Work vehicle

Abstract

To provide a work vehicle that outputs a warning or the like to alert an operator when abnormal sound associated with a machine failure is included in noise transmitted to an operation section.SOLUTION: An operation section (5) is covered by a cabin (8). The operation section (5) is provided with a microphone (21) which collects noise transmitted to the cabin (8) and a speaker (24) which generates sound having a reverse phase with respect to the noise. A controller (30) stores basic noise preliminarily collected with the microphone (21). When abnormal sound is included in the noise as a result of comparing the current noise with the basic noise, the controller (30) outputs an alarm through the speaker (24).SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a work vehicle having a function of alerting an operator when abnormal noise is included in the noise transmitted to the control unit.

Background Art

[0002] Conventionally, in work vehicles, a technique is known in which a sound having a phase opposite to that of the noise generated by an engine or the like is output from a speaker to reduce the noise transmitted to the control unit. (Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when the noise transmitted to the control unit is reduced, there has been a problem that it becomes difficult for the operator to recognize abnormal noise associated with a failure of a device such as an engine included in the noise.

[0005] Therefore, an object of the present invention is to provide a work vehicle that outputs an alarm or the like to alert the operator when abnormal noise associated with a failure of a device is included in the noise transmitted to the control unit.

Means for Solving the Problems

[0006] The present invention that has solved the above problems is as follows. That is, the invention according to claim 1 provides a pair of left and right front wheels (2) and rear wheels (3) on the lower side of an airframe frame (1) equipped with an engine (E), and a cab (5) for an operator to board on the upper side of the airframe frame (1). A PTO shaft (6) for transmitting the output rotation of the engine (E) is provided on the lower rear side of the cab (5), and in a work vehicle in which a work implement (7) is connected to the PTO shaft (6), covering the cab (5) with a cabin (8), and providing a microphone (21) for collecting noise propagated in the cabin (8) and a speaker (24) for generating a sound of opposite phase to the noise in the cab (5). The basic noise pre-collected by the microphone (21) is stored in a controller (30). The controller (30) compares the basic noise with the noise, and when the noise contains an abnormal sound, outputs an alarm from the speaker (24). It is a work vehicle characterized by this.

[0007] The invention according to claim 2 is the work vehicle according to claim 1, wherein when the noise contains an abnormal sound, the controller (30) stores the noise containing the abnormal sound, and when the playback switch (16) of the cab (5) is pressed, the speaker (24) outputs the noise containing the abnormal sound.

[0008] The invention according to claim 3 is the work vehicle according to claim 1 or 2, wherein the microphone (21) and the speaker (24) are provided on earphones (20) worn by an operator boarding the cab (5).

[0009] The invention according to claim 4 is the work vehicle according to claim 3, wherein the basic noise is pre-collected according to the operating condition of the work vehicle.

[0010] The invention according to claim 5 is the work vehicle according to claim 4, wherein the basic noise is pre-collected according to the output rotation speed of the engine (E).

[0011] The invention according to claim 6 is the work vehicle according to claim 4, wherein the basic noise is collected in advance according to the connection and disconnection of the clutch provided in the transmission path between the engine (E) and the PTO shaft (6).

[0012] The invention according to claim 7 is the work vehicle according to claim 4, wherein the basic noise is collected in advance according to the working posture and the retracted posture of the working machine (7).

Advantages of the Invention

[0013] According to the invention described in claim 1, the control unit (5) is covered with the cabin (8), and the control unit (5) is provided with a microphone (21) for collecting the noise propagated in the cabin (8) and a speaker (24) for generating a sound of opposite phase to the noise. The basic noise collected in advance by the microphone (21) is stored in the controller (30). The controller (30) compares the basic noise with the noise, and when the noise contains an abnormal sound, an alarm is output from the speaker (24). Therefore, the noise propagated in the cabin (8) can be reduced. In addition, when a failure occurs in the engine (E) or the like, the attention of the operator can be called.

[0014] According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, when the noise contains an abnormal sound, the noise containing the abnormal sound is stored in the controller (30). When the playback switch (16) of the control unit (5) is pressed, the noise containing the abnormal sound is output from the speaker (24). Therefore, the operator can easily identify the members such as the engine (E) in which a failure has occurred by listening to the noise.

