A drum washing machine that realizes dynamic balance by combining active and passive methods

Abstract

The present application discloses a drum washing machine that achieves dynamic balancing by combining active and passive methods, and relates to the technical field of drum washing machines. The drum washing machine has a plurality of liquid injection cavities and a plurality of passive balancing cavities uniformly distributed along the circumference of the drum wall. Each passive balancing cavity is provided with a plurality of balancing balls, and the movement direction of the balancing balls in the passive balancing cavity is along the axial direction of the drum. When a controller controls the rotation of the drum, the balancing balls move in the passive balancing cavity along the axial direction of the drum under the action of the unbalanced mass-diameter moment of the drum to passively balance the mass-diameter moment. The controller injects liquid into the liquid injection cavity in the target liquid injection direction based on the front-end displacement signal and the rear-end displacement signal to actively balance the mass-diameter product. The drum washing machine achieves passive balancing of the mass-diameter moment through the passive movement of the balancing balls and active balancing of the mass-diameter product through the injection of liquid. The combination of active and passive methods makes up for the shortcomings of a single balancing method and can achieve a better dynamic balancing effect.

Description

Technical Field

[0001] The present application relates to the technical field of drum washing machines, and in particular to a drum washing machine that achieves dynamic balance by combining active and passive methods. Background Art

[0002] Washing machines have become an indispensable tool in people's daily lives. They are developing towards low noise, multi-function and low energy consumption. Among them, drum washing machines are becoming more and more popular among modern people due to their advantages such as high cleaning ratio, low wear rate and water saving.

[0003] In the prior art, a drum washing machine rotates at high speed during dehydration operation, which produces greater vibration than during washing operation. This is mainly due to the uneven distribution of clothes in the drum during dehydration, which causes excessive eccentricity. The motor drives the drum to rotate at high speed. When the eccentric load is too large, it is easy to cause violent vibration and walking of the washing machine, which not only generates loud noise and affects people's normal living environment, but also causes vibration of parts inside the machine, greatly shortening the service life of the washing machine.

[0004] To suppress the violent vibration during dehydration, existing drum washing machines mostly adopt the method of adding counterweights or using a balancing ring structure for passive vibration suppression. However, the existing methods have certain limitations. The evenly distributed counterweight blocks are limited to axial movement, and it is difficult to dynamically balance the mass with eccentricity, so the balancing effect is not ideal.

[0005] At present, there are also some methods of achieving active balancing by injecting water. For example, the existing patent document application number 202010878439.X, titled "A balanced and shock-absorbing drum washing and dehydrating machine and dehydration method", discloses a method of setting sector-shaped partitions in the drum, and replenishing water into each sector-shaped partition through a water guide ring to achieve balanced shock absorption. The current patent document application number 201220019367.4, titled "Balancing device for the drum in a fully automatic washing and dehydrating machine", also discloses a method of providing a balancing water tank on the inner wall of the drum, and balancing and shock absorption by injecting water into the water tank. These active balancing methods can balance the mass to a certain extent, but the vibration and walking of the washing machine are not only affected by the mass, so the balancing effect of the existing active balancing method is difficult to achieve an ideal state. Summary of the Invention

[0006] In response to the above-mentioned problems and technical requirements, the applicant has proposed a drum washing machine that achieves dynamic balancing by combining active and passive methods. The technical solution of this application is as follows:

[0007] A drum washing machine that achieves dynamic balancing by combining active and passive methods, characterized in that Hall effect displacement sensors are fixed to both ends of the side walls of the drum, and a magnetic plate that matches the Hall effect displacement sensors on the drum is fixed to the inner wall of the casing of the drum washing machine;

[0008] The wall surface of the drum disposed in the outer barrel is uniformly distributed with a plurality of liquid injection cavities along the circumference. The wall surface of the drum is also uniformly distributed with a plurality of passive balancing cavities along the circumference. A plurality of balancing balls are disposed in each passive balancing cavity, and the balancing balls move in the passive balancing cavity along the axial direction of the drum.

[0009] When the controller controls the rotation of the drum, the balancing ball moves in the passive balancing cavity along the axial direction of the drum under the action of the unbalanced mass-diameter moment of the drum to passively balance the mass-diameter moment; the controller injects liquid into the injection cavity in the target injection direction according to the front-end displacement signal and the rear-end displacement signal to actively balance the mass-diameter product.

[0010] A further technical solution is that the method executed by the controller includes:

[0011] If it is detected that the signal difference between the front displacement signal and the rear displacement signal collected by the two Hall displacement sensors on the outer barrel is not within a preset range, wait until the signal difference between the two displacement signals is within the preset range, the signal difference includes an amplitude difference and / or a phase difference;

[0012] If it is detected that the amplitude average of the front-end displacement signal and the rear-end displacement signal exceeds the amplitude threshold, liquid is injected into the injection cavity in the target injection direction according to the phase of the front-end displacement signal and the rear-end displacement signal until the amplitude average of the front-end displacement signal and the rear-end displacement signal does not exceed the amplitude threshold;

[0013] After injecting liquid into the liquid injection cavity, wait until the signal difference between the two displacement signals is within a preset range.

