WO2024089938A1

WO2024089938A1 - Drum washing machine

Info

Publication number: WO2024089938A1
Application number: PCT/JP2023/023895
Authority: WO
Inventors: 瀛申傅; 優金内; 真井村; 真理黒澤; 康博松井; 昌坂東
Original assignee: 日立グローバルライフソリューションズ株式会社
Priority date: 2022-10-28
Filing date: 2023-06-28
Publication date: 2024-05-02
Also published as: JP2024064511A

Abstract

Provided is a drum washing machine with which it is possible to minimize any longitudinal vibrations of an outer tub, and to minimize any increase in vibrations transmitted to a housing and an installation floor. In a plan view of a clothing loading opening 11op of an outer tub 11 from the front, when a Y-Y dividing line is virtually set in the direction of gravity passing through the center of the clothing loading opening, at least one anti-vibration damper 24d of a plurality of anti-vibration dampers 24 is installed in the area to the left of the dividing line when the rotation direction of a rotating drum 21 during water-draining operation is counterclockwise, and the one anti-vibration damper 24d is installed in the area to the right of the dividing line when the rotation direction of the rotating drum during water-draining operation is clockwise. Furthermore, an outer-tub-side attachment part 11d of the one anti-vibration damper 24d and the outer tub 11 is disposed closer to the clothing loading opening when viewed in the axial direction of the outer tub, and a housing-side attachment part 1d of the one anti-vibration damper 24d and the housing is disposed further from the clothing loading opening 11op than the outer-tub-side attachment part 11d when viewed in the axial direction of the outer tub 11.

Description

Drum washing machine

The present invention relates to a washing machine that washes clothes, and in particular to a drum-type washing machine with a horizontally positioned washing tub.

Generally, a drum-type washing machine is composed of an outer tub that holds water, a rotating drum that acts as a rotatable washing tub contained within the outer tub, and a housing that contains the outer tub and the rotating drum, and the outer tub is supported by vibration-proof structures such as vibration dampers and hanging springs from the housing. During the clothes spin cycle, the rotating drum is rotated at high speed to spin the clothes using centrifugal force, so if the distribution of clothes inside the rotating drum is uneven, vibrations will occur in the outer tub.

For this reason, vibration dampers and suspension springs are used to suppress vibration of the outer tub. Examples of vibration dampers that suppress vibration of the outer tub include those described in JP 2015-53947 A (Patent Document 1) and JP 5-84389 A (Patent Document 2).

The drum-type washing machine in Patent Document 1 comprises a first vibration damper disposed on the side in the direction in which the drum rotates, closer to the front than the center of gravity of the tub unit, and a second vibration damper disposed on the rear than the center of gravity of the tub unit, and the housing connection part to which the first and second vibration dampers are connected is attached to the washing machine housing via third cushioning material A and third cushioning material B. The first and second vibration dampers, and third cushioning material A and third cushioning material B, can also dampen vibrations of the tub unit in the front-back and left-right directions.

The drum-type washing machine in Patent Document 2 has a suspended water tub and a drum that rotates within the water tub, and is equipped with a pair of dampers that are installed between the bottom of the water tub and the washing machine body at an angle θ between them and are inclined in the front-to-rear direction. The pair of dampers also generate a damping force in the front-to-rear direction, suppressing vibration of the water tub.

JP 2015-53947 A Japanese Patent Application Laid-Open No. 5-84389

As is well known, during the spin cycle of a drum-type washing machine, the rotation speed of the rotating drum is increased in stages to perform centrifugal spin-drying at high speeds, which often causes vibrations in the outer tub due to uneven distribution of clothes during spin cycle. If the outer tub vibrates excessively, it can lead to abnormal vibrations caused by contact between the outer tub and the housing, and in the worst case scenario, damage to the drum-type washing machine. In particular, in drum-type washing machines with a long drum depth, even if the amount of uneven distribution of clothes is small, the moment arm becomes large, and the back-and-forth vibrations caused by the swinging movement of the outer tub become a problem.

