JPS63255102A - Driven wheel device - Google Patents

Abstract

PURPOSE:To make slippage in the cross direction of a turning shaft to be produced at time of a changeover forward-backward movements of a conveyor car absorbable by attaching a slide guide to the conveyor car in a direction at a right angle to the forward direction, and assembling a slider in this slide guide. CONSTITUTION:A driven wheel 1 is supported on a bracket 3 by a horizontal turning shaft 2, and in this bracket 3, there is provided with a swivel shaft 4 which makes a vertical axis Q in a position taking an offset (a) to a vertical line P passing through a ground point S of the driven wheel 1 a central axis, while this swivel shaft 4 is attached to a base fitting 5. And, this base fitting 5 is attached to the base of a slider 7 which is, in turn, assembled to a slide guide 8. In addition, a coil spring 11, energizing elastic force to both sides of the slider 7, is inserted into the inside of the slide guide 8. The driven gear device constituted like this is used after being attached to the base of a conveyor bar 6. With this constitution, any slippage in the cross direction of the swivel shaft 4 to be produced at time of a changeover of forward-backward movements of this conveyor car 6 is made absorbable.

Description

[Detailed description of the invention] [Object of the invention 1 (Industrial application field) The present invention relates to a driven wheel device.

(Prior Art) A transport vehicle that transports cargo in a factory or warehouse has, as its running device, drive wheels for supplying running power and driven wheels that do not have running power. The conventional driven wheel device used as the driven wheel of such a conveyance vehicle is
It has a configuration as shown in FIGS. 6 and 7. In other words,
In order to improve the followability of the driven wheel 1, a horizontal rotating shaft 2 that rotatably supports the driven wheel 1 is supported by a bracket 3,
This bracket 3 is provided with a pivot shaft 4 at a predetermined offset a with respect to the vertical IIaP passing through the grounding point S of the driven wheel 1, and the pivot shaft 4 is rotatably fixed to the base metal fitting 5. be. This driven wheel device is then attached to the transport vehicle 6 and used.

In such a conventional driven wheel device, when traveling, the rotating axis 4 is the traveling direction, and the vertical plane including the vertical line Q passing through the center of the rotating axis 4 and the grounding point S of the driven wheel 1 is always the traveling direction. Drive in the same direction.

(Problems to be Solved by the Invention) However, in the case of the conventional driven wheel device as described above, no particular problem occurs when traveling in a straight line, but a problem occurs when switching between forward and backward travels. In other words, when switching forward or backward, the driven wheel 1 turns about 180 degrees around the rotation axis 4, but at this time, the rotation axis 4 draws a circle with the grounding point S of the driven wheel 1 as the center and the offset a as the flat diameter. Turn like this.

Therefore, the conveyance vehicle 6 starts traveling after it deviates laterally by an amount of offset a to the left and right with respect to the traveling direction. If there is a lateral shift of 8 minutes offset like this, it becomes difficult to perform forward/backward switching operations in a narrow space, and there is also the problem of having to widen the gap between the transport vehicle and the station where cargo is transferred. was there.

The present invention was made to solve these conventional problems, and it is an object of the present invention to provide a driven wheel device that does not cause lateral slippage when switching between forward and backward directions, and is capable of switching forward and backward directions of a guided vehicle in a narrow space. purpose.

[Structure of the Invention] (Means for Solving the Problems) The driven wheel device of the present invention has a rotating shaft offset from the driven wheel attached to a slider, and slides the slider in the horizontal direction. In addition to assembling the slider into a slide guide, an elastic member is provided to apply a force to return the slider to a specified position.

(Function) In the driven wheel device of the present invention, the slide guide is installed horizontally with respect to the carrier. When the guided vehicle equipped with this driven wheel device switches forward and backward, the slider absorbs the lateral deviation of the turning axis by sliding horizontally along the slide guide, and after turning 180 degrees, the elastic member moves the slider back and forth. Return to the original specified position.

Therefore, even when switching between forward and backward movement of the transport vehicle, it is possible to prevent the occurrence of lateral deviation due to the offset of the turning axis.

