JPH10310060A - Walk type carriage provided with assist power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a walk type carriage provided with an assist power having an assist function by an electric motor in which assist force by the electric motor is effectively applied on wheels to restrict a battery consumption to the utmost while achieving reduction of required labor, and in which residual battery capacity can be displayed at favorable precision by a simple detection circuit. SOLUTION: Pushing forces at a pair of a right and a left hand-push handles 20 extended from both sides of a load frame 11 backward are respectively detected by pushing force detection sensors 73, actuation of an electric motor 30 is controlled by a control means based on detected values by both pushing force detection sensors 73, and residual capacity of batteries 28, 29 to supply power to the electric motor 30 is displayed in a display means 101 in accordance with operation of an operation switch which is disposed at a position where operation by a hand gripping a grip 56 provided at a back end of the hand-push handle 20 is impossible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a walk-behind carrier such as a hand-pushed one-wheel carrier, and more particularly to a walk-behind carrier having an assisting function using an electric motor.

[0002]

2. Description of the Related Art A walk-behind transport vehicle such as a wheeled single-wheel transport vehicle can easily pass through narrow passages, transporting materials and parts at construction sites, or harvesting in fields, orchards, and forests. Although it is widely used for transporting fertilizers and fertilizers, it is driven by human power, so large roads with pebbles and rubble and on steep slopes require a large amount of labor, so the range of use is limited. .

Therefore, for example, Japanese Utility Model Laid-Open No. 3-100568.
And Japanese Patent Application Laid-Open No. 7-40354, the assisting force of an electric motor operated by electric power supplied from a battery is applied to wheels to reduce labor. ing.

[0004]

However, in the Japanese Unexamined Utility Model Publication No. Hei 3-100568 and Japanese Unexamined Utility Model Publication No. 7-40354, a switch provided at the rear end of the push handle is turned on. Thus, a constant assist force from the electric motor is applied to the wheels. At this time, the constant assist force has to be set relatively large so that the assist force does not run short.Therefore, when the operation relying on the assist force is continued, the electric motor exerts an excessive assist force when necessary. Battery consumption becomes faster, which is inconvenient, and increasing the capacity of the battery increases the weight and impairs the function of the walk-behind transport vehicle. is there.

On the other hand, the present applicant has made it possible to reduce the battery consumption as much as possible by applying an assisting force corresponding to the pushing force to the wheels from the electric motor when the pushing force on the push handle increases. We have already proposed a walk-behind transport vehicle that reduces labor while suppressing it (Japanese Patent Application No. 9-78156).
doing.

However, in the case where the electric motor is controlled in accordance with the pressing force of the hand push handle as in the above proposal, the load fluctuates greatly and the terminal voltage of the battery frequently fluctuates greatly. In order to detect the remaining battery level from a low battery terminal voltage, there is a problem that the detection circuit must be complicated, for example, by detecting the integrated discharge current.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and aims to reduce the labor while minimizing battery consumption by effectively applying the assisting force of the electric motor to the wheels. It is an object of the present invention to provide a walking cart with auxiliary power, which can display the remaining amount of the battery with high accuracy.

[0008]

According to a first aspect of the present invention, there is provided a walking cart with auxiliary power, comprising: a loading frame; and a wheel supported at a lower center of the loading frame. ,
A pair of left and right hand push handles extending rearward from both sides of the load frame, an electric motor mounted on the load frame, and the electric motor capable of transmitting power between the electric motor and wheels only when the electric motor is operated. Power transmission means provided between the wheels, a battery for supplying power to the electric motor, a pair of pressing force detection sensors for detecting the pressing force of the two-handed push handle, and detection values of the two pressing force detection sensors. Control means for controlling the operation of the electric motor based on the operation switch, an operation switch disposed at a position where a hand holding a grip provided at a rear end of the two-hand push handle is not allowed to operate, and a remaining battery for the battery. Display means for displaying the amount in response to the operation of the operation switch.