By increasing the damping performance of the vibration isolation mechanism (so-called vibration damper) that connects the outer tub to the housing, it is possible to suppress vibration of the outer tub at the rotation speed range where the outer tub resonates. On the other hand, with a vibration isolation mechanism with high damping performance, the vibration of the outer tub is transmitted to the housing during high-speed rotation, causing the housing and the floor on which the drum washing machine is placed to vibrate. Since the vibration of the housing and the vibration of the floor on which the washing machine is placed can lead to discomfort for the user, it is necessary to simultaneously suppress the vibration of the outer tub and the vibration of the housing and the floor on which the washing machine is placed.

In Patent Document 1, multiple vibration dampers are provided under the outer tub, and cushioning material is provided at the connection between the vibration dampers and the housing, suppressing vibration of the outer tub in the left-right, up-down, and front-back directions when viewed from the front of the washing machine.

The vibration damper is installed in a position that attenuates vibrations in the left-right and up-down directions of the outer tank, while vibrations in the front-back direction are mainly suppressed by the damping of the cushioning material. This requires cushioning material with high damping performance, which may increase the vibrations transmitted to the housing and installation floor during high-speed rotation.

In addition, in Patent Document 2, there are multiple vibration dampers attached to the bottom of the outer tub at an angle in the front-to-rear direction, and vibration in the outer tub is suppressed by damping the vibration in the front-to-rear direction. However, since the front-to-rear vibration mode during resonance of the outer tub is not taken into consideration, even if large vibration in the front-to-rear direction occurs due to the swinging movement of the outer tub, the vibration dampers cannot stroke widely, and conversely, there is a risk that a vibration damper with low damping performance cannot sufficiently dampen the vibration. Therefore, in order to suppress vibration in the front-to-rear direction, it is necessary to use a vibration damper with high damping performance, which, like Patent Document 1, may result in an increase in vibration transmitted to the housing and installation floor during high-speed rotation.

The object of the present invention is to provide a drum-type washing machine that can suppress vibrations in the front-to-rear direction of the outer tub and suppress an increase in vibrations transmitted to the housing and installation floor.

The present invention provides a drum-type washing machine including a housing, an outer tub supported within the housing and capable of storing wash water therein, a rotary drum contained within the outer tub and rotated by an electric motor, and a plurality of vibration dampers connecting a lower portion of the outer tub to a bottom of the housing,
In a plan view of the clothes insertion opening of the outer tub seen from the front, when a dividing line is imaginarily set in the direction of gravity passing through the center of the clothes insertion opening, at least one of the plurality of vibration dampers is
When the rotating drum rotates counterclockwise during the dehydration operation, the drum is installed in the area to the left of the dividing line, and when the rotating drum rotates clockwise during the dehydration operation, the drum is installed in the area to the right of the dividing line.
Furthermore, the outer tub side mounting portion between one vibration damper and the outer tub is positioned closer to the clothing insertion opening when viewed in the axial direction of the outer tub, and the housing side mounting portion between one vibration damper and the housing is positioned farther from the clothing insertion opening than the outer tub side mounting portion when viewed in the axial direction of the outer tub.

It is possible to suppress vibrations in the front and rear directions of the outer tank, and also to suppress the increase in vibrations transmitted to the housing and installation floor.

1 is a perspective view of a drum-type washing machine to which the present invention is applied; FIG. 2 is a cross-sectional view showing a vertical cross section illustrating an internal configuration of the drum type washing machine. FIG. 4 is a chart showing a control pattern of the rotation speed of the rotating drum during a dehydration process. 10A and 10B are explanatory diagrams illustrating changes in vibration phase in each vibration direction of the outer tank. 11 is an explanatory diagram illustrating a vibration trajectory as viewed from the side of the clothes insertion opening of the outer tub. FIG. FIG. 11 is an explanatory diagram illustrating the swinging motion of the outer tub. 1 is a configuration diagram showing the outer tub as viewed from the front, illustrating the positional relationship between the outer tub, the housing, and the vibration damper according to an embodiment of the present invention. FIG. 1 is a configuration diagram seen from the side of the outer tank to explain the positional relationship between the outer tank, the housing, and the vibration damper according to an embodiment of the present invention. FIG. 4A to 4C are explanatory diagrams for explaining a first behavior of the vibration damper in the present embodiment. 10 is an explanatory diagram for explaining a second behavior of the vibration damper in the present embodiment. FIG.

