JPH08268286A - Electric wheelbarrow - Google Patents

Abstract

(57) [Summary] [Purpose] To provide an electric hand-operated work vehicle that enables simpler traveling control. [Structure] The handle 3 pushed by the walking operator is mounted on the vehicle body 2
And a wheel 6 for supporting the vehicle body 2 so that the vehicle body 2 can travel, which can be driven by an electric motor 5.
Is provided with a detection means 12 for detecting a pressing state, and a traveling control means 8 for driving and controlling the electric motor 5 in the steering wheel pressing direction side in association with the detection of a pressing force larger than a setting force by the detection means 12. It is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric hand-operated work vehicle in which a handle which is manually pushed by a walking operator is attached to a vehicle body and wheels for supporting the vehicle body can be driven by an electric motor.

[0002]

2. Description of the Related Art Heretofore, as an electric hand-operated work vehicle of this type, there has been known one in which an accelerator lever is provided on a handle and an accelerator is operated to drive an electric motor to drive the vehicle. ing.

[0003]

However, in the conventional structure described above, the operation amount of the accelerator lever is detected, and the electric motor is driven based on the detection result. Therefore, it is necessary to control the vehicle speed so that the vehicle speed is increased according to the operation amount of the accelerator lever, and the control configuration is complicated. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an electric hand-operated work vehicle capable of more easily traveling control.

[0004]

According to a first aspect of the present invention, there is provided an electric hand-operated work vehicle in which a handle manually pushed by a walking operator is attached to a vehicle body, and wheels for movably supporting the vehicle body are driven by an electric motor. And a detection means for detecting the pressing state of the handle, and drivingly controlling the electric motor in the steering wheel pressing direction side in conjunction with the detection of the pressing force with a force larger than a set value by the detecting means. A characteristic configuration is that a travel control means is provided.

According to a second aspect of the present invention, there is provided an electric hand-operated work vehicle in which a handle manually pushed by a walking operator is attached to a vehicle body, and wheels for movably supporting the vehicle body can be driven by an electric motor. Traveling is provided with detection means for detecting the forward pressing state of the steering wheel, and drivingly controlling the electric motor in the forward direction side in conjunction with the detection of the forward pressing force with the detection means. Control means is provided, and pulling state detection means for detecting that the steering wheel is being pulled with respect to the vehicle body is provided, and the pulling state detection means detects that the steering wheel is being pulled. Based on the above, a handle-corresponding braking means for switching the drive circuit of the electric motor to the dynamic braking circuit is provided.

According to a third aspect of the present invention, there is provided an electric hand-operated work vehicle, in which a handle manually pushed by a walking operator is attached to a vehicle body, and wheels for supporting the vehicle body can be driven by an electric motor. A detection means is provided for detecting the pressing state of the handle, and a traveling control means is provided for controlling the drive of the electric motor in the steering wheel pressing direction in association with the detection of the pressing force with a force larger than the setting by the detecting means. A vehicle speed detecting means for detecting the rotation speed of the wheel is provided, and a vehicle speed corresponding brake for switching the electric motor to a dynamic braking state by judging that the vehicle speed is higher than a predetermined speed based on the detection result of the vehicle speed detecting means. A feature is that means is provided.

According to a fourth aspect of the present invention, in the electric hand-operated work vehicle according to the third aspect, the vehicle speed-corresponding braking means has a higher vehicle speed based on the vehicle speed detected by the vehicle speed detecting means. It is configured to set a large braking force at the time of dynamic braking of the electric motor. The operation and effect of this characteristic configuration are as follows.

[0008]

That is, according to the characterizing feature of the first aspect, the detecting means for detecting the pressing state of the steering wheel is provided, and the detecting means detects the pressing force with a force larger than the set value. Since the traveling control means for driving and controlling the electric motor in the steering wheel pushing direction side is provided, it is possible to perform forward and backward operations by simply pushing the steering wheel forward or backward. As a result, the operation for moving the vehicle body becomes extremely simple, and the control structure thereof can be simplified.

