JPH09249129A - Conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep the power of an operator constant and keep the conveying speed constant during the travel on a slope like the travel on a flat road. SOLUTION: This conveying device 1 is provided with a carriage 3 loaded with a cargo 2, a device main body 4 provided at the rear section of the carriage 3, a hold section 5 fitted at the upper section of the device main body 4, front wheels 6a, 6b provided on both sides of the bottom section of the carriage 3, the right and left rear wheels 7a, 7b provided on both sides of the bottom section of the device main body 4, and motors individually driving the rear wheels 7a, 7b. A tilt angle sensor 10 detecting the tilt angle in the advancing direction of the carriage 3 is fitted in the device main body 4. A control device 11 controls the assisting force, i.e., driving force of the motors, corresponding to the tilt angle of a slope in response to the tilt angle detected by the tilt angle sensor 10. The conveying device 1 can be operated and traveled to ascent the slope like on a flat road.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier device, and more particularly, to a carrier device configured to drive a trolley in accordance with an operation force of an operator to perform power assist.

[0002]

2. Description of the Related Art For example, a carrier device for driving a carriage and power-assisting it according to a pressing operation of an operator when carrying a load or the like is under development. In this type of transport device, a trolley on which luggage is placed is equipped with a motor for driving wheels, a battery for rotating the motor, a control device for controlling drive torque of the motor, and the like. In addition, the transport device has a sensor for detecting the operating force of the operator.
For example, a force sensor is provided in the operation unit for operating the dolly, and the control device controls the motor to generate a driving force of a predetermined ratio (for example, half the operating force) of the operating force obtained from the output signal from the force sensor. , The voltage supplied to the motor is controlled.

Therefore, for example, when a heavy load is loaded on a carriage, the driving torque of the motor is increased by strongly pressing the force sensor of the operating portion, and the labor of the operator is reduced. Further, when the load loaded on the trolley is relatively light, the force sensor of the operation unit is pressed with a light force so that the driving torque of the motor is reduced.

[0004]

In the transport apparatus having the power assist function configured as described above, even when the vehicle travels uphill, the burden on the operator is constant as if traveling on a flat road. Is desirable.

However, in the conventional transport apparatus, when traveling uphill, even if the force required to move the transport apparatus increases as the inclination angle of the uphill increases, the operation by the operator is increased. Since the ratio of the driving force of the motor to the force is constant, the operator needs a larger operating force as the inclination angle of the uphill increases when the package is conveyed using the conventional conveying device. was there.

For example, when a beginner who is not accustomed to the operation operates the transport device, sufficient driving torque cannot be obtained unless the pressing force on the force sensor is increased on the uphill, or the force sensor is operated on the downhill. If the pressing force is not relaxed, the trolley may be accelerated further. Therefore, in the conventional transfer device, when passing through an uphill or a downhill, the pressing force applied to the force sensor must be finely adjusted according to the inclination angle, which is difficult to operate.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a carrier device that solves the above problems.

[0008]

Means for Solving the Problems To solve the above problems, the present invention is characterized by taking the following means. The present invention includes a carriage having wheels, a driving unit that drives the wheels, and a control unit that controls the driving force of the driving unit according to the magnitude of the operating force of the operator to the carriage. In the apparatus, an inclination angle sensor for detecting an inclination angle of the traveling direction of the carriage is provided, and the wheels are driven by a driving force according to the inclination angle detected by the inclination angle sensor.

Therefore, according to the present invention, the wheel is driven by the driving force corresponding to the tilt angle detected by the tilt angle sensor. For this reason, the driving force of the motor can be made higher than that on a flat road when passing through an uphill, and the labor of the operator can be reduced.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a side view of an embodiment of the carrying device of the present invention, and FIG. 2 is a rear view of the carrying device. The carrier device 1 includes a trolley 3 on which the luggage 2 is placed, a device body 4 provided at a rear portion of the trolley 3, a grip portion 5 attached to an upper portion of the device body 4 as an operation unit, and a trolley 3 of the trolley 3. Front wheels 6a, 6b provided on both sides of the bottom, left and right rear wheels 7a, 7b provided on both sides of the bottom of the apparatus body 4, and rear wheels 7a, 7b
Motors 8a and 8b for individually driving

The front wheels 6a, 6b are provided so as to turn so as to face the traveling direction. A battery 9 serving as a drive source of the motors 8a and 8b is housed inside the apparatus body 4. The battery 9 is charged by a household AC 100V power source when the carrier device 1 is not used.