The following describes in detail an embodiment of the present invention with reference to the drawings. However, the present invention is not limited to the following embodiment, and the scope of the present invention includes various modifications and applications within the technical concept of the present invention.

FIG. 1 is a perspective view of a drum-type washing machine 100 to which the present invention is applied, and FIG. 2 is a side view showing the internal structure of the drum-type washing machine 100. Below, the general configuration and operation of the drum-type washing machine 100 will be explained using FIG. 1 and FIG. 2.

The housing 1 that constitutes the outer shell of the drum-type washing machine 100 shown in FIG. 1 is attached to a housing base 1a and is composed of left and right side panels 1b (only the right side panel is shown in FIG. 1), a front cover 1c, a rear cover 1d (see FIG. 2), a top cover 1e, and a lower front cover 1f.

The top cover 1e is provided with a water supply hose connection port 30 for supplying water from a water tap to the drum-type washing machine 100. The housing 1, including the base 1a, forms a box-shaped outer frame, and has sufficient strength as an outer frame.

The door 2 is used to cover a clothing insertion opening (not shown) located approximately in the center of the front cover 1c for inserting and removing clothing, and is supported so as to be openable and closable by a hinge (not shown) provided on the front cover 1c. The door 2 is opened by pulling the door opening handle 2a towards the user, which releases a locking mechanism (not shown), and is closed by pressing the door 2 against the front cover 1c. The front cover 1c has a circular clothing insertion opening for inserting and removing clothing, approximately concentric with the clothing insertion opening of the outer tub 11 described below.

The operation and display panel 3 provided on the top of the housing 1 includes a power switch 4, an operation switch 5, and a display 6. The operation and display panel 3 is electrically connected to a control unit 7 (see FIG. 2) provided on an upper reinforcing member 13 (see FIG. 2) provided on the top of the housing 1. A cooling fan (not shown) is attached to the control unit 7. The control unit 7 also includes a memory capable of recording the operation of the drum washing machine. A drain hose 14 for draining water is attached near the housing base 1a.

The housing 1 of the drum-type washing machine 100 shown in FIG. 2 is provided with an outer tub 11 for storing water. The upper part of the outer tub 11 is connected by two sets of suspension means 8 consisting of coil springs in order to maintain the position of the outer tub 11. The lower part of the outer tub 11 is connected by a number of vibration dampers 24a-24d attached to the housing 1. The connection parts between both ends of the vibration dampers 24a-24d and the outer tub 11 and housing 1 are attached in a state where they can swing in the vibration direction of the outer tub 11.

The number of vibration dampers 24 may be two or more, and the configuration is not limited. In this embodiment, there are four, as described above. Note that this embodiment is characterized by the arrangement of vibration dampers 24d, which are provided in a position closer to the door 2 side of the outer tub 11, when the door 2 side is the front. This will be explained using Figures 7A and 7B.

The outer tub 11 contains a rotating drum 21 for washing clothes. An electric motor 22 for rotating the rotating drum 21 is provided at the rear of the outer tub 11. The electric motor 22 has a shaft 22a that serves as the rotation axis, which passes through the outer tub 11 and is mechanically connected to the rotating drum 21. When the electric motor 22 rotates and is driven, the rotating drum 21 is driven to rotate in both forward (counterclockwise when viewed from the front of the door 2 of the drum type washing machine 100) and reverse (clockwise when viewed from the front of the door of the drum type washing machine 100).

The rotation axis Az of the rotating drum 21 shown in FIG. 2 is horizontal from the front to the rear on the door 2 side of the drum-type washing machine 100, or is inclined so that the rear side is downwards (FIG. 2 shows the rear side inclined so that the rear side is downwards). The electric motor 21 is provided with a rotation speed detection device 10 that detects the rotation speed.

The inner circumferential surface of the rotating drum 21 is provided with a number of dewatering holes 21b for draining the washing water in the rotating drum 21 into the outer tub 11, and a number of baffles 23 (only one is shown in FIG. 2) spaced apart around the circumference of the rotating drum 21 for lifting clothes placed in the rotating drum 21. The baffles 23 extend in the front-to-rear direction of the rotating drum 21.

