JPH0327628Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a brake release device for an electric wheelchair.

(Prior Art) A braking device for an electric wheelchair uses a braking motor in addition to a traveling motor provided to rotate the traveling wheels, and the rotation of the output shaft of this braking motor is used for braking. There is a method designed to release this. In this case, if a worm gear is used as a speed reduction device for the braking motor, the rotational force from the wheel side will not be able to rotate the braking motor, so the braking state or This means that the brake release state can be maintained, resulting in good operability and power saving.

(Problem to be solved by the invention) However, in the case of the braking device with the above structure,
Although it has the above advantages, when replacing wheels or moving the vehicle using external force,
There is a problem in that the wire is always stretched, making the work extremely difficult. In order to solve this problem, it is only necessary to loosen the stretched wire using a simple mechanism. The present invention was developed in view of this point, and even if the electric wheelchair is in a braking state, the braking can be temporarily released with a simple operation, thereby eliminating the need for the above-mentioned wheel replacement work or external force. The purpose is to enable vehicle movement work by

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides a braking motor 16 for applying a braking force to the wheels 1 in addition to a traveling motor for rotationally driving the wheels 1. The lever 15 is connected to the braking motor 16 via a worm gear, and the lever 15 is connected to the braking motor 16 via a worm gear.
Electric braking of an electric wheelchair, in which a movable member (cam 9) is connected to the movable member (cam 9) via a wire 12, and the movement of the movable member (cam 9) presses the braking member (brake linings 7, 8) against the wheel 1 side. In the device, a release arm 19 having a pulley 21 that engages with the wire 12 is rotatably provided in a region near the wire 12 at its tip, and the position of the release arm 19 can be adjusted depending on the attitude of the release arm 19. The wire 1
The release arm 19 is positioned so that a large tension is applied to the wire 12 in a steady state in a direction perpendicular to 2, and there is no tension in the folded state, and a stopper 25 is provided near the release arm 19 in the folded state. , release arm 1
A switch 26 is provided to energize the traveling motor when the wire 9 is in the steady state orthogonal to the wire 12.

(Function) With this configuration, the release arm 1
By tilting the roller 9 so that the roller 21 attached to its tip is at an angle that does not apply tension to the wire 12, the braking motor 16 can be released without being energized. Since the brake can be released, it is possible to replace the wheels 1 or move the vehicle using external force.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 is a wheel, and 2 is a drum that rotates integrally with the wheel 1. Although not shown, a running motor is connected to the wheels 1 via a speed reducer, and when the running motor is energized, the wheels 1 are rotationally driven and run. The drum 2 rotates together with the wheel 1, and during braking, braking force is transmitted from the drum 2 side to the wheel 1.
Describe its structure. Inside the drum 2, two brake shoes 3 and 4, which are braking members, are provided with their upper ends pivoted on a shaft 5 so as to be freely expandable, and are moved toward each other by a return spring 6. being drawn. Brake linings 7 and 8 are attached to the outer periphery of the brake shoes 3 and 4,
They are opposed to the inner circumference of the drum 2 with a slight gap between them.

A cam 9, which is a movable member, is rotatably supported by a shaft 10 between the lower ends of the brake shoes 3 and 4. The cam 9 has a non-circular shape, and when a lever 11 provided integrally with the cam 9 is rotated about a shaft 10, its posture changes.
The brake shoes 3 and 4 are expanded against the tensile force of the return spring 6. Lever 11
is a lever 15 attached to an output shaft 14 of a reducer 13 with a built-in worm gear via a wire 12.
is attached to the tip of the 16 is a braking motor, 1
7 is a control device, and 18 is a battery serving as a power source.

In the vicinity of the wire 12, a release arm 19 serving as a relaxation mechanism for the wire 12 is rotatably supported by a shaft 20 with respect to the vehicle body (not shown). A pulley 21 that engages with the wire 12 is attached to the lower end of the release arm 19 by a shaft 22, so that it does not come off the wire 12. A handle 23 is provided at the upper part of the release arm 19. Stoppers 24 and 25 are provided on the vehicle body (not shown).
is provided so that the release arm 19 can be maintained in the state shown by the solid line and the state shown by the broken line. And near the stopper 24 there is a switch 2.
6 is provided so that the running motor (not shown) can be energized only when the release arm 19 is in the position shown by the solid line in the figure.

