JP2004042756A - Irregular ground traveling device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To ensure ground contact of a driving wheel and a driven wheel even on an irregular ground surface to enable stable traveling, simplify a structure, reduce required space as much as possible and a movable part, prevent stability from being lost even when using a soft spring, and provide high irregularity absorbing capability. <P>SOLUTION: Four wheels mounted on a vehicle body 1 are arranged at positions equivalent to each square corner part. Two wheels arranged at positions equivalent to corner parts on a diagonal line on one side in the square shape among these wheels are used as the driving wheels 2, 2. Two wheels arranged at positions equivalent to corner parts on a diagonal line on the other side are used as the driven wheels 3, 3. Either of both wheels among both driving wheels and both driven wheels are mounted on the vehicle body 1 through a movable mechanism 4 common for both wheels and moving both wheels integrally and vertically so as to move vertically. An energizing means 5 for springily energizing the movable mechanism downward is provided to fix the other both wheels to the vehicle body. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a traveling unit such as a manual type, an electric type other cart, a wheelchair, and the like, and more particularly, to an uneven terrain traveling device capable of stable traveling without driving wheels floating even on uneven ground.
[0002]
[Prior art]
Many of the conventional electric transport carts are of a four-wheel fixing type that does not have a suspension, so that it is difficult to smoothly travel on uneven ground. In wheelchairs and robotic running parts, the suspension using springs absorbs the unevenness of the ground to ensure ground contact of the wheels. If the spring is hard and the suspension stroke is short, the absorption performance of the unevenness is reduced, so that the performance cannot be sufficiently exhibited in various situations.
[0003]
In order to solve such a problem, a traveling device (Japanese Patent Laid-Open No. 2001-112821) has been developed in which the four wheels are appropriately moved up and down by mechanical interlocking without using a spring. According to this device, the grounding of the wheel can be almost completely secured even on the uneven surface, and stable and smooth driving is possible.In this case, it is necessary to equip a plurality of movable frames in a linked manner, It requires a lot of space and has many moving parts, which increases costs.
[0004]
In addition, in a transport vehicle that uses springs and has a pair of casters fixed to the left and right of the front end and rear end of the vehicle body, a pair of drive wheels are arranged on the left and right of the center of the vehicle body to drive each drive. There has been proposed an electric transport vehicle (Japanese Patent Laid-Open No. 9-169271) in which the wheels are individually pressed against the ground with a spring. However, on uneven ground, if the elasticity of the spring is soft, an unstable tilt or shake occurs in the vehicle body, so a soft spring cannot be used, and the followability to the unevenness is poor. For example, if one of the four casters rides on the convex part, the load is supported by the four casters, the diagonal casters and the two drive wheels, and the other two wheels are lifted. If the spring that presses is soft, the vehicle body will be unstablely tilted or shaken due to changes in the center of gravity or external force. Will fall and it will be bad.
[0005]
Also proposed is a six-wheeled wheelchair (Japanese Patent Laid-Open No. 2000-10269) in which two casters are arranged before and after the left and right power wheels, respectively, so that the left and right power wheels move integrally up and down. ing. However, in this wheelchair, there is no problem when the left and right power wheels ride on the step at the same time, but when only one power wheel rides on the convex part, the power wheel together with the one power wheel Since the power wheel on the opposite side is also lifted and floats from the ground, there is a drawback that it becomes difficult to travel.
[0006]
[Problems to be solved by the invention]
Therefore, the present invention enables stable and smooth running by ensuring that the driving wheel and the driven wheel are in contact with each other even on an uneven surface, simplifying the structure, minimizing the required space, and reducing the number of moving parts. Thus, it is intended to reduce the cost and to enable a traveling device that does not lose stability even when a soft spring is used and has high ability to absorb irregularities.
[0007]
[Means for Solving the Problems]
From such a point of view, the invention of the rough terrain vehicle according to claim 1 is arranged such that the four wheels to be mounted on the vehicle body 1 are arranged at positions corresponding to the respective corners of a rectangle such as a rhombus or a substantially rhombus or a rectangle. 2 wheels arranged at positions corresponding to corners on one diagonal in the quadrangle as driving wheels 2 and 2 and wheels arranged at positions corresponding to corners on the other diagonal Can be moved up and down on the vehicle body 1 via a common movable mechanism 4 that moves both the driving wheels 2 and 2 and the driven wheels 3 and 3 together. In addition, the urging means 5 is provided on the movable mechanism 4 to urge downward, and the other wheels are fixed to the vehicle body 1.