According to such a configuration, when the pushing force of the push handle becomes large, the assisting force corresponding to the pushing force is applied to the wheels from the electric motor. In addition to running on uneven terrain and climbing over debris, the battery consumption can be reduced without operating the electric motor in a light load state such as when the loading platform is empty or when moving on flat ground. In addition, in order to operate the operation switch and display the remaining battery level on the display means, it is necessary to release the hand from the grip at the rear end of the hand push handle. It suffices to detect the remaining battery level in a no-load state that is not affected by fluctuations and display the same on the display means. Since the remaining amount display operation cannot be performed by mistake, accurate remaining amount display can be performed.

According to the second aspect of the present invention, by using a lead battery having a relatively large change in the terminal open voltage with respect to the discharge amount in a no-load state, the detection of the terminal open voltage to the battery remaining amount is easy. Can be detected relatively accurately.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

1 to 11 show a first embodiment of the present invention. FIG. 1 is a side view of a hand-operated single-wheeled vehicle, FIG. 2 is a plan view of FIG. FIG. 4 is a front view as viewed in the direction of arrow 3 in FIG. 1, FIG. 4 is a view showing the configuration of the power transmission means, and FIG.
FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 2, FIG.
FIG. 8 is an enlarged sectional view taken along line 7-7 of FIG. 6, FIG. 8 is a view showing the configuration of the control means, FIG. 9 is a front view of the display box, and FIG. circuit diagram,
FIG. 11 is a terminal voltage characteristic diagram of the battery.

First, in FIGS. 1 to 3, a load frame 11 provided in the single-wheeled transport vehicle is provided with a pair of parallel frame portions 12, 12 extending substantially parallel to the front-rear direction, and a pair of parallel frame portions 1 and 12.
A connecting frame portion 13 formed in a substantially U-shape which is connected to the front ends of the front and rear ends and extends forward and is closed at the front end portion, and a pair of front and rear horizontal frame portions provided between the parallel frame portions 12 and 12. A pair of left and right support frames 16, 16, which are connected to the front horizontal frame 14 at the center between the parallel frames 12, 12 and extend forward and downward, the front side is closed. About U
A pair of left and right reinforcing frames 1 extending between the wheel supporting frame 17 formed in the shape of a letter and connected to the two supporting frames 16, 16;
8, 18 and a pair of left and right reinforcing frames 19, 19 extending between the front portion of the connecting frame portion 13 and the wheel supporting frame portion 17.

The front ends of a pair of left and right hand push handles 20, 20 extending rearward and upward are connected to the rear ends of the parallel frame portions 12, 12, and a reinforcing frame 21 is provided between the two hand push handles 20, 20. Is provided. Moreover, both parallel frame portions 12,
12, connecting frame portion 13 and push handle 20, 20
Are integrally formed by bending a metal pipe.

The support frames 16, 16 and the wheel support frame 17 are integrally formed by bending a metal pipe, and a pair of left and right bearings 22, 24 fixed to the wheel support frame 17 are provided. At 22, an axle 24 of a single wheel 23 is rotatably supported.

The upper ends of legs 25, 25 formed in a substantially triangular shape are fixed between the rear portions of the two parallel frame portions 12, 12 and the intermediate portion of the two-hand push handle 20, 20. When the wheels 23 touch the ground 26 where the wheels 23 touch the ground, the two parallel frame portions 12
6 is formed so as to maintain the posture of the load frame 11 so as to be substantially parallel to the position thereof.

On both front sides of the parallel frame portions 12, 12, the connection frame portion 13, and the push handles 20, 20, a plate-like carrier 27 is provided.
Is provided.

First and second batteries 28 and 29, which are lead batteries, are attached to a lower portion of the loading frame 11, and an electric motor 30 which is operated by electric power supplied from the batteries 28 and 29, An electric motor 30 and a power transmission means 31 provided between the wheels 23 are mounted so that the assist force by the operation of the motor 30 can be transmitted to the wheels 23. The first battery 28 is attached to the left or right side of the wheel 23, in this embodiment, to the front of the wheel 23 and to the lower side of the load frame 11 on the right side of the wheel 23. That is, the battery tray 32 is fixed to the right side of the connection frame 23, and the first battery 28 is attached to the battery tray 32.

