JP2758295B2 - Small electric car - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is designed to drive a vehicle by means of an electric motor, to provide an artificial operation tool capable of changing the driving speed of the electric motor, and to provide a manually operated friction brake in the traveling drive system. The present invention relates to a small-sized electric vehicle in which an electromagnetic brake configured as a negative brake for releasing a braking state by energization is provided.

[0002]

2. Description of the Related Art Conventionally, in the above-mentioned small electric vehicle, as shown in, for example, Japanese Patent Application Laid-Open No. 3-98404, an electromagnetic brake is energized to a braking operation side, and a braking state is set by energizing and exciting. It is configured as a negative brake type so as to release it, and when the driver leaves the vehicle body for a long period of time, the power is released to automatically act as a parking brake. However, when the vehicle is temporarily stopped during traveling, the traveling of the vehicle body is braked by the friction type brake by manual operation. Further, when the vehicle is stopped for a relatively long time, the brake state is maintained by operating a lock lever dedicated to locking the operating device of the friction brake in the braking state.

[0003]

However, in the conventional structure described above, when the vehicle is temporarily stopped, if the driver accidentally forgets to operate the lock lever and releases the brake operating tool without turning off the power switch, the vehicle travels. Drive system braking is gone,
When the vehicle is on a slope, there is a possibility that a problem such as running of the vehicle under its own weight may occur. An object of the present invention is to eliminate the above disadvantages.

[0004]

SUMMARY OF THE INVENTION The feature of the present invention is that, in the small electric vehicle described at the beginning, detecting means for detecting that the friction type brake is in a braking state, and detecting means for detecting that the friction type brake is in a braking state. Brake switching means for switching the electromagnetic brake to a braking operation state when switched to a detection state; and braking the electromagnetic brake in a braking operation state accordingly when the artificial operation tool switches from a stop position to a running state. And a brake release means for switching to a release state.

[0005]

[Function] To temporarily stop the vehicle during running or temporarily stop the vehicle, operate the friction type brake to the braking state, and then release the power to the electric control system without releasing the hand or foot from the brake operating tool. Even if it is released, at this time, the detection means detects that the friction type brake has been released, and then the detection means detects that the friction type brake has been released. The electromagnetic brake is automatically switched to the braking state. Therefore,
Even if the operation of the friction brake is released, the vehicle body surely stops. In addition, when the electromagnetic brake is set to the braking state and the speed changing operation tool is again switched to the traveling state in order to travel, the braking of the electromagnetic brake is automatically released accordingly. This allows the aircraft to travel.

[0006]

Thus, the brake operation tool is braked even in the case of temporary stoppage, even though the automatic brake is constituted by adopting the negative brake type electromagnetic brake for the parking brake. There is no need to perform extra operations such as locking at the operating position. Therefore, it is possible to reliably prevent the aircraft from being accidentally put into the non-braking state,
In addition, since the above-described braking state is released in accordance with the operation of the traveling speed setting operation tool, there is no adverse effect of driving the electric motor in a state where the braking is applied, and the traveling safety is improved. is what happened.

[0007]

Embodiments will be described below with reference to the drawings. FIG.
Shows a small electric vehicle. This electric vehicle has one front wheel 2 that can be steerably operated by operating a steering handle 1.
And a transport bed 4 is detachably connected to the rear of a traveling body having a pair of left and right rear wheels 3 driven by an electric motor M for towing travel.

The connecting part 5 of the carrier 4 is shown in FIGS.
As shown in FIG. 5, the horizontal pin 7 provided on the connecting tool 6 on the carrier 4 enters into the concave portion 9 of the connecting tool 8 on the traveling body and is engaged to prevent the vertical movement. A U-shaped hook 10 is pivotally supported on the lateral side of the concave portion 9 so as to be swingable about a horizontal axis, and the hook 10 prevents relative movement in the front-rear direction. That is, in the state before the connection, the hook 10 is opened rearward along the opening of the concave portion 9, and the horizontal pin 7 is engaged with the hook 10 by the relative longitudinal movement of the traveling body and the carrier 4. It enters inside the recess 9. Then, when the hook 10 reaches the predetermined position, the hook 10 is further prevented from swinging by the stopper 11, and the cam member 12 is prevented from swinging backward, so that the hook 10 is fixedly connected. And
In the vicinity of the hook 10, a limit switch SW1 for detecting that the hook 10 has been set to the connection position is provided. With the detection operation of the limit switch SW1,
The confirmation lamp 14 provided on the control panel 13 is turned on so that the operator can confirm the connection state.