A cylindrical fluid balancer 21c is provided at the front end (door 2 side) of the rotating drum 21. The outer tub 11 is roughly cylindrical with an opening at the front and a closed rear, and has a bottom. The clothes insertion opening of the outer tub 11 and the clothes insertion opening of the housing 1 are connected by a bellows 16 that easily expands and contracts in the front-to-rear direction. The bellows 16 is an annular packing that seals the rotating drum 21 against water when the door 2 is closed.

The clothing insertion opening of the housing 1, the clothing insertion opening of the outer tub 11, and the clothing insertion opening of the rotating drum 21 are all connected to each other, and opening the door 2 makes it possible to put clothes in and take them out of the rotating drum 21. The outer tub 11 can also be divided into a side that includes the clothing insertion opening and a side where the electric motor 22 is attached.

The drain port 19 provided at the bottom of the outer tub 11 is connected to the internal drain hose 14. The lint collection box 17 is provided with a circulation pump 20 for circulating the wash water, and the wash water is sprayed into the rotating drum 21 via a circulation path 20a. The external drain hose 15 is provided with a drain valve 15a, and water is stored in the outer tub 11 by closing the drain valve 15a and supplying water, and the water in the outer tub 11 is discharged outside the machine by opening the drain valve 15a.

Furthermore, the lower part of the outer tub 11 is provided with an outer tub vibration detection unit 18 that detects the vibration of the outer tub 11. When the vibration of the outer tub 11 exceeds a preset threshold, the rotation of the rotating drum 21 is temporarily stopped, the clothes are corrected, and the spin-drying process is restarted. Only when the vibration is below the threshold is the rotation speed of the rotating drum 21 increased to prevent excessive vibration.

Next, the operation of the drum type washing machine 100 configured as above will be described. In the drum type washing machine 100 configured as above, the user first presses the power switch 4, which starts the drum type washing machine 100.

Then, the user pulls the door opening handle 2a to open the door 2 and place the clothes into the rotating drum 21. After closing the door 2, the user operates the operation switch 5 to start operation.

When operation begins, the rotating drum 21 rotates to calculate the laundry volume before water is poured in. The laundry volume is calculated based on the rotation speed and current value of the electric motor 22. At this time, the greater the laundry volume, the greater the load on the electric motor 22, and therefore the greater the current value, so the laundry volume is determined from the current value. Then, the amount of detergent to be added is displayed on the display 6 based on the laundry volume. At this time, the greater the calculated laundry volume, the greater the amount of detergent to be added. The user checks the display 6, pours a specified amount of detergent into the detergent container 12, and starts the washing process.

In the washing process, the water supply valve 32 is opened, and water supplied from the water supply hose connection port 30 is supplied into the outer tub 11 together with detergent via the internal water supply hose 31 and detergent container 12. At this time, the greater the calculated volume of clothes, the greater the amount of water supplied in the washing process. Furthermore, undissolved detergent and water are agitated in the circulation pump 20. This efficiently dissolves the detergent and produces a highly concentrated detergent solution. After this operation is performed for a predetermined time, a washing operation is performed for a predetermined time in which the rotating drum 21 is rotated forward, stopped, reversed, and stopped repeatedly. At this time, the clothes are lifted by the baffle 23 and dropped repeatedly, thereby washing the clothes.

After the washing process, the spin-drying process is performed. The spin-drying process will be described with reference to FIG. 3. FIG. 3 shows the control pattern of the rotation speed of the rotating drum 21 in the spin-drying process. First, by opening the drain valve 15a after the washing process is completed, the water in the outer tub 11 is drained to the outside (outside the machine) of the drum-type washing machine 100 via the drain hose 14. In the spin-drying process, the rotation speed of the rotating drum 21 is increased to the target rotation speed range (t5-t6) while passing through a low rotation speed range (t1-t2) in which the clothes are spread and attached to the inner surface of the rotating drum 21, a resonance range (t2-t3) of the outer tub 11, a resonance range (t3-t4) of the housing 1, and a post-resonance range (t4-t5) of the housing 1, thereby centrifugally spinning off the moisture contained in the clothes.

In the low-speed rotation range, the rotation speed of the rotating drum 21 is increased to ω ₀ (e.g., 50 r/min). At this time, clothes that have absorbed moisture during the washing process are lifted by the baffle 23 as the rotating drum 21 rotates, and as the clothes fall, they are spread out on the inner circumferential surface of the rotating drum 21. When the rotation speed of the rotating drum 21 reaches ω ₀ , the rotating drum 21 is operated at ω ₀ for a time T1 (e.g., 10 seconds) in order to detect the uneven distribution of the clothes at ω ₀ .

