 is not involved in traveling, so that the belt 17 can be prevented from being soiled. People and objects can be prevented from being caught, and safety can be ensured. When the belt 17 is in the second position 27, traveling can be assisted when the belt 17 abuts against the ground or an obstacle. For example, even when the wheel 12 is buried or when there are protrusions between the front and rear wheels 12 and all four wheels float in the air, the chassis 11 is released from the protrusions by driving the belt 17 that contacts the ground. can do.

FIG. 4 is a block diagram showing the traveling device 10, in which functional blocks necessary for traveling are described.
As illustrated in FIG. 4, the functional blocks of the traveling device 10 are a traveling control unit 31, a storage unit 32, an electric motor 13, an actuator 22, a GPS receiving unit 35, and a sensor unit 36.

  The traveling control unit 31 includes a CPU (Central Processing Unit), and controls each unit to perform a traveling operation. In particular, it is possible to control traveling by controlling the electric motor 13 and to control the movement of the pulley 21 by controlling the actuator 22 and to change the position of the belt 17 to function as an endless track.

  The storage unit 32 includes a memory such as a RAM and a ROM, and a large capacity storage device such as an HDD, and stores computer programs and various data. The CPU that is the travel control unit 31 can realize processing functions related to travel control by reading this computer program from the storage unit 32 and executing it. The program describing the processing contents can be recorded on a computer-readable recording medium. Examples of the computer-readable recording medium include a magnetic recording device, an optical disk, a magneto-optical recording medium, and a semiconductor memory. It is also possible to store the program in a storage device of a server computer and transfer the program from the server computer to another computer via a network.

The GPS receiving unit 35 receives radio waves from the GPS and acquires position information of the traveling device 10.
The sensor unit 36 is for detecting a traveling state or an obstacle of the traveling device 10, and includes various sensors. For example, a bumper, an inclination sensor, an acceleration sensor, an orientation sensor, a distance sensor, and the like. The bumper is a sensor for detecting an external force generated in the front, and for example, an impact sensor such as a vibration sensor or an acceleration sensor can be applied. The tilt sensor detects the tilt angle of the traveling device 10. The direction sensor is, for example, a geomagnetic sensor using geomagnetism, and detects the direction of the traveling direction. The distance sensor is a device using known light, a device using ultrasonic waves, or the like, and measures a distance to an object.

  FIG. 5 is a flowchart illustrating a belt position switching process when the traveling device according to the first embodiment performs autonomous traveling.

  The traveling control unit 31 of the traveling device 10 sets the belt 17 to the first position 26 (step S11). The pulley 22 is inscribed in the upper side of the belt 17 and pushed up by the actuator 22 to hold the belt 17 in the first position. As shown in FIG. 1, the belt 17 is accommodated in the chassis 11.

  The traveling control unit 31 drives the electric motor 13 to travel with the four wheels 12 (step S12), and determines the traveling state based on the detection results of the sensor unit 36 and the GPS receiving unit 35 (step S13). If it is determined that a running failure has occurred, the belt 17 is moved to the second position (step S14). The pulley 22 is inscribed in the lower side of the belt 17 and pushed down by the actuator 22 to hold the belt 17 in the second position.

  The travel control unit 31 drives the electric motor 13 to travel the travel device 10 while holding the belt 17 in the second position (step S15). At this time, as shown in FIG. 3, a part of the belt 17 protrudes from the bottom of the chassis 11 and functions as an endless track. Accordingly, when an obstacle or the ground comes into contact with the belt 17, the traveling device 10 travels by the belt 17.

The traveling control unit 31 confirms whether a predetermined time has elapsed after the belt 17 is in the second position (step S16). Within a predetermined time, the belt 17 is driven at the second position. If the predetermined time has passed, the traveling control unit 31 confirms whether a traveling failure has occurred (step S17). If no running failure has occurred, the process returns to step S11, and the belt 17 is returned to the first position to run again. If a running failure has occurred, the running device is stopped because the running cannot be performed even if the belt 17 is held at the second position (step S18).
In this way, the vehicle continues to travel on a preset route unless it stops due to a travel failure.

  In this way, when a running failure occurs, the belt 17 can function as an endless track, and other than that, it can be run using wheels, so that the belt 17 can be prevented from being damaged, noise can be suppressed, and when necessary. Only the belt 17 can function as an endless track, and the running life can be extended.

  In addition, although said process was about the autonomous traveling type traveling apparatus, the position of the belt 17 is switchable by a user's remote control operation, for example. In this case, the traveling control unit 31 receives the instruction signal from the remote controller and performs an operation of changing the position of the belt 17.

[Second Embodiment]
In the second embodiment, the second position of the pulley can be changed.
FIG. 6 is a side view showing a traveling device according to the second embodiment.

  For example, if the friction coefficient of the wheel 12 is small and the vehicle cannot travel because the ground surface is an ice burn, unless the second position 27 of the belt 17 reaches the lower end of the wheel 12 as in the first embodiment, the traveling obstacle is It cannot be resolved. Therefore, as shown in FIG. 6, if the second position 27-2 is at the same height as the lower end of the wheel 12, the belt 17 is in contact with the ground even when the wheel has a small friction coefficient and cannot travel. Is possible.

  The traveling control unit 31 determines the state of the ground and the rotation and movement state of the wheels based on detection by the sensor unit 36, and pushes down the pulley 21 until a driving force is obtained by the actuator 22. At this time, a movement limit of the pulley 21 is provided, and a limit is provided at the second position of the belt 17.

  FIG. 7 is a flowchart illustrating a belt position switching process when the traveling device according to the second embodiment performs autonomous traveling.

