CN116180386A

CN116180386A - Noise control system of washing machine and washing machine

Info

Publication number: CN116180386A
Application number: CN202210685722.XA
Authority: CN
Inventors: 王庆来; 丹尼尔科瓦奇
Original assignee: BSH Electrical Appliances Jiangsu Co Ltd; BSH Hausgeraete GmbH
Current assignee: BSH Electrical Appliances Jiangsu Co Ltd; BSH Hausgeraete GmbH
Priority date: 2021-11-26
Filing date: 2022-06-16
Publication date: 2023-05-30
Also published as: EP4187008A1

Abstract

A noise control system of a washing machine and a washing machine. The system comprises: a first acquisition unit configured to acquire a first vibration signal of a first vibration of the motor; the second acquisition unit is used for acquiring a rotating speed signal of the motor; the control unit is used for receiving the first vibration signal and the rotating speed signal sent by the first acquisition unit and the second acquisition unit and processing the first vibration signal and the rotating speed signal to generate a control signal; and the execution unit is used for receiving the control signal and generating second vibration acting on the motor based on the control signal, wherein the first vibration is opposite to the second vibration in phase so as to offset the first vibration of the motor, and therefore exciting force transmitted to the cylinder and the washing machine shell through the motor is reduced. In this way, vibration excitation sources are actively controlled, so that vibration reduction and noise reduction are realized.

Description

Noise control system of washing machine and washing machine

Technical Field

The invention relates to the technical field of household appliances, in particular to a noise control system of a washing machine and the washing machine.

Background

With the continuous development of washing machine technology, washing machines realize more and more functions, the washing capacity is larger and larger, and the dehydration rotating speed is higher and higher. The vibration and noise problems are more and more prominent while bringing convenience to the life of the user. Excessive noise can affect people's life and even physical well-being.

The most general drum type washing machine in the market at present has a structure that a drum is mounted on an outer casing through a spring and a damper, and a motor is rigidly mounted on the drum. The motor is connected to the drum by a belt having a typical ratio of 10:1, and if the drum is rotated at 1400RPM at maximum during dewatering, the motor is rotated at least 14000RPM. Even if the motor rotor has a small unbalanced mass, relatively large vibrations are caused, the vibration frequency is expressed as 1 st order of rotation, and the 1 st order vibrations eventually cause 1 st order tonal noise of the whole motor. On the other hand, the rotor of the drive motor is supported in the bearing housing by 2 rolling bearings having specific component characteristic frequencies, such as a bearing outer race passing frequency, a bearing inner race passing frequency, and the like. When the washing machine is dehydrated, the rotating speed of the motor is increased from 0 to the highest rotating speed, and when the exciting force frequency is matched with the characteristic frequency of the bearing, resonance is caused, so that single-frequency noise is radiated.

The 1 st order noise and the single frequency noise corresponding to the characteristic frequency of the bearing can cause higher overall noise. In some cases, even if the noise value of the whole machine is not high, the single-frequency noise is dominant, so that the sound quality of the whole machine is obviously affected, and the user is uncomfortable in hearing. Therefore, noise reduction processing must be performed on such noise.

Vibration and noise reduction of the washing machine is basically not different from vibration and noise reduction of other equipment in principle, and two common noise reduction methods are passive noise reduction and active noise reduction. At present, whether passive noise reduction or active noise reduction is carried out, noise reduction measures are taken after noise is generated but before the noise is transmitted to human ears, and corresponding measures are not taken before noise radiation is generated, namely vibration reduction and noise reduction are considered from the perspective of an excitation source.

There is no technical solution in the prior art to solve the technical problems encountered above.

Disclosure of Invention

In order to solve at least the above problems, the present invention provides a noise control system of a washing machine, wherein the washing machine includes a washing machine housing, a drum disposed in the washing machine housing, and a motor for driving the drum to rotate; the system comprises: a first acquisition unit configured to acquire a first vibration signal of a first vibration of the motor; the second acquisition unit is used for acquiring a rotating speed signal of the motor; the control unit is used for receiving the first vibration signal and the rotating speed signal sent by the first acquisition unit and the second acquisition unit and processing the first vibration signal and the rotating speed signal to generate a control signal; and the execution unit is used for receiving the control signal and generating second vibration acting on the motor based on the control signal, wherein the first vibration is opposite to the second vibration in phase so as to offset the first vibration of the motor, and therefore exciting force transmitted to the cylinder and the washing machine shell through the motor is reduced.

By the mode, the vibration excitation source is actively controlled, namely, vibration is controlled from the source of noise generation, and excitation force transmitted to the cylinder and the shell is reduced, so that vibration reduction and noise reduction, especially noise generated by high-rotation-speed dehydration, are realized.