(Example) Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 and FIG. 2 show an embodiment of this invention,
Components that are the same as those of the conventional example shown in FIGS. 6 and 7 will be described with the same reference numerals. The driven wheel 1 is rotatably supported by a bracket 3 by a horizontal rotating shaft 2, and the bracket 3 has a vertical line Q at a position offset a from a vertical line P passing through the grounding point S of the driven wheel 1. A pivot shaft 4 having a center axis is provided, and this pivot shaft 4 is rotatably attached to a base metal fitting 5.

The base metal fitting 5 is attached to the bottom of the slider 7,
This slider 7 is slidably assembled to a horizontal slide guide 8. Further, in order to improve the sliding between the slider 7 and the slide guide 8, a ball 9 is provided on the slider 7 side and engaged with a ball guide groove 10 formed in the slide guide 8.

Coil springs 11°11 having the same spring strength are further inserted into the slide guide 8 on both sides of the slider 7, and bias the slider 7 with elastic force to position it at a predetermined position of approximately medium heat. There is. Note that 12.12 is a coil spring guide.

The driven wheel device having the above configuration is used by being attached to the bottom of the transport vehicle 6, as shown in FIGS. 1 and 2.
A slide guide 8 is attached to a predetermined position on the bottom of the carrier 6 so as to extend horizontally in the left and right directions, the slider 7 is assembled to the slide guide 8, and the entire driven wheel device is attached to the carrier 6.

In the driven wheel device attached to the carrier vehicle 6 in this way,
By pushing the carrier vehicle 6, the rotating shaft 4 is moved forward in the direction of travel, and the vehicle moves in the direction of a vertical plane that includes the central axis Q of the rotating shaft 4 and the grounding point S of the driven wheels 1.

The operation of switching the transport vehicle 6 between forward and backward movement is shown in FIG. In FIG. 3, during normal travel, the lower side of the figure is the front in the traveling direction, and the upper side is the rear in the traveling direction.

Now, as shown in Fig. 3<a>, when the conveyance vehicle 6 is stopped while traveling forward in the direction of travel and is to be switched between forward and backward movement, it operates as shown in Fig. 3) to (e). . The entire driven wheel device rotates in either the left or right direction around the grounding point S of the driven wheel 1. When the carrier 6 starts to be pulled backward, the pivot shaft 4 starts to rotate clockwise (or counterclockwise) as shown in FIG.
1A, it moves by a distance 11i1id1 to a position B1 backward. At this time, the rotation axis 4 will be slightly deviated to the left with respect to the reference plane R in the front-rear direction. , and absorbs the shift of the transport vehicle 6 itself to the left.

When the conveyance vehicle 6 is further pulled rearward and the driven wheels 1 are completely oriented in the left-right direction as shown in FIG. 2=
(a) Rotate 90° to the retreated position of B2. At this time, the leftward deviation of the pivot shaft 4 and the slider 7 is maximum, and the distance is an offset of 8 minutes. This leftward deviation is caused by the slider 7 relative to the slide guide 8.
is absorbed by further sliding to the left, and the transport vehicle 6 itself does not shift laterally.

When the rotation further progresses to the point shown in FIG. 3, the pivot shaft 4 reaches position B3, which is moved backward from the original position A by a distance of 111td3. At this time, slider 7 is
It is in a state where it has returned slightly to the right side from the maximum lateral deviation Ffla. The slider 7 returns due to the restoring force of the coiled adhesive 11, and the slide guide 8 and the carrier 6 itself fixed to the slide guide 8 do not shift laterally.

As shown in FIG. 3(e), when the pivot shaft 4 is completely rotated by 180°, the distance d 4 (
=2a>The slider 7 reaches the retreated position B4, and the slider 7 returns to its original central position by the left and right coil springs 11, and begins to move backward.