According to the characterizing feature of claim 2,
For example, when the vehicle is traveling on a downhill or the like and the acceleration is unreasonable, the steering wheel is pulled, so that the electric motor for traveling is not driven in conjunction with the pulling operation, but the dynamic braking is performed. Since the circuits are switched as described above, it is possible to solve the problem that the vehicle is unreasonably driven at an unreasonably high speed and becomes unwieldy.

According to the characteristic construction of claim 3,
For example, when the vehicle is traveling on a downhill or the like and the acceleration is unreasonably high, the vehicle speed becomes high. Therefore, when the vehicle speed exceeds a predetermined value, braking is applied so that the electric motor for traveling is used for dynamic braking. Since the circuits are switched, it is possible to solve the problem that the hand truck is unreasonably driven at a high speed and becomes difficult to handle.

According to the characterizing structure of claim 4,
When the vehicle speed is unreasonably high, the braking force is increased according to the speed, and when the vehicle speed is relatively low, it is set so that the braking force is weakened. Has become.

[0012]

Therefore, according to the characterizing feature of the first aspect, the forward and backward operations can be performed by simply pushing the handle forward or backward so as to push the handle. The operation for advancing is extremely simple, and its control structure can be simplified.

According to the characterizing feature of claim 2,
When traveling at an unreasonably high speed such as when the steering wheel is pulled, the steering mode can be switched to the dynamic braking state, which facilitates the steering wheel operation.

According to the characteristic construction of claim 3,
When the vehicle is traveling at an unreasonably high speed such as when the steering wheel is pulled, the steering can be easily operated because the state is switched to the dynamic braking state based on the detection result of the vehicle speed.

According to the characterizing feature of claim 4,
When the vehicle speed is high in accordance with the vehicle speed, the dynamic braking strongly acts, and when the vehicle speed is low, the dynamic braking acts weakly, which makes it easier to handle.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an electric hand truck according to the present invention. This electric hand truck has a loading platform 1 for transportation.
A pair of left and right hand push handles 3 are erected on the rear end of the vehicle body 2 configured as described above, and the front wheels 4 of the caster wheels are
And a pair of left and right rear wheels 6, 6 driven by the electric motor 5.
The vehicle body 2 is supported so that it can travel. Then, as shown in FIG.
A battery 7 and a control device 8 as a traveling control unit are installed on the lower abdomen.

As shown in FIGS. 1 to 3, the pair of left and right hand push handles 3 are supported by a pair of left and right stays 9 of the vehicle body 2 so as to be swingable back and forth around the horizontal axis P.
A pair of upper and lower springs 10, 10 are elastically biased to the rod body of the hand-pushing handle 3 along the up-and-down direction over the vehicle body 2 and above the horizontal axis P and below the horizontal axis P, respectively. The hand push handle 3 is maintained in a neutral position in a balanced state by these springs 10 and 10.
The springs 10 and 10 are not shown in FIG. Further, a potentiometer 12 as a detection means linked to the hand push handle 3 via a link mechanism 11.
Is provided on the right-hand stay 9. The potentiometer 12 is configured so as to detect the swing position of the hand-pushing handle 3 in the front-rear direction, and its detection signal is input to the control device 8 as shown in FIG.

On the other hand, the output of the electric motor 5 drives the left and right rear wheels 6, 6 via the deceleration mission 13. A brake 14 that is manually operated for braking is provided on the axle 15 of the rear wheels 6 and 6, and a brake lever 16 for operating the brake 14 is provided on the hand push handle 3.

A circuit for driving the electric motor 5 and for dynamic braking will be described. As shown in FIG. 3, the circuit connecting the battery 7 and the electric motor 5 includes a drive element 17 for turning on the circuit by a signal for driving the electric motor 5 from the control device 8, and a control device 8 for braking. The relay 19 switches the circuit from the state in which the battery 7 is connected to the electric motor 5 to the state in which the terminals of the electric motor 5 are connected to each other via the braking load resistor 18 in accordance with the braking control signal. ing.