Furthermore, compared with active noise reduction, the active noise reduction system is used for collecting noise signals and is easy to be interfered by the outside, and particularly for low-frequency noise, the system is complex and has poor stability. The noise control system in the scheme mainly aims at medium-low frequency vibration reduction through collecting vibration signals, is little affected by external interference, and is relatively simple in system design and good in stability.

Further, the noise control system can also significantly reduce 1 st order noise caused by unbalanced mass of the motor rotor, thus allowing the motor rotor to have relatively larger unbalanced mass, and is easier to control in the manufacturing process.

In addition, the noise control system can also remarkably reduce single-frequency noise caused by the characteristic frequency of the rolling bearing of the motor, the bearing selection is more flexible in the motor design process, and only certain specific bearings can be selected without considering noise.

In a possible embodiment, the control signal comprises a second vibration signal, and the execution unit generates a corresponding second vibration according to the second vibration signal, so that the execution unit generates a corresponding vibration reduction force wave to reduce or even cancel the vibration generated by the motor.

In one possible embodiment, the mounting position of the first acquisition unit is associated with the vibration direction of the motor to acquire the first vibration signal of the motor in the corresponding vibration direction by the first acquisition unit. For example, the first acquisition unit acquires first vibration signals in three mutually perpendicular directions of the motor, respectively. The vibration of the motor in different directions is acquired through the first acquisition unit, so that the vibration of the motor in multiple directions is controlled through the control unit and the execution unit, the noise of the washing machine system is better improved, and the sound quality of the whole machine is improved.

The motor comprises a motor end cover, and the first acquisition unit is arranged on the motor end cover, so that vibration signals of the motor can be acquired more accurately.

The first acquisition unit includes a vibration sensor. The noise control system of this scheme is vibration signal through vibration sensor collection, and is little to well low frequency damping, receives external interference influence, and system design is simple relatively and stability is good.

In one possible embodiment, the execution units are respectively installed in three directions of the motor; wherein the execution unit is used for respectively generating second vibration in three directions based on the first vibration in three directions. For example, the actuator unit comprises a vibration exciter and is rigidly connected to the motor. The motor is controlled to vibrate in multiple directions through the control unit and the execution unit, so that the noise of the washing machine system is better improved, and the sound quality of the whole machine is improved.

In one possible embodiment, the exciter is fixed to a surface of the motor such that vibration generated by the exciter directly acts on the motor, thereby solving a noise problem of the washing machine at a source of noise generation.

In one possible embodiment, the second acquisition unit includes a rotation speed sensor, which is disposed on the washing machine drum and may be used to acquire a motor rotation speed signal.

In a possible embodiment, the control unit is provided on the inner wall of the washing machine housing, and may also be integrated with the control module of the washing machine itself.

A washing machine includes a washing machine housing; the cylinder body is arranged in the washing machine shell; the motor is connected with the cylinder and used for driving the cylinder to rotate; the noise control system of the washing machine is also included. In the working process of the washing machine, particularly in the high-speed dehydration work, the noise control system controls the vibration from the source of noise generation by actively controlling the vibration excitation source, so that the excitation force transmitted to the cylinder body and the shell by the motor is reduced, and vibration reduction and noise reduction are realized. Particularly, the narrow-band noise caused by resonance can be remarkably reduced, the noise value is reduced, and the sound quality is improved.

Drawings

FIG. 1 is a schematic structural view of a washing machine according to an embodiment of the present invention;

FIG. 2 is a logic block diagram of a noise control system of a washing machine according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a noise control system of the washing machine of fig. 2.

Detailed Description

As shown in fig. 1, which shows a brief structure of a washing machine, the washing machine 1 includes a washing machine housing 10, a tub 20 provided in the washing machine housing 10, wherein the tub 20 and the washing machine housing 10 are connected by a support member 70. The support member 70 may be an elastic member, such as a spring provided at an upper position of the cylinder 20, for pulling the cylinder 20; the damper provided in the lower position of the cylinder 20 can support the cylinder 20 from below.

The washing machine 1 further includes a motor 30 for driving the drum 20 to rotate. The motor 30 is connected to the cylinder 20. The motor 30 may be connected to the cylinder 20 by directly connecting a motor shaft to the cylinder 20 to drive the cylinder 20 to rotate, or may drive the cylinder 20 to rotate by belt transmission, or may be connected to other transmission methods, which are not limited herein.

Generally, a washing machine generates noise during operation, particularly, during dehydration. Noise originates on the one hand from the motor rotor, and because of the unbalanced mass of the rotor, relatively large vibrations are caused, the frequency of which appears as 1 st order of rotation, which 1 st order vibrations ultimately lead to 1 st order tonal noise of the whole machine. On the other hand, noise is derived from machine resonance. Specifically, the rotor of the motor is supported in the bearing housing by 2 rolling bearings having specific component characteristic frequencies, such as a bearing outer race passing frequency, a bearing inner race passing frequency, and the like. When the washing machine is dehydrated, the rotating speed of the motor is increased from 0 to the highest rotating speed, and when the exciting force frequency is matched with the characteristic frequency of the bearing, resonance is caused, so that single-frequency noise is radiated.