[0008]
The rough terrain traveling device according to claim 2 uses a spring 6 as the biasing means 5.
[0009]
According to a third aspect of the present invention, the rough terrain traveling apparatus includes the hydraulic cylinder 7 and the accumulator 22 as the biasing means 5.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
1.
FIGS. 1 to 5 show embodiments of the present invention according to claims 1 and 2, in which the four wheels mounted on the vehicle body 1 are positions corresponding to the corners of the rhombus. Of these wheels, two wheels arranged at positions corresponding to diagonal corners in the lateral direction in the rhombus, that is, two wheels arranged on the left and right in the middle part in the front-rear direction in the vehicle body 1 Both of them are mounted on the vehicle body 1 so as to be movable up and down through a common movable mechanism 4 that moves up and down integrally as drive wheels 2 and 2, and the movable mechanism 4 is attached to the movable mechanism 4 and thus both the drive wheels 2 and 2 are mounted. Urging means 5 comprising a spring 6 that springs downward, and on the two wheels arranged at positions corresponding to the corners on the diagonal in the front-rear direction in the rhombus, that is, on the center line in the front-rear direction in the vehicle body 1 The two wheels arranged in front and rear are driven wheels 3, 3 They are allowed to settle to the vehicle body 1 Te.
[0011]
The vehicle body 1 is composed of a rectangular main body frame 1a, and the main body frame 1a is equipped with the driving wheels 2 and 2 and the driven wheels 3 and 3 as described above. The pair of driven wheels 3, 3 form a pair of front and rear, and the pair of left and right drive wheels 2, 2 are mounted on the main body frame 1a via the common movable mechanism 4 so as to be movable up and down. The driving wheels 3 and 3 are directly fixed to the front end portion and the rear end portion of the main body frame 1a as casters.
[0012]
The movable mechanism 4 swings the front end portion of the movable frame 1b, which is adapted to the main body frame 1 and formed in a substantially half length, to a pair of left and right brackets 8 and 8 suspended from the front portion of the main body frame 1. The pair of drive wheels 2 and 2 are mounted on the rear end of the movable frame 1b so that the pair of drive wheels 2 and 2 can be vertically moved. Yes. In the figure, reference numerals 10 and 10 denote electric motors for the drive wheels 2 and 2, respectively.
[0013]
The biasing means 5 comprising a spring 6 projects a bracket 11 rearward from the center of the rear end of the movable frame 1b, and a beam 12 is constructed on the main body frame 1 in correspondence with the bracket 11. In addition, a spring 6 is interposed between the drive wheel 2 and the bracket 11 so that the drive wheels 2 and 2 are pressed downward with a force approximately half the mass of the vehicle as a whole. As the spring 6, for example, in the case of a four-wheel traveling device having a mass of about 100 kg, a compression spring having a spring constant of 2.5 kgf / mm is used for the four wheels as a conventional technique in consideration of both the stability of traveling and following the unevenness. If it is used, the traveling device of the present invention uses a compression spring (0.25 kgf / mm × 2) having a spring constant of about 1/10 for the two drive wheels, so that a sufficient stroke can be obtained with a larger stroke. A ground load can be obtained, and at the same time, it is possible to prevent tilting and shaking of the vehicle body due to an external force and a movement of the center of gravity that are unavoidable in the prior art.
[0014]
Because of the above configuration, the load borne by the drive wheels 2 and 2 is determined by the pressing force of the spring 6, and if the spring constant of the pressing spring 6 is sufficiently small, the load applied to the drive wheel is almost constant within the stroke range. become. Even when the road surface is lost due to the unevenness, the grounding of the four wheels is ensured by the expansion and contraction of the spring and the inclination of the vehicle body 1, so that the vehicle can travel on rough terrain (FIG. 2).
[0015]
Next, the stability of the posture of the traveling device described above will be described.
In the case of a general suspension that uses four springs individually for each of the four wheels, and the center of gravity shifts slightly from the center, a corresponding rotational moment is generated and the vehicle body tilts. In the above-described traveling device according to the present invention, the pair of left and right drive wheels 2 and 2 are integrally moved up and down by one movable frame 1b, so that the rotational moment is smaller than the strength of the spring 6, as shown in FIG. The vehicle body 1 does not tilt. That is, since the spring 6 has a strength to support almost half of the mass of the entire vehicle, if the center of gravity is within about 1/2 between the center and one of the wheels, the vehicle body is stable without tilting. It is. When approximately 1/2 is exceeded, the spring 6 is in a compressed state (FIG. 4) in the left-right direction, and the spring 6 is in an extended state (not shown) in the front-rear direction, so that the vehicle body 1 is greatly inclined. Therefore, use within the range not exceeding.
