JPH0849262A - Virtual sound producing device for operation of excavating machine - Google Patents

Abstract

PURPOSE:To provide a virtual sound producing device for operation of an excavating machine with which it is practicable to grasp the working conditions certainly and perform proper maneuvering even under remote control. CONSTITUTION:Operation signals of operational levers 11La-11Lc of a remote control device 10 are wirelessly transmitted to a control device 23 on the excavating machine side so that proportional solenoids 2a-21c of control valve are energized, and thereby the excavating machine is driven. The working force (arm twist and excavating force) of the excavating machine is sensed by a working force sensing device 26 and transmitted wirelessly to a control device 13 in the remote control device 10. and the frequency converter 138F of the control device 13 emits a frequency signal in compliance with the twist of the arm. This frequency signal is amplified by an amplifier 138A with a rate of amplification in accordance with the excavating force, and the amplified signal is emitted from a speaker 17 as a virtual sound. The working condition can be grasped by listening to the virtual sound to enable proper operation of the working machine.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a virtual sound generator for operating an excavator used when operating an excavator such as a hydraulic excavator by remote control.

[0002]

2. Description of the Related Art An excavator is one in which an operator operates a control lever to drive a corresponding actuator to perform a desired excavation work, and a typical example thereof is a hydraulic excavator. FIG. 8 shows a hydraulic excavator. FIG. 8 is a side view of the hydraulic excavator. In this figure, 1 is a lower traveling structure, and 2 is an upper revolving structure provided on the lower traveling structure 1 so as to be rotatable. A front mechanism 3 is composed of a boom 4 rotatably attached to the upper swing body 2, an arm 5 rotatably attached to the boom 4, and a bucket 6 rotatably attached to the arm 5. 4S is a hydraulic cylinder that drives the boom 4, 5S is a hydraulic cylinder that drives the arm 5, and 6S is a hydraulic cylinder that drives the bucket 6.
6P ₁ is a pin that connects the tip of the arm 5 and the bucket 6, and 6P ₂ is a pin that connects the bucket 6 and the link mechanism interposed between the hydraulic cylinder 6S and the bucket 6. A driver's cab 7 has an operating lever inside. The operator operates a control valve (not shown) by operating a required operation lever among the operation levers in the operator's cab 7, and a hydraulic cylinder corresponding thereto is operated.
An actuator such as a traveling motor or a swing motor is driven at a speed according to the operation amount to perform excavation or other required work.

[0003] The work by such a hydraulic excavator is usually carried out by an operator riding in the operator's cab 7 and operating the operation lever. However, work at a dangerous place, for example, near a cliff or at the risk of collapse. When performing work in the vicinity of a certain building, in a river, etc., or in removing work of a debris flow from a volcano, it is dangerous for an operator to board and work, so remote control means is used.

The remote control means comprises a control device on the hydraulic excavator side which operates each control valve in response to a received signal, and a remote control device which transmits a signal to this control device by wire or wirelessly. The remote control device is equipped with an operation lever corresponding to the operation lever of the hydraulic excavator, and the operator operates each operation lever of the remote control device provided at the remote location in the same manner as the operation lever of the hydraulic excavator. , Sends a signal according to the operation amount to the control device on the hydraulic excavator side to operate the hydraulic excavator.

[0005]

[Problems to be Solved by the Invention]
When operating a hydraulic excavator while boarding a vehicle, the operator can perform excavation, etc. based on the work location and the vibration and tilt of the vehicle body while listening to the relief sound and engine sound of the hydraulic circuit. Understand the working conditions of and perform appropriate operations to prevent overload that may damage the vehicle body. However, when operating the hydraulic excavator by the remote control means, the operator cannot detect the vibration or tilt of the vehicle body because the operator does not board the operator's cab 7. Further, when the location to be remotely controlled is far away from the hydraulic excavator. Can not see the work place in the car, and almost no work sound is generated in the cab or work place (even if you hear it, you do not know what it is), you need to know the working state of the hydraulic excavator. It is impossible to know that an overload has occurred, and proper operation of the hydraulic excavator is extremely difficult.