The control device 8 is configured to drive the electric motor 5 based on the input signal from the potentiometer 12. That is, when the walking operator pushes the hand push handle 3 forward from the neutral state, the control device 8
The hand push handle 3 swings forward around the horizontal axis P, and the amount of forward swing is measured by the potentiometer 12.
Is detected and a signal for driving the electric motor 5 is output to the drive element 17 based on the detection signal so that the vehicle speed corresponds to the swing amount of the steering wheel 3. Further, when the handle 3 is swung rearward from the neutral state, that is, when the handle 3 is pushed backward (pulled), the control device 8 detects the swinging state by the potentiometer 12, and the detection is performed. Based on the result, the output of the signal to the drive element 17 is stopped, the signal for driving the relay 19 is output, the connection between the battery 7 and the electric motor 5 is disconnected, and the terminals of the electric motor 5 are connected to each other. Connecting. As a result, when the vehicle body 2 continues to travel in a state where the handle 3 is swung rearward from the neutral state, the electric power generated by the rotational driving of the electric motor 5 conversely applies braking to the rotational driving. Will be done. Therefore, like a downhill,
On the contrary, when the running speed naturally increases rather than pushing the push handle 3 forward, and the push handle 3 has to be pulled backward, dynamic braking is performed to prevent the vehicle speed from unreasonably increasing. It is configured to be opened. Here, the potentiometer 12 also constitutes the pulling state detection, and the controller 8 and the drive element 17 are also provided.
The relay 19 and the relay 19 constitute a handle-corresponding braking means 23.

Next, examples according to claims 3 and 4 of the present invention will be described. The description of the same structure as in the above embodiment will be omitted and the same reference numerals will be given. As shown in FIG. 1 and FIG. 4, the spring 1 is swingable around the horizontal axis P and is maintained in a neutral position.
A hand-pushing handle 3 that is elastically biased in the front-rear direction by 0 and 10 is installed on the vehicle body 2. Axle 15 of rear wheel 6
Is provided with a rotary encoder 20 as a vehicle speed detecting means for detecting the rotation speed of the axle 15.
The detection signal of the rotary encoder 20 is supplied to the control device 8
Is input to Then, as shown in FIG. 4, in the circuit connecting the battery 7 and the electric motor 5 for traveling, the drive element 17 to which the signal for driving the electric motor 5 from the control device 8 is input, A relay 19 for switching the circuit from a state in which the battery 7 and the electric motor 5 are connected to a state in which the terminals of the electric motor 5 are connected via the braking load resistor 18 by a braking control signal from the control device 8 in FIG. And through. Further, a braking signal corresponding to the vehicle speed output from the control device 8 is input to the circuit of the braking load resistor 18, and a braking element 21 for performing intermittent control of the circuit is interposed. .

With the above structure, when the walking operator pushes the hand push handle 3 forward from the neutral state, the control device 8 swings forward around the horizontal axis P and moves forward. The amount of swing is detected by the potentiometer 12, and a signal for driving the electric motor 5 is output to the drive element 17 based on the detection signal so that the vehicle speed becomes a speed corresponding to the amount of swing of the steering wheel 3. Further, the control device 8
Is driven by the rotary encoder 20 by traveling downhill or the like.
When it is determined that the vehicle speed detected at is equal to or higher than a predetermined speed, for example, 6 km / h or more, the output of the signal to the drive element 17 is stopped and the signal for driving the relay 19 is output to output the battery 7 And the electric motor 5 are disconnected, and the terminals of the electric motor 5 are connected to each other. Moreover,
The control device 8 increases the vehicle speed based on the vehicle speed signal detected by the rotary encoder 20 in that state,
The duty ratio of the pulse signal as the ON signal to the braking element 21 is increased to increase the braking force of the electric braking by the electric motor 5 so that the vehicle speed can be quickly reduced. As a result, when the vehicle body 2 continues to travel in a state where the handle 3 is swung rearward from the neutral state, the electric power generated by the rotational driving of the electric motor 5 conversely applies braking to the rotational driving. Will be done. Therefore, as in the case of going downhill, when the handwheel 3 is pushed forward, the traveling speed naturally increases and the handwheel 3 has to be pulled backward. It is configured to perform dynamic braking according to the vehicle speed so as not to become a high speed. Here, the control device 8, the drive element 17, the relay 19, and the braking element 21 constitute a vehicle speed-corresponding braking means 24.