[0015] According to the invention described in claim 3, in addition to the effect of the invention described in claim 1 or 2, the microphone (21) and the speaker (24) are provided on the earphone (20) worn by the operator boarding the control unit (5). Therefore, the noise propagated in the cabin (8) can be efficiently reduced. In addition, when a failure occurs in the engine (E) or the like, the attention of the operator can be efficiently called.

[0016] According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, since the basic noise has been collected in advance according to the operating conditions of the work vehicle, the basic noise and the noise can be compared according to the operating conditions of the work vehicle, and the attention of the operator can be quickly aroused.

[0017] According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, since the basic noise has been collected in advance according to the output rotational speed of the engine (E), the basic noise and the noise can be compared according to the output rotational speed of the engine (E), and the attention of the operator can be aroused more quickly.

[0018] According to the invention described in claim 6, in addition to the effect of the invention described in claim 4, since the basic noise has been collected in advance according to the connection and disconnection of the clutch provided in the transmission path between the engine (E) and the PTO shaft (6), the basic noise and the noise can be compared according to the connection and disconnection of the clutch, and the attention of the operator can be aroused more quickly.

[0019] According to the invention described in claim 7, in addition to the effect of the invention described in claim 4, since the basic noise has been collected in advance according to the working posture and the retracted posture of the work implement (7), the basic noise and the noise can be compared according to the working posture and the retracted posture of the work implement (7), and the attention of the operator can be aroused more quickly.

Brief Description of the Drawings

[0020]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0021] As shown in FIG. 1, a working vehicle such as a tractor is provided with a pair of left and right front wheels 2 at the front part below the body frame 1, and a pair of left and right rear wheels 3 at the rear part below the body frame 1.

[0022] A bonnet 4 for storing the engine E is provided at the front part above the body frame 1, a cab 5 for the operator to board is provided at the rear side of the bonnet 4, and a PTO shaft 6 extending in the front-rear direction to which the output rotation of the engine E is transmitted is provided at the lower rear side of the cab 5. A working machine 7 such as a rotary tiller for cultivating a field is connected to the rear part of the PTO shaft 6. Further, the cab 5 is covered with a cabin 8.

[0023] A steering column 13 for supporting a steering wheel 12 is provided in front of the driver's seat 11 of the cab 5, and a monitor 14 for displaying the output rotation speed of the engine E and the like is provided in front of the steering wheel 12.

[0024] A clutch pedal 18 is provided at the lower left part of the steering column 13, and an accelerator pedal 19 is provided at the lower right part.

[0025] As shown in FIG. 2, the operator sitting on the driver's seat 11 wears earphones 20 and operates the steering wheel 12.

[0026] As shown in Fig. 3, the earphone 20 includes a microphone 21 that collects ambient noise during operation around the driver's seat 11, an A / D conversion unit 22 that converts an analog signal input from the microphone 21 into a digital signal, a D / A conversion unit 23 that converts a digital signal input from a controller 30 (to be described later) into an analog signal, and a speaker 24 that outputs sound according to the analog signal input from the D / A conversion unit 23. Note that the microphone 21, the A / D conversion unit 22, the D / A conversion unit 23, and the speaker 24 can also be provided near the driver's seat 11 in the control unit 5.

[0027] As shown in Fig. 4, the controller 30 includes a processing unit 31 composed of a CPU or the like, a storage unit 32 composed of a ROM, a RAM, a hard disk drive, a flash memory, or the like, and a communication unit 33 for data communication with the outside.

[0028] The processing unit 31 compares the basic noise or the like propagated from the engine E collected in advance (to be described later) to the control unit 5 with the working noise (the "noise" in the claims) collected by the microphone 21, and determines whether the working noise collected by the microphone 21 contains abnormal noise.

[0029] The storage unit 32 stores the basic noise propagated from the engine E collected in advance (to be described later) to the control unit 5, the working noise collected by the microphone 21 during operation, and the like.

[0030] The communication unit 33 performs transmission and reception with a portable controller (not shown).

[0031] On the input side of the controller 30, a collection switch 15 that collects the basic noise propagated from the engine E to the control unit 5 via the microphone 21, a playback switch 16 that performs inverse Fourier transform on the working noise collected by the microphone 21 and stored in the storage unit 32, and an A / D conversion unit 22 that performs A / D conversion on the analog signal that is the working noise collected by the microphone 21 are connected via a predetermined input interface circuit.