Detection of uneven distribution of clothes in the low rotation speed range is determined based on the magnitude of rotation fluctuation. The rotation fluctuation is calculated, for example, from the difference between the speed at which clothes are lifted from the bottom of the rotating drum 21 to the top (minimum speed) and the speed at which clothes are lowered from the top of the rotating drum 21 to the bottom (maximum speed) when the rotating drum 21 makes one rotation. The smaller the rotation fluctuation, the less uneven distribution of clothes can be confirmed. When it is determined that the rotation fluctuation is equal to or less than a preset threshold value in detecting uneven distribution of clothes at _ω0 , the rotation speed of the rotating drum 21 is increased from _ω0 to _ω1 (e.g., 80 r/min).

When the rotation speed of the rotating drum 21 reaches _ω1 , it is operated at _ω1 for a time T2 (e.g., 5 seconds) to detect uneven distribution of the clothes. Note that _ω0 and _ω1 are rotation speeds for detecting the degree of adhesion of the clothes, with _ω0 being the rotation speed at which the clothes start to adhere to the inner circumferential surface of the rotating drum 21 and _ω1 being the rotation speed at which the clothes completely adhere to the inner circumferential surface of the rotating drum 21.

After operating at _ω1 for a predetermined time, if it is determined that the rotational fluctuation is equal to or less than a preset threshold value in the uneven distribution of clothes detection at _ω1 , the rotation speed of the rotating drum 21 is increased to _ω2 (e.g., 400 r/min) to pass through the resonance zone of the outer tub 11. If the vibration amplitude of the outer tub 11 is smaller than a predetermined value when passing through the resonance zone of the outer tub 11, the rotation speed of the rotating drum 21 is increased to _ω3 (e.g., 600 r/min) to pass through the resonance zone of the housing 1.

When passing through the resonance zone of the housing 1, if the vibration amplitude of the outer tub 11 is smaller than a predetermined value, the rotation speed of the rotating drum 21 is increased to a target (e.g., 900 r/min). In the target rotation speed zone, the rotating drum 21 is operated for a predetermined time at T3 (e.g., 180 seconds), and then the rotation speed of the rotating drum 21 is decreased to 0 r/min (t6 to t7) to end the dehydration process.

If the clothes stuck to the inner surface of the rotating drum 21 during the dehydration process are unevenly distributed, the rotational fluctuations of the rotating drum 21 and the vibration amplitude of the outer tub 11 will exceed a threshold value. Therefore, the rotation speed of the rotating drum 21 will be reduced or the rotation of the rotating drum 21 will be stopped, and an operation will be performed to correct the uneven distribution of the clothes by repeating forward and reverse rotation of the rotating drum 21 to loosen the clothes or by injecting water.

Next, after the spin cycle, the rinsing cycle is performed. In this rinsing cycle, the water supply valve 32 is opened and tap water supplied from the water supply hose connection port 30 is supplied into the outer tub 11 via the water supply hose 31 and detergent container 12. As with the washing cycle, the greater the calculated laundry volume, the greater the amount of water supplied. In this rinsing cycle, as with the washing cycle, the rotating drum 21 repeatedly rotates forward, stops, reverses, and stops. At this time, an agitation operation is performed for a predetermined period of time, in which the clothes lifted by the baffle 23 fall.

Then, the above-mentioned spin-drying process and rinsing process are repeated a predetermined number of times, and the machine moves to the final spin-drying process. The operating time in the target rotation speed range for this final spin-drying process is set longer than that for the spin-drying process (e.g., 300 seconds).

In this way, during the spin-drying process, the vibration of the drum-type washing machine 100 changes across multiple resonance regions depending on the rotation speed and the uneven distribution of clothes. Figure 4 shows the changes in the rotation speed of the rotating drum 21 and the vibration phase in each direction (up and down, left and right, front and back) in the resonance range of the outer tub (e.g., 100 r/min to 400 r/min).

