JP2000211519A - Transportation vehicle with auxiliary power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence to a hand-pushing force due to the change in the loading weight of a transportation vehicle with auxiliary power. SOLUTION: A transportation vehicle (cart) 1 with auxiliary power is provided with load sensors 15, springs 16, and guide members 17 between the load table 3 and the base 2, and the loading weight on the load table 3 is measured by the load sensors 15. The force added to the operator's handle 6 in the directions of +e and -e is detected by a human-power detecting sensor inside the handle 6, and based on the maximum speed, acceleration, or the like of the cart previously calculated by a control part 14 in accordance with the loading weight, a driving motor 9 and a continuously variable transmission 10 are controlled to rotatingly drive a driving wheel 11 so as to assist the human power.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier with an auxiliary power which detects an operator's pushing force on a carrier and is energized by auxiliary power, and more particularly to an auxiliary power for energizing a vehicle by measuring a loaded weight. The present invention relates to a transport vehicle with auxiliary power for controlling a vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been a carrier with auxiliary power, in which an operator simply turns on and off the auxiliary power or controls the amount of auxiliary power by pulling a lever. A proposal for controlling the speed of driving wheels by extracting left and right separate sensor outputs from a handle gripped by the operator by providing two driving wheels, a driving motor, a control unit, and the like on the left and right is disclosed in, for example, Japanese Patent Application No. Hei. It is found in documents such as 32645.

One example will be described with reference to FIG. FIG.
0 (a) is a perspective view of the transport vehicle, and FIG. 10 (b) is a detail of a pressure-sensitive sensor section provided below the handle 64. In the figure, a loading platform 61 on which luggage is loaded has a left drive wheel 6
2. A right drive wheel 63, a left drive motor 70 for rotating the drive wheels, a right drive motor 71, a left drive control unit 67 for controlling the rotation of the drive motor, a right drive control unit 68, and a battery 69 as a power source are housed. are doing. As shown in FIG. 10B showing the right end of the handle 64, the U-shaped tip of the handle 64 attached to the front of the loading platform 64 is connected to a fulcrum extending from a column supporting the loading platform 61. 72 are supported therethrough.

Therefore, when the operator presses the handle 64, the handle 64 swings around the pin 72 in the elliptical groove of the limit plate 75, and when released, is urged by the spring 74 to return to the neutral point. Has been made. The displacement of the handle 64 is detected by a load cell 73 which is a pressure-sensitive sensor disposed below the limit plate 75. A similar mechanism is the handle 6
4, the outputs of the left and right load cells 73 are separately taken out and added to the left or right driving section 67 or 68, so that the left driving wheel 62 outputs the left load cell output and the right driving wheel 63 outputs the right driving wheel 63. Is given a rotation according to the output of the load cell.

[0005]

In such a carrier vehicle with auxiliary power, the carrier can be operated with a small effort by pushing the handle 64, but the handle required for starting the carrier is pushed. Since the force varies depending on the weight loaded on the loading platform, for example, as the loading load increases, it is necessary to push the handle strongly when the truck starts, and when the loading load is small, the truck runs fast. There is a problem of too much. That is, there is a problem that operability is not good because it is necessary to increase or decrease the pushing force of the handle due to the loaded load at the time of departure to assist the driving of the transport vehicle.

[0006]

In order to solve such a problem, the present invention provides a load sensor for detecting a load weight and a control means for controlling a driving force of an auxiliary drive unit based on an output of the load sensor. And an output characteristic of the control means that changes based on the calculated detection value of the load sensor.

Further, according to the present invention, there is provided a carrier with auxiliary power, wherein the control means is set so that a traveling speed and an acceleration rate of the carrier vary depending on a load weight of the carrier. The invention also provides an auxiliary powered vehicle using a pressure-sensitive resistance element for the load sensor. Further, the auxiliary drive unit of the carrier vehicle with auxiliary power of the present invention includes a motor for driving a battery, a speed change unit, and at least one
It has two driving wheels.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a carrier vehicle with auxiliary power (hereinafter abbreviated as a bogie) 1 according to the present invention will be described with reference to FIGS. FIG. 1 is a projection view of a truck, FIG. 1 (a) is a front view seen from a position where a person pushing the truck stands, FIG. 1 (b) is a side view, and FIG. It is the bottom view which looked at the bottom. FIG. 2A is a perspective view of the entire bogie, and FIG.
(B) is an auxiliary drive unit 8 attached to the bottom surface of the base 2
It is a perspective view of. The embodiment will be described in the context of a luggage carrying truck mainly used in factories and the like, but the carrier vehicle with auxiliary power of the present invention can be widely applied to a personal carrier device for nursing care such as a wheelchair. It is possible.