[0032] On the output side of the controller 30, a monitor 14 and a D / A conversion unit 23 that D / A-converts the digital signal of the processing unit 31 to operate the speaker 24 are connected via a predetermined output interface circuit.

[0033] As shown in FIG. 5, the operator presses the collection switch 15 to collect the basic noise propagated from the engine E to the control unit 5 through the microphone 21 of the earphone 20 for a predetermined time, for example, for 1 minute.

[0034] As shown in FIGS. 5(a) and 5(c), after the collected basic noise is divided at predetermined time intervals, for example, at 10-second intervals, as shown in FIGS. 5(b) and 5(d), it is subjected to Fourier transform and frequency analysis. Thereby, abnormal sounds can be easily extracted and the sources of the abnormal sounds can be identified. Note that in FIGS. 5(a) and 5(c), the horizontal axis represents time and the vertical axis represents amplitude, and in FIGS. 5(b) and 5(d), the horizontal axis represents frequency and the vertical axis represents magnitude.

[0035] Next, as shown in FIG. 5(e), the average values such as those in FIGS. 5(b) and 5(d) are calculated. Thereby, noises such as the voice of the operator included in the collected basic noise can be removed, abnormal sounds can be accurately extracted, and the sources of the abnormal sounds can be identified.

[0036] As shown in FIG. 6, the operator presses the collection switch 15 to pre-collect the basic noise propagated from the engine E to the control unit 5, the basic noise propagated from the PTO shaft 6 to the control unit 5, and the basic noise propagated from the work implement 7 to the control unit 5, and stores them in the storage unit 32 of the controller 30. Thereby, the basic noise for comparison with the working noise collected by the microphone 21 during work can be selected according to the working conditions of the work vehicle, and the source of the abnormal sound can be identified. Note that when the work vehicle is traveling on a public road, the operator stops wearing the earphone 20, so the collection of the working noise by the microphone 21 is stopped.

[0037] Fig. 6(a) shows the frequency analysis when the output rotation speed of the engine E is at a low speed (rotation speed 1), and Fig. 6(b) shows the frequency analysis when the output rotation speed of the engine E is at a high speed (rotation speed 2). Also, the increase and decrease of the output rotation speed of the engine E can be performed by operating the accelerator pedal 19.

[0038] Fig. 6(c) shows the frequency analysis when the clutch of the PTO shaft 6 is connected at a low output rotation speed of the engine E, and Fig. 6(d) shows the frequency analysis when the connection of the clutch of the PTO shaft 6 is released at a low output rotation speed of the engine E. Also, the connection and disconnection of the clutch can be performed by operating a clutch lever (not shown) provided on the right side of the driver's seat 11, and the clutch is provided between the engine E and the PTO shaft 6 in the transmission path of the output rotation of the engine E.

[0039] Fig. 6(e) shows the frequency analysis when the clutch of the PTO shaft 6 is connected at a low output rotation speed of the engine E and the working machine 7 is lowered to the working position, and Fig. 6(f) shows the frequency analysis when the clutch of the PTO shaft 6 is connected at a low output rotation speed of the engine E and the working machine 7 is raised to the retracted position. Also, the raising and lowering of the working machine 7 can be performed by operating a raising and lowering lever (not shown) provided on the left side of the driver's seat 11.

[0040] <Method for Canceling Working Noise> As shown in Fig. 7, in step S1, the processing unit 31 of the controller 30 determines whether the collection switch 15 has been pressed. If it is determined that the collection switch 15 has been pressed, the process proceeds to step S2. If it is determined that the collection switch 15 has not been pressed, step S1 is repeated.

[0041] In step S2, the processing unit 31 collects the working noise propagated to the operation unit 5 via the microphone 21 and the A / D conversion unit 22 and proceeds to step S3.

[0042] In step S3, the processing unit 31 performs a frequency analysis on the working noise as shown in Figs. 8(b) and (c) and proceeds to step S4.