In this device configured as described above, when the electric wheelchair is put into normal use, the release arm 19 is connected to the wire 12 as shown by the solid line in the figure.
It will be maintained perpendicular to the direction in which it is stretched. When traveling, the braking motor 16 is made to take a brake release state as described later,
In this state, a running motor (not shown) is energized to drive the vehicle. When applying a braking force to the wheels 1 to stop the vehicle, first the power to the running motor is cut off to eliminate the running driving force, and then the braking motor 16 is energized for braking. Then, the braking motor 16 is moved to the lever 15 via the reducer 13 that has a built-in worm gear.
is rotated counterclockwise around the output shaft 14. As a result, the wire 12 is pulled to the right in the figure and the attitude of the cam 9 is changed via the lever 11, so that the brake shoes 3 and 4 are pushed open and put into a braking state.

At this time, part of the wire 12 is removed from the release arm 19.
It is in a state where tension is applied by a pulley 21 pivotally attached to the lower end of the motor 16, and in this state, the braking action described above and the action of releasing the braking by passing a current in the opposite direction to the braking motor 16 are performed. Since the worm gear is used in the reducer 13 as described above, the posture of the cam 9 will be maintained regardless of whether the braking state is in the braking state or the braking release state if the power to the braking motor 16 is cut off. Become.

Now, if it becomes necessary to disable the braking action in order to replace the wheel 1 or move the vehicle by external force in this state, pull the handle 23 in the direction of the arrow and move the release arm 19 to the shaft 20. Rotate clockwise around the center. As a result, the release arm 19 is tilted to the point where it comes into contact with the stopper 25 as shown by the broken line, and this state is maintained. Therefore, the wire 12, which had been strongly tensioned until then, loosens (see the dashed line diagram), so the tension of the wire 12 does not act on the cam 9.
It is in a state where it can rotate around the shaft 10, and it is in a state where the brake is released. After completing the replacement work for wheel 1,
In order to return the braking mechanism to its original state, the release arm 19 may be rotated in the direction opposite to the arrow indicated by the solid line to return to the position indicated by the solid line.

When operating the release arm 19 in this way,
A switch 26 is provided near the stopper 24 so that the state of the release arm 19 can be detected. Therefore, only when the release arm 19 maintains the posture shown by the solid line in the figure, the running motor (not shown) is activated. By configuring the circuit such that the running drive circuit is energized, running without the braking device being activated is prevented, and safety can be ensured.

In the embodiment described above, a drum brake was used as the braking device, but it can also be applied to a disc brake by replacing the movable member with a cam and using a piston, and replacing the braking member with a brake shoe and using a disc. can. Further, by changing the shape of the release arm and making it lever-like, the operating force can be reduced, and if it has a link mechanism, the stroke during operation can be reduced.

(Effect of the invention) Since the present invention is a brake release device for an electric wheelchair configured as described above, when the brake mechanism is to be prevented from operating due to wheel replacement work or movement due to external force, the power supply is required for the operation. This has the effect of making it easier to operate. and,
If the wire tensioning mechanism is equipped with a reducer having a worm gear, due to the nature of the worm gear,
If the braking motor is in a de-energized state, the wire cannot be loosened, but in the present invention, the wire can be loosened by manually operating the release arm, making it easier to perform tasks such as replacing wheels. . Further, the tension (braking force) can be easily adjusted in the operating state by moving the unit to which the stopper and switch are fixed in a direction perpendicular to the wire. Furthermore, by appropriately selecting the tilting angle of the release arm, there is also the effect that the braking force can be changed.

[Brief explanation of the drawing]

The figure is a system diagram of an embodiment of the present invention. 1... Wheel, 2... Drum, 3, 4... Brake shoe, 7, 8... Brake lining, 9...
...Cam, 11, 15...Lever, 12...Wire, 13...Reducer, 14...Output shaft, 16...
Motor, 19... Release arm, 20, 22...
Shaft, 21...Pulley, 24, 25...Stopper,
26...Switch.

Claims (1)

[Scope of utility model registration request] In addition to the driving motor that rotationally drives the wheels, a braking motor is provided to apply a braking force to the wheels, and a lever is connected to the braking motor via a worm gear, and a movable member is connected to the lever via a wire. In an electric braking device for an electric wheelchair, the braking member is brought into pressure contact with the wheel side by the movement of the movable member, in which a pulley that engages the wire at its tip is pivotally attached to a portion near the wire. The arm is rotatably provided, and the position of the release arm is set to
The position of the release arm is set so that a large tension is applied to the wire in a steady state in which the direction is perpendicular to the wire, and there is no tension when the release arm is in the folded state, and a stopper is provided near the release arm in the folded state. A brake release device for an electric wheelchair, further comprising: a switch that energizes the traveling motor when the release arm is in the steady state in which the release arm is perpendicular to the wire.