In FIG. 1, a cart 1 has a pair of fixed casters 4 attached to a lower front side of a rectangular shallow dish-shaped base 2 made of, for example, a metal plate, and a pair of free casters 5 attached to a lower rear side. Here, the direction of the axle supporting the caster wheels with respect to the base 2 is fixed in the fixed caster 4, and the direction of the axle of the universal caster 5 can be changed to any direction by an external force. A pair of columns 7 behind the base 2
Are fixed substantially vertically, and the handle 6 is provided horizontally via a handle support 7a at the upper end. The handle support 7a is fixed integrally with the column 7.

The auxiliary drive unit 8 has a drive unit base 12 fixed to the lower surface of the base 2 and a drive motor 9 attached to the drive unit base 12.
The drive wheel 11 is rotatably supported by a drive wheel bearing 12 a fixed to the drive unit base 12. Although the drive motor 9 and the drive wheel 11 can be directly connected to each other and driven, in this case, for example, V
The drive wheels 11 are rotated in the forward or reverse direction via a continuously variable transmission 10 having a belt and a V-pulley having a variable diameter. The drive motor 9 usually has a built-in reduction gear so that an optimum speed can be obtained in combination with the reduction ratio of the continuously variable transmission 10. When a force is applied to the handle 6 in a direction opposite to the traveling direction, the drive motor 9 rotates in the reverse direction to act as a brake. Further, not only the forward movement (+ e direction), but also the auxiliary power works effectively when the carriage is moved backward (in the -e direction). It is also possible to change the control level between forward and reverse.

A rectangular plate-shaped carrier 3 on which cargo carried by the carriage 1 is loaded is arranged on the base 2. At least a load sensor 15 is provided between the bed 3 and the base 2, and a spring 16 and a guide 17 are placed as necessary to detect the weight of the load loaded on the bed 3. Detailed description of these will be described later. A battery 13 which is a power source of the auxiliary driving unit is housed below the base 2.

The details of the structure will be described later.
A human-power detection sensor is incorporated in the inside of the device, and detects a component in the + e or -e direction of the force with which the operator grips and pushes the handle 6. Therefore, it is normal for the operator to hold the handle 6 with both hands from the left side in FIG. 1B and push the cart in the + e direction. As described above, the bogie has two types of pressure-sensitive sensors, a load sensor that detects the weight of the load loaded on the loading platform 3 and a human-power detection sensor that detects the force of pushing and pulling the handle 6 by the operator. Operation control can be performed as follows.

FIG. 3A shows a motor 9 for driving the carriage 1.
FIG. 3B is a block diagram of the rotation control system, and FIG. 3B shows a change in the traveling speed of the carrier that changes when a constant force is applied to the steering wheel 6. Conventionally, a traveling state such as an appropriate traveling state (for example) depends on the magnitude of the loaded load. When the luggage to be transported by the cart is loaded on the carrier 3, the weight is added as an output of the load sensor 15 to the drive information calculation unit 41 inside the control unit 14. The output of the load sensor is input as a coefficient for calculating drive information such that the running speed shown in FIG. 3B has a constant speed characteristic regardless of the load. The drive information is supplied to the continuously variable transmission 10 to control the acceleration characteristics of the bogie at the start, and to control the motor M via the controller 43 and the driver 44 (PWM control). The speed of the bogie is detected by a speed detection sensor -42 attached to the drive wheel 11, and a servo system is constructed such that the speed does not exceed a certain speed by being fed back to the controller 43. In this way, a constant running characteristic can be obtained only by the force of the operator applied to the steering wheel, regardless of the magnitude of the load mounted on the bogie. That is, conventionally, the relationship between the force applied to the steering wheel 6 and the traveling speed changes depending on the large, medium, and small load weights as shown in FIG. 3B. However, the drive control of the bogie is performed by providing a weight sensor. According to the present invention, regardless of the weight, the bogie can be steered with speed characteristics as indicated by, for example. The gear ratio of the transmission 10 for setting the acceleration characteristic of the bogie at the start is 3
In many cases, the speed may be fine, but if the speed is made variable by taking advantage of the continuously variable transmission, the speed characteristics can be strictly maintained. Alternatively, the transmission may be omitted, and the acceleration control may be performed only by the motor control.