In order to solve the above problems, an embodiment of the present invention provides a noise control system for the above washing machine. Specifically, referring to fig. 1 and 2, the washing machine further includes a noise control system 2 including:

a first acquisition unit for acquiring a first vibration signal of a first vibration of the motor 30;

a second acquisition unit for acquiring a rotational speed signal of the motor 30;

the control unit is used for receiving the first vibration signal and the rotating speed signal sent by the first acquisition unit and the second acquisition unit and processing the first vibration signal and the rotating speed signal to generate a control signal;

and an execution unit for receiving the control signal and generating a second vibration acting on the motor 30 based on the control signal, wherein the first vibration is opposite to the second vibration in phase to cancel the first vibration of the motor 30, thereby reducing an exciting force transmitted to the drum 20 and the washing machine housing 10 by the motor 30.

The scheme adopts an active vibration reduction mode to actively control the vibration excitation source, namely, the vibration is controlled from the source generated by noise, and the excitation force transmitted to the cylinder body and the shell is reduced, so that vibration reduction and noise reduction, especially the noise generated by high-rotation-speed dehydration, are realized.

Further, the noise control system is mainly used for reducing narrow-band vibration generated by the motor in the dewatering process of the washing machine so as to reduce single-frequency noise in the dewatering process. Such as 1 st order rotation (speed/60), 2 nd order rotation, and single frequency vibration corresponding to the characteristic frequency of the bearing.

In particular, the noise control system can significantly reduce 1 st order noise caused by unbalanced mass of the motor rotor, thus allowing the motor rotor to have relatively large unbalanced mass, and is easier to control during the manufacturing process. In addition, the noise control system can remarkably reduce single-frequency noise caused by the characteristic frequency of the rolling bearing of the motor, the bearing selection in the motor design process is more flexible, and only certain specific bearings can be selected without considering noise.

Further, the noise control system has a remarkable noise reduction effect on medium-low frequency vibration, and the passive noise reduction measure has a limited noise reduction effect on medium-low frequency noise. The installation position of the active noise reduction secondary sound source is required to have a certain wavelength distance from the primary sound source, the wavelength of sound waves is relatively longer for middle-low frequency noise, the installation of the secondary sound source is required to be relatively longer from the primary sound source, the internal space of the actual washing machine is limited, and the installation is basically impossible.

Details are described below in connection with fig. 1 and 2.

The noise control system comprises a first acquisition unit, a second acquisition unit, a control unit and an execution unit. The first acquisition unit may be a vibration sensor 40, and may be disposed on an end cover of the motor 30. For example, the vibration sensor 40 is a piezoelectric acceleration sensor or other type, and is fixed to the motor end cover by a screw connection.

In one embodiment, the mounting position of the vibration sensor 40 is associated with the vibration direction of the motor 30 to obtain a first vibration signal of the motor in the corresponding vibration direction by the vibration sensor 40.

Further, the motor 30 may vibrate in three mutually perpendicular directions in space, and the vibration sensor 40 may acquire first vibration signals in the three mutually perpendicular directions of the motor 30, respectively.

The second acquisition unit may include a rotational speed sensor 80 (not shown in the drawings). The rotation speed sensor is not necessary for the system, and the rotation speed signal can be obtained from the motor control unit integrated with the washing machine. If the signal cannot be obtained, an additional rotation speed sensor, such as a photoelectric sensor or a laser sensor, may be installed on the washing machine drum 20 to collect the rotation speed signal.

The control unit 60 may be fixed to the washing machine outer case 10 as shown in fig. 1; or integrated with the control module of the washing machine itself.

The actuator unit comprises a vibration exciter 50 and is rigidly connected to the motor 30. The vibration exciter 50 may be an electric vibration exciter, and is rigidly fixed to the surface of the motor 30.

In one embodiment, the vibration exciter 50 may be respectively installed in three directions of the motor 30; wherein the vibration exciter 50 is configured to generate second vibrations in three directions based on the first vibrations in the three directions, respectively.

For example, the motor 30 has vibrations in 3 directions, i.e., X, Y, Z. The vibration of the 1 st order is perpendicular to the direction Y of the axis of the motor, and resonance caused by the characteristic frequency of the bearing can be axial Z or vertical X. Therefore, if vibration damping in multiple vibration directions is required, a plurality of vibration sensors and vibration exciters are required to be respectively installed in corresponding directions, but noise control algorithms in different directions are the same. However, if a plurality of different single-frequency vibrations are in the same direction, only one vibration sensor and one vibration exciter are required.

