JP3342029B2 - Press machine noise reduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise reduction device for a press machine, and more particularly, to a noise reduction device for a press machine which measures vibration of the press machine and reduces noise by a signal waveform having an opposite phase. .

[0002]

2. Description of the Related Art Conventionally, a noise reduction method of a press machine includes a method of reducing a pressure change by lowering a machine speed, a method of increasing a machine rigidity to reduce a deformation and a vibration amplitude, or a method of reducing a vibration amplitude. There is a method of adding a cushion, a sound absorbing material, and the like.

There is also a method of canceling a specific sound by emitting a sound having a phase opposite to that of the noise. This relates to the cancellation of noise from the air conditioning duct. The sound in the duct is picked up by an upstream microphone and subjected to signal processing to create a sound of the opposite phase. The sound is amplified by an amplifier, and a sound is output from a speaker installed downstream to cancel the noise.

[0004]

However, in the method of reducing the speed of the machine, the amount of work is reduced, and the work efficiency is reduced. Further, the method of increasing the rigidity of the machine or the method of adding a rubber cushion or the like has a problem that a significant increase in cost, an increase in dimensions, and the like are caused. In particular, in the method of adding a rubber cushion or the like, since the periphery of the machine is covered with a cover or the like, the usability of the machine is deteriorated.

[0005] On the other hand, a method of producing a sound having an opposite phase is effective for canceling a continuously generated sound such as a rotating sound of a fan, but has a single tone like a press and a waveform of the sound. Items that change from time to time (due to punch, die, plate thickness, etc.) were difficult to counteract. Further, when this method is applied to a press machine, there arises a problem that the reproduction accuracy deteriorates, for example, other noise enters from a microphone, and a sound pressure changes depending on a temperature.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and provides a noise reduction device for a press machine capable of reducing noise without significantly modifying the press machine. The purpose is to:

[0007]

Means for Solving the Problems In order to solve the above problems, a noise reduction device for a press machine according to the present invention comprises:
A vibration sensor that detects a vibration waveform during the operation of the press machine, a waveform processing unit that converts the vibration waveform into a cancellation signal of an opposite phase of noise, and a storage unit that stores the cancellation signal with the input of a timing signal, Reproducing means for extracting and outputting a canceling signal from the storage means in response to the input of the timing signal; distortion detecting means for monitoring an operating state of the press machine to detect a distortion signal; and distortion signal detected by the distortion detecting means. A timing signal synchronized with the operation of the press machine at the time of storage of the storage means and at the time of reproduction of the reproduction means from the rise due to the mold touch of the amplifying means for outputting to the storage means and reproduction means, and output from the reproduction means. And a speaker for reproducing the cancellation signal as a cancellation sound.

[0008]

When a workpiece is set on a press machine and a punching operation is performed, a vibration waveform at that time is detected by a vibration sensor and sent to a waveform processing means. The vibration waveform is converted into a cancellation signal having a phase opposite to that of the noise by the waveform processing means, and is stored in the storage means by a timing signal from the amplification means. Next, when a timing signal is sent from the amplifying means to the reproducing means in synchronization with the operation of the press machine, a canceling signal is taken out from the storage means and reproduced as a canceling sound from the speaker. The canceling noise cancels the vibration of the frame and reduces the noise of the press machine.

[0009]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view showing a noise reduction device for a press machine according to an embodiment of the present invention;

FIG. 1 is a configuration diagram showing an embodiment of a press machine to which a noise reduction device according to the present invention is applied. This press machine 1 comprises a C-shaped frame 2 and a punch 3
The workpiece is placed between the die 4 and the die 4 for punching. In FIG. 1, a power supply unit and a power unit are omitted.

The noise reduction device 10 added to the press machine 1 includes a vibration sensor 11 for detecting a vibration waveform during the operation of the press machine, and a waveform processing for converting the vibration waveform into a noise cancellation signal of opposite phase. Means 12, storage means 13 for storing the cancellation signal of the opposite phase, reproduction means 14 for extracting and outputting the cancellation signal of the opposite phase from the storage means 13, and monitoring the operating state of the press machine to generate a distortion signal. A distortion gauge 15 to be detected, a timing signal at the time of storage and reproduction are generated from the distortion signal, an amplifying unit 16 which outputs to the storage unit 13 and the reproduction unit 14, and a cancellation signal from the reproduction unit 14 is reproduced as a cancellation sound. And a speaker 17.