For example, in a gutter digging operation using a hydraulic excavator, the hydraulic excavator is stopped in parallel with the gutter, and a swing force is applied to the upper swing body 2 to press the side surface of the bucket 6 against one side wall of the gutter to excavate the groove. Do it. in this case,
If the turning force is excessively large, the pressing force against the side wall of the gutter becomes excessively large, and excavating stress is applied to this, so that the connecting pin 6P ₁ of the bucket is damaged. Such a state can be immediately sensed by the inclination of the vehicle body when the operator is on board, but cannot be detected in the case of remote control, and as described above, the work place is far away. In some cases it is even unclear whether work is being done.

Usually, in remote control, a hydraulic excavator is equipped with a camera, a microphone, or both, and the image of the camera and the sound of the microphone are received by the remote control device side to see the image of the excavation site and hear the sound. However, a means for remotely controlling the hydraulic excavator is used. But,
With such means, it is not possible to detect the vibration or tilt of the vehicle body, and moreover, the field of view of the camera is limited,
It is not possible to keep the work area in sight at all times, and when a microphone intervenes, it sounds different than when it is heard directly, and when multiple hydraulic excavators are working at the same location, they are not able to hear themselves. It is difficult to distinguish the sound of a hydraulic excavator. For this reason, even if the hydraulic excavator is equipped with a camera or a microphone, it is difficult to properly operate the distant point.

An object of the present invention is to solve the above-mentioned problems in the prior art, and to provide a virtual sound generator for operating an excavator capable of surely grasping the working state and performing appropriate control even in the case of remote control. To provide.

[0009]

In order to achieve the above object, the present invention provides an excavator having a working mechanism driven by an actuator, which comprises a twist of the working mechanism and an excavating force of the excavator. Working force detecting means for detecting force and audible sound generating means for generating audible sound based on the magnitude of the twist and the excavating force detected by the working force detecting means are provided.

[0010]

When the operating means of the remote control device is operated, the actuator is driven, and a working force acts on the working mechanism of the excavator during excavation. This work force is represented by the twist of the work mechanism and the excavating force. Based on the magnitude of the twist and the excavating force, a sound (virtual sound) completely different from the sound generated by the audible sound generating means during work is generated. ) Is generated. The operator can intuitively grasp the work state by listening to the generated virtual sound, and on the basis of this, the operator can operate the excavator appropriately without generating an overload that may cause damage. it can.

[0011]

The present invention will be described below with reference to the illustrated embodiments. FIG. 1 is a block diagram of a virtual sound generator for operating a hydraulic excavator according to an embodiment of the present invention. In this figure, 10
Indicates a remote control device, and 20 indicates a device provided in the work machine. First, in the remote control device 10, 11L _a , 1
1L _b and 11L _c are operation levers, 12L _a and 12L _b ,
12L _c is each operation lever 11L _a , 11L _b , 11L _c
2 shows an operation signal generator that generates an electric signal proportional to the operation amount of. The number of operation levers is determined by the working machine, and is not limited to three as shown in the figure. Thirteen
Is a control device, 14 is a wireless transmission device, 14a is a transmission antenna, 15 is a wireless reception device, 15a is a reception antenna,
Reference numeral 16 is an acoustic amplifier, and 17 is a speaker.

