JP2000214015A - Applying force detector, controller for driver, and car fitted with driving force supporting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an apparatus superior in responsiveness and fittability such as requiring less time and labor for fitting work, easiness of accurate fitting to fitting positions, unnecessity of detailed adjusting work also for the fitting positions, etc. SOLUTION: An applying force detector 1 is constituted of a semiconductor strain gauge 2 which senses applied force, a holder 4 provided with a housing holding space portion 3 which houses and holds the strain gauge 2 detachably, and a hammer 5 to be fitted to the sensing portion 2A of the strain gauge 2. The holder 4 is constituted of a cap 4B which opens and closes the space portion 3, a window portion 6 which causes the hammer 5 to face the outside, and a fitting hole 7 for fitting the holder 4 detachably. A controller for drivers has constitution for controlling the output of a driver in accordance with force detected by the applying force detector 1. Besides, a car fitting with a driving force supporting device performs control in accordance with the force detected by the applying force detector 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a weight detection device, a control device for a driving device using the weight detection device, and a vehicle with a driving force assist device using the weight detection device, and more particularly to an improvement in the structure of the weight detection device. About technology.

[0002]

2. Description of the Related Art Conventionally, a device for controlling a driving device such as a motor based on an applied force is known. As a technology to which such a device is applied, a bogie with a driving force assisting device for assisting a driving force, A vehicle with a driving force assisting device such as a forklift with a steering force assisting device for assisting a steering force is known (JP-A-63-215459, JP-A-8-282498, and JP-A-10-6996). JP, JP-A-10-29538, JP-A-10-10
9647).

[0003] The above-mentioned carriage with a traveling power assisting device has, for example, a base plate provided with traveling wheels and a handle connected to the base plate and to which human power can be applied by an operator. Is driven forward and backward by a drive device such as a motor, and has a weight detection device that detects the magnitude of the force in the front-rear direction of the human force applied to the handle, and outputs the output of the drive device according to the detected value. I try to control.

In a forklift equipped with a steering force assisting device, for example, a force in a steering direction is detected by detecting an external force applied to an operating portion of a vehicle body, and a force corresponding to the detected force in the steering direction is detected. The torque assist force is generated at the driving source of the steering wheel.

[0005]

In these auxiliary devices, devices for detecting an applied force include:
Potentiometers that detect displacement (stroke) of the position according to the applied force and indirectly detect the applied force are employed. Therefore, since the applied force is not directly measured, if there is a gap due to clearance or play even if no force is applied, this will be output as a displacement, causing a problem in terms of responsiveness. was there.

In particular, when the switch is turned off and stopped with the handle tilted, according to the potentiometer,
Since the gap in the state where the handle is tilted is output as a displacement, when restarted, a driving force corresponding to the tilt direction is suddenly exerted by the auxiliary device. Therefore, at the time of such restart, there is a problem that the assist force is not exerted in the direction intended by the operator.

Further, in order to directly mount such a sensor, a mounting tool different from the sensor is required. However, the sensor itself may have a complicated shape, and a wiring cord or the like may be used. Because it is included, it is difficult to install, and it takes time and labor to install. In addition, it is difficult to accurately attach to the mounting position, and it is necessary to carefully adjust the mounting position.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has good responsiveness, does not require time and labor for the mounting work, and can be easily mounted accurately at the mounting position. Provided are a weight detection device which is excellent in mountability, which does not require detailed adjustment work of a mounting position, a control device for a driving device using the weight detection device, and a vehicle with a driving force assist device using the weight detection device. The purpose is to:

[0009]

According to a first aspect of the present invention, there is provided a sensor for sensing an applied force and a storage space for detachably storing and holding the sensor. A holder and a hammer mounted so as to be able to abut on the sensor of the sensor, wherein the holder includes an opening / closing unit for opening and closing a storage space, and a hammer mounted on the sensor of the sensor. And a mounting part for detachably attaching the holder to a predetermined mounting part.

According to the present invention, the holder comprises a base and a cap as the opening / closing portion which is removably assembled to the base and forms a storage space between the base and the holder. 2. The weight detection device according to claim 1, wherein the mounting portion is formed on the base, and the window is formed on the cap.

According to a third aspect of the present invention, there is provided the weight detecting device according to the first or second aspect, wherein the sensor is a weight sensor for directly sensing an applied force.

According to a fourth aspect of the present invention, there is provided the weight detecting device according to the third aspect, wherein the weight sensor is a strain gauge.

According to a fifth aspect of the present invention, the weight sensor is a sensor in which a conductive rubber is mounted on a metal plate or a conductive member formed in a predetermined pattern. Provide equipment.