[0014] A further technical solution is that the method executed by the controller includes:

[0015] Control the rotation of the drum and increase the speed until the speed of the drum reaches the equilibrium speed;

[0016] When the drum rotates at the balancing speed, the mass-diameter moment is passively balanced by the balancing balls and / or liquid is injected into the liquid injection chamber to actively balance the mass-diameter product until the signal difference between the front displacement signal and the rear displacement signal is within a preset range and the amplitude mean does not exceed the amplitude threshold corresponding to the balancing speed;

[0017] Controlling the rotation of the drum and increasing the speed until the speed of the drum reaches the next equilibrium speed, and then again performing the steps of passively balancing the mass-diameter moment by balancing balls and / or actively balancing the mass-diameter product by injecting liquid into the liquid injection chamber until the speed of the drum reaches the maximum speed;

[0018] Among them, each equilibrium speed is greater than the critical speed, and the critical speed is the speed at which the centrifugal force is greater than the gravity.

[0019] A further technical solution is that magnets and Hall switch sensors are installed on the outer wall of the end surface of the drum and the inner wall of the outer barrel respectively, and at least three liquid injection cavities are evenly distributed along the circumference of the wall of the drum;

[0020] The method for the controller to determine the injection cavity of the target injection direction according to the phase of the front-end displacement signal and the rear-end displacement signal includes:

[0021] The controller uses the Hall switch sensor to detect the zero position signal during the rotation of the drum, and determines the angle of the eccentric mass in the drum relative to the zero position signal as the phase average of the front displacement signal and the rear displacement signal;

[0022] Determine the centrifugal force F generated by the eccentric mass u On the circumferential plane of the drum, point from the center of the circle to the location of the eccentric mass, and determine the centrifugal force F generated by the eccentric mass on the circumferential plane of the drum u The opposite direction of the counterbalancing force F b ;

[0023] If the opposing balancing force F b Pointing to one of the injection chambers, determine the reverse balance force F b The injection cavity pointed to is the injection cavity in the target injection direction;

[0024] If the opposing balancing force F b If the position between two of the injection cavities is pointed to, the two injection cavities are determined to be the injection cavities in the target injection direction.

[0025] A further technical solution is that the method in which the controller injects liquid into the injection cavity in the target injection direction includes:

[0026] If there is only one injection cavity in the target injection direction, inject liquid into the injection cavity in the target injection direction until the average amplitude of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold;

[0027] If there are two injection chambers in the target injection direction, then according to the opposite balance force F b Liquid is injected into the corresponding two injection cavities according to the proportional relationship of the balanced force components in the two target injection directions until the amplitude average of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold.

[0028] A further technical solution is to perform a cross-correlation operation on any one of the front-end displacement signal and the rear-end displacement signal and take τ = 0 to obtain R XS (0), perform cross-correlation operation on the displacement signal and the cosine signal and take τ = 0 to obtain R XC (0), the amplitude of the displacement signal is determined to be Phase is T is the period of one rotation of the drum.

[0029] A further technical solution is that a drain port is further provided on the liquid injection chamber, a piston is provided inside the liquid injection chamber at the drain port, a piston rod of the piston is perpendicular to the wall of the liquid injection chamber and is adapted to the drain port, a spring is sleeved on the piston rod, and two ends of the spring respectively abut against the piston head of the piston and the inner wall of the liquid injection chamber;

[0030] When the speed of the drum is lower than the speed threshold, the piston disengages from the drain port under the action of the elastic force of the spring, the injection chamber is connected to the outside through the drain port, and the liquid in the injection chamber is discharged from the drain port; when the speed of the drum reaches the speed threshold, the piston overcomes the elastic force of the spring under the action of centrifugal force and blocks the drain port.

[0031] Its further technical solution is that a number of balancing mechanisms are evenly distributed on the wall surface of the drum along the circumference, and a number of spaced partitions are provided in each balancing mechanism to divide the interior of the balancing mechanism into a number of sub-cavities, wherein a balancing ball is provided in at least one sub-cavity to form a passive balancing cavity; through holes are opened on each partition so that the sub-cavities are interconnected and form a liquid injection cavity as a whole.

[0032] Its further technical solution is that the end of the drum is equipped with a water inlet mechanism with an annular structure, and the water inlet mechanism includes several water collecting rings installed together in a concentric ring structure. The number of water collecting rings is consistent with the number of injection chambers, and each water collecting ring is connected to the corresponding injection chamber, and each water collecting ring is equipped with a nozzle connected to the external water supply mechanism; the controller controls the external water supply mechanism to inject liquid into the corresponding water collecting ring through the nozzle, and the inner wall surface of each water collecting ring is arranged with several inclined baffles at intervals along the circumferential direction. The liquid injected into the water collecting ring through the nozzle rotates and disperses to different areas of the water collecting ring under the action of the baffle, and the liquid injected into the water collecting ring enters the injection chamber connected to the water collecting ring under the action of centrifugal force.

[0033] Its further technical solution is that the water inlet mechanism also includes a cache ring, which is installed together with each water collecting ring in a concentric ring structure and is located at the outermost ring. The cache ring includes several cache cavities, and the number of cache cavities is consistent with the number of injection cavities. Each water collecting ring is connected to the corresponding injection cavity through the corresponding cache cavity. The liquid injected into the water collecting ring is introduced into the corresponding cache cavity under the action of centrifugal force and enters the corresponding injection cavity.

