JP2002264856A - Stair climbing/descending device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a lightweight and simplified stair climbing/descending device capable of autonomously and smoothly climbing and descending stairs by using a planetary gear mechanism in a rotary arm with a wheel-type stair climbing/descending device. SOLUTION: The stair climbing/descending device is provided with a body frame 1, a driving wheel arm 3 rotatably provided on the body frame 1, a wheel 4 rotatably provided on the tip of the arm, an axle gear 6 provided on an axle of the wheel, a planetary gear 7 meshing with an axle gear and journalled by a driving wheel arm 3, a sun gear 8 meshing with the planetary gear and rotatably arranged on the same shaft with the driving wheel arm independently from the driving wheel arm, and a driving gear 9 meshing with the sun gear. It is characterized in that it travels by rotating the driving gear and rotating the wheel via the sun gear, the planetary gear, and the axle gear, and when the rotation of the wheel is interfered by a step, it can climb over the step by autonomously switching to the rotation of the driving wheel arm.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stair elevating device, and more particularly to a rotating arm type stair elevating device with wheels, in which a planetary gear mechanism is used to allow a stair to be smoothly and autonomously raised and lowered. The present invention relates to a stair-climbing device capable of realizing weight reduction and simplification. INDUSTRIAL APPLICABILITY The stair climbing device of the present invention is effectively applied to wheelchairs, cargo handling, transportation of goods in dangerous facilities, inspection, and the like, and can greatly contribute to social participation of wheelchair users who have difficulty walking.

[0002]

2. Description of the Related Art As a mobile robot capable of moving up and down stairs, several systems using a crawler, legs, and the like have been proposed. The method of traveling on level ground and moving up and down stairs by a crawler has already been put to practical use because the drive mechanism and its control are simple. However, the crawler has a high running resistance, so that it is difficult to run at a high speed, and the available places and conditions are limited. In addition, a robot having a mechanism for moving with legs such as humans and insects is suitable for use on uneven terrain. However, since the motor is driven by a plurality of motors, the weight increases, the computer control for the motors becomes complicated, and the moving speed decreases.

Further, there has been proposed a traveling vehicle that employs a gear drive mechanism to perform traveling on a flat ground by a grounding wheel and traveling over a step due to revolution of the grounding wheel accompanying rotation of a support arm by using a single drive source. (Japanese Unexamined Patent Publication No.
No. 97074). The stair climbing device described in this publication extends a plurality of support arms 105 radially with respect to an axle 104 that supports an airframe as shown in FIG. A lifting and lowering vehicle configured to support and support the respective support arms 105 to rotate around the axis of the axle 104 so that the vehicle can run on a step;
9 and the driving wheel 109 and each of the grounding wheels 106
Are connected to each other so as to be able to transmit rotational power in the same rotational direction, and a cylindrical shaft 108 is fitted on the radially outer side of the axle 104 with substantially the same axial center, and the cylindrical shaft 108 and each of the support arms 105 And a drive switching mechanism A capable of switching between a state in which the axle 104 is rotationally driven and a state in which the cylindrical shaft 108 is rotationally driven.

The drive switching mechanism A is housed in a transmission case 107. The drive switching mechanism A has a shift gear 111 spline-fitted on a drive shaft 100 driven by an electric motor M, and the shift gear 111 is mounted on the axle 104. A shift fork 114 is provided which can be shifted between a state in which the driven gear 112 is engaged with the driven gear 112 and a state in which the driven gear 113 is engaged with the driven gear 113 attached to the cylindrical shaft 108. It is configured to be able to switch to each of the above states by operating. Accordingly, in this device, traveling on a flat surface by the grounding wheel and traveling over a step due to revolution of the grounding wheel accompanying rotation of the support arm can be performed by one drive source, but switching between traveling on a flat surface and traveling over a step is performed. Requires a mode switch, and is not autonomous.

[0005] Separately from the above, a rotatable arm having wheels that rotate on its tip is used. The vehicle travels on level ground by the rotation of the wheels. When the rotation of the wheels is hindered by steps, the arm rotates autonomously. A rotating arm type stair climbing device with wheels that can be switched over a step has been proposed (JP-A-10-243967). The mobile robot using the rotating arm with wheels has advantages in that it can move at high speed on flat ground and can easily control a motor as compared with other methods. However, the rotating arm type stair climbing device with wheels proposed so far has a problem in practical use such as a complicated mechanism and a large weight. In addition, the rotating arm type stair climbing device with wheels cannot be moved up and down the stairs smoothly because the relationship between the centers of adjacent wheels and the radius of the wheels has not been sufficiently studied. Was.