[0043] In step S4, as shown in FIGS. 8(a) and 8(c), the processing unit 31 compares the basic noise stored in the storage unit 32 with the working noise to determine whether an abnormal noise is generated in the working noise. If it is determined that no abnormal noise is generated, the process proceeds to step S5. If it is determined that an abnormal noise is generated, the process proceeds to step S6.

[0044] As shown in FIG. 8(c), the processing unit 31 determines that an abnormal noise is generated when there is a peak at a frequency different from the basic noise in the working noise, or when the frequency is the same as the basic noise but the magnitude is large, for example, 150% or more.

[0045] In step S5, the processing unit 31 generates a canceling noise with a reverse phase to the working noise and returns to step S1. As a result, the working noise propagated to the operator's ear through the D / A conversion unit 23 and the speaker 24 from the processing unit 31 disappears, and the working environment of the operator can be improved.

[0046] In step S6, the processing unit 31 generates a canceling noise with a reverse phase to the working noise and proceeds to step S7. As a result, the working noise propagated to the operator's ear through the D / A conversion unit 23 and the speaker 24 from the processing unit 31 disappears, and the working environment of the operator can be improved.

[0047] In step S7, the processing unit 31 creates an alarm sound, propagates it to the operator's ear through the D / A conversion unit 23 and the speaker 24, and proceeds to step S8. As a result, the operator can be made aware that an abnormality such as deformation has occurred in the members constituting the working machine 7 or the like. In addition, the processing unit 31 can perform a warning display on the monitor 14 together with the alarm sound.

[0048] In step S8, the processing unit 31 stores the result of the frequency analysis of the working noise in the storage unit 32 and proceeds to step S9.

[0049] In step S9, the processing unit 31 determines whether the playback switch 16 has been pressed. If it is determined that the playback switch 16 has not been pressed, the process returns to step S1. If it is determined that the playback switch 16 has been pressed, the process proceeds to step S10.

[0050] In step S10, the processing unit 31 performs an inverse Fourier transform on the result of the frequency analysis and propagates the working noise to the operator's ear via the D / A conversion unit 23 and the speaker 24, and then returns to step S1. As a result, the operator can listen to the working noise in which an abnormal sound is generated and easily identify members such as the working machine 7 in which a failure has occurred.

Explanation of Signs

[0051] 1 Body frame 2 Front wheel 3 Rear wheel 5 Control unit 6 PTO shaft 7 Working machine 8 Cabin 16 Playback switch 20 Earphone 21 Microphone 24 Speaker 30 Controller E Engine

Claims

1. A work vehicle is provided with a pair of left and right front wheels (2) and rear wheels (3) on the lower side of a body frame (1) equipped with an engine (E), a cab (5) for an operator to ride on is provided on the upper side of the body frame (1), and a PTO shaft (6) for transmitting the output rotation of the engine (E) is provided on the lower rear side of the cab (5), and a working machine (7) is connected to the PTO shaft (6). In this work vehicle, the cab (5) covers the cab (8), a microphone (21) for collecting noise propagated in the cab (8) and a speaker (24) for generating a sound with a reverse phase to the noise are provided in the cab (5), the basic noise collected in advance by the microphone (21) is stored in a controller (30), the controller (30) compares the basic noise with the noise, and when the noise contains an abnormal sound, the controller (30) outputs an alarm from the speaker (24). The work vehicle is characterized by this.

2. When the noise contains an abnormal sound, the controller (30) stores the noise containing the abnormal sound. When the playback switch (16) of the cab (5) is pressed, the speaker (24) outputs the noise containing the abnormal sound. The work vehicle according to Claim 1.

3. The work vehicle according to Claim 1 or 2, wherein the microphone (21) and the speaker (24) are provided in earphones (20) worn by an operator riding on the cab (5).

4. The work vehicle according to Claim 3, wherein the basic noise is collected in advance according to the operating condition of the work vehicle.

5. The work vehicle according to Claim 4, wherein the basic noise is collected in advance according to the output rotation speed of the engine (E).

6. The work vehicle according to Claim 4, wherein the basic noise is collected in advance according to the connection and disconnection of a clutch provided in the transmission path between the engine (E) and the PTO shaft (6).

7. The work vehicle according to Claim 4, wherein the basic noise is collected in advance according to the working posture and the retracted posture of the working machine (7).

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