[0034] The beneficial technical effects of this application are:

[0035] This application discloses a drum washing machine that achieves dynamic balancing through a combination of active and passive methods. This method achieves passive mass-diameter-moment balance through the passive movement of balancing balls, and active mass-diameter-product balance through the injection of liquid. This combined active and passive approach overcomes the shortcomings of a single balancing method and achieves improved dynamic balancing. Furthermore, the balancing balls are typically steel balls, which have a much higher density than liquids, resulting in a stronger balancing effect than when using only liquids, further optimizing the dynamic balancing effect.

[0036] The drainage mechanism connected to the liquid injection chamber adopts the method of automatically opening and closing the drain outlet according to the rotational speed. At low speed, no balancing is required and the drain outlet is open; when the speed rises, the drain outlet is automatically closed due to the centrifugal force, and water injection balancing can be performed. The structure is simple and does not require additional circuit control.

[0037] The ring-shaped water inlet mechanism has a simple structure, small size and light weight, which helps to quickly and efficiently supply the water sprayed into the nozzle to the corresponding liquid injection cavity through the buffer cavity, effectively preventing water from gathering in the water inlet mechanism and having good practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The figure is a schematic diagram of the installation of sensors on the casing, outer tub and drum of a drum washing machine in one embodiment.

[0039] Figure 2 Schematic diagram of the structure of a drum in an embodiment.

[0040] Figure 3 yes Figure 2 Schematic diagram of the structure of the balancing mechanism of the inner wall of the drum in the embodiment shown.

[0041] Figure 4 yes Figure 2 A schematic diagram of the partial structure of a balancing mechanism in the illustrated embodiment.

[0042] Figure 5 It is a partial schematic diagram of the drainage structure connected to the injection cavity.

[0043] Figure 6 FIG. 1 is a cross-sectional view of a water inlet mechanism in an embodiment.

[0044] Figure 7 It is a front view of the water inlet mechanism in an embodiment along the axial direction of the drum.

[0045] Figure 8 It is a schematic diagram of the partial connection between the water inlet mechanism and the balancing mechanism in an embodiment.

[0046] Figure 9 It is a dynamic balance diagram on the axial section of the drum.

[0047] Figure 10 This is a graph of experimental data of the amplitude and vibration angle of a drum washing machine in an example without injecting liquid.

[0048] Figure 11 The figure is a flow chart of active and passive combined dynamic balancing implemented by a controller in one embodiment.

[0049] Figure 12 It is a force decomposition diagram of the centrifugal force of the eccentric mass and its counterbalancing force on the circumferential plane of the drum in an example.

[0050] Figure 13 The figure is a flow chart of a controller realizing multi-speed point dynamic balancing in one embodiment. DETAILED DESCRIPTION

[0051] The specific implementation of this application will be further described below with reference to the accompanying drawings.

[0052] The present application discloses a drum washing machine that realizes dynamic balance by combining active and passive methods. The drum washing machine comprises a housing 1, an outer tub 2 disposed in the housing 1, and a drum 3 that can roll in the outer tub 2. Figure 1 The outer tub 2 of the drum washing machine has Hall displacement sensors fixed at both ends of its side wall, including a front Hall displacement sensor 21 fixed at the front end of the outer tub 2 and a rear Hall displacement sensor 22 fixed at the rear end of the outer tub 2. The front end of the outer tub 2 is the end close to the opening of the drum 3, and the rear end is the opposite end. The inner wall of the drum washing machine casing 1 is fixed with a magnetic plate that matches the Hall displacement sensor on the outer tub 2, such as Figure 1 As shown, it includes a magnetic plate 11 that matches the front Hall displacement sensor 21, and a magnetic plate 12 that matches the rear Hall displacement sensor 22. The outer wall of the end surface of the drum 3 and the inner wall of the outer barrel 2 are correspondingly installed with a magnet 31 and a Hall switch sensor 32, as shown in FIG. Figure 1 As shown, in one embodiment, the magnet 31 is fixed to the outer wall of the unopened end surface of the drum 3 , and the Hall switch sensor 32 is fixed to the inner wall of the outer tub 2 .

[0053] The wall surface of the drum 3 is uniformly distributed along the circumference with a number of liquid injection cavities. The wall surface of the drum 3 is also uniformly distributed along the circumference with a number of passive balancing cavities. Each passive balancing cavity is provided with a number of balancing balls. The balancing balls move along the axis of the drum 3 within the passive balancing cavity. The balancing balls in each passive balancing cavity have equal mass.