According to a sixth aspect of the present invention, in the control device for a driving device for controlling the output of the driving device according to the force detected by the weight detecting device, the weight detecting device is a sensor for detecting the applied force. And a holder provided with a storage holding space for detachably storing and holding the sensor, and a hammer mounted so as to be able to abut on a sensor of the sensor, wherein the holder is a storage holding space An opening / closing unit for opening / closing the sensor, a window for allowing a hammer attached to the sensing unit of the sensor to be exposed from the inside of the storage space, and a mounting unit for detachably mounting the holder to a predetermined mounting unit. A control device for a driving device is provided.

According to a seventh aspect of the present invention, in the vehicle with the driving force assisting device controlled in accordance with the force detected by the weight detecting device, the weight detecting device includes a sensor for sensing the applied force; A holder provided with a storage holding space for detachably storing and holding the sensor, and a hammer mounted so as to be able to abut on a sensing portion of the sensor, wherein the holder opens and closes the storage holding space. Opening / closing section, a window section for allowing a hammer attached to the sensing section of the sensor to be exposed from the inside of the storage space section, and an attaching section for detachably attaching the holder to a predetermined attaching section. A vehicle with a driving force assist device is provided.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings. First, FIG. 1 and FIG. 2 show one embodiment of the weight detection device of the present invention.

That is, the load detecting device 1 includes a semiconductor strain gauge 2 as a sensor for sensing an applied force, and a holder 4 having a storage holding space 3 for detachably storing and holding the semiconductor strain gauge 2. And a hammer 5 that is mounted so as to be in contact with the sensing unit 2A of the semiconductor strain gauge 2.

The holder 4 has an opening / closing unit for opening and closing the storage space 3 and a hammer 5 mounted so as to be in contact with the sensing unit 2A of the semiconductor strain gauge 2 from the inside of the storage space 3 to the outside. It has a window portion 6 and a mounting hole 7 as a mounting portion for removably mounting the holder 4 to a predetermined mounting portion.

In this case, in this embodiment, the holder 4
Consists of a base 4A and a cap 4B as the opening / closing part which is removably assembled to the base 4A and forms a storage space 3 between the base 4A and the base 4A. 7 is formed, and the window 6 is formed in the cap 4B.

Here, the base 4A has a cylindrical portion 4a at the tip, and a male screw portion 4 is formed on the outer peripheral surface of the cylindrical portion 4a.
b is formed. The mounting hole 7 is formed in the center of the rear end of the base 4A. In addition, base 4
A has one end portion between the cylindrical portion 4 and the cap 4B.
a, and a groove 4c for forming a hole 8 for leading the wiring cord 2B of the semiconductor strain gauge 2 to the outside, that is, a wiring lead hole 8 communicating with the inside of the wire a and having the other end opened to the outer peripheral surface of the holder 4. Are formed.

The cap 4B is formed in a substantially cylindrical shape.
The window 6 is formed in a circular shape at the center of one end. A female screw portion 4 that can be fitted to the external thread portion 4b of the outer peripheral surface of the cylindrical portion 4a of the base 4A is provided on the inner peripheral surface of the cap 4B.
d is formed. In such a configuration, the cap 4
B is the internal thread 4d and the external thread 4b on the base 4A side.
By being fitted with the above, it is detachably attached to the cylindrical portion 4a of the base 4A.

When the cap 4B is mounted on the base 4A, the groove 4e formed on the distal end surface of the base 4A, the inside of the cylindrical portion 4a, and the groove 4f formed on the inner peripheral surface of the window 6 of the cap 4B. The storage space 3 is formed, and the semiconductor strain gauge 2 housed in the storage space 3 is pressed and held on the base 4A side by the cap 4B, and is fixed so that an initial pressure is not applied.

The semiconductor strain gauge 2 thus held
Hammer 5 attached so as to be able to contact the sensing part 2A at the tip of the
Is projected from the window 6 to the outside. The hammer 5 has a substantially hemispherical portion protruding from the window 6 to the outside by metal, and has a sensing portion 2A on the opposite side.
Is provided with a projection 5A that comes into contact with the projection.

The weight detecting device 1 is detachably attached to a mounting shaft (not shown) provided at a portion to which the weight detecting device 1 is attached by fitting a mounting hole 7 of the base 4A. The load applied to the sensing unit 2A via the hammer 5 is detected by the semiconductor strain gauge 2.

In this case, the hammer 5 and the semiconductor strain gauge 2
Is preferably set so that the semiconductor strain gauge 2 can detect up to the maximum load by moving the hammer 5 of several microns.