The controller 13 has the following configuration. Thirteen
Reference numeral 1 denotes an A / D converter for converting the output signals of the operation signal generators 12L _a , 12L _b , 12L _c into digital values, 13
Reference numeral 2 is a CPU for performing necessary arithmetic and control operations, 133 is a RAM for temporarily storing data, and 134 is a ROM in which the operating procedure of the CPU 132 is stored. Reference numeral 135 is an output interface, 136 is an input interface, 137 is a D / A converter that converts predetermined data into an analog value, and 138 is a conversion device that generates a virtual sound signal based on the output signal of the D / A converter 137. is there. In the above configuration, ROM134
Is the A / D conversion program 134a and the transmission program 1
34b, reception program 134c, calculation program 13
4d and D / A conversion program 134e. The conversion device 138 is composed of a known frequency converter 138F such as a VF converter and a variable gain amplifier 138A (may be a multiplier).

Next, in the device 20 on the working machine side, 21
Reference characters a, 21b, and 21c are proportional solenoids for driving the control valves of the hydraulic excavator.
Of the operating levers 11L _a , 11L _b , and 11L _c . 22 is a driver that supplies a drive current to each proportional solenoid 21a, 21b, 21c, 23 is a control device, 24 is a wireless receiving device, 24a is a receiving antenna, 25 is a wireless transmitting device, 25a is a transmitting antenna, and 26 is a work force detection. It is a device. The work force detection device 26 will be described later with reference to FIGS. 2, 3, and 4.

The control device 23 has the following configuration. 23
Reference numeral 1 is an A / D converter for converting the detection value of the load detection device 26 into a digital value, and 232 is C for performing necessary calculations and controls.
PU, 233 is a RAM that temporarily stores data, and 234 is a ROM that stores the operating procedure of the CPU 232.
Reference numeral 235 is an output interface, 236 is an input interface, and 237 is an operating lever 11L _a , 11L _b , 11L.
D / which converts the data according to the manipulated variable of _c into an analog value
A converter. The ROM 234 stores the reception program 23.
4a, a D / A conversion program 234b, an A / D conversion program 234c, and a transmission program 234d.

FIG. 2 shows the arm 5 along the line II-II shown in FIG.
FIG. The arm 5 has a rectangular hollow structure, and detectors 26A and 26B are attached to opposite side walls thereof (a surface corresponding to the paper surface in FIG. 8 and an opposite surface thereof). A working force detection device 26 is configured by these detectors 26A and 26B. Hereinafter, these detectors 26A,
The structure of 26B will be described. Since they are the same structure, only the specific structure of one detector 26A will be described with reference to FIGS. 3 and 4.

FIG. 3 is a partially cutaway side view of the detector 26A. In the figure, 5 is an arm and 26A is a detector. The detector 26A includes a cover 261, four strain gauges 262a,
262b, 262c, 262d, connectors 263, 26
4, having a cable 265. Strain gauge 262a,
262b, 262c and 262d are attached to the wall surface of the arm 5, respectively. C ₁ and C ₂ indicated by broken lines in the drawing indicate virtual lines in a direction inclined by 45 degrees with respect to a line parallel to the axis of the arm 5. The strain gauges 262a and 262c are
The strain gauges 262b and 262d are attached so as to detect strain in the virtual line C ₁ direction, and the strain gauges 262b and 262d are attached so as to detect strain in the virtual line C ₂ direction.

FIG. 4 is a strain gauge 262a shown in FIG.
It is a circuit diagram of a bridge circuit constituted by 262b, 262c and 262d. In the figure, 266 is a DC power supply and 267 is a differential amplifier.

Here, the detection operation of the detectors 26A and 26B will be described. If no load acts on the arm 5,
The output of the differential amplifier 267 is 0. When a load acts in the direction shown by the arrow W in FIG. 3, a shear strain is generated in the arm 5, and this strain causes the strain gauges 262a, 26a.
2c expands, and strain gauges 262b and 262d contract.
The resistance value of each strain gauge changes according to this deformation, and the differential amplifier 267 outputs an electric signal proportional to the shear strain. Now, assuming that the output of the differential amplifier 267 of the detector 26A is V _A and the output of the differential amplifier of the detector 26B is V _B , the sum W _F (V _A + V _B ) of both is the force in the arrow W direction, that is, Represents the excavating force of the bucket 6, while the difference W between the two
_M (V _A -V _B) becomes to represent the arrow M direction of twist of the arm 5 shown in FIG.