[0016]
The spring 6 may be provided with pressing force adjusting means 13 shown in FIG. The pressing force adjusting means 13 is formed by pressing a pressing force adjusting screw 14 from above on the beam 12 of the main body frame 1 so as to correspond to the upper end of the spring 6, and pressing the pressing force adjusting screw 14 attached to the tip of the pressing force adjusting screw 14. The upper end of the spring 6 is crushed by the plate 15 and the pressing force of the spring 6 can be arbitrarily adjusted by the screwing of the pressing force adjusting screw 14. In FIG. 5, reference numeral 16 denotes a lock nut that is tightened after adjustment to stop the movement of the pressing force adjusting screw 14.
[0017]
According to the pressing force adjusting means 13, the amount of contraction of the spring 6 can be changed by the screwing of the pressing force adjusting screw 14, and appropriate pressing corresponding to the load applied to the vehicle body 1 is applied to both the drive wheels 2 and 2. A force can be applied, and the load sharing between the drive wheels 2 and 2 and the other driven wheels 3 and 3 can be changed. Therefore, for example, when the wheel gets over the step, the load on the wheel is reduced, so that it is possible to easily climb the step.
[0018]
No.2.
FIG. 6 shows another embodiment according to the first and second aspects of the invention, and the illustrated one is an example of four wheels mounted on the vehicle body 1 at positions corresponding to the corners of the rhombus. The two wheels arranged at the positions corresponding to the corners on the diagonal line in the rhombus, that is, the two wheels arranged on the left and right in the middle part in the front-rear direction in the vehicle body 1 are used as the drive wheels 2 and 2. The two wheels fixed at 1 and arranged at positions corresponding to the corners on the diagonal in the front-rear direction in the rhombus, that is, the two wheels respectively arranged on the front and rear on the center line in the front-rear direction in the vehicle body 1 are both The driven wheels 3 and 3 are mounted on the vehicle body 1 so as to be vertically movable via a common movable mechanism 4 that is integrally moved up and down, and the movable mechanism 4 and thus both the drive wheels 2 and 2 are moved downward. The biasing means 5 consisting of the spring 6 .
[0019]
In this case, in the rectangular main body frame 1a of the vehicle body 1, a pair of left and right brackets 17 are suspended from an intermediate portion in the front-rear direction, and the pair of left and right drive wheels 2, 2 are fixed to the bracket 17, respectively. A crosspiece 18 is installed at an intermediate portion in the front-rear direction of the frame 1a, and a movable frame 1b that is long in the front-rear direction is installed at the center of the crosspiece 18 via the movable mechanism 4 at the middle point thereof. The driven wheels 3 and 3 are mounted on the front end and the rear end of the movable frame 1b. In this case, the movable mechanism 4 has a slide guide cylinder 19 with rotation prevention vertically installed at the center of the crosspiece 18. The slide rod 20 is inserted into the slide guide cylinder 19 with rotation prevention from below so as to be slidable up and down, and a spring 6 is attached to the slide rod 20 between the crosspiece 18 and the movable frame 1b to move the movable rod. And rolling the over arm 1b, so that pressing the pair of driven wheels 3 longitudinal downward. Note that casters are used as the driven wheels 3 and 3.
Also in this case, the above-described first embodiment. It exhibits substantially the same function as the above and produces the same effect. In addition, the embodiment 1. The same operation and effect can be obtained by providing the same pressing force adjusting means 13 as in FIG.
[0020]
3
FIG. 7 shows an embodiment according to the first and third aspects of the present invention. The hydraulic cylinder 7 is used instead of the spring 6.
As shown in FIG. 8, the hydraulic cylinder 7 is connected to an accumulator 22 via a stop valve 21. In this case, the stop valve 21 can be set in a fixed state.
In this case as well, the above-described first embodiment. Exhibits the same function and produces the same effect. However, the pressing force adjusting means 13 can be adjusted over a wider range by changing the pressure of the cylinder 7 by moving the pressing force adjusting cylinder 23 with a cam 24 or the like operated by a motor or a manual operation. .