The second battery 29 is attached to the lower part of the cargo frame 11 behind the wheels 23. That is, the battery tray 33 is fixed to the front and rear horizontal frame portions 14 and 15, and the second battery 29 is mounted on the battery tray 33. In addition, the battery tray 33, that is, the second battery 29 is arranged so that the weight balance between the left and right wheels 23 is maintained, and the ground portion of the wheels 23 and the two-hand push handle 20 It is determined that at least a part, preferably most of the second battery 29 is present in a virtual triangle 34 connecting to the rear end of the second battery 29.

In FIG. 4, a power transmission means 31 includes a drive shaft 37 coaxially connected to an output shaft 36 of the electric motor 30;
A first gear 38 fixed to the drive shaft 37;
A first intermediate shaft 39 having an axis parallel to the first intermediate shaft 3
9, a second gear 40 meshed with the drive gear 38, a one-way clutch 41 provided between the first intermediate shaft 39 and the second gear 40, and a second gear 40 fixedly mounted on the first intermediate shaft 39. A third gear 42, a second intermediate shaft 43 having an axis parallel to the first intermediate shaft 39, a fourth gear 44 meshed with the third gear 42 and fixed to the third intermediate shaft 43, and formed as a bevel gear And the fifth gear 45 fixed to the second intermediate shaft 43
And a driven shaft 46 having an axis orthogonal to the second intermediate shaft 43.
A sixth gear 47 formed on a bevel gear and fixed to the driven shaft 46 and meshing with the fifth gear 45; a sprocket 48 fixed to the driven shaft 46; and fixed to the axle 24 of the wheel 23. Sprocket 49 and an endless chain 50 wound around both sprockets 48, 49.
And

Among such power transmission means 31, the drive shaft 37, the first gear 38, the first intermediate shaft 39, the second gear 4
0, one-way clutch 41, third gear 42, second intermediate shaft 4
The third gear 44, the fifth gear 45, a part of the driven shaft 46, and the sixth gear 47 are housed in a gear housing 51 to which the electric motor 30 is connected.
The gears 39, 43, and 46 are rotatably supported by a gear housing 51, and a sprocket 48 is fixed to an end of the driven shaft 46 protruding from the gear housing 51.

The one-way clutch 41 includes a second gear 40
Is transmitted to the first intermediate shaft 39 from the first intermediate shaft 3.
9 to the second gear 40 side, so that the power transmission means 31
Only when the operation is 0, power transmission between the electric motor 30 and the wheels 23 is enabled.

The electric motor 30 and the power transmission means 31 are disposed on the opposite side of the first battery 28 with respect to the wheels 23, that is, in the present embodiment, on the left side of the wheels 23 while facing forward, Attached to

Referring also to FIG.
1, a support arm 53 to which the front end of the support arm 52 is fastened and which extends upward is integrally provided.
Is fixed to the horizontal frame portion 14, and the upper end of the support arm 53 is fastened to the connection frame portion 13.

6 and 7, the front ends of the handle shafts 55 extending rearward are fixed to the rear ends of the two-hand push handles 20. Most of the handle shafts 55 except for the front parts are fixed. Are covered with grips 56.

The grip 56 includes a metal cylindrical support cylinder 57 coaxially covering the handle shaft 55, and a support cylinder 57.
A cover member 58 fixed to the support cylinder 57 so as to close the rear end opening, and a synthetic resin covering member 59 for integrally covering most of the support cylinder 57 except for the front part. An adjusting shaft 60 having an engaging operation portion 60a at the outer end and projecting the inner end into the support cylinder 57 is screwed to the lid member 58 so as to be able to advance and retreat in the axial direction, and can be engaged with the outer surface of the lid member 58. A lock nut 61 is screwed onto the adjustment shaft 60.
An opening 62 is provided at the rear end of the covering member 59 so that the nut 61 is rotatably operable. A flange 59a extending outward in the radial direction is integrally provided at the front end of the covering member 59.