The twisting of the arm 5 is caused, for example, by the force (turning force) that the bucket 6 receives from the lateral direction when the hydraulic excavator is performing the above-mentioned ditch digging. In this way, by detecting the twist of the arm 5, the force that the bucket 6 receives from the lateral direction is detected. Note also, the calculation of the sum W _F and difference W _M of the respective output V _A, V _B, the detector 26A, 26B each output V _A of the, V
_This is performed by the control device 13 after _B is transmitted to the remote control device 10 as a work force signal.

Next, the operation of this embodiment shown in FIG. 1 will be described. The operator operates each operation lever 11 of the remote control device 10.
L _a, 11L _b, and performs necessary work by driving a hydraulic excavator of a remote location by selectively operating the 11L _c. The operator operates the operation levers 11L _a , 11
L _b, when the 11L _c selectively operated, an operation signal generator 12L _a response to this, 12L _b, the electrical signal is output from the 12L _c. In the control device 13, the A / D conversion program 134a is activated, and the CPU 132 follows the A / D conversion program 134a in accordance with the operation signal generator 12L _a ,
The operation signals output from 12L _b and 12L _c are converted into digital values, which are temporarily stored in the RAM 133, and then the operation signals are extracted from the RAM 133 according to the transmission program 134b, and the output interface 13
5, wirelessly transmits to the hydraulic excavator via the wireless transmitter 14 and the transmitting antenna 14a.

The transmitted operation signal is input to the control device 23 via the receiving antenna 24a of the hydraulic excavator side device 20, the radio receiver 24, and the input interface 236. The reception program 234a of the control device 23 is always activated, and when a transmission signal is input, it is stored in the RAM 23.
3 is temporarily stored and the CPU 232 is interrupted to notify the input of the transmission signal. As a result, the CPU 232 receives the operation signal transmitted according to the reception program 234a, converts the operation signal into an analog signal according to the D / A conversion program 234b, and outputs the analog signal to the driver 22.
The driver 22 supplies a current corresponding to the operation signal to the corresponding one of the proportional solenoids 21a, 21b, and 21c according to the input operation signal. This allows
The corresponding control valve is operated and its hydraulic actuator is driven to perform the required work.

The work force generated by the execution of this work is detected by the detectors 26A and 26B as described above (V
_A , V _B ) is detected by the work force detection device 26, and the detected value (work force signal) is output to the control device 23. The CPU 232 of the control device 23 has already started A /
The A / D converter 231 is operated according to the D conversion program 234c to convert the detection value of the work force detection device 26 into a digital value, and this work force signal is output according to the transmission program 234d, the output interface 235, the wireless transmitter 25, and the transmission. It wirelessly transmits to the remote control device 10 via the antenna 25a.

The transmitted work force signal (detection values V _A , V
_B ) is input to the control device 13 via the receiving antenna 15a of the remote control device 10, the wireless receiver 15, and the input interface 136. The CPU 132 of the control device 13 receives the work force signal according to the reception program 134c, and temporarily stores the work force signal in the RAM 133. Next, the calculation program 134d is started. The CPU 132, in accordance with the program 134d, detects the detected value V _A , which is a work force signal,
Sum of V _B W _F (magnitude of excavation force) and detected value V _A ,
The difference W _{M of} V _B (the magnitude of the twist of the arm 5) is calculated. The calculated values are stored in the RAM 133.

Next, the D / A conversion program 134e is activated, and the CPU 132 causes the D / A conversion program 13 to operate.
4e, the sum value W previously obtained from the RAM 133 according to 4e
The value W _M of the difference between _F and _F is read, the value W _M of the difference is used as the frequency command data signal S ₁ , and the value W _F of the sum is used as the amplification factor command data signal S ₂ , and the frequency conversion of the converter 138 is performed. To the amplifier 138F and the amplifier 138A.