Further, an inclination angle sensor 10 for detecting the inclination angle of the carriage 3 in the traveling direction is attached inside the apparatus body 4. Since the tilt angle sensor 10 is for detecting the tilted state of the carriage 3, the mounting position may be inside the device body 4 installed in the carriage 3 or may be directly mounted on the carriage 3. May be.

The tilt angle sensor 10 is, for example, a displacement type sensor which directly outputs the angle of the pendulum from the reference axis indicating the direction of gravity, or the torque generated by passing a current through the electromagnetic coil and the torque due to the tilt of the pendulum. A torque balance type that balances and holds the pendulum at zero is used.

Further, in the control device 11, the operator holds the grip portion 5
When the rear wheels 7a, 7b are rotated by pressing, the motors 8a, 7b
The operating force of the operator is detected by the magnitude of the current value flowing in the coil of 8b, and the motors 8a and 8b are rotationally driven so that the conveying speed corresponds to the operating force.

FIG. 3 is a diagram for explaining a force relationship that acts when the transport device 1 goes up a slope. The overall force F considering the inclination angle θ when the transport device 1 goes up a slope is obtained by the following equation (1).

F = ma + μmgcos θ + mgsin θ (1) In the equation (1), θ is the slope angle of the slope, μ is the coefficient of friction of the slope, g is the acceleration of gravity, and m is the conveyance device 1 and the load 2.
Is the combined mass. Although the weight of the carrier device 1 is known in advance, the weight of the luggage 2 varies depending on the time, and therefore the total weight m is set to the own weight of the carrier device + α.

Next, the control processing executed by the control device 11 will be described with reference to the flowchart of FIG. The control device 11 executes the process shown in FIG. 4 when a main power switch (not shown) provided on the device body 4 is turned on.

That is, when the power is turned on, the motor 8
Power is supplied to a and 8b (S1), and power is supplied to the controller 11 (S2). After that, the control system is initialized (S3). In the next step S4, a timer interrupt is performed every 0.1 seconds until the power is turned off. When the timer interrupt is entered in S4, the process proceeds to S5, in which the motor current value converted into a digital signal by the A / D converter (not shown) incorporated in the control device 11, the rotation speed, and the detection of the inclination angle sensor 10 are detected. Read the value (tilt angle θ).

At the next step S6, the operator's ability f is calculated based on the conversion data read at step S5. Then, in S7, the output value of the current corresponding to the operator's ability f is set to the control device 1
A D / A converter (not shown) built in the unit 1 converts it into an analog signal and drives the motors 8a and 8b. Therefore, the torque of the motors 8a and 8b is controlled by the output value of the control device 11. Therefore, the transport device 1
Is the rear wheels 7a, 7 with a force corresponding to the magnitude of the operating force of the operator.
Rotate b to assist the labor of the operator.

FIG. 5 is a flow chart for explaining the calculation process of S6 in detail. In S8 of FIG. 5, the acceleration a of the conveyor 1 is calculated from the rotation speeds of the motors 8a and 8b. In the present embodiment, since the processing of S5 to S7 is executed every 0.1 seconds, the current motors 8a, 8
By comparing the number of revolutions of b with the number of revolutions of the motors 8a and 8b sampled last time, the acceleration a of the conveyance device 1 is increased.
Can be calculated.

Next, the force F required to move the transport device 1 is calculated based on the equation (1) as described above (S9).
That is, the force F corresponding to the magnitude of the tilt angle θ is obtained.
When traveling on a flat road, the calculation is performed with the inclination angle θ = 0. In next step S10, the driving force of the motors 8a and 8b is calculated by multiplying the current value by the coefficient k. Then, the amount of force f by which the operator presses the grip portion 5 is calculated (S1).
1). The force f of the operator can be obtained by subtracting the driving force of the motors 8a and 8b from the force F required to move the transport device 1.