In FIG. 1, the bogie 1 is described as having a pair of fixed casters in front and driving wheels 11 between them. However, the driving wheels are placed at the positions of the left and right fixed casters so that one wheel can be driven on one side. No trouble occurs. Depending on the purpose of use, the fixed casters may be removed, and three-point support of one drive wheel and a pair of rotating casters may be advantageous.
Similarly, even if an independent continuously variable transmission is not used to change the acceleration rate, the drive information calculation unit in the control unit 14 changes the acceleration rate electrically and as a part of the control of the drive motor 9. It is also possible to change the acceleration rate electrically. Also, in the above description, the effects of the load were completely removed, and the optimum constant acceleration rate and upper limit speed were always set.However, the operator should be aware of the weight of the load to some extent so that the weight of the handle may be reduced. May be controlled to slightly change.

A specific configuration example of the load sensor will be described with reference to FIG. FIG. 4A is a perspective view of the base 2 of the carriage 1, and shows the arrangement of the load sensor 15, the spring 16, and the guide 17 through the bed 3. FIG. 4B is a plan view of the base 2, also showing the carrier 3 in a see-through manner.
The own weight of the carrier 3 and the weight of the loaded luggage are supported by, for example, three springs 16. The upper end of the spring 16 is on the carrier 3,
The lower ends are fixed to the base 2 respectively. Guide 17
The upper end of the cylinder fixed to the base 2 is engaged with a column fixed to the carrier 3 to slide vertically, thereby restricting the movement of the carrier 3 in a direction other than the vertical direction.

FIG. 5A shows the details of the load sensor 15. A pressure-sensitive sensor 15a is attached to the upper surface of the base 2. As an example of the sensor, a pressure-sensitive conductive polymer film on which a pressure-sensitive resistance element is printed is used, and the property that the electric resistance decreases as the force applied to the film surface increases is used. Two electrodes are provided on the film surface, and lead wires 15
c is drawn to measure the resistance value between the electrodes. Although there are various sizes depending on the application, the width B of the sensor is about 15 mm, the thickness is about 0.2 to 1 mm, the length L is about 200 mm, and the diameter of the pressure-sensitive area 15b is 9.5 m.
The m-th position is common.

The upper end of the pressure rod 15d is fixed to the carrier 3,
Pressure is applied to the pressure-sensitive area 15b via the cushioning material 15e attached to the lower end. The relationship between the electric conductivity, which is the reciprocal of the electric resistance in the pressure-sensitive area 15b, and the pressure acting on the pressure-sensitive area 15b is qualitatively as shown in FIG. 5B, and the middle of the graph has a considerable linearity. ing. If the pressure-sensitive sensor 15a having such characteristics is used, the weight of the luggage loaded on the carrier 3 can be measured with necessary accuracy. FIG.
In such a configuration, such load sensors 15 are provided at the four corners of the carrier 3 so that there is no error even if the cargo is loaded at a position where the carrier 3 is offset. If less accuracy is required, two or one sensor may be placed in the center.

The details of the human power detection sensor 25 provided inside the handle 6 will be described with reference to FIG. FIG. 6 (a)
Is a cross-sectional view of the handle 6 projected from above, (b) is a front cross-sectional view, (c) is a cross-sectional view cut along the axis of the pressure rod 23,
(D) is a perspective view of the human power detection sensor 25, and shows the internal sensor part with the handle 6 removed. Arrows + e and -e are valid in common in FIGS. 6A and 6C, and indicate the same direction as + e and -e in FIG. The handle 6 is made of, for example, a metal pipe, and is supported at both ends by a handle support 7 a fixed to the upper end of the column 7.
When the operator grips the handle 6 with both hands and applies a force in the direction in which the bogie is to be advanced, the handle 6 bends, and the human power detection sensor detects the + e and -e directions of the flexural components.

That is, a center beam 18 supported at both ends independently of the handle 6 by grooves formed in the handle support 7a.
A support plate 19 is fixed to a central portion of the base plate with small screws 21. A pressure-sensitive sensor 22 is attached to a predetermined position of the center beam 18. The pressure-sensitive sensor 22 uses, for example, the same type of pressure-sensitive resistance element as the load sensor 15a.
The pressure rod 23 has a cylindrical portion inserted into a hole in the support plate 19 and is slidably supported. A buffer 24 is attached to a flange portion having a diameter larger than the cylindrical portion. Contacting pressure area. In the example of FIG. 6, four sets of pressure-sensitive sensors 22 are used. Middle beam 18 with handle 6
When each of the pressure rods 23 is supported by the handle support 7a, the tip of the pressure rod 23 is pushed by the inner diameter of the handle 6 and the pressure-sensitive sensor 2 is
The length of the pressure rod 23 is determined so as to give an initial pressure to the pressure rod 2.