The frequency converter 138F includes an oscillator (not shown), the frequency of which is converted according to the input signal S ₁ (voltage), and the frequency-converted signal is amplified by the amplifier 138A.
Is output to In the signal output amplifiers 138A, is amplified by an amplification factor corresponding to the signal S ₂ that is input at that time, the amplified signal sound amplifier 1 as a virtual sound signal
6 is output to the outside, and a sound (virtual sound) corresponding to the virtual sound signal is generated from the speaker 17 to the outside. The operator of the remote control device 10 grasps the working state of the hydraulic excavator by this virtual sound, and accordingly the operating levers 11L _a , 1
1L _b, and selectively operating the 11L _c drives the appropriate hydraulic excavator performs desired work.

Here, the outline of the operation of the conversion device 138 will be further described with reference to FIGS. 5, 6 and 7. FIG. 5 is a diagram showing changes in twist (W _M ), where the horizontal axis represents time and the vertical axis represents the magnitude of twist. FIG. 6 is a diagram showing changes in the excavating force (W _F ), in which the horizontal axis represents time and the vertical axis represents the magnitude of the excavating force. FIG. 7 is a block diagram in which a signal waveform is added to the conversion device 138, and the same portions as those shown in FIG. 1 are designated by the same reference numerals. In FIG. 7, S _F is the frequency converter 1
38F shows the waveform of the output signal, and S _FA shows the waveform of the output signal of the amplifier 138A (the output signal of the conversion device 138).

As shown in FIG. 5, the twist of the arm 5 is initially small, gradually increases, increases in the middle, and finally decreases rapidly. In this case, the frequency converter 138F outputs a low frequency signal when the twist is small and the signal S ₁ is small, and outputs a high frequency signal when the twist is large and the signal S ₁ is large. An outline of the waveform of such a signal is shown in FIG. 7 as signal S _F.

The relationship between the twist and the frequency can be arbitrarily set other than the proportional relationship described above. In that case,
A conversion program may be newly provided in the ROM 134 to program a desired relationship of frequency with respect to twist, and the frequency may be output as frequency command data (signal S ₁ ).

On the other hand, as shown in FIG. 4, the excavating force is assumed to increase relatively slowly at first and reach a large value, and then maintain this value for a while, and then rapidly decrease. In this case, the amplifier 138A amplifies the signal S _F with a small amplification factor to reduce the level when the excavation force is small and the signal S ₂ is small, and the signal S _F is greatly amplified when the excavation force is large and the signal S ₂ is large. Amplify by a factor to raise its level. An outline of the waveform of the signal thus amplified is shown in FIG. 7 as the signal S _FA . The relationship between the excavating force and the amplification factor can be arbitrarily selected by the same means as the relationship between the twist and the frequency.

When the torsion and excavation force are changed in the configurations shown in FIGS. 5 and 6, the speaker 17 initially produces a low and small sound, then the sound gradually becomes louder and louder, and finally becomes low again. You will hear a small sound. If you hear a high and loud sound, this sound is pin 6P.
A warning that there is a risk of damage ₁ will be given, and the operator can appropriately operate the operation lever to avoid the damage. Also, the start of actual excavation can be known from the beginning of the sound.

Further, regarding the case where the bucket 6 is digging into the ground for excavation, an excessive load is applied to the bucket 6 at a time when the volume of the speaker 17 is high regardless of whether the sound is low or high. However, the operator finds that the excavation force does not increase even if the operation lever is continuously operated further, and the power is wasted, and the operator once stops the excavation operation and stops the bucket 6 operation.
You will find that it is better to return the drill, change the posture a little and perform the drilling again. On the contrary, when the volume of the speaker 17 is low, the operator knows that the bucket 6 can be digged deeper into the ground to excavate a larger amount, and the operation according to this is performed. After all, the operator can surely grasp the excavation state even when the excavation site is located at a remote location and cannot be seen, and can perform an appropriate operation of the hydraulic excavator, thereby improving work efficiency.