  The traveling control unit 31 of the traveling device 10 sets the belt 17 to the first position 26 (step S21). The pulley 22 is pushed up in contact with the upper side of the belt 17 by the actuator 22 to hold the belt 17 in the first position, and the belt 17 is accommodated in the chassis 11 as shown in FIG.

  The traveling control unit 31 drives the electric motor 13 and travels with the four wheels 12 (step S22), and determines the traveling state based on the detection results of the sensor unit 36 and the GPS receiving unit 35 (step S23). If it is determined that a running failure has occurred, the belt 17 is moved to the second position (step S24). The actuator 22 pushes down the pulley 21 in contact with the lower side of the belt 17 to hold the belt 17 at the second position 27-1.

  The travel control unit 31 drives the electric motor 13 to travel the travel device 10 while holding the belt 17 at the second position 27-1 (step S25). At this time, as shown in FIG. 3, a part of the belt 17 protrudes from the bottom surface of the chassis 11.

  The traveling control unit 31 confirms whether or not a predetermined time has elapsed since reaching the second position 27-1 (step S26). Within a predetermined time, the belt 17 is driven at the second position 27-1. If the predetermined time has passed, the traveling control unit 31 confirms whether a traveling failure has occurred (step S27). If no running failure has occurred, the process returns to step S21, and the belt 17 is returned to the first position 26 to run again. If a running failure has occurred, it is confirmed whether the current position of the belt 17 is a limit value (step S28).

  If it is not the limit value, the traveling control unit 31 further lowers the belt 17 and changes the second position of the belt 17 (step S29). For example, as shown in FIG. 6, the position is changed to the second position 27-2. In FIG. 6, two stages are set, but it may be set in multiple stages. If it is a limit value, the traveling apparatus 10 is stopped (step S30).

  In this way, by changing the second position 27 in accordance with the traveling state, the belt 17 can travel with the grip force supplemented.

  In addition, although said process was about the autonomous traveling type traveling apparatus, it is good also as changing the position of a belt variously, for example by a user's remote control operation etc. In this case, the traveling control unit 31 receives an instruction signal from the remote controller and performs an operation of changing the position of the belt 17 to a desired position.

[Third Embodiment]
In the third embodiment, a roller is attached to the front of the chassis 11 in the traveling direction, the obstacle is detected by the rotation thereof, and the belt is changed from the first position to the second position.
FIG. 8 is a side view showing the traveling device in the third embodiment, and FIG. 9 is a plan view showing the traveling device in the third embodiment.

  A rotatable columnar roller 51 having a diameter of 15 cm and protruding from the chassis body is provided in front of the chassis 11. When there is an obstacle 53 higher than the bottom surface of the chassis, the roller 51 first contacts the obstacle 53 and rotates by the driving force of the chassis 11. By detecting this rotation in the sensor unit 36, the traveling control unit 31 can determine that there is an obstacle 53 ahead.

  Further, the traveling device 10 moves forward, gets over the obstacle 53, and the bottom of the chassis part comes into contact with the obstacle 53. At this time, since it can be determined from the detection results of the GPS receiving unit 35 and the sensor unit 36 that a running failure has occurred, the pulley 21 is moved by the actuator 22 so that the belt 17 that is an endless member is in the second position. Is inscribed in the lower side of the belt 17 and pushed up. Since the belt 17 surface protrudes from the bottom surface of the chassis 11, the chassis 11 can be pushed out by driving the belt 17 even if all four wheels are lifted by the obstacle 53. The position of the belt 17 can be realized by reading the rotation of the roller 51 with an encoder or the like and changing the position of the pulley 21 with the actuator 22.

  In 3rd Embodiment, although the roller was provided in the front direction, you may provide in back. This is because the traveling direction is not limited to the forward direction, and it may be possible to go back.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the invention may be changed in design without departing from the gist of the present invention. Is also included.

DESCRIPTION OF SYMBOLS 10: Traveling apparatus 11: Chassis 12: Wheel 12-1: Front wheel 12-2: Rear wheel 13: Electric motor 14: Transmission 16: Sprocket 16-1: Front wheel sprocket 16-2: Rear wheel sprocket 17: Belt ( Endless member)
21: Pulley 22: Actuator (moving means)
26: 1st position 27: 2nd position 27-1: 2nd position 27-2: 2nd position 31: Traveling control part 51: Roller

Claims (5)

A pair of left and right wheels attached to the front and rear of the chassis,
A sprocket provided integrally with the wheel and having a smaller diameter than the wheel;
Endless members suspended on the front and rear sprockets;
A pulley capable of changing the position of the endless member in contact with the inner peripheral surface of the endless member;
Moving means for moving the pulley;
With
The moving means moves the pulley downward so as to be inscribed in the lower side of the endless member, thereby moving the endless member from a first position connecting the lower ends of the front and rear sprockets. 2. A drive mechanism for a traveling apparatus, wherein the drive mechanism is moved to a position of 2 so that the endless member functions as an endless track. The first position is above a bottom surface of the chassis;
The drive mechanism for a travel device according to claim 1, wherein the second position is below a bottom surface of the chassis.   3. The drive of the traveling device according to claim 1, wherein the moving unit holds the endless member in a first position by inscribed the pulley on an upper side of the endless member. mechanism.   4. The driving mechanism of the traveling device according to claim 1, wherein the moving unit can selectively change the second position according to a traveling state. 5. Protruding rollers that can rotate in the traveling direction of the chassis,
5. The travel according to claim 1, wherein, when the roller rotates, the moving means moves the pulley to move the endless member to the second position. 6. The drive mechanism of the device.

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