Grooves 63 extending in the axial direction are provided at the outer periphery of the handle shaft 55 and at least three places spaced apart in the circumferential direction of the handle shaft 55, in this embodiment, three places spaced evenly in the circumferential direction. Can be Meanwhile, grip 5
6, three grooves 64... Corresponding to the respective grooves 63 of the handle shaft 55 are provided on the inner circumference of the support cylinder 57 so as to extend in the axial direction.

Handle shaft 55 and grip 56
Between the grooves 63, 64, the steel balls 65, which are capable of rolling along the grooves 63, 64, correspond to each other.
Are arranged in plurality. Therefore grip 5
5 can move in the axial direction with respect to the handle shaft 55 by rolling the steel balls 65.

A cylindrical support member 66 is coaxially disposed between the outer periphery of the handle shaft 55 and the inner periphery of each grip 56, and the support member 66 is provided with grooves 63,. A plurality of support holes 67 are provided at corresponding positions at an interval in the axial direction, and the steel balls 65 are rotatably held by the support holes 67, respectively.

At the rear end of the handle shaft 55, a fitting hole 68 whose inner end is closed is provided coaxially.
The front end of the adjustment shaft 60 at 6 is slidably fitted in the fitting hole 68. A coil spring 69 is provided between the inner end closing portion of the fitting hole 68 and the front end of the adjusting shaft 60, and the grip 56 is moved rearward with respect to the handle shaft 55 by the coil spring 69. Will be energized.

A long hole 70 is provided at the front of the handle shaft 55 in the axial direction of the handle shaft 55, and both sides of the long hole 70 are opened to the outer periphery of the handle shaft 55. On the other hand, a regulating pin 71 is attached to the grip 56 along one diameter line of the grip 56, and the regulating pin 71 is inserted into the elongated hole 70. Therefore, the relative movement of the grip 56 with respect to the handle shaft 55 in the axial direction is restricted within a range in which the restriction pin 71 contacts both ends of the long hole 70.

By the way, when a pushing force is applied to the grip 56 in order to move the walk-type carrier forward, the grip 56
Moves forward with respect to the handle shaft 55 to a position where the spring force of the coil spring 69 and the pressing force are balanced, and the pressing force can be detected by detecting the amount of forward stroke of the grip 56. It is. In addition, by adjusting the advance / retreat position of the adjustment shaft 60, it is possible to adjust the amount of forward stroke of the grip 56 corresponding to the spring force of the coil spring 69, that is, the pressing force.

In order to detect the amount of forward stroke of the grip 56, that is, the pressing force applied to the grip 56, the detector 72a is attached to the bracket 72 fixedly attached to the rear end of the push handle 20 in the rearward direction. The flange 74 of the pressing force detection sensor 73 directed to the side is fastened, and the contact plate 75 that contacts the detector 73a is fixed to the front end of the support cylinder 57 in the grip 56.

The pressing force detection sensor 73 is provided with a grip 5 attached to the rear end of the two-handed push handle 20, 20.
In order to detect the pressing force acting on both grips 56, 56 by detecting the movement strokes 6, 56, they are attached to the rear ends of the two-hand push handles 20, 20, respectively.

In FIG. 8, both pressing force detecting sensors 73, 7
Numeral 3 is provided with variable voltage dividing resistors 78 for changing the output voltage in accordance with the axial movement amount of the grip 56 with respect to the handle shaft 55. based on the voltage, the operation of the drive means 79 allowed to drive the electric motor 30 is controlled by the control means 80 _1.