[0021]
In the embodiment described above, the four wheels to be equipped on the vehicle body 1 are arranged at positions corresponding to the respective corners of the rhombus, and among these wheels, the corners on one diagonal line of the rectangle are arranged. The two wheels arranged at the corresponding positions are the driving wheels 2 and 2, and the two wheels arranged at the positions corresponding to the corners on the other diagonal line are the driven wheels 3 and 3, but the four wheels are substantially diamond-shaped. The two wheels may be similarly used as the drive wheels 2 and 2 and the driven wheels 3 and 3 at positions corresponding to the corners of a square such as a square.
[0022]
【The invention's effect】
According to the present invention, by adopting the above-described configuration, the grounding of the driving wheel and the driven wheel can be secured even on the uneven surface, and stable and smooth running is possible, the structure can be simplified, and the required space can be reduced as much as possible. Costs can be reduced by reducing the number of movable parts. Moreover, even if a soft spring is used, a traveling device that does not lose stability and has high ability to absorb irregularities can be obtained. Further, by adding the pressing force adjusting means 13 to the urging means 5, the load sharing between the driving wheels 2, 2 and the other driven wheels 3, 3 can be changed, and the climbing of the wheels to the level difference can be facilitated. can do.
Therefore, by applying it to wheelchairs and mobile robots, traveling on uneven ground, which has been difficult to travel, can be easily performed at low cost, and the range of activities for wheelchair users can be expanded. It can be applied to construction sites.
[0023]
Then, by using the spring 6 as the biasing means 5, a simple structure can be achieved, and a simple configuration with the pressing force adjusting screw 14 can be achieved even if the pressing force adjusting means 13 is added.
[0024]
In addition, by using the hydraulic cylinder 7 and the accumulator 22 as the biasing means 5, the pressing force adjusting cylinder 13 can be used by moving the pressing force adjusting cylinder 23 with the cam 24, etc. Can be made possible.
[Brief description of the drawings]
FIG. 1 shows an embodiment of the rough terrain traveling device according to the first and second aspects of the invention. FIG.
FIG. 2 shows the first embodiment of FIG. It is a perspective view which shows the level | step difference corresponding state in.
FIG. 3 shows the first embodiment of FIG. It is explanatory drawing of the stable range in.
FIG. 4 shows the first embodiment of FIG. It is explanatory drawing at the time of the vehicle body inclination in.
5 shows the first embodiment of FIG. It is an expanded cutaway side view of the principal part which shows the pressing force adjustment means as an example of application.
FIG. 6 shows an embodiment 2 of the rough terrain traveling device according to the first and second aspects of the present invention. FIG.
FIG. 7 is a diagram showing an embodiment of the rough terrain travel device according to claims 1 and 3; FIG.
FIG. 8 shows the third embodiment of FIG. It is a systematic diagram of the air cylinder in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Car body 1a ... Main body frame 1b ... Movable frame 2 ... Drive wheel 3 ... Driven wheel 4 ... Movable mechanism 5 ... Energizing means 6 ... Spring 7 ... Hydraulic cylinder 8 ... Bracket 9 ... Pivoting 10 ... Electric motor 11 ... Bracket 12 ... Crosspiece 13 ... Pushing force adjusting means 14 ... Pushing force adjusting screw 15 ... Pressing plate 16 ... Lock nut 17 ... Bracket 18 ... Crosspiece 19 ... Slide guide cylinder 20 ... Slide rod 21 ... Stop valve 22 ... Accumulator 23 ... For adjusting the pushing force Cylinder 24 ... Cam

Claims (3)

Four wheels to be mounted on the vehicle body 1 are arranged at positions corresponding to each corner of the quadrangle, and two of these wheels arranged at positions corresponding to corners on one diagonal line of the quadrangle are driving wheels 2. , 2 and two wheels arranged at positions corresponding to the corners on the other diagonal line as driven wheels 3, 3, and either one of the two driving wheels 2, 2 and both driven wheels 3, 3 The vehicle body 1 is mounted on the vehicle body 1 so as to move up and down via a movable mechanism 4 that moves both wheels up and down integrally, and a biasing means 5 is provided on the movable mechanism 4 to urge downward. A rough terrain traveling device characterized by being fixed to the vehicle body 1. The rough terrain travel device according to claim 1, wherein a spring 6 is used as the biasing means 5. The rough terrain travel device according to claim 1, wherein a hydraulic cylinder and an accumulator are used as the biasing means.

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