When the bending moment of the handle 6 acts on the handle support 7a, the handle support 7a rotates and the center beam 1
Since there is a possibility that the handle 8 is bent, for example, a ring-shaped protrusion ring 6a protruding from both ends of the handle 6 may be provided to eliminate the influence of the bending moment. The two pressure-sensitive sensors 22 are configured in a well-known bridge circuit, and their outputs are differentially taken out to compensate for the influence of the external environment such as temperature. A pressure sensor 22 is provided. Even if the left and right hand forces are not equal due to changes in direction, etc., the position of the maximum deflection of the handle 6 is in a narrow range near the center of the handle. There is an advantage that can be detected.

The human power detecting sensor for detecting the deflection of the handle 6 has the following features. First, the pressure sensor 2
Since the initial pressure is applied to 2, if the operator applies a force to the handle, the operator can immediately respond and obtain an output proportional to the applied force, and then use the slight deflection of the handle. The operator hardly notices the movement of the steering wheel itself, and can eliminate unnatural play of the steering wheel.

The direction change can also be performed with the help of the drive motor 9. 7 and 8 show an embodiment of a transport vehicle 30 (hereinafter referred to as a bogie) with a direction changing auxiliary power according to the present invention. FIG. 7 is a projection view of the cart 30, and FIG.
FIG. 71 is a front view as viewed from a position where a person pushing the cart stands, FIG.
FIG. 7B is a side view, and FIG. 7C is a bottom view of the bottom of the bogie viewed from the ground. FIG. 8A is a perspective view of the entire carriage 30, and FIG. 2B is a perspective view of an auxiliary drive unit 8 a attached to the bottom surface of the base 2. The difference between the bogie 1 shown in FIGS. 1 to 3 and the bogie 30 of this example is based on the point that the pressures of the left and right hands are separately detected by the handle and when the drive wheels 11 of the auxiliary drive unit 8a change directions. This is the point of shaking the head. In particular, only this difference will be described.

As shown in FIG. 7A, the handle 35 is cut off at the center, and the force exerted on the handle 35 by the operator is detected separately for the left and right sides. The configuration of the pressure-sensitive sensor installed inside the handle 35 will be described later. The auxiliary drive unit 8a is provided with a drive motor 9 and a continuously variable transmission 10 mounted on a fan-shaped rotary base 31, and the drive wheels 11 are rotatably supported by a drive wheel receiver 31a fixed to the rotary base 31. The drive wheels 11 are driven through the continuously variable transmission 10 by the rotation of the drive motor 9.
Rotating is not different from the previous example.

The rotation base 31 can swing about a support shaft 32 implanted in the base 2 in parallel with the bottom surface of the base 2. A sector gear 31b is formed by cutting a tooth shape in an arc portion of the rotation base 31. The steering motor 34 is fixed to the base 2 with the output shaft facing downward, and the pinion 33 attached to the output shaft is
is engaged with b. Therefore, if the steering motor 34 rotates, the pinion 33 attached to its output shaft
Rotates the sector gear 31b, the rotation base 31 swings around the support shaft 32, the drive wheel 11 also changes its rotation surface, and the truck 30 can change the traveling direction.

The front of the base 2 of the carriage 30 (+ e direction)
, A pair of free casters and a pair of fixed casters at the rear. Although the mounting positions of the casters are in front of and behind the bogie 1 shown in FIG. 1, the types of the casters are selected so that the direction can be easily changed. As described in the configuration of the bogie 1, the bogie 30 of this time also allows various changes other than the basic configuration, such as the required number of casters and the presence or absence of a continuously variable transmission.