As described above, in this embodiment, the signal frequency is converted based on the twist of the arm of the hydraulic excavator, the frequency-converted signal is amplified according to the excavating force of the bucket, and the amplified signal is amplified. Since the virtual sound is generated based on the above, it is possible to surely grasp the working state of the hydraulic excavator and operate the hydraulic excavator appropriately even at a remote location where the working location cannot be seen.

Further, in a conventional device using a camera or a microphone, a wide frequency band is occupied by these video signals and audio signals, and there has been a situation in which transmission of data necessary for operation is greatly restricted. However, since the working force signal is only transmitted as a digital signal in the present embodiment, the occurrence of the above situation can be completely avoided.

In the description of the above embodiment, an example in which the frequency is converted according to the twist of the arm and the amplification factor is changed according to the excavating force has been described, but conversely, according to the twist of the arm. It is also possible to change the amplification factor and perform frequency conversion according to the excavating force. Further, the frequency conversion may be performed in such a manner that when the input signal is large, it is converted to low frequency, and when the input signal is small, it is converted to high frequency. Further, in the above description of the embodiment, the remote control device provided with the operating lever has been described, but the present invention is also applicable to a push button type remote control device. Further, as the working force detector 26, in addition to the structure described in the above embodiment, for example, Japanese Patent Publication No.
The excavation force measuring device presented in Japanese Patent No. 50047 is mentioned. This device has a force acting on the pin 6P ₂ shown in FIG. 8 obtained from the angle of the bucket 6 detected by the angle detector and the pressure of the bucket cylinder 6S detected by the pressure detector, and the connecting pin 6P ₁ . The two forces of the force acting on the bucket detected by the attached strain gauge are used as the working force, and the vector sum of the two forces is the magnitude of the excavating force.
The vector difference can also be used as the magnitude of arm twist.

Further, in the description of the above embodiment, the difference value W
An example has been described in which _M is the signal S ₁ and the sum value W _F is the signal S _2, and these signals are output to the conversion device 138 to obtain a virtual sound, but a virtual sound can also be obtained by the following means. That is, a new arithmetic program is provided in addition to the arithmetic program 134d, and the next arithmetic operation is performed using the values W _F and W _M obtained by the arithmetic operation previously performed by this arithmetic program. A = k ₁ · W _F + k ₂ ω = k ₃ · W _M + k ₄ Here, k ₁ , k ₂ , k ₃ and k ₄ are defined coefficients. The above values A and ω are input to the voice synthesizer, and this voice synthesizer calculates X = Asin (ωt). Then, if the value X is output to the D / A converter and the signal from the D / A converter is input to the speaker,
A virtual sound similar to that in the above embodiment can be obtained. This virtual sound is a high-pitched sound when the twist is large and a low-pitched sound when the twist is small, and is a sound in which the sound volume is high when the excavation force is large and is low when the excavation force is small.

It should be noted that instead of using the twist value ω, a value (1 / ω) is used.
You may make it produce a low tone when it is small. further,
In the voice synthesizer, instead of the above calculation, X = ωsin (At) or X = ωsin (t / A) may be calculated. As a result, the low and high tones of the virtual sound are determined according to the excavating force.

[0037]

As described above, according to the present invention, the working force composed of the twist of the working mechanism and the excavating force of the excavator is detected by the working force detecting means, and based on the detected twist and the magnitude of the excavating force. Since a virtual sound is generated by using the virtual machine, even when the remote control is performed at a remote location where the work location cannot be seen, the work state of the work machine can be surely grasped and the work machine can be operated appropriately. . Further, since the work force signal is transmitted as a digital signal, the frequency band used for the transmission is narrow, and there is no problem in transmitting and receiving other data.