[0054] Theoretically, the liquid injection chamber and the passive balancing chamber can be independent of each other, and the position and number of the layout can be customized and adjusted. Generally, there are at least three liquid injection chambers and at least three passive balancing chambers evenly distributed along the circumference of the wall surface of the drum 3 to better achieve balance at different angles. However, the larger the capacity of the liquid injection chamber, the more liquid can be injected, and the better the mass eccentricity can be balanced. The liquid injection chamber and the passive balancing chamber are generally located on the inner wall surface of the drum 3, which will occupy the limited internal space of the drum. Considering that more space inside the drum should be used to place clothes as much as possible in actual use, based on this consideration, the capacity of the liquid injection chamber should not be too large. Therefore, in order to balance the dynamic balancing ability achieved by the liquid injection chamber and the space it occupies, in one embodiment, such as Figure 2 and 3 As shown, the wall surface of the drum 3 is evenly distributed with several balancing mechanisms 4 along the circumference. Figure 2 The dotted line represents the balancing mechanism 4 on the inner wall of the drum 3. Figure 2 and 3 Taking the example of three balancing mechanisms 4 evenly distributed along the circumferential direction on the wall surface of the drum 3 , the interval between two adjacent balancing mechanisms 4 in the circumferential direction is 120°.

[0055] Please refer to Figure 4 The schematic diagram of the structure of each balancing mechanism 4 is shown. In each balancing mechanism 4, a plurality of spaced partitions 41 are provided to divide the interior of the balancing mechanism 4 into a plurality of sub-cavities, such as Figure 4 For example, the balancing mechanism 4 includes two partitions 41 to divide the balancing mechanism 4 into three sub-cavities. At least one of the sub-cavities is provided with a balancing ball 42 to form a passive balancing cavity. Figure 4 Taking the example of two passive balancing chambers formed by two sub-cavities on either side, each with three balancing balls 42 positioned within it, the actual number of passive balancing chambers and balancing balls can be customized. Through holes are provided in each partition 41, interconnecting the sub-cavities and forming a liquid injection chamber. This means that liquid can be injected into the sub-cavities forming the passive balancing chambers, simultaneously serving as liquid injection chambers. The entire interior of the balancing mechanism 4 functions as a liquid injection chamber. Figure 4 The balancing mechanism 4 of this structure integrates the liquid injection chamber and the passive balancing chamber together, and the passive balancing chamber is also used for liquid injection and serves as the liquid injection chamber at the same time, reusing the space of the passive balancing chamber, so that the space of the liquid injection chamber can be increased as much as possible without occupying too much space in the drum washing machine, so as to better achieve eccentric balance and improve space utilization.

[0056] Under normal conditions, there is no liquid in the injection cavity. When dynamic balancing is required, liquid will be injected into the injection cavity. The injected liquid will then need to be drained. Therefore, the injection cavity is also connected to the drainage mechanism 5. Figure 4In the structure shown, although the sub-cavities are interconnected, the sub-cavities without balancing balls 42 contain more liquid. Therefore, the drainage mechanism 5 is generally located in the sub-cavities of the balancing mechanism 4 without balancing balls 42 to improve drainage efficiency. Multiple drainage mechanisms 5 can be provided to further improve drainage efficiency. Liquid in the sub-cavities serving as passive balancing cavities can also enter the sub-cavities without balancing balls 42 through the through-holes in the partition 41, thereby achieving drainage.

[0057] Please refer to the structure of the discharge mechanism 5 Figure 5 The liquid injection chamber is also provided with a drain port 51, which also extends through the wall of the drum 3. A piston 52 is positioned at the drain port 51. The piston 52 is located within the liquid injection chamber, with its piston rod perpendicular to the wall and aligned with the drain port 51. A spring 53 is mounted on the piston rod of the piston 52, with its ends respectively abutting against the piston head of the piston 52 and the inner wall of the liquid injection chamber. When this liquid discharge mechanism 5 is employed, when the speed of the drum 3 falls below a speed threshold, the spring 53 forces the piston 52 out of the drain port 51 under the elastic force of the piston 53, allowing the liquid in the liquid injection chamber to communicate with the outside through the drain port 51, allowing the liquid in the liquid injection chamber to be discharged through the drain port 51. When the speed of the drum 3 reaches the speed threshold, the centrifugal force of the piston 52 overcomes the spring 53's elastic force, compressing the spring and blocking the drain port 51 via the spring rod, sealing the interior of the liquid injection chamber.

[0058] When the drum washing machine of the present application is in use, the controller needs to inject liquid into the liquid injection cavity to achieve active balance, so the drum washing machine also includes a water inlet mechanism 6, please refer to Figure 2 The water inlet mechanism 6 is annular and is mounted on the end of the drum 3. Figure 6 The water inlet mechanism 6 includes a plurality of water collecting rings 61 installed together in a concentric ring structure. The number of the water collecting rings 61 is consistent with the number of the injection chambers, and each water collecting ring 61 is connected to the corresponding injection chamber. Figure 2 The structure has three balancing mechanisms 4, and the water inlet mechanism 6 includes three water collecting rings 61. Each water collecting ring 61 is equipped with a nozzle 62 connected to the external water supply mechanism. The controller controls the external water supply mechanism to inject liquid into the corresponding water collecting ring 61 through the nozzle 62. The inner wall surface of each water collecting ring 61 is arranged with a number of inclined baffles 63 at intervals along the circumference. The liquid injected into the water collecting ring 61 through the nozzle 62 rotates and disperses to different areas of the water collecting ring 61 under the action of the baffle 63, avoiding excessive accumulation of liquid at the nozzle 62. The liquid injected into the water collecting ring 61 enters the liquid injection cavity connected to the water collecting ring 61 under the action of centrifugal force.