[0006]

For this reason, the present inventor has already proposed a rotating arm type stair climbing / falling device with wheels which can solve the above-mentioned problems (Japanese Patent Laid-Open No. 10-1).
No. 47243). The rotating arm type stair climbing and lowering device with wheels described in this publication includes a chassis, a cross-shaped rotating arm rotatably provided on the left, right, front and rear of the chassis,
A wheel rotatably provided at the tip of the arm, a toothed pulley provided on the axle of the wheel provided on the rotating arm provided on the rear of the chassis, a left and right power motor provided on the chassis, and a rotating shaft of the motor Power toothed pulley provided on the rotary arm, an endless toothed belt wound around the toothed pulley of the wheel provided on the rotary arm and the left and right power toothed pulleys, and the toothed belt is driven by a power motor. In addition, the wheel provided on the rotating arm is rotated, so that the vehicle runs on flat ground by the rotation of the wheel, and when the rotation of the wheel is hindered by the step, the vehicle can autonomously switch to the rotation of the arm to get over the step. It is a stair climbing device and has achieved satisfactory results.

However, subsequent studies have revealed that this stair climbing device employs a drive mechanism using a chain or a belt, so that there is play before and after the drive mechanism, and the accuracy of control during use cannot be improved. Was. Therefore, the present invention can greatly change the ratio of the number of teeth between the sun gear and the wheel shaft gear by shifting the mounting position of the planetary gear from the straight line connecting the wheel shaft gear and the sun gear, and adjust the distance between the shafts. It is an object of the present invention to provide a rotating arm-type stair climbing and lowering device with wheels adopting a new method that makes it easier to solve the above problems. The present invention has a simple structure and is easy to manufacture as compared with the conventional mechanism using the planetary gears shown so far, and a part of the stairs enters between adjacent wheels. The possibility of contact with the mechanical components is low, and the play before and after the drive mechanism can be reduced, so that control during use is easy, and the cover for the drive components attached to the arm, such as the wheel axle gear, is attached. There are advantages such as easy attachment.

[0008]

For this reason, the technical solution adopted by the present invention is to provide a vehicle body frame, a drive wheel arm rotatably provided on the vehicle body frame, and a rotatably provided at the tip of the arm. A wheel, a wheel axle provided on a wheel axle of the wheel, a planetary gear meshed with the wheel axle, and supported by the drive wheel arm, and meshed with the planetary gear, and the drive wheel arm A sun gear independently rotatably arranged concentrically with the drive wheel arm, and a drive gear meshing with the sun gear, comprising: rotating the drive gear, sun gear, planetary gears, wheels via the wheel gears. A stair climbing and descending device characterized by being able to run while rotating, and to autonomously switch to rotation of a drive wheel arm to get over a step when rotation of a wheel is obstructed by a step. . Also, the planetary gear is a stair climbing and lowering device, wherein the planetary gear is displaced from a straight line connecting the center of the wheel shaft gear and the center of the sun gear. The number of teeth of the wheel shaft gear is set to be smaller than the number of teeth of the sun gear. Also, increasing the tooth width of the sun gear, one side of the tooth width and the drive gear,
A stair climbing device characterized by meshing the remaining part with a planetary gear. Further, the body frame holds a posture holding arm movably in the vertical direction with respect to the body frame by a posture holding arm guide. A stair climbing and lowering device characterized in that the center of gravity of a vehicle body is brought close to the center of a drive wheel arm to prevent idling of the drive wheel arm and wheels, and that a posture angle of a body frame is maintained constant. Also,
The means for moving the attitude holding arm is a stair climbing and lowering device, which is constituted by a rack and pinion mechanism.
An auxiliary wheel arm is rotatably mounted in front of the vehicle body frame. An auxiliary wheel is mounted at each end of the auxiliary wheel arm, and an auxiliary wheel arm is rotatably mounted on an auxiliary wheel shaft which supports the auxiliary wheel arm. A stair climbing and lowering device, wherein a gear for use is attached, and the gear can be driven by an auxiliary drive motor.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A rotating arm type stair climbing and lowering device with wheels according to an embodiment of the present invention will be described below with reference to FIG.
Is a schematic side view of a wheel mechanism of the present apparatus, and FIG. 2 is a plan view of one wheel mechanism portion of the apparatus.