[Embodiment] The embodiment in which the displacement of the handle due to pressing is detected is shown in the above embodiment, but a load sensor for detecting the degree of distortion of the handle due to the pressing is not detected, but the displacement of the handle is detected. You may comprise as a detection means. As shown in FIG. 5, the detection means may be a limit switch 22 that uses a microswitch that can detect only forward pressing. Further, the pulling state detecting means may also be constituted by another limit switch. As another embodiment to claim 2, a plurality of load resistors having different resistance values are provided in parallel in a circuit connecting terminals of the electric motor 5 for dynamically braking the electric motor 5, and a rotary encoder or the like is provided. Control for selecting one or a suitable load resistance in the circuit connecting the terminals of the electric motor 5 based on the detection result of the detection means for detecting the vehicle speed and changing the resistance value in the circuit according to the vehicle speed. You may go. The pressing force may be detected as described above, in which only the pressing force on the front side can be detected.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an overall side view showing an electric hand truck.

FIG. 2 is an overall plan view showing an electric hand truck.

FIG. 3 is a circuit diagram showing a control circuit of an embodiment according to claims 1 and 2 (showing a dynamic braking state).

FIG. 4 is a circuit diagram showing a control circuit of an embodiment according to claim 1, claim 3, and claim 4 (showing a dynamic braking state).

FIG. 5 is an overall side view showing an electric hand truck according to another embodiment.

[Explanation of symbols]

 2 vehicle body 3 handle 5 electric motor 6 wheels 8 traveling control means 12 detection means (pulling state detection means) 20 vehicle speed detection means 23 steering wheel compatible braking means 24 vehicle speed compatible braking means

Continued Front Page (72) Inventor Jiro Kuramoto 64 Ishizukita-machi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd.

Claims (4)

[Claims] 1. A handle (3) pushed by a walking operator.
Is attached to the vehicle body (2), and a wheel (6) for movably supporting the vehicle body (2) is configured to be drivable by an electric motor (5) to detect a pressing state of the handle (3). (12) is provided, and the detection means (12)
An electric hand-operated work vehicle provided with travel control means (8) for driving and controlling the electric motor (5) in the steering wheel pressing direction side in conjunction with detection of pressing with a force higher than a set value. 2. A handle (3) pushed by a walking operator.
Is mounted on the vehicle body (2), and a wheel (6) for movably supporting the vehicle body (2) is configured to be drivable by an electric motor (5) to detect a forward pressing state of the handle (3). A traveling means which is provided with a detection means (12) for controlling the electric motor (5) to drive in the forward direction side in conjunction with the detection of a pressing force with a force equal to or greater than a preset value by the detection means (12). A pulling state detecting means (12) is provided for detecting that the handle (3) is being pulled with respect to the vehicle body (2) by providing a control means (8), and the pulling state detecting means (12). An electric hand-pushing operation provided with a handle-corresponding braking means (23) for switching the drive circuit of the electric motor (5) to the dynamic braking circuit based on the detection result of the pulling operation of the handle (3) in FIG. car. 3. A handle (3) pushed by a walking operator.
Is attached to the vehicle body (2), and a wheel (6) for movably supporting the vehicle body (2) is configured to be drivable by an electric motor (5) to detect a pressing state of the handle (3). (12) is provided, and the detection means (12)
Is provided with travel control means (8) for driving and controlling the electric motor (5) in the steering wheel pressing direction in association with the detection of pressing with a force higher than the setting, and the rotation speed of the wheels (6) is controlled. A vehicle speed detecting means (20) for detecting is provided, and the circuit is switched to the dynamic braking state of the electric motor (5) by judging that the vehicle speed is equal to or higher than a predetermined speed based on the detection result of the vehicle speed detecting means (20). An electric hand-operated work vehicle provided with a vehicle speed-compatible braking means (24). 4. The vehicle speed-corresponding braking means (24) increases the braking force of the electric motor (5) during dynamic braking as the vehicle speed increases based on the vehicle speed detected by the vehicle speed detection means (20). The electric hand-operated work vehicle according to claim 3, which is configured to be set to.