[0059] In one embodiment, the water collecting ring 61 is not directly connected to the liquid injection cavity, please refer to Figure 7The water inlet machine 6 also includes a cache ring 64, which is installed together with each water collecting ring 61 in a concentric ring structure and is located at the outermost ring. The cache ring 64 includes a plurality of cache cavities, and the number of the cache cavities is consistent with the number of the injection cavities. Figure 7 The outermost cache ring 64 is divided into three mutually isolated cache cavities. Each water collecting ring 61 is connected to the corresponding liquid injection cavity through the corresponding cache cavity. Figure 7 As shown, the outermost ring water collecting ring 61 is directly connected to the corresponding cache cavity through the opening, and the other inner ring water collecting rings 61 are connected to the corresponding cache cavity through the through pipe 65. Each cache cavity is connected to the corresponding injection cavity through the drainage groove 66. Figure 2 The structure of Figure 7 The shown connecting balance mechanism 4, the liquid injected into the water collecting ring is introduced into the corresponding buffer cavity under the action of centrifugal force, and enters the corresponding liquid injection cavity. The drainage groove 66 is generally large to ensure that the liquid enters the liquid injection cavity smoothly.

[0060] Based on the drum washing machine of this structure of the present application, the controller realizes dynamic balancing in the following manner:

[0061] When the controller controls the rotation of drum 3 and the mass-diameter-moment imbalance of drum 3 occurs, the axis of drum 3 will experience significant oscillation. This oscillation causes balancing ball 42 to autonomously move along the axis of drum 3 within the passive balancing chamber. Under the influence of the unbalanced mass-diameter-moment of drum 3, balancing ball 42 moves along the axis of drum 3 within the passive balancing chamber to passively balance the mass-diameter-moment. In addition to passively balancing the mass-diameter-moment, when the mass of the clothes in the drum is eccentric, the controller can also actively balance the mass-diameter product by injecting liquid into the liquid injection chamber.

[0062] The drum washing machine is affected by two-order swing modes, including the rocking mode and the translation mode. Unlike the vertical rotor, the rocking mode of the horizontal rotor has a lower frequency than the translation mode. Considering that the liquid itself has a low density and limited balancing ability, the present application designs a dynamic balancing method that combines active and passive elements of "liquid injection + balancing ball". The balancing ball 42 can passively adjust the balance of mass-diameter moment above the rocking mode frequency, thereby achieving a better dynamic balancing effect.

[0063] The principle of the passive balance mass-diameter moment of the balancing ball 42 is as follows Figure 9 As shown in the figure, m b1 、m b2 are the eccentric mass m u The total equivalent mass of the balancing balls 42 on both sides, r b1 、r b2 h is the distance between the equivalent mass of each sphere and the central axis of the drum 3, b1 、h b2 are the eccentric masses mu The distance between the total equivalent mass of the balancing balls 42 on both sides and the middle reference plane. u is the eccentric mass m u Distance from the central axis, h u is the eccentric mass m u Distance from the middle reference plane. m w is the equivalent mass of the liquid injected into the injection chamber, r w h is the distance from the equivalent center of mass of the liquid injected into the injection cavity to the central axis, w is the distance between the equivalent center of mass of the liquid injected into the injection chamber and the middle reference plane. In the steady-state stage, after the balancing ball 42 crosses the plane and corrects, the mass-diameter moment of the rotor system satisfies the following constraints:

[0064] m u r u h u -m b1 r b1 h b1 -m b2 r b2 h b2 +m w r w h w =0;

[0065] When the equivalent mass m of the liquid injected into the injection chamber w = 0, the calculation results of the rotor amplitude and vibration angle during the cross-plane correction process of the balancing ball 42 are as follows: Figure 10 As shown, it is not difficult to see that although the steady-state amplitude is not zero, the rotor's own vibration angle tends to zero, resulting in a vibration pattern similar to that of a planar rotor. Based on the passive balancing of the balancing balls 42, by injecting the required liquid to adjust the rotor's mass-diameter product, the system can ultimately be fully balanced, that is, the following equilibrium state can be achieved:

[0066]

[0067] When the drum washing machine vibrates or walks, the Hall displacement sensor will move with the outer drum, causing the distance between the Hall displacement sensor and the corresponding magnetic plate to change, and the magnetic field strength felt by the Hall displacement sensor will also change accordingly. Therefore, the signal output by the Hall displacement sensor can reflect the change in the distance between the Hall displacement sensor and the casing, thereby reflecting the dynamic balance of the drum washing machine such as vibration or walking. Therefore, the controller collects the front-end displacement signal through the front-end Hall displacement sensor 21 and the rear-end displacement signal through the rear-end Hall displacement sensor 22, and controls the dynamic balance according to the front-end displacement signal and the rear-end displacement signal. For details, please refer to Figure 11 The flowchart shown:

[0068] If the controller detects that the signal difference between the front displacement signal and the rear displacement signal collected by the two Hall displacement sensors on the outer barrel is not within the preset range, it is determined that the balancing ball 42 has not yet completed the passive balance of mass-diameter moment and is still in the process of moving. The controller then waits until the signal difference between the two displacement signals is within the preset range. The signal difference includes the amplitude difference and / or phase difference. That is, it needs to meet σ A , σ φ are the preset thresholds for amplitude difference and phase difference, respectively. b 、φ b is the amplitude and phase of the rear-end displacement signal, A f 、φ f are the amplitude and phase of the front-end displacement signal.