In the weight detection device 1 having such a configuration, the semiconductor strain gauge 2 as a sensor for detecting the applied force
Is a weight sensor that directly senses the applied force,
Other strain gauges may be used as the weight sensor. Further, for example, a sensor in which conductive rubber is mounted on a metal plate can also be used. Furthermore, by using a conductive member formed in a predetermined pattern, for example, a predetermined pattern is formed from a conductive material on an arbitrary substrate, and a conductive rubber is provided to be able to abut on this pattern. Is also good.

According to the weight detecting device 1, the semiconductor strain gauge 2 is housed in the holder 4 in advance, that is, the semiconductor strain gauge 2 is unitized.
There is no need to use a separate mounting tool,
It can be easily attached to necessary places with one touch,
In addition, the unitized shape is compact, and the mounting operation does not require much time and effort. In addition, it is easy to accurately attach to the mounting position, and there is no need for detailed adjustment of the mounting position.

Next, a description will be given of a control device for a driving device using the weight detection device described based on the above embodiment. That is, as shown in FIG. 3, the control device for a driving device includes a driving device such as a motor 9 and a weight detection device 10.
And a controller 11 as control means for controlling the output of a driving device such as the motor 9 in accordance with the force detected by the control unit. As an application example of such a control device for a driving device, for example, in a traveling force assisting device that assists a traveling force of a wheelbarrow according to a force (a pushing force or the like) applied to the wheelbarrow, it is applied to the wheelbarrow. A device that detects a force by a weight detection device and controls a motor or the like as a driving device according to the force is conceivable.

Alternatively, in a steering force assisting device for assisting the steering force of a forklift in accordance with the force applied to the steering wheel of the forklift, a motor or the like as a driving device is controlled in accordance with the force applied to the steering wheel. Devices are conceivable. The handcart and forklift in the above-described application examples correspond to an embodiment of a vehicle with a driving force assist device using the weight detection device of the present invention. A specific example of use will be described.

FIG. 4 shows the structure of the push handle of the pushcart. In FIG. 4, a gate-shaped handle 12 is shown.
A gate-shaped operation unit 13 is fixedly attached to the center of the upper part by bolts. One end of an operating shaft 14 extending downward is fixedly attached to a lower portion of a horizontal central portion of the horizontal shaft portion 13A of the operation portion 13. A mounting shaft 14A extending in the lateral direction is provided on each of the left and right sides of the lower end of the operating shaft 14, and the load detecting device 1 shown in FIG.
Are attached respectively.

That is, the weight detection device 1 is mounted on each of the mounting shafts 14A by fitting the mounting holes 7 of the base 4A. On the other hand, a rectangular cylindrical box 15 is placed and fixed at a position between the two longitudinal axes 13B of the operation unit 13 in the upper central part of the handle 12.

Then, two weight detection devices 1 are inserted and arranged inside the box 15, and each weight detection device 1
Of the hammer 5 comes into contact with its inner wall surface. In such a configuration, when the operator pushes the handcart with his / her hand and runs, the operation unit 13 above the handle 12 is operated.
4 is pushed and pulled in the front-rear direction indicated by the arrow in FIG. 4 to apply a weight via the hammer 5 to the sensing portion 2A of the semiconductor strain gauge 2 of both the load sensing devices 1, which causes a semiconductor strain. The power is detected by the gauge 2 and a motor or the like of a running force assist device that assists the running force of the handcart is controlled in accordance with the force.

FIG. 5 shows the structure of a steering force assisting device of a forklift, that is, a power steering device. In this figure, a driven sprocket 18 is attached to a rotary drive shaft 17 of a drive unit 16 of a steering mechanism of a forklift, and the driven sprocket 18 is connected to a rotary drive shaft 21 of a power steering motor 20 via a chain 19. The drive sprocket 22 is connected to the drive sprocket 22.

The first side of the drive unit 16 has a first
Of the second bracket 24 is connected to a connecting portion 23A of the first bracket 23 on the side opposite to the mounting portion via a bolt 25 passing through a handle mounting center. The first bracket 2
3 and the second bracket 24 are, as in the present embodiment,
Although they may be formed of separate members and integrated by the bolt 25, they may be integrally formed. The distal end of an operating shaft 27 of a handle 26 is connected to a mounting portion 24 </ b> B on the side opposite to the connecting portion of the second bracket 24 via a pin 28.

Then, the two weight detecting devices 1 shown in FIG. 1 are connected to both connecting portions 23A, 24 between both brackets 23, 24.
A is inserted and arranged on both sides of A, and the tip of the hammer 5 of each weight detection device 1 is in contact with the inner wall surface of the second bracket 24.