In the next step S12, the assist ratio B is calculated in order to calculate the current output value to the motors 8a and 8b according to the assist ratio B (auxiliary drive ratio of the motor) when the force f of the operator is 1. Calculate as follows. To move the transport device 1 at the same speed, a flat road and a slope with an inclination angle of θ
When the operator's ability f is set to be the same, the assist ratio B is expressed by the following equation (2).

B = {F (θ) −f (0)} / f (0) (2) (where F (θ) is the total force at the tilt angle θ, f
(0) is the force of the operator on a flat road) Here, in the case where the assist ratio B is 1 on a flat road, that is, half the total force F (0), f ( 0) = 1 / (1 + B) F (0) = 1 / 2F (0) (3) Therefore, the assist ratio B is expressed by the following equation (4).

B = {F (θ) − (1 / 2F (0)} / (1 / 2F (0)) (4) According to this assist ratio B, the current output value to the motors 8a and 8b is It is calculated by the equation (5): Output value = B × force amount f (5) The current calculated by the equation (5) is the motor 8a, 8b.
Supplied to

As described above, the control device 11 calculates the force f of the operator from the current change of the motors 8a and 8b, the speed (motor rotation speed) and the gross weight of the conveyance, and controls the force f to be the output of the motor. By performing the above, the assisting force corresponding to the inclination angle of the slope, that is, the driving force of the motors 8a and 8b is controlled, and even when going up the slope, the pressing operation is performed in the same manner as on the flat road, so that the transport device 1 can travel. it can.

Therefore, even when climbing a slope at the same speed as when traveling on a flat road, the operator's ability f does not increase, and the burden on the operator can be made constant. Therefore, the carrier device 1
When climbing up a slope while pressing, the operator needs the same effort as traveling on a flat road by the assisting force according to the inclination angle of the slope, and the luggage 2 can be stably and smoothly transported.

On the other hand, when going down a slope, the driving force of the motors 8a and 8b is reduced to reduce the assist force, contrary to the case where the road is going up. Thereby, the transport device 1
Is prevented from accelerating on slopes. Therefore, even if the operator is not accustomed to operating the transport device 1, regardless of the slope angle of the slope, even if the operator descends the slope at the same speed as when traveling on the flat road, the operator's force f is flat. This is the same as in the case of a road, and it is possible to operate safely and smoothly when carrying heavy objects.

FIG. 6 shows a modification of the present invention. Device body 4
The weight setting switches 12 to 14 for setting the weight of the luggage 2 are provided on the upper surface of the. The weight setting switch 12 is a switch that is turned on when the load 2 is 100 kg or less.
The weight setting switch 13 is a switch that is turned on when the load is 200 kg or less, and is turned on when the load 2 is 200 kg or more.

In the above-described embodiment, since the weight of the luggage 2 is different at that time, the weight of the luggage 2 is set to α, and the total weight m is set to the self-weight of the carrier 1 + α. The weight of the luggage 2 can be input to the control device 11 by selectively operating 14 according to the weight of the luggage 2.

Therefore, when the control device 11 calculates the force F for moving the carrying device 1 in S9, the total weight m is set according to the weight of the parcel 2, so that the total weight m matches the weight. The motor driving force is calculated. Therefore, when the weight of the baggage 2 is large, the transporting device 1 uses the motors 8a and 8a.
The assist force of b is increased, and when the weight of the luggage 2 is small, the assist forces of the motors 8a and 8b are controlled to be reduced.

As a result, the operator can carry the load 2 with substantially the same operating force even if the weight of the load 2 is changed. That is, even when the transport device 1 travels on a slope, the driving force of the motors 8a and 8b is controlled by the assist ratio according to the weight of the baggage 2 and the inclination angle of the sloped road at that time. The package 2 can be transported at a substantially constant speed regardless of the change in the slope angle of the slope.