Vibration sensor 40 and vibration exciter 50 are arranged in different directions of motor vibration, so that vibration and noise reduction control in a plurality of corresponding directions is realized, and the sound quality of the whole machine is improved remarkably.

In one embodiment the control unit may acquire the signals of the vibration sensor 40 and the rotational speed sensor 80 and process and analyze the first vibration signal and the rotational speed signal using a control algorithm to generate a control signal. The control signal includes a second vibration signal from which the exciter 50 can generate a corresponding second vibration to cancel the first vibration of the motor 30, thereby reducing the exciting force transmitted to the tub 20 and the washing machine housing 10 by the motor 30.

The control algorithm of the noise control system can comprise feedforward control, feedback control, feedforward control, hybrid method control algorithm and the like.

A schematic diagram of a noise control system of a washing machine is shown in fig. 3.

Specifically, in connection with fig. 3, the noise control system operates as follows:

the vibration sensor 40 is typically mounted on the motor 30. When the washing machine 1 starts to operate, the exciting force of the motor 30 acts on the washing machine 1 due to the motor 30. The vibration sensor 40 acquires a residual vibration signal of the washing machine 1, particularly, a first vibration signal of the first vibration of the motor 30, including a vibration frequency, an amplitude and a phase, after vibration reduction of the motor 30 in real time. Meanwhile, a rotational speed signal of the motor 30 is acquired through the control unit 60 or the rotational speed sensor 80 of the motor 30.

The vibration sensor 40 and the rotation speed sensor 80 transmit the collected residual vibration signal and rotation speed signal to the control unit 60 in real time, and the control unit analyzes and processes the signals according to an integrated algorithm thereof.

The control unit 60 outputs the processed control signal to the exciter 50. Wherein the control signal comprises the frequency, amplitude, phase of the signal to be generated.

The vibration exciter 50 emits vibration damping force waves having the same frequency, the same amplitude and opposite phases as those of the first vibration signal according to the control signal, i.e., generates second vibration to cancel the first vibration generated by the motor 30.

The control unit 60 adjusts the vibration damping force waves output in real time according to the fed-back residual vibration signals so as to achieve higher vibration damping and noise reduction effects.

According to the scheme, the vibration excitation source is actively controlled, so that the excitation force transmitted to the cylinder body and the shell is reduced, vibration reduction and noise reduction are realized, and the sound quality of the whole machine is improved.

The present invention is not limited to the above embodiments, and various equivalent modifications and substitutions can be easily made by those skilled in the art within the technical scope of the present invention, and these modifications and substitutions are intended to be included in the scope of the present invention. Therefore, the protection scope of the invention is subject to the protection scope of the claims.

Claims

1. A noise control system of a washing machine, wherein the washing machine comprises a washing machine housing, a cylinder arranged in the washing machine housing, and a motor for driving the cylinder to rotate;

characterized in that the system comprises:

a first acquisition unit configured to acquire a first vibration signal of a first vibration of the motor;

the second acquisition unit is used for acquiring a rotating speed signal of the motor;

and the execution unit is used for receiving the control signal and generating second vibration acting on the motor based on the control signal, wherein the first vibration is opposite to the second vibration in phase so as to offset the first vibration of the motor, and therefore exciting force transmitted to the cylinder and the washing machine shell through the motor is reduced.

2. The system of claim 1, wherein the control signal comprises a second vibration signal, and the execution unit generates a corresponding second vibration based on the second vibration signal.

3. The system of claim 1, wherein the mounting location of the first acquisition unit is associated with a vibration direction of the motor to acquire a first vibration signal of the motor in a corresponding vibration direction by the first acquisition unit.

4. The system according to claim 2, wherein the first acquisition unit acquires first vibration signals in three mutually perpendicular directions of the motor, respectively.

5. The system of claim 1, wherein the motor comprises a motor end cap, the first acquisition unit being disposed on the motor end cap.

6. The system of any of claims 1-5, wherein the first acquisition unit comprises a vibration sensor.

7. The system of claim 4, wherein the execution units are respectively installed in three directions of the motor; wherein the execution unit is used for respectively generating second vibration in three directions based on the first vibration in three directions.

8. The system of claim 1 or 7, wherein the actuator unit comprises a vibration exciter and is rigidly connected to the motor.

9. The system of claim 8, wherein the exciter is affixed to a surface of the motor.

10. The system of claim 1, wherein the second acquisition unit comprises a rotational speed sensor disposed on the washing machine bowl.

11. The system of claim 1, wherein the control unit is disposed on an interior wall of the washing machine housing.

12. A washing machine includes a washing machine housing; the cylinder body is arranged in the washing machine shell; the motor is connected with the cylinder and used for driving the cylinder to rotate; a washing machine noise control system as claimed in any one of claims 1 to 11.