In this case, mounting shafts 23B extending in the front-rear direction are provided on both sides of the first bracket 23, respectively.
The weight detection devices 1 are respectively attached to the attachment shafts 23B. That is, the weight detection device 1 is attached to each of the attachment shafts 23B by fitting the attachment holes 7 of the base 4A.

In this configuration, when the operator operates the handle, when the handle 26 is swung in the left-right direction indicated by the arrow in FIG. 5, the operating shaft 27 is similarly swung about the rotary drive shaft 17 of the drive unit 16. Move. On this occasion,
Since there is an interval between the first bracket 23 and the second bracket 24, the positional relationship between them is slightly distorted. As a result, the semiconductor strain gauge 1 of any of the weight detection devices 1
Is applied via the hammer 5 to the sensing unit 2A, which is detected by the semiconductor strain gauge 2, and the power steering motor 20 for assisting the steering force of the forklift is controlled in accordance with the force, and the power steering motor 20 The assist force is applied to the drive unit 16 via the driving sprocket 22, the chain 19, and the driven sprocket 18.

The control circuit for the hand truck and the forklift will be described below with reference to FIG. 6. The weight detection device on the front side of the handcart and the weight detection device on the left side of the forklift will be referred to as a first sensor 29. And the right weight detection device in the forklift are referred to as a second sensor 30.

An amplifier 31, an amplifier 31,
The sensor output is amplified by the amplifiers 31 and 32. The output values of the amplifiers 31 and 32 are input to a comparison circuit 34 provided in a left and right (front and back) recognition circuit 33, and are compared and determined by the comparison circuit 34, and the larger output value is output via an analog switch 35. The data is output to the control circuit 36 as it is.

In the control circuit 36, as shown in FIG. 7, the drive circuit 37 compares the sensor signal a with the triangular wave b output from the triangular wave oscillator 38, and outputs a pulse signal when a> b. The pulse signal is generated (ON), and when a ≦ b, the pulse signal is not generated (OFF). The width of this pulse signal becomes longer as a becomes larger.

The control circuit 36 is connected to the driver 40 of the DC motor 39. The control circuit 36 increases the driving force of the DC motor 39 as the width a of the pulse signal increases, that is, as the ON time increases. Control is performed to increase the value (to increase the time for flowing the current).

Note that limiter circuits 41 and 42 are interposed between the amplifiers 31 and 32 and the left and right (front and rear) recognition circuit 33, and a limiter is applied to the sensor signal a so as not to exceed the voltage of the triangular wave b. I'm trying to put it on. The reason why such a configuration is adopted is that when the sensor signal a exceeds the voltage of the triangular wave b, the DC motor 39 is completely turned on, and the maximum output is obtained.
Since the output of the sensor approaches zero, force must be applied again. And once you apply force again, it is completely O
The state of N state is repeated. This is the same as the case where the ON / OFF operation of the switch is repeated, and the smooth operation is impaired.

Further, by offsetting the triangular wave by the offset circuits 43 and 44 connected to the amplifiers 31 and 32, it is possible to adjust so that a pulse signal is not generated at the neutral position (prevention of chattering near the neutral position). 4) for wheelbarrows
In the forklift, the DC motor 39 does not operate unless a certain force is applied to the handle 26 in FIG. An unexplained reference numeral 45 in the control circuit 36 is an overcurrent detection circuit for preventing an excessive load from being applied to the motor.

According to the drive control device and the vehicle with the driving force assisting device having the above-described configuration, by using the unitized weight detection device 1, in addition to the advantages of the above-described weight detection device itself, the following advantages can be obtained. There are such advantages.

That is, when the above-described weight detection device 1 is used as the weight detection device, the weight detection device 1 detects the actual weight. When the weight is detected, the hammer 5 is pressed. The feeling of this pressure is close to human sensitivity, and it responds faithfully when force is applied or when the worker rests his hand. It is obtained by following the operation well, has good responsiveness, and is excellent in running feeling and steering feeling. Further, when the steering wheel 26 and the like are temporarily stopped in a state of being inclined at a predetermined angle, the weight becomes zero in that state. Therefore, when restarting, the weight at the restart is determined to be zero and the weight is detected, so that the assist force is exerted in the direction intended by the operator at the restart.

[0046]

According to the weight detection device, the control device for the drive device, and the vehicle with the driving force assist device of the present invention, the configuration of the weight detection device includes a sensor for detecting an applied force and a detachable sensor. A holder having a storage space for storing and holding, and a hammer to be mounted which can be brought into contact with a sensing part of the sensor, wherein the holder has an opening / closing part for opening and closing the storage space, A window unit that allows the hammer attached to the sensing unit to be exposed to the outside from inside the storage space, and an attachment unit that detachably attaches the holder to a predetermined attachment unit so as to be configured as a unit. As a result, the weight detection device can be easily attached to a required location with a single touch, so that the attachment can be improved.