In this way, when the slide guide 8 is attached and the conveyor vehicle 6 is to be switched forward or backward, the rotation axis 4 is rotated 180° so as to draw a circle with a radius of offset a centering on the grounding point S of the driven wheel 1. However, the lateral deviation of the rotation axis 4 can be absorbed by the sliding movement of the slider 7 with respect to the slide guide 8, and as a result, the direction can be changed on the spot without moving the carrier 6 itself in the left-right direction. It can be done.

Incidentally, when analyzing the strength of the coil spring 11 provided in the slide guide 8, the maximum displacement of the coil spring 11 is the offset distance a of the rotation axis 4, and if the spring constant is k, the displacement of the coil spring causes the transfer vehicle 6 The maximum value fmax of the reaction force received by is fmax=2nka in the state shown in FIG. 3(C). Here, n is the number of driven wheels attached to the transport vehicle 6, and a is the offset distance of the rotation axis 4.

If the lateral control torque of the transport vehicle 6 is T, and the lateral distance of the rotation axis 4 from the control center of the transport vehicle 6 is x, then T≧2nka ・x, and if the spring constant k is determined from this, k ≦T/2
becomes nax. Therefore, by taking a spring constant k that satisfies the above equation, the conveyance vehicle 6 can change direction without shifting in the lateral direction with respect to the traveling direction when switching between forward and backward directions.

FIG. 4 and FIG. 5 show another embodiment of the present invention, and show a driven wheel device that can be used when the traveling direction of the conveyance vehicle is made to be in any direction of 36 degrees.

In this embodiment, the bracket 3 supporting the driven wheel 1
is attached to a base metal fitting 5 via a pivot shaft 4, and this base metal fitting 5 is attached to the lower surface of a cylindrical slider 14 having a sliding flange 13. This slider 14 is inserted into a cylindrical slide guide 16 having an opening 15 on the bottom surface. Coil springs 1i and ii are provided in at least 63 directions in the slide guide 16, and in the case of the embodiment, in 4 directions.

... are connected to the slider 14.

In the case of the driven wheel device of this embodiment, the cylindrical slide guide 16 is attached to the bottom of the conveyance vehicle to allow it to travel, but regardless of the direction in which the conveyance vehicle travels within 360°, it can move forward or backward in the direction of travel. At the time of switching, the slider 14 moves against the slide guide 1 in response to the offset rotation of the pivot shaft 4.
6, and can absorb the lateral movement of the transport vehicle 6.

In addition, in the first embodiment described above, in order to easily slide the slider 7 against the slide guide 8, the ball 9 is
However, it is also possible to use a low-friction material instead of such a ball. Further, even if the coil spring 11, which serves as an elastic member for returning the slider to the specified position of the thrust guide, is provided only on one side, the effect remains the same.

[Effects of the Invention] As described above, according to the present invention, a slide guide is attached to the transport vehicle in a direction perpendicular to the direction of movement of the transport vehicle, and a slider is assembled () to this slide guide. The slider slides within the slide guide to absorb the lateral deviation of the turning axis that occurs when the vehicle is switched between forward and backward movement, thereby preventing lateral deviation of the transport vehicle itself. Therefore, the width of the travel path can be narrowed, and the gap between the conveyance vehicle and the station where the cargo is delivered and received can be narrowed, so that the receiving and handing of the cargo can be carried out even more smoothly.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway front view of one embodiment of the present invention, Fig. 2 is a side view of the above embodiment, and Fig. 3 is an explanatory diagram illustrating the 13 actions of the above embodiment when switching forward and backward. , FIG. 4 is a sectional view of another embodiment of the present invention, FIG. 5 is a partially broken bottom view of the second embodiment, FIG. 6 is a side view of the conventional example, and FIG. 7 is a diagram of the conventional example. It is a bottom view.

Claims (1)

[Claims] A horizontal rotating shaft supporting the driven wheel is supported by a bracket, and this bracket is attached to the slider by a vertical pivot shaft provided at a predetermined offset with respect to a vertical line passing through the grounding point of the driven wheel. A driven wheel device, which supports this slider on a horizontal slide guide and includes an elastic member that applies a force to return the slider to a specified position on the slide guide.