1 and 2, reference numeral 1 denotes a body frame of the apparatus, on which a chair, an operation panel, and the like (not shown) are mounted. A rear wheel axle 2 is provided on the body frame 1, and a cross-shaped drive wheel arm 3 is attached to both ends of the axle. A wheel 4 is attached to each end of the drive wheel arm 3 by a wheel shaft 5. It is rotatably supported. A wheel shaft gear 6 is attached to the wheel shaft 5, and the wheel 5 rotates when the wheel shaft gear 6 rotates. Further, a planetary gear 7 is rotatably disposed on the drive wheel arm 3 so as to mesh with the wheel shaft gear 6. This planetary gear 7 has a central axis of the drive wheel arm 3,
A sun gear 8 rotatably mounted independently of the arm 3 is arranged, and a driving gear 9 mounted on an output shaft of a main driving motor 10 is meshed with the sun gear 8. In addition, the mounting position of the planetary gears is displaced from the straight line connecting the wheel shaft gear and the sun gear, and this arrangement greatly changes the ratio of the number of teeth of the sun gear and the wheel shaft gear, and the distance between the shafts. Making it possible. It is important that the number of teeth Z2 of the wheel shaft gear 6 be smaller than the number of teeth Z1 of the sun gear 8.

In addition, a vertical portion of a substantially L-shaped posture holding arm 11 is held by a posture holding arm guide 12 in front of the body frame 1 so as to be movable up and down (up and down in the figure) with respect to the body frame 1. The vertical portion of the posture holding arm 11 is configured as a rack 11a. A drive gear 13 for a posture holding arm attached to an output shaft of a posture holding drive motor (not shown) meshes with the rack 11a, and the rack and pinion mechanism constitutes means for moving the posture holding arm 11. .
Further, a cross-shaped auxiliary wheel arm 14 is rotatably mounted on the end of the horizontal portion of the posture holding arm 11, and an auxiliary wheel 15 is mounted on each end of the auxiliary wheel arm. An auxiliary wheel arm rotating gear 17 is integrally attached to the auxiliary wheel arm 14, and an auxiliary wheel arm driving gear 18 provided on a shaft of an auxiliary driving motor (not shown) meshes with the gear 17. The main drive motor 10, the attitude holding drive motor, and the auxiliary drive motor are electrically connected to a control device, and are driven and controlled by a command from the control device.

In the stair-climbing device of the above construction, when the main drive motor 10 is driven, its rotation is transmitted to the sun gear 8 via the drive gear 9, and the rotation of the sun gear is transmitted via the planetary gear 7 for changing the rotation direction. To the wheel shaft gear 6.
That is, when the driving gear 9 is rotated, the sun gear 8 rotates, the wheel shaft gear 6 and the wheel 4 rotate in the same direction as the sun gear 8, and the main body moves forward. When the wheel 4 comes into contact with a step such as a stair, the rotation of the wheel is stopped. In this state, the torque of the sun gear increases as shown in FIG. 3A, and the rotational moment acting on the drive wheel arm 3 increases, as shown in FIG. The drive wheel arm 3 starts to rotate autonomously, and the center axis of the drive wheel arm 3 is raised, so that the vehicle body 1 is pushed upward, and the wheels come into contact with the upper surface of the stairs and climb over the stairs.
In addition, in order to prevent a change in the inclination angle of the vehicle body frame 1 when climbing up and down stairs, the attitude angle of the vehicle body frame is detected by a sensor (not shown), and the control device controls the vehicle body frame 1 so that the inclination angle is always constant. A posture holding motor (not shown) is driven by a command, and the posture holding arm 11 is moved downward by the posture holding arm drive gear 13 in FIG. 1 to adjust the position of the auxiliary wheel arm 14. Further, the auxiliary wheel arm 14 is rotated by rotating the auxiliary wheel arm rotating gear 17 by the auxiliary drive motor at the time of going up and down the stairs,
The vehicle climbs over the stairs while repeating such a process that can reduce the propulsive force of the drive wheels 4 required when going up and down the stairs.