[0036] The control means 80 _1, the first and second regulator 81 for regulating the power from the battery 29 to be constant, both the variable voltage dividing resistor 78 is connected in series with the regulator 81, A voltage-dividing resistor 82 connected in series to a parallel circuit consisting of a pair 78, diodes 83 and 84 respectively connected to the output terminals of the pressing force detection sensors 73 and 73, and these diodes 83 and 84 are connected to each other. A / D converter 8 for converting a voltage obtained at connection point 85, that is, an analog electric signal to a digital electric signal.
6 and an arithmetic control unit 87 that determines a control signal based on a digital signal output from the A / D converter 86 and controls the operation of the driving unit 79 based on the control signal.

[0037] According to such a control unit 80 _1, the connecting point 85 of the two diodes 83 and 84, the larger of the detected value, that the output voltage obtained at both pushing force detecting sensors 73 and 73 are selected becomes, the control means 80 _1,
When the larger one of the detection values of the two pressing force detection sensors 73 and 73 is equal to or greater than the set value, the electric motor 30 exerts an assist force according to the larger detection value. Based on the larger detection value, the electric motor 30
Will be controlled.

By the way, with the hand holding the grips 56 at the rear ends of both handle shafts 55, the electric motor 30 is moved to a position where operation is impossible, for example, to the reinforcing frame 21 connecting the two handle shafts 55. Batteries 28, 2
A switch 98 for enabling power supply from the power supply 9;
The display box 99 is attached.

In FIG. 9, on the surface of the display box 99, an operation switch 100 of a push button type and a display means 101 for displaying the remaining amount of both batteries 28 and 29 by operating the operation switch 100 are provided. The display means 101 includes first, second, and third light emitting diodes 102, 103, and 104 arranged in parallel, and a triangular index 105 drawn alongside the diodes 102 to 104.
It is composed of

In FIG. 10, one end of an operation switch 100 is connected to batteries 28 and 29, and the other end of the operation switch 100 is connected via a series circuit including a first voltage dividing resistor 106 and a constant voltage diode 111. Grounded. The first voltage dividing resistor 106 and the constant voltage diode 1
11 are connected to the second voltage dividing resistor 107 and the third voltage dividing resistor 1
08, a fourth voltage dividing resistor 109 and a fifth voltage dividing resistor 110 are connected to ground. Further, the other end of the operation switch 100 is connected in parallel with a series circuit including a first voltage dividing resistor 106 and a constant voltage diode 111,
A series circuit including the sixth voltage dividing resistor 112 and the seventh voltage dividing resistor 113 is connected.

The connection point of the second and third voltage dividing resistors 107 and 108 is connected to the non-inverting input terminal of the comparator 114, and the connection point of the third and fourth voltage dividing resistors 108 and 109 is connected to the second comparator 115. And the connection point of the fourth and fifth voltage dividing resistors 109 and 110 is connected to the third comparator 116.
Is connected to the non-inverting input terminal. That is, the first comparator 1
The first non-inverting input terminal 14 receives a first reference voltage V ₁ which is relatively high, and the non-inverting input terminal of the second comparator 115 has a constant voltage which is lower than the first reference voltage V ₁ . Second
The reference voltage V ₂ (<V ₁ ) is input and the third comparator 116
The third reference voltage V ₃ (<V ₂ ), which is lower in voltage than the second reference voltage V ₂ , is input to the non-inverting input terminal.

On the other hand, first to third comparators 114 to 11
6, the sixth and seventh voltage dividing resistors 11
2 and 113 are connected to each other, and the terminal voltages of the batteries 28 and 29 are changed to the sixth and seventh voltage dividing resistors 11 and 12, respectively.
2, 113, the first to third comparators 114 to
It is input to each inverting input terminal 116.

Further, the other end of the operation switch 100 is
The output terminal of the second comparator 115 is connected to the output terminal of the first comparator 114 via a series circuit including the first light emitting diode 102 and the resistor 117, and is connected to the output terminal of the first comparator 114 via the series circuit including the second light emitting diode 103 and the resistor 118. To the output terminal of the third comparator 116 via a series circuit including the third light emitting diode 104 and the resistor 119.