[0069] When the signal difference between the two displacement signals is within the preset range, it can be determined that the balancing ball 42 has completed its movement. At this time, if it is detected that the amplitude mean of the front-end displacement signal and the rear-end displacement signal exceeds the amplitude threshold, liquid is injected into the injection cavity in the target injection direction according to the phase of the front-end displacement signal and the rear-end displacement signal. After the liquid is injected into the injection cavity, the balance of mass, diameter and moment will be broken again, which will prompt the balancing ball 42 to move again and make a new position adjustment. Therefore, after the injection is completed, it is delayed again to wait until the signal difference of the two displacement signals is within the preset range, and the balance of mass, diameter and moment is completed again. Liquid is injected in this way until the amplitude mean of the front-end displacement signal and the rear-end displacement signal does not exceed the amplitude threshold.

[0070] After the liquid is injected, it will have a significant impact on the dynamic balance of the drum washing machine, causing the amplitude and / or phase of the front displacement signal and the rear displacement signal to change accordingly. Therefore, in actual implementation, it is generally unlikely that the amplitude mean value will not exceed the amplitude threshold by continuously injecting liquid into the injection cavity in the target injection direction in a single time. In practice, liquid is generally injected in small amounts multiple times in a periodic manner. That is, when the signal difference between the two displacement signals is within the preset range and the amplitude mean value is detected to exceed the amplitude threshold, liquid is injected into the injection cavity in the target injection direction within one injection cycle, and then wait for the completion of another mass-diameter-moment balance. If it is detected that the amplitude mean value of the front displacement signal and the rear displacement signal at this time does not exceed the amplitude threshold, the dynamic balance is completed. If it is detected that the amplitude mean value of the front displacement signal and the rear displacement signal at this time still exceeds the amplitude threshold, liquid is re-injected into the injection cavity in the target injection direction according to the phase of the front displacement signal and the rear displacement signal at this time, and the above process is repeated until the amplitude mean value of the two displacement signals does not exceed the amplitude threshold.

[0071] In the above process, the controller needs to use the amplitude A of two displacement signals to achieve dynamic balance. b 、Af and phase φ b 、φ f , the method of determining the amplitude and phase of the front-end displacement signal and the rear-end displacement signal is the same. Taking the front-end displacement signal as an example, assuming that the collected front-end displacement signal is x(t) = A f sin(2πf0t+φ f )+n(t), where f0 is the fundamental frequency signal and n(t) is the sum of all other signals except the fundamental frequency signal. Considering that the direct use of the mixed displacement signal for calculation is susceptible to interference signals, in this application, the signal sampling range is set to [0, T], where T is the period of one rotation of the drum. The front displacement signal is cross-correlated with the sinusoidal signal s(t) and τ = 0 to obtain R XS (0), perform cross-correlation operation on the displacement signal and the cosine signal c(t) and take τ = 0 to obtain R XC (0):

[0072]

[0073]

[0074] Since n(t) has a different frequency from the fundamental signal, according to the principle that different frequencies are unrelated, the above formula can be simplified to:

[0075]

[0076]

[0077] The amplitude and phase of the front-end displacement signal can be calculated as follows:

[0078]

[0079]

[0080] The same method can be used to determine the amplitude and phase of the rear-end displacement signal. The period T of one rotation of the drum can be determined using the Hall switch sensor 32. As the drum rotates, the magnet 31 on the drum end surface passes the position of the Hall switch sensor 32, causing the voltage level of the Hall switch sensor 32 to change. This voltage level change is the zero-position signal, providing a reference point in the direction of the drum's rotation. Therefore, the drum emits a zero-position signal with each rotation. The controller uses the Hall switch sensor to detect the zero-position signals during the drum's rotation and determines the interval between two adjacent zero-position signals as the period T of one rotation of the drum. This also allows the determination of the drum's rotational speed as 60 / T.

[0081] The controller injects liquid into the injection cavity in the target injection direction according to the phase of the front displacement signal and the rear displacement signal. The controller uses the Hall switch sensor to detect the zero position signal during the rotation of the drum and determines the eccentric mass m in the drum. u The angle of the position relative to the zero position signal is the phase mean of the front-end displacement signal and the rear-end displacement signal. Please refer to Figure 12 , in determining the eccentric mass m u After the location of the eccentric mass m is determined, u The centrifugal force F u On the circumferential plane of the drum, the centrifugal force F generated by the eccentric mass on the circumferential plane of the drum can be determined. u The opposite direction of the counterbalancing force F b If the opposite balance force F b Pointing to one of the injection chambers, determine the reverse balance force F b The injection cavity pointed to is the injection cavity in the target injection direction. b If the position between two injection cavities is pointed, then these two injection cavities are determined to be the injection cavities in the target injection direction. Figure 12 In the middle, the opposite balance force F b If it points to between the injection chambers X1 and X3, the injection chambers X1 and X3 are the injection chambers in the target injection direction.