When descending the stairs, the sun gear 8 is reversed and descends. In FIG. 3C, the wheel comes first, and when the wheel starts falling from the step, the arm rotates. This rotation is accelerated by the effect of gravity,
The motor falls while applying a reverse voltage to the motor to adjust the rotation speed of the sun gear 8. Thus, the stairs can be stably descended by the opposite operation to the above. In addition, by controlling the rotation of the auxiliary wheel arm rotating gear 17 by the auxiliary driving motor, the propulsive force of the driving wheel 4 at the time of descending the stairs is controlled.

Next, the conditions under which the above driving mechanism is established will be examined. FIG. 4 shows the configuration of a gear in one drive wheel arm. The pitch circle radii of the sun gear 8, the planetary gear 7, and the wheel shaft gear 6 are denoted by ra and rb rc. In FIG.
The rotation angle θa of the sun gear 8 when the arm rotates by θA without the wheel 4 rotating is determined. First, the rotation angle of each gear with respect to the drive wheel arm 3 will be considered. When the drive wheel arm 3 rotates clockwise by θA, the planetary gear 7 rotates in the same direction as the drive wheel arm 3, and the engagement length with the wheel shaft gear 6 at this time is rc · θA. The rotation of the planetary gear 7 causes the sun gear 8 to rotate counterclockwise by the same engagement length with respect to the drive wheel arm 3, so that the rotation angle θa
1 is represented by the following equation. θa1 = − [rc / ra] · θA Further, assuming that the wheel 4 rotates together with the drive wheel arm 3, the rotation angle θA of the sun gear 8 is equal to the rotation angle θa2 of the arm. Rotation angle θa2 = rotation angle θA Therefore, rotation angle θa of sun gear 8 when drive wheel arm 3 rotates without wheels 4 rotating can be obtained as the sum of θa1 and θa2. θa = θa1 + θa2 = (1−rc / ra) · θA Therefore, in order to rotate the sun gear 8 and the drive wheel arm 3 in the same direction, it can be seen from the above equation that rc / ra <1.

Next, the relationship between the driving torque T applied to the sun gear 8 and the rotational moment M generated in the driving wheel arm will be described.
In FIG. 5, the external force acting on each gear when the torque T is applied to the sun gear 8 is shown in FIG. The sun gear 8 shown in FIG. 5A has a force P = T / r from the planetary gear 7 due to the torque T.
And the rotation force O on the drive wheel arm 3
A force P is applied to a. The planetary gear 7 shown in FIG. 5B receives a force of the same magnitude as the force P from the sun gear 8 from the wheel shaft gear 6 due to the moment balance, and the reaction force thereof is applied to the rotating shaft Ob on the drive wheel arm. Works. FIG. 5C shows the external force acting on the rotation axes Oa and Ob on the drive wheel arm and the dimensions of the drive wheel arm. A straight line connecting the rotation axis Oc and the point Ob and a straight line connecting the points Oa and Ob are inclined by an angle α. Driving wheel arm 3 centering on rotation axis Oc of the wheel shaft gear
The relationship between the rotational moment M acting on the sun gear and the torque T applied to the sun gear is expressed by the following equation. M = P [ra + rb + (rb + rc) cosα− (rb + rc) − (rb + rc) cosα] = P · (ra−rc) = (1−rc / ra) · T As a result, the moment M with respect to the torque T is increased. Therefore, it is necessary to reduce the value of rc / ra. When rc / ra = 1, no rotational moment is generated, and when this value is larger than 1, torque is generated on the contrary. Next, in FIG. 4, the propulsion force F of the wheel when the driving torque T is given to the sun gear 8 is expressed by the following equation, where the radius of the wheel is rw. F = [rc / (ra · rw)] · T

Although the embodiment of the present invention has been described above, the shape of each arm is not necessarily limited to the cross shape, and the holding of the posture of the body frame is not limited to the embodiment. Further, the planetary gear mechanism including the sun gear, the planetary gear, the wheel shaft gear, and the like is not limited to the illustrated one, and any other type of planetary gear mechanism can be used as long as the mechanism can achieve the same operation and effect. Moreover, the present invention may be embodied in any other form without departing from its spirit or essential characteristics. Therefore, the above-described embodiment is merely an example in every aspect and should not be interpreted in a limited manner.