As shown in FIG. 4, ultrasonic proximity sensors 15R and 15L for detecting that an external object has approached are provided on both right and left sides of the carrier 4. One of the proximity sensors 15R is provided. , 15L are detected, the corresponding one of the left and right warning lamps 16R, 16L disposed on the control panel 13 is illuminated, so that the driver always checks the rear when turning or the like. While avoiding the possibility of contact between the transport bed 4 and an external object, the configuration is made.

As shown in FIGS. 1 and 5, the operation amount is detected by a potentiometer PM in accordance with the operation of an operation pedal 18 (an example of an artificial operation tool) provided in the operation unit step 17, and the potentiometer PM is used. The output of the meter PM is input to the control device 19, and the control device 19 controls and drives the motor drive circuit 20 to rotate the electric motor M at a drive speed corresponding to the output, thereby driving the vehicle. In the system, a manually operated friction brake 21 and an electromagnetic brake 22 are interposed. The friction brake 21 is configured to apply friction braking to the rear wheel drive shaft in accordance with the operation of a brake lever 23 which is provided near the grip portion 1a of the steering handle 1 so as to be freely operable. The electromagnetic brake 22 is urged toward the braking side by a spring (not shown), and the solenoid 2
4 is configured as a negative brake type so as to release the braking urging force by energizing and energizing 4. An excitation current is supplied to the solenoid 24 via a brake drive circuit 25 based on a control signal from the control device 19.

In the vicinity of the brake lever 23,
A limit switch SW2 (an example of a detecting means) for detecting that a brake operation has been performed is provided. When the limit switch SW2 switches from a detection state to a non-detection state, a brake switching means A for switching the electromagnetic brake 22 to a braking state.
When the operation pedal 18 is depressed from the vehicle body stop position, that is, the released state, and changes to the vehicle running state, the brake release means B that switches the electromagnetic brake 22 in the braking operation state to the brake release state accordingly. It is prepared.
More specifically, the means A and B are provided in the control device 19 in the form of a control program, and the control device 19 executes control as follows. As shown in FIG. 2, from the body running state, the operating pedal 18 is loosened in order to stop the vehicle body, the running speed is reduced, and when the brake lever 23 is depressed and operated in the lowered state, the limit switch SW2 is turned on and operated,
The friction brake 21 acts to stop the vehicle body. When the hand is released from the brake lever 23, the limit switch SW2 is turned off, that is, in a non-detection state, and the control device 19 stops the exciting current supplied to the drive circuit 25 of the electromagnetic brake 22. To quickly switch to the braking state. Then, after that, when the operation pedal 18 is again depressed to start running the airframe again, the control device 19 starts supplying the drive circuit 25 while gradually increasing the excitation current. The braking is reliably released in a state where the drive output is increased to some extent, thereby preventing a situation where the output is insufficient on a slope or the like.

In the claims, reference numerals are provided to facilitate comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a control block diagram.

FIG. 2 is a control timing chart.

FIG. 3 is an overall side view of a small electric vehicle.

FIG. 4 is a plan view of a small electric vehicle.

FIG. 5 is a plan view of a control unit.

FIG. 6 is a side view of a connecting portion.

FIG. 7 is a side view of the connecting portion.

[Explanation of symbols]

 18 Artificial operation tool 21 Friction brake 22 Electromagnetic brake A Brake switching means B Brake release means SW2 Detecting means

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B60T 17/22 B60T 17/22 C (72) Inventor Gonshiro Kawabata 64 Ishizukitamachi, Sakai-shi, Osaka Kubota Sakai Works (56) References JP-A-61-33345 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B60T 13/58 B60T 17/22 B60T 7/12

Claims (1)

(57) [Claims] An artificial motor (M) is configured to be driven to travel by an electric motor (M), and an artificial operation tool (18) capable of changing the driving speed of the electric motor (M) is provided. For friction type brake (21) and excitation
By constructing a negative brake that releases the braking state more
A small electric vehicle interposed with a certain electromagnetic brake (22), a detecting means (SW2) for detecting that the friction type brake (21) is in a braking state, and the detecting means (SW2) The brake switching means (A) for switching the electromagnetic brake (22) to the braking operation state when the state is switched from the detection state to the non-detection state, and when the artificial operation tool (18) switches from the stop position to the traveling state, A small electric vehicle comprising: a brake release means (B) for switching the electromagnetic brake (22) in a braking operation state to a brake release state accordingly.