[0082] After determining the injection cavity in the target injection direction, liquid can be injected into the injection cavity in the target injection direction: if there is only one injection cavity in the target injection direction, liquid is injected into the injection cavity in the target injection direction, and the front displacement signal and the rear displacement signal are synchronously detected until the amplitude average of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold. If there are two injection cavities in the target injection direction, the reverse balance force F is used. b Liquid is injected into the corresponding two injection chambers according to the proportional relationship of the balanced force components in the two target injection directions until the amplitude average of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold. Figure 12 In accordance with Liquid is injected into the injection chambers X1 and X3 in a proportional relationship until the average amplitude of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold. b When decomposing the force to obtain the balanced force components in the two target injection directions, it is necessary to combine the injection cavity in the target injection direction with the reverse balanced force F b The angle θ between X1 ,θ X2 , and the angle θ X1 ,θ X2It is related to the design position of the liquid injection chamber and can be determined according to the actual situation. Figure 11 Instead of the dynamic balancing operation shown in the figure, a multi-speed point step-by-step balancing method is used. Please refer to Figure 13 The flowchart shown:

[0083] The controller controls the rotation of the drum and increases the speed until the speed of the drum is increased to a balanced speed. The balanced speed is pre-set. Multiple different balanced speeds are pre-set and each balanced speed is greater than the critical speed. The critical speed is the speed at which the centrifugal force is greater than the gravity.

[0084] When the drum rotates at the current balance speed, the controller executes Figure 11 The process shown is to passively balance the mass-diameter moment by balancing balls and / or inject liquid into the injection chamber to actively balance the mass-diameter product until the signal difference between the front-end displacement signal and the rear-end displacement signal is within a preset range and the amplitude mean does not exceed the amplitude threshold corresponding to the balancing speed, that is, dynamic balancing is completed at the current balancing speed. The amplitude thresholds corresponding to different balancing speeds are generally different.

[0085] The controller then controls the drum to rotate and increase its speed until the drum reaches the next equilibrium speed. The process of passively balancing the mass-diameter moment using the balancing balls and / or actively balancing the mass-diameter product by injecting liquid into the injection chamber is repeated, completing dynamic balancing at the next equilibrium speed. This process is repeated until the drum reaches its maximum speed.

[0086] During the controller's dynamic balancing process, dynamic balancing is generally not required when the drum speed is low, and there's no need to inject liquid into the injection chamber. Therefore, leaving the drain port open has no effect. When the drum speed increases, the drain port automatically closes due to centrifugal force, preventing any liquid injected into the chamber from leaking. When the cycle is complete, the drum speed gradually decreases, and during this process, the drain port automatically opens again, draining the liquid injected for active balancing.

[0087] The above description is only a preferred embodiment of the present application, and the present application is not limited to the above embodiments. It is understood that other improvements and variations directly derived or imagined by those skilled in the art without departing from the spirit and concept of the present application should be considered to be included in the scope of protection of the present application.

Claims

1. A drum washing machine that realizes dynamic balance by combining active and passive methods, characterized in that: Hall displacement sensors are fixed at both ends of the side walls of the outer drum of the drum washing machine, and a magnetic plate matching the Hall displacement sensors on the outer drum is fixed on the inner wall of the casing of the drum washing machine; The wall surface of the drum disposed in the outer barrel is uniformly distributed with a plurality of liquid injection cavities along the circumference, and the wall surface of the drum is also uniformly distributed with a plurality of passive balancing cavities along the circumference, each passive balancing cavity is provided with a plurality of balancing balls, and the movement direction of the balancing balls in the passive balancing cavity is along the axial direction of the drum; When the controller controls the rotation of the drum, the balancing ball moves in the passive balancing cavity along the axial direction of the drum under the action of the unbalanced mass-diameter moment of the drum to passively balance the mass-diameter moment; the controller injects liquid into the injection cavity in the target injection direction according to the front-end displacement signal and the rear-end displacement signal to actively balance the mass-diameter product.

2. The drum washing machine according to claim 1, characterized in that: The method executed by the controller includes: If it is detected that the signal difference between the front displacement signal and the rear displacement signal collected by the two Hall displacement sensors on the outer barrel is not within a preset range, wait until the signal difference between the two displacement signals is within the preset range, the signal difference including the amplitude difference and / or the phase difference; If it is detected that the amplitude average of the front displacement signal and the rear displacement signal exceeds the amplitude threshold, liquid is injected into the injection cavity in the target injection direction according to the phase of the front displacement signal and the rear displacement signal until the amplitude average of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold; After injecting liquid into the liquid injection cavity, wait until the signal difference between the two displacement signals is within the preset range.