FIG. 7 shows another modification of the present invention. Trolley 3
A weight sensor 15 for measuring the weight of the luggage 2 is attached to the upper surface of the. The weight sensor 15 is composed of, for example, a load cell, measures the weight of the luggage 2 placed on the carriage 3, and outputs an electric signal corresponding to the weight to the control device 11.

Therefore, the load 2 is placed on the carriage 3 of the carrier 1, and the weight of the load 2 is detected by the weight sensor 15. Then, the control device 11 uses the weight sensor 15
The total weight m is calculated by adding the weight α of the luggage 2 output from the weight of the control device 11 itself.

Therefore, in the above S9, the transport device 1
Since an accurate total weight m is set when calculating the force F for moving the motor, a motor driving force suitable for the weight of the total weight m is calculated. Therefore, the carrier device 1 can be controlled to increase or decrease the assisting force of the motors 8a and 8b according to the weight of the luggage 2.

Therefore, the operator can carry the luggage 2 with the same operating force even when the weight of the luggage 2 to be carried is different. That is, even when the transport device 1 travels on a slope, the driving force of the motors 8a and 8b is controlled by the assist ratio according to the weight of the baggage 2 and the inclination angle of the sloped road at that time. The luggage 2 can be transported at a constant speed regardless of the change in the inclination angle of the slope.

In the above embodiment, the case where the luggage 2 is placed on the carriage 3 and conveyed is given as an example, but the present invention is not limited to this. For example, the conveyance device 1 may be another carriage or a bed having wheels. Of course, it can be applied to the case of carrying. Further, in the above embodiment, the motors 8a and 8b are
The force f of the operator is calculated by subtracting the driving force of the motor obtained from the current values of the motors 8a and 8b from the force F required to move the conveyance device 1 obtained using the acceleration a calculated from the rotation speed of The required transporting device is given as an example, but the present invention is not limited to this, and it is needless to say that a transporting device that directly measures the force f of the operator by providing a force sensor or the like on the operating portion of the transporting device can be applied.

Also in this case, the assist ratio corresponding to the tilt angle θ may be set using the equations (1), (2) and (5). Further, in the above embodiment, the assist ratio B on the flat road is set to 1, but the present invention is not limited to this, and the assist ratio on the flat road can be set to different values depending on the application of the transport device. In this case, the value of the assist ratio B used in the equation (3) may be changed.

In the above embodiment, the operating force f (θ) of the operator on a slope is the same as the operating force f on a flat road at the same speed.
Although the assist ratio B is calculated to be the same as (0), the operating force f (θ) is larger than f (0) in order to make the operator recognize that it is a slope, You may make it smaller than when the ratio is constant,
In this case, the equations (2), (3), and (4) may be changed so as to calculate the assist ratio B ′ with B <B ′ <1.

[0039]

As described above, according to the present invention, since the wheels are driven by the driving force corresponding to the inclination angle detected by the inclination angle sensor, the labor of the operator increases as the inclination angle of the uphill increases. Can be reduced. Therefore, even an operator who is not accustomed to the operation can safely and smoothly operate a heavy object regardless of the inclination angle of the uphill.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of a carrying device according to the present invention.

FIG. 2 is a rear view of the transfer device.

FIG. 3 is a diagram showing a force relationship when traveling on a slope.

FIG. 4 is a flowchart of a control process executed by a control device.

FIG. 5 is a flowchart for explaining in detail the output value calculation processing executed in S6 of FIG.

FIG. 6 is a plan view of an apparatus main body for explaining a modified example of the present invention.

FIG. 7 is a side view for explaining another modification of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transport device 2 Luggage 3 Cart 4 Device body 5 Grips 6a, 6b Front wheels 7a, 7b Rear wheels 8a, 8b Motor 10 Inclination angle sensor 12-14 Weight setting switch 15 Weight sensor

Claims (1)

[Claims] 1. A carrier device having a carriage having wheels, a drive section for driving the wheels, and a control section for controlling the drive force of the drive section according to the magnitude of the operation force applied to the carriage, A carrier device, comprising: a tilt angle sensor for detecting a tilt angle of the carriage in a traveling direction, and driving the wheels with a driving force according to a tilt angle detected by the tilt angle sensor.