[Brief description of drawings]

FIG. 1 is a block diagram of a virtual sound generation device for a hydraulic excavator according to an embodiment of the present invention.

FIG. 2 is a sectional view of an arm.

FIG. 3 is a diagram showing the detector shown in FIG. 2;

FIG. 4 is a circuit diagram of a bridge circuit of the detector shown in FIG.

FIG. 5 is a diagram showing a change in twist.

FIG. 6 is a diagram showing changes in excavating force.

FIG. 7 is a block diagram of the conversion device shown in FIG. 1.

FIG. 8 is a side view of the hydraulic excavator.

[Explanation of symbols]

10 the remote control device 11L _a ~11L _c operating lever 13 the control device 16 sound amplifier 17 speakers 21a~21c proportional solenoid 22 drivers 23 control device 26 work force detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yasuo Tanaka 650 Kazunachi-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Tsuchiura factory (72) Inventor Yutaka Watanabe 650 Kintate-cho, Tsuchiura-shi, Ibaraki Hitachi Construction Machinery Co., Ltd. Ceremony Company Tsuchiura Factory (72) Inventor Seiji Yamashita, 650 Kazunachicho, Tsuchiura City, Ibaraki Prefecture Hitachi Construction Machinery Co., Ltd. Tsuchiura Factory

Claims (11)

[Claims] 1. An excavator equipped with a working mechanism driven by an actuator, wherein the working force detecting means detects a working force composed of a twist of the working mechanism and an excavating force of the excavator, and the working force detecting means. An audible sound generating means for generating an audible sound based on the detected twist and the magnitude of the excavating force, and a virtual sound generating device for operating an excavator. 2. The virtual sound generating device for operating an excavator according to claim 1, wherein the audible sound generating means is included in a device for remotely controlling the excavator. 3. The frequency converter according to claim 1, wherein the audible sound generator generates a frequency signal according to the magnitude of the twist, and an output of the frequency converter according to the magnitude of the excavating force. A virtual sound generating device for operating an excavator, comprising: a level changing unit that changes a signal level. 4. The working machine according to claim 3, wherein the frequency conversion device outputs a high frequency when the magnitude of the twist is large and a low frequency when the magnitude of the twist is small. Virtual sound generator for operating. 5. The working machine according to claim 3, wherein the frequency conversion device outputs a high frequency when the magnitude of the twist is small and a low frequency when the magnitude of the twist is large. Virtual sound generator for operating. 6. The frequency converter according to claim 1, wherein the audible sound generator generates a frequency signal according to the magnitude of the excavating force, and an output of the frequency converter according to the magnitude of the twist. A virtual sound generating device for operating an excavator, comprising: a level changing unit that changes a signal level. 7. The frequency conversion device according to claim 6, wherein the frequency converter outputs a high frequency when the magnitude of the excavating force is large, and outputs a low frequency when the magnitude of the excavating force is small. Virtual sound generator for operating work machines. 8. The frequency converter according to claim 6, wherein the frequency converter outputs a high frequency when the magnitude of the excavating force is small, and outputs a low frequency when the magnitude of the excavating force is large. Virtual sound generator for operating work machines. 9. The audible sound generating means according to claim 1, wherein the cycle is a value corresponding to the magnitude of the twist or a reciprocal of the value, and the amplitude is a value corresponding to the magnitude of the excavating force. A virtual sound generation device for operating an excavator, which is a voice synthesizer for generating a sine wave that generates 10. The audible sound generating means according to claim 1, wherein a period corresponding to the magnitude of the excavation force or a reciprocal of the value is used as a period, and a value corresponding to the magnitude of the twist is used as an amplitude. A virtual sound generation device for operating an excavator, which is a voice synthesizer for generating a sine wave that generates 11. The working machine according to claim 1, wherein the working force detecting means is a means for detecting a deformation of the working mechanism or a stress acting on an excavation part forming a part of the working mechanism. Virtual sound generator for operating.