FIG. 2 shows various waveforms and cancellation signals generated during the press operation. Normally, the noise and the vibration of the frame correspond, so the waveform (a)
And (b) have substantially the same shape. Waveform processing means 12 of FIG.
Then, a process such as filtering and phase adjustment is performed on the vibration waveform (b) measured by the vibration sensor 11, and the vibration waveform (b) is converted into a cancellation signal (d) having a phase opposite to that of the noise waveform. However,
Since complicated processing is required to convert the signal into a completely inverted signal, a signal obtained by an approximate calculation is used as an inverted signal here. On the other hand, a distortion signal of the frame 2 is extracted from the distortion gauge 15. The frame distortion is
As shown in (c), it gradually increases from the touch to the breakthrough, and is released at once after the breakthrough. The distortion signal detected by the distortion gauge 15 is sent to the amplifying means 16, where a timing signal for storage and reproduction is output in accordance with the rise of the waveform (c). That is, the amplifying unit 16 sends a timing signal to the storage unit 13 in synchronization with the operation of the press, and stores the opposite phase signal. Similarly, a timing signal is sent to the reproducing means 14 in synchronization with the operation of the press to output an opposite phase signal.

The operation of the noise reduction device 10 described above is as follows. First, when a workpiece is set on the press machine 1 and a punching operation is performed on a trial basis, a vibration waveform at that time is detected by the vibration sensor 11 and sent to the waveform processing means 12.
The vibration waveform is converted by the waveform processing means 12 into a cancellation signal having a phase opposite to that of the noise, and is stored in the storage means 13 by the timing signal from the amplification means 16. Next, when the actual press operation is performed, a timing signal is sent from the amplifying unit 16 to the reproducing unit 14 in synchronization with the operation of the press,
The cancellation signal is extracted from the storage means 13. This cancellation signal is reproduced from the speaker 17 as a cancellation sound. The canceling noise cancels the vibration of the frame and reduces the noise of the press machine.

Each time (or in advance) the cancellation signal corresponding to the condition is stored in accordance with the change in the press condition, and the cancellation signal is selected and reproduced in accordance with the condition, so that the change in the noise can be prevented. Can correspond.

FIG. 3 is a block diagram showing a case where the noise reduction device shown in FIG. 1 is adapted to a plurality of press working conditions. This noise reduction device is provided with a plurality of storage means 13 and has SW1 and SW1 on its input side and output side, respectively.
2 and the other configuration is the same as that of FIG. The user can supply a processing condition signal to SW1 and SW2 from an input device (not shown). The processing condition signal is a signal of information such as a material, a plate thickness, a punch, and a type of a die.
SW2 is switched, and a canceling sound matching the conditions is output.

[0016]

As described above, in the noise reduction device for a press machine according to the present invention, the vibration of the frame during the press working is measured, and a cancellation signal of the opposite phase of the noise is generated based on the vibration waveform. In order to output the cancellation signal of the opposite phase stored in the memory in synchronism with the operation of the press machine as a cancellation sound from the speaker at the time of processing, the sound is generated in a single tone like a press machine. Even when the waveform changes occasionally, the noise can be sufficiently reduced. Also, as compared with a method of increasing the rigidity of the machine or a method of adding a rubber cushion or the like, the press machine does not need to be significantly modified and can be easily mounted. In this case, an increase in cost, an increase in size, and the like can be minimized, and the usability of the machine is not impaired. Furthermore, compared to a method of taking in sound from a microphone, the method is less affected by noise, and high reproduction accuracy can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a press machine to which a noise reduction device according to the present invention is applied.

FIG. 2 is a diagram showing various waveforms and a canceling signal generated according to a pressing operation.

FIG. 3 is a configuration diagram in a case where the noise reduction device is adapted to cope with a plurality of press working conditions.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Press machine, 2 ... Frame, 11 ... Vibration sensor, 1
2 ... waveform processing means, 13 ... storage means, 14 ... reproduction means,
15: strain gauge, 16: amplifying means, 17: speaker

──────────────────────────────────────────────────続 き Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B30B 15/00 B25D 17/11 G01H 17/00 G10K 11/178

Claims (1)

(57) [Claims] 1. A vibration sensor for detecting a vibration waveform during operation of a press machine, a waveform processing means for converting the vibration waveform into a cancellation signal having a reverse phase of noise, and storing the cancellation signal in response to a timing signal input. Storage means for performing, a reproduction means for extracting and outputting a cancellation signal from the storage means in response to the input of the timing signal, a distortion detection means for monitoring an operation state of the press machine and detecting a distortion signal, and the distortion detection means. Amplifying means for generating a timing signal synchronized with the operation of the press machine at the time of storage of the storage means and at the time of reproduction of the reproduction means from the rising of the detected distortion signal due to the mold touch,
A noise reduction device for a press machine, comprising: a speaker configured to reproduce a cancellation signal output from the playback unit as a cancellation sound.