FIG. 9 shows the details of the human power detection sensor incorporated in the handle 35. FIG. 9A is a cross-sectional view of the handle as viewed from above, and the arrow directions of + e and -e correspond to the arrow directions of FIG. FIG. 9B is a cross-sectional view of the handle parallel to the ground. The handle 35 and the center beam 18 are supported by a handle support 7b attached to the upper end of the column 7. The handle 35 is cut at the center, and the handle 35 (L) gripped by the left hand and the handle 35 (R) gripped by the right hand of the operator.
And each is supported in a cantilever manner by a handle support 7b. A soft spacer 35a is fitted in the center to cover the foreign matter from entering the inside of the handle. Middle beam 18 and pressure sensor 2 attached to it
2, the pressure bar 23, the cushioning material 24, the support plate 19, and the like have the same configuration as in FIG.

In the case of FIG. 9, since the handle support 7b supports the handle 35 in a cantilever manner and receives the rotational moment of the handle 35, consideration is given to preventing the rotational moment from being transmitted to the center beam 18. 2 on the (L), (R) side 1
A set of pressure-sensitive sensors are assembled in a bridge and processed differentially to cancel disturbances such as temperature changes. As shown in FIG. 9 (c), Wr and Wl are compared, and the smaller value Wl is the amount of forward movement, and the difference ΔW between the two is the amount of left turn in this case, which is processed by the control unit to control the steering motor 34. Turn left.

In the above, an example using a low-cost pressure-sensitive resistance element as a pressure-sensitive sensor has been described. However, the present invention is not limited to the pressure-sensitive resistance element, and a conventionally used resistance wire strain gauge is used. A similar effect can be obtained with a general pressure-sensitive sensor such as a so-called load cell. Further, the human-power detection sensor for detecting the deflection of the steering wheel may be replaced with a pressure-sensitive sensor arranged to detect the movement of the entire steering wheel including the column 7.

[0029]

As described above, the auxiliary powered vehicle according to the present invention can measure the weight of the load and set the acceleration rate of the drive motor and the maximum speed of the bogie to optimal values. Therefore, the operator who operates the trolley can operate the trolley with the same level of force even with a light load or a heavy load.

Further, even when the load is light, the maximum speed does not increase too much and the brake can be applied properly, so that the safety can be remarkably increased. Further, it is possible to perform control such that the operator feels a little light when the load is light and feels a certain amount of heavy load, so that the operator is somewhat aware of the weight of the load. These advantages are not only effective for carrying luggage, but also great for nursing vehicles.

[Brief description of the drawings]

FIG. 1 is a projection view of a carrier vehicle with auxiliary power.

FIG. 2 is a perspective view of the cart of FIG. 1;

FIG. 3 is a block diagram of the bogie of FIG. 1;

FIG. 4 is a structural diagram of a load sensor;

FIG. 5 is a conceptual diagram showing the shape and characteristics of a load sensor.

FIG. 6 is a projection view and a perspective view of a human-power detection sensor incorporated in a handle of a cart.

FIG. 7 is a projection view of a bogie using auxiliary power for driving and changing directions.

FIG. 8 is a perspective view of the cart shown in FIG. 7;

FIG. 9 is a configuration example of a handle that individually detects pressures of left and right hands.

FIG. 10 is a perspective view of a conventional bogie with auxiliary power.

[Explanation of symbols]

1. Transport vehicle with auxiliary power (abbreviated as trolley), 2 base, 3 carrier, 6, 35 handle, 8 auxiliary drive,
9 drive motor, 10 continuously variable transmission, 11 drive wheels,
14 control unit, 15 load sensor, 15a pressure sensor, 15b pressure rod, 15c cushioning material 25 human power detection sensor, 30 transport vehicle with auxiliary power for direction change, 31 rotation base, 34 steering motor,

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3D050 AA01 BB02 DD03 EE08 EE09 EE11 EE15 GG06 KK03 KK14 5H115 PG10 PI13 PU01 RB08 TB01 TO10 TO30

Claims (4)

[Claims] 1. A load sensor for detecting a load weight, and control means for controlling a driving force of an auxiliary drive unit based on an output of the load sensor, wherein the control means is based on a calculated detection value of the load sensor. A vehicle with auxiliary power, wherein output characteristics of the vehicle are changed. 2. The vehicle according to claim 2, wherein the control unit is configured to control a traveling speed of the vehicle.
2. The auxiliary powered vehicle according to claim 1, wherein an acceleration rate is set so as to change in accordance with a loaded weight of the vehicle. 3. 3. The vehicle with auxiliary power according to claim 1, wherein a pressure-sensitive resistance element is used for the load sensor. 4. The transport vehicle according to claim 1, wherein the auxiliary drive unit has a motor for driving a battery, a speed change unit, and at least one drive wheel.