3. The drum washing machine according to claim 2, characterized in that: The method executed by the controller includes: Controlling the rotation of the drum and increasing the speed until the speed of the drum reaches a balanced speed; When the drum rotates at the balancing speed, the mass-diameter moment is passively balanced by the balancing balls and / or the mass-diameter product is actively balanced by injecting liquid into the liquid injection cavity, until the signal difference between the front-end displacement signal and the rear-end displacement signal is within the preset range and the amplitude mean does not exceed the amplitude threshold corresponding to the balancing speed; Controlling the rotation of the drum and increasing the speed until the speed of the drum reaches the next equilibrium speed, and then again performing the steps of passively balancing the mass-diameter moment by balancing balls and / or actively balancing the mass-diameter product by injecting liquid into the liquid injection chamber until the speed of the drum reaches the maximum speed; Among them, each equilibrium speed is greater than the critical speed, and the critical speed is the speed at which the centrifugal force is greater than the gravity.

4. The drum washing machine according to claim 2 or 3, characterized in that: A magnet and a Hall switch sensor are installed on the outer wall of the end surface of the drum and the inner wall of the outer barrel respectively, and at least three liquid injection cavities are evenly distributed along the circumference of the wall of the drum; The method for the controller to determine the injection cavity of the target injection direction according to the phase of the front-end displacement signal and the rear-end displacement signal includes: The controller uses the Hall switch sensor to detect a zero position signal during the rotation of the drum, and determines that the angle of rotation of the eccentric mass in the drum relative to the zero position signal is the phase average of the front displacement signal and the rear displacement signal; Determine the centrifugal force F generated by the eccentric mass u On the circumferential plane of the drum, the centrifugal force F generated by the eccentric mass on the circumferential plane of the drum is determined. u The opposite direction of the counterbalancing force F b ; If the opposing balancing force F b Pointing to one of the injection chambers, determine the reverse balance force F b The injection cavity pointed to is the injection cavity in the target injection direction; If the opposing balancing force F b If the position is directed to a position between two of the injection cavities, the two injection cavities are determined to be the injection cavities in the target injection direction.

5. The drum washing machine according to claim 4, characterized in that: The method of injecting liquid into the injection cavity in the target injection direction by the controller includes: If there is only one injection cavity in the target injection direction, inject liquid into the injection cavity in the target injection direction until the average amplitude of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold; If there are two injection chambers in the target injection direction, then according to the opposite balance force F b Liquid is injected into the corresponding two injection cavities according to the proportional relationship of the balanced force components in the two target injection directions until the amplitude average of the front displacement signal and the rear displacement signal does not exceed the amplitude threshold.

6. The drum washing machine according to claim 2, characterized in that: For any one of the front-end displacement signal and the rear-end displacement signal, the displacement signal is cross-correlated with the sinusoidal signal and τ=0 is taken to obtain R XS (0), perform cross-correlation operation on the displacement signal and the cosine signal and take τ = 0 to obtain R XC (0), determine the amplitude of the displacement signal to be Phase is T is the period of one rotation of the drum.

7. The drum washing machine according to claim 1, characterized in that: The injection chamber is also provided with a drain port, and a piston is provided inside the injection chamber at the drain port. The piston rod of the piston is perpendicular to the wall of the injection chamber and is adapted to the drain port. A spring is mounted on the piston rod, and the two ends of the spring respectively abut against the piston head of the piston and the inner wall of the injection chamber; When the rotation speed of the drum is lower than the rotation speed threshold, the piston disengages from the drain port under the elastic force of the spring, the liquid injection chamber is connected to the outside through the drain port, and the liquid in the liquid injection chamber is discharged from the drain port; when the rotation speed of the drum reaches the rotation speed threshold, the piston overcomes the elastic force of the spring under the action of centrifugal force and blocks the drain port.

8. The drum washing machine according to claim 1, characterized in that: The wall surface of the drum is evenly distributed with several balancing mechanisms along the circumference, and each balancing mechanism is provided with several spaced partitions to divide the interior of the balancing mechanism into several sub-cavities, wherein at least one sub-cavity is provided with a balancing ball to form a passive balancing cavity; each partition is provided with a through hole so that the sub-cavities are interconnected and form a liquid injection cavity as a whole.

9. The drum washing machine according to claim 1, characterized in that: The end of the drum is equipped with a water inlet mechanism of an annular structure, and the water inlet mechanism includes several water collecting rings installed together in a concentric ring structure. The number of the water collecting rings is consistent with the number of the injection chambers, and each water collecting ring is connected to the corresponding injection chamber. Each water collecting ring is equipped with a nozzle connected to the external water supply mechanism; the controller controls the external water supply mechanism to inject liquid into the corresponding water collecting ring through the nozzle, and the inner wall surface of each water collecting ring is provided with several inclined baffles arranged at intervals along the circumferential direction. The liquid injected into the water collecting ring through the nozzle rotates and disperses to different areas of the water collecting ring under the action of the baffle, and the liquid injected into the water collecting ring enters the injection chamber connected to the water collecting ring under the action of centrifugal force.

10. The drum washing machine according to claim 9, characterized in that: The water inlet mechanism also includes a cache ring, which is installed together with each water collecting ring in a concentric ring structure and is located at the outermost ring. The cache ring includes a plurality of cache cavities, and the number of cache cavities is consistent with the number of injection cavities. Each water collecting ring is connected to the corresponding injection cavity through the corresponding cache cavity. The liquid injected into the water collecting ring is introduced into the corresponding cache cavity under the action of centrifugal force and enters the corresponding injection cavity.

Images