[0017]

As described in detail above, according to the present invention, in the stair climbing device configured as described above, By attaching a driving device for rotating the driving wheel arm to the driving wheel arm 3, when the arm rotates and the driving force of the driving wheel becomes insufficient, a torque in a direction opposite to the traveling direction is applied to the arm to increase the driving force. Can be done. When the arm is rotated by about 20 degrees or more from the two-wheel contact state on the horizontal plane, the rotation of the arm is 1 / (1-Z2 / Z1) times the average rotation angle of the left and right sun gears. By controlling the angle, only the arm is rotated stably without rotating the wheel, and rapid rotation of the arm due to the influence of gravity is prevented. Further, when the seat is greatly inclined backward, a torque can be applied to the arm so that a load is applied to the rear wheel, thereby preventing the arm from falling. 2. By using a sun gear with a large tooth width and engaging one side of the tooth width with the motor shaft gear and the other part with the planetary gear, the number of parts can be reduced and the mechanism can be simplified. 3. By installing a mechanism for applying a rotational torque to the auxiliary wheel arm, it is possible to reduce the propulsive force of the drive wheels required when going up and down stairs. 4. The posture-holding arm uses a rack and pinion or a direct-acting arm such as a fire ladder instead of a rotating type such as a parallel link, so that useless movement in the front-rear direction is eliminated, and use in narrow places and on slopes It can be used on steep stairs. 5. When traveling on level ground, by rotating the drive wheel arm to ground only the rear wheels, the running conditions are the same as those of a normal electric wheelchair. be able to.

[Brief description of the drawings]

FIG. 1 is a side view of a wheel mechanism of the present device.

FIG. 2 is a plan view of one wheel mechanism portion of the device.

FIG. 3 is an explanatory diagram when the device is moved up and down stairs.

FIG. 4 is a diagram showing a configuration of a gear in one drive wheel arm.

FIG. 5 is a diagram showing external forces acting on each gear when a torque T is applied to the sun gear.

FIG. 6 is a mechanism diagram of a conventional stair climbing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body frame 2 Rear wheel axle 3 Drive wheel arm 4 Wheel 5 Wheel shaft 6 Wheel shaft gear 7 Planetary gear 8 Sun gear 9 Drive gear 10 Main drive motor 11 Posture holding arm 12 Posture holding arm guide 14 Auxiliary wheel arm 15 Auxiliary wheel 17 Auxiliary wheel arm rotation gear 18 Auxiliary wheel arm drive gear

Claims (7)

[Claims] 1. A vehicle body frame, a driving wheel arm rotatably provided on the vehicle body frame, a wheel rotatably provided at a tip of the arm, a wheel shaft gear provided on a wheel shaft of the wheel, and A planetary gear meshed with the wheel shaft gear and supported by the drive wheel arm; and a sun gear meshed with the planetary gear and arranged to be rotatable concentrically with the drive wheel arm independently of the drive wheel arm. And a drive gear that meshes with the sun gear.The drive gear rotates, the sun gear, the planetary gear, and the wheels rotate through the wheel shaft gears. A stair climbing device characterized by being able to switch over the rotation of the drive wheel arm to get over a step. 2. The stair climbing and lowering device according to claim 1, wherein the planetary gears are displaced from a straight line connecting the center of the wheel shaft gear and the center of the sun gear. 3. The stair climbing device according to claim 1, wherein the number of teeth of the wheel shaft gear is set smaller than the number of teeth of the sun gear. 4. The sun gear according to claim 1, wherein a tooth width of the sun gear is increased, and one side of the tooth width is meshed with a drive gear, and the remaining part is meshed with a planetary gear. Stair climbing equipment. 5. A posture holding arm is held on the body frame by a posture holding arm guide so as to be vertically movable with respect to the body frame. The center of gravity of the vehicle body is moved closer to the center of the drive wheel arm at the time of elevating to prevent idling of the drive wheel arm and wheels, and the attitude angle of the vehicle body frame is maintained constant. Item 5. The stair climbing device according to any one of Items 4. 6. The moving means of the posture holding arm is a rack
6. The apparatus according to claim 5, wherein said pinion mechanism is used.
The stair climbing device according to item 1. 7. An auxiliary wheel arm is rotatably mounted in front of the vehicle body frame. An auxiliary wheel is mounted at each end of the auxiliary wheel arm, and an auxiliary wheel shaft supporting the auxiliary wheel arm is provided with an auxiliary wheel. The stair climbing device according to any one of claims 1 to 6, wherein a wheel arm rotating gear is mounted, and the gear can be driven by an auxiliary driving motor.