According to such a circuit, the battery 28,
29 and the sixth and seventh voltage dividing resistors 112 and 11
3 is the first reference voltage V₁When it's over
Indicates that the outputs of the first to third comparators 114 to 116 are
The first to third light emitting diodes 102 to 1 become eggplants.
All 03 light up. Also, the terminal voltage of the batteries 28 and 29
The pressure was divided by the sixth and seventh voltage dividing resistors 112 and 113.
The value is the first reference voltage V ₁Less than the second reference voltage V_Two
When the above is true, the first light emitting diode 102 is turned off.
However, the second and third light emitting diodes 103 and 104
It remains lit and the terminal voltages of the batteries 28 and 29
Value divided by the sixth and seventh voltage dividing resistors 112 and 113
Is the second reference voltage V_TwoLess than the third reference voltage V_ThreeLess than
When it is above, the first and second light emitting diodes 10
2 and 103 are turned off, but the third light emitting diode 104 is turned on.
The terminal voltage of the batteries 28 and 29 is
The values divided by the sixth and seventh voltage dividing resistors 112 and 113 are
Third reference voltage V_ThreeIf less than all light emitting diodes 1
02 to 104 are turned off.

Incidentally, when the batteries 28 and 29 are Ni-C
The battery terminal voltage at the time of no load when the battery is a d battery or a Ni-hydrogen battery is as shown by a broken line A in FIG. 11, and the change in the battery voltage with respect to the discharge amount is relatively small. In contrast, batteries 28, 29
11 is a solid battery B in FIG. 11, the battery terminal voltage under a constant load is a solid line C in FIG. 11, and the battery terminal voltage under a constant load is a solid line D in FIG. The amount of change in the battery terminal voltage with respect to the amount of discharge of the lead battery when there is no load is
The battery 28, 29 is detected by detecting the terminal voltage of the battery 28, 29 at no load, which is larger than the Ni-Cd battery or the Ni-hydrogen battery.
It is possible to accurately estimate the discharge amount, that is, the remaining amount.

Next, the operation of the first embodiment will be described. The first battery 28, which is relatively heavy, and the electric motor 30 and the power transmission means 31, which are relatively heavy, are mounted on the left and right sides of the wheels 23. Since the wheels 23 are divided and disposed below the load frame 11, a good weight balance between the left and right wheels 23 can be achieved. Therefore, it becomes easy to maintain a stable posture of the cargo frame 11 even when the posture of the cargo frame 11 is likely to be unstable at the time of carrying work on uneven terrain or sloping ground.

In addition, in order to maintain the assisting force of the electric motor 30 for a relatively long time, a second battery 29 is mounted on the load frame 11 in addition to the first battery 28. A virtual triangle which is attached to the lower part of the load frame 11 behind the wheels 23 and connects the ground portion of the wheels 23 and the rear ends of the two-handed push handles 20, 20 with the load frame viewed from above. The arrangement of the second battery 29 is determined so that the most part of the second battery 29 is present in 34 and the weight balance of the left and right wheels 23 is maintained. Therefore, the weight balance of the cargo frame 11 can be favorably maintained while the power capacity is increased by the second battery 29.

Also, grips 56 respectively covering the handle shafts 55 fixed to the rear ends of the two-hand push handles 20, 20 can move relative to the handle shafts 55 in the axial direction within a limited range. The grips 56 are elastically urged rearward by coil springs 69 provided between the handle shafts 55 and the grips 56, respectively. For this reason, the grip 56
Are transmitted to the handle shafts 55 and the hand-held handles 20, 20 via the coig springs 69. The grips 56 corresponding to the pressing forces acting on the grips 56, respectively. .. Relative to the respective handle shafts 55.
The pressing force detection sensors 73 provided on the 0 and 20 sides respectively,
When the larger one of the detection values of the pressing force detection sensors 73, 73 is equal to or greater than the set value, the operation of the electric motor 30 is controlled based on the larger detection value. It is controlled by the 80 _1.