Further, since a weight sensor for directly sensing the applied force, for example, a strain gauge such as a semiconductor strain gauge, or a sensor in which conductive rubber is mounted on a metal plate is used as the sensor, the applied force is Can be sensed directly. Therefore, for example, when the present invention is applied to a weight detection device in a driving force or steering force assist device, the assist feeling of the driving force or steering force can be obtained by following the operation of the worker well, and the driving feeling or steering feeling can be obtained. Excellent.

[Brief description of the drawings]

FIG. 1 is a sectional view of a weight detection device showing one embodiment of a weight detection device of the present invention.

FIG. 2 (A) is a plan view of the weight detection device of the above,
(B) is a side view.

FIG. 3 is a block diagram showing one embodiment of a control device for a driving device according to the present invention.

FIG. 4A is a perspective view showing a configuration of a push handle of a pushcart according to an embodiment of the vehicle with a driving force assisting device of the present invention, and FIG. FIG.

FIG. 5 is a plan view showing a configuration of a steering force assisting device of a forklift according to another embodiment of the vehicle with a driving force assisting device of the present invention.

FIG. 6 is a block diagram illustrating a configuration of a control device that controls a motor based on the weight detected by the weight detection device in the handcart and the forklift.

FIG. 7 is a diagram illustrating generation of a motor control pulse signal in the control device of the above energy management system;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Weight detection apparatus 2 Semiconductor strain gauge 3 Storage and holding space part 4 Holder 4A Base 4B Cap 5 Hammer 6 Window part 7 Mounting hole 9 Motor 10 Weight detection apparatus 11 Controller 12 Handle 13 Operation part 20 Power steering motor 26 Handle

Continuing on the front page (72) Inventor Ken Natsui 1-2-14, Shintoda, Hamamatsu-shi, Shizuoka Pref. Japan Automation Co., Ltd. (72) Inventor Hiroshi Fujiwara 1-2-14, Shintoda, Hamamatsu-shi, Shizuoka Pref. Japan Within the automation (72) Inventor Yoshikazu Sugiura 3-88, Sumiyoshi-cho, Hekinan-shi, Aichi F-term (reference) in Sugikuni Kogyo Co., Ltd. 2F051 AA01 AB10 BA07 3D050 GG06 KK14

Claims (7)

[Claims] 1. A sensor for sensing an applied force, a holder having a storage space for storing and holding the sensor in a detachable manner, and a hammer mounted so as to be in contact with a sensor of the sensor. The holder is an opening / closing unit that opens and closes a storage space, a window that allows a hammer attached to a sensor of the sensor to be exposed to the outside from inside the storage space, and a holder attached to a predetermined mounting portion. A weight detection device, comprising: a mounting portion detachably attached. 2. The holder comprises: a base; and a cap as the opening / closing part which is detachably attached to the base and forms a storage holding space between the base and the holder.
The weight detection device according to claim 1, wherein the attachment portion is formed on the base, and the window is formed on the cap. 3. The weight detection device according to claim 1, wherein the sensor is a weight sensor that directly senses an applied force. 4. The weight detection device according to claim 3, wherein the weight sensor is a strain gauge. 5. The weight detection device according to claim 3, wherein the weight sensor is a sensor in which conductive rubber is mounted on a metal plate or a conductive member formed in a predetermined pattern. 6. A control device for a driving device for controlling an output of a driving device according to a force detected by a weight detection device, wherein the weight detection device includes a sensor for detecting an applied force,
A holder provided with a storage holding space for detachably storing and holding the sensor, and a hammer mounted so as to be able to abut on a sensor of the sensor, wherein the holder opens and closes the storage holding space Opening / closing section, a window section for allowing a hammer attached to the sensing section of the sensor to be exposed from the inside of the storage space section, and an attaching section for detachably attaching the holder to a predetermined attaching section. A control device for a driving device, comprising: 7. A vehicle with a driving force assist device controlled according to a force detected by a weight detection device, wherein the weight detection device includes a sensor for detecting an applied force,
A holder provided with a storage holding space for detachably storing and holding the sensor, and a hammer mounted so as to be able to abut on a sensor of the sensor, wherein the holder opens and closes the storage holding space Opening / closing section, a window section for allowing a hammer attached to the sensing section of the sensor to be exposed from the inside of the storage space section, and an attaching section for detachably attaching the holder to a predetermined attaching section. A vehicle with a driving force assisting device.