Therefore, when the pushing force of the push handles 20, 20 is increased, the assisting force of the electric motor 30 is applied to the wheels 23 according to the pushing force.
The electric motor 30 operates when the load 27 is in an empty state or in a light load state such as when moving on a flat ground, while reducing the labor required for running on uneven terrain or moving over rubble when the load 27 is full. Without doing so, the consumption of the batteries 28 and 29 can be reduced. In addition, the posture of the cargo frame 11 tends to be unstable during transportation work on uneven or sloping terrain, and the force for supporting the push handles 20, 20 may be different between the left and right sides. In many cases, the collapse is strongly supported by one of the two-hand push handles 20, 20, but the operation of the electric motor 30 is performed based on the load state of the left or right hand push handle 20, 20, which has the larger pressing force, that is, the load state of the strongly supported side. Is controlled, an appropriate assisting force can be applied to the wheels 23 in response to the collapse of the weight balance due to the unstable posture.

In the case of a walk-behind transport vehicle, the grip 56
.. Are lifted so as to apply a pressing force to the hand-push handles 20, 20, and a plurality of steel balls 6 are provided between the grip 56 and the handle shaft 55.
.. Can intervene smoothly in the axial direction of the grip 56 with respect to the handle shaft 55 even when a lifting load is applied to the grip 56. In particular, the two-handed push handle 20, Even when strongly supported by one of the grips 20, the axial relative movement of the grip 56 accurately corresponding to the pressing force is enabled,
The pressing force acting on the grip 56 can be detected by the pressing force detection sensor 73, and an appropriate assisting force can be applied to the wheels 23.

Further, on the outer periphery of the handle shaft 55 and the inner periphery of the grip 56, at least three circumferentially spaced grooves 63, 64 extending in the axial direction of the grips 55, 56 correspond to each other. Are provided and a plurality of steel balls 65 are rolled along the grooves 63, 64,... So that the handle shaft 55 and the grip 56 are held coaxially while rotating about the axis of the grip 56. , And the relative movement of the grip 56 with respect to the handle shaft 55 in the axial direction can be further ensured.

Further, each of the steel balls 65 can be rotated one by one into a plurality of support holes 67 provided in a cylindrical support member 66 disposed between the outer periphery of the handle shaft 55 and the inner periphery of the grip 56. , The positions of the steel balls 65 along the axial direction of the handle shaft 55 and the grip 56 can be fixed. Even if a lifting load is applied to the grip 56, the handle shaft The grip 56 can be supported by the handle shaft 55 at a plurality of fixed points distributed along the axial direction of the grip 55 and the grip 56.

The battery 28,
In order to display the remaining amount of 29, the push handle 20 ...
Release your hand from the grip 56 at the rear end of the operation switch 1.
00, the traveling of the transport vehicle must be stopped without fail. Therefore, the remaining amounts of the batteries 28 and 29 in a no-load state which is not affected by load fluctuations are detected and displayed on the display means 101. And therefore the battery 28,
The circuit for detecting the remaining 29 can be simplified as shown in FIG.

Further, a lead battery having a relatively large change in the terminal open voltage with respect to the discharge amount in the no-load state is used as the battery 2.
By using them as 8 and 29, it is possible to relatively accurately detect the remaining battery level from the terminal open voltage, which is easy to detect.

FIG. 12 shows a second embodiment of the present invention, in which parts corresponding to those in the first embodiment are denoted by the same reference numerals.

[0056] Based on the detected value or the output voltage of both the pushing force detection sensor 73, the control means 80 ₂ controls the operation of the drive means 79, the first and second battery 28,2
Regulator 81 for adjusting the power from the power supply 9 to a constant value
And a voltage dividing resistor 82 connected in series to the regulator 81 and connected in series to a parallel circuit composed of the variable voltage dividing resistors 78 and 78, and connected to output terminals of the pressing force detection sensors 73 and 73, respectively. And the amplifier 9 connected in series to the resistors 89 and 90, respectively.
1, 92, resistors 93 and 94 connected in series to the output terminals of the amplifiers 91 and 92 and connected to each other at a connection point 95, an amplifier 96 to which the voltage at the connection point 95 is input, and an amplifier 96 A / D converter 86 for converting an output voltage of 96, that is, an analog electric signal into a digital electric signal
And an arithmetic control unit 87 that determines a control signal based on a digital signal output from the A / D converter 86 and controls the operation of the driving unit 79 based on the control signal.

[0057] According to such a control means 80 _2, from the amplifier 96 will be a voltage corresponding to the sum of the detection values of both the pushing force detection sensor 73 is outputted, hence the control unit 80 _2, The operation of the electric motor 30 is controlled based on the sum of the detection values of the two pressing force detection sensors 73, 73, and more precise assist force control can be performed in accordance with the load amount of the entire cargo frame 11. .

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0059]

As described above, according to the first aspect of the present invention, it is possible to reduce the amount of labor while keeping the battery consumption low, and to travel on uneven terrain or to move over rubble with a full load carrier. In addition, the operation of the operation switch must be performed so that the traveling of the transport vehicle must be stopped in order to display the remaining battery level on the display means. Can be accurately detected and displayed on the display means, and the circuit for detecting the remaining battery level can be simplified.

According to the second aspect of the present invention, it is possible to relatively accurately detect the remaining battery level from the terminal open voltage, which is easy to detect.

[Brief description of the drawings]

FIG. 1 is a side view of a manually driven single wheel carrier of a first embodiment.

FIG. 2 is a plan view as viewed in the direction of arrow 2 in FIG.

FIG. 3 is a front view as viewed in the direction of arrow 3 in FIG. 1;

FIG. 4 is a diagram showing a configuration of a power transmission unit.

FIG. 5 is an enlarged view of a main part of FIG. 1;

FIG. 6 is an enlarged sectional view taken along line 6-6 of FIG. 2;

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 6;

FIG. 8 is a diagram showing a configuration of a control unit.

FIG. 9 is a front view of the display box.

FIG. 10 is an electric circuit diagram for detecting a battery voltage and causing the display means to start a fire.

FIG. 11 is a terminal voltage characteristic diagram of a battery.

FIG. 12 is a diagram illustrating a configuration of a control unit according to a second embodiment.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11 ... Load frame 20 ... Push handle 23 ... Wheel 28, 29 ... Battery 30 ... Electric motor 31 ... Power transmission means 56 ... Grip 73 ... Pushing force detection sensor 80 ₁ , 80 ₂ ··· control means 100 ··· operation switch 101 ··· display means

Claims (2)

[Claims] 1. A loading frame (11), a wheel (23) pivotally supported at a lower center of the loading frame (11), and a pair of left and right extending rearward from both sides of the loading frame (11). The power transmission between the electric motor (30) and the wheels (23) is enabled only when the electric pusher (20), the electric motor (30) mounted on the packing frame (11), and the electric motor (30) are operated. Power transmission means (31) provided between the electric motor (30) and the wheels (23); batteries (28, 29) for supplying electric power to the electric motor (30);
A pair of pressing force detection sensors (73) for detecting the pressing force of the two-hand push handle (20), respectively, and the operation of the electric motor (30) is controlled based on the detection values of the two pressing force detection sensors (73). and control means (80 _1, 80 _2), the two-hand push operation switch disposed at a position to disable operation by the hand gripping the grip (56) provided at the rear end of the handle (20) and (100) , The battery (2
8. A walking truck with auxiliary power, characterized by comprising a display means (101) for displaying the remaining amount of the operation switch (8, 29) according to the operation of the operation switch (100). 2. The walking vehicle with auxiliary power according to claim 1, wherein the batteries (28, 29) are lead batteries.