Here, (1) vertical vibration means vibration in the direction of gravity in a plan view with the door 2 facing forward when the drum washing machine is installed on the installation floor of a house, (2) left-right vibration means vibration in a direction perpendicular to the direction of gravity in a plan view with the door 2 facing forward, and (3) front-rear vibration means vibration in the direction in which the rotation axis Az (see Figure 2) of the rotating drum 21 extends, and also in the direction around the center of gravity. In addition, the reference for the vibration phase is "0°" when the clothes are biased to the far right of the outer tub 11 (the right part that intersects with the X-X dividing line in Figure 5).

In Figure 4, as the rotation speed of the rotating drum 21 increases, the vibration phase in each direction shifts, and the vibration mode of the outer tub 11 changes. The vibration phase in the front-to-rear direction shifts from an initial phase of 0° to approximately 90° when the outer tub 11 resonates (shown as resonant rotation speed Nrm), and then shifts from the initial phase of 0° to 180° as the rotation speed of the rotating drum 21 increases. Note that due to spring components such as the suspension means 8 for supporting the posture of the outer tub 11, the rotation speed at which the vertical vibration phase resonates is higher than that of the horizontal vibration phase. Furthermore, as the rotation speed of the rotating drum 21 increases, resonance in the front-to-rear direction occurs due to the swinging motion of the outer tub 11.

Figure 5 shows the vibration trajectory when the outer tub 11 is viewed from the front (clothing opening side) when a resonant mode of vibration in the front-to-rear direction occurs, and similarly Figure 6 shows the vibration trajectory when the outer tub 11 is viewed obliquely. Here, for convenience of explanation in Figure 5, the clothing opening 11op is virtually divided into four areas, the "upper right area", "lower right area", "upper left area", and "lower left area", by a Y-Y dividing line in the vertical direction (gravity direction) that passes through the center C of the clothing opening 11op, and an X-X dividing line that is perpendicular to this and passes through the center C in the horizontal direction. Note that the clothing opening 11op is shown without showing related parts such as the bellows 16.

At the rotation speed Nrm (see Figure 4) at which the outer tub 11 experiences a resonant mode of vibration in the front-to-rear direction, the phase difference between the left-to-right and up-to-down vibration phases of the outer tub 11 is significantly smaller than 90°; for example, in Figure 4, the phase difference is approximately 25°. Therefore, when the rotating drum 21 performs a spin-dry operation in the forward direction (left rotation), the outer tub 11 vibrates along an elliptical vibration locus that slopes upward to the right, spanning from the lower left region to the upper right region when viewed from the front of the clothing insertion opening 11op of the outer tub 11.

Thus, it was found that the upper right and lower left areas of the outer tub 11 were subjected to large swinging vibrations.
In the resonance mode of vibration in the front-to-rear direction of the outer tub 11, the upper right part of the upper right region and the lower left part of the lower left region at the front end side (the side where the clothes insertion opening 11op is formed) of the outer tub 11 oscillate widely back and forth, as shown in Fig. 6. On the other hand, when the rotating drum 21 performs a spin-drying operation in the reverse direction (clockwise rotation), the upper left part of the upper left region and the lower right part of the lower right region at the front end side of the outer tub 11 oscillate widely.

In other words, in the resonance mode of the vibration in the front-to-back direction of the outer tub 11, when the rotating drum 21 rotates in the forward direction, the upper right and lower left parts vibrate back and forth in a large oscillating vibration, and when the rotating drum 21 rotates in the reverse direction, the upper left and lower right parts vibrate back and forth in a large oscillating vibration. This oscillating motion leads to an increase in the vibration transmitted to the housing and the floor on which the drum washing machine is installed.

Therefore, this embodiment proposes a vibration damper arrangement that suppresses this swaying vibration. Although a friction damper is used as the vibration damper, an oil damper filled with oil may also be used, and various other dampers may also be used as required.

Figures 7A and 7B show the arrangement of vibration dampers 24 (four dampers used) that suppress vertical and horizontal vibrations, including swaying vibrations, of the outer tub 11. Here, Figure 7A shows the configuration as seen from the side of the clothes insertion opening 11op on the front of the outer tub 11, and Figure 7B shows the configuration as seen from the side of the outer tub 11. Also, Figure 7A shows the Y-Y dividing line in the vertical direction and the X-X dividing line perpendicular to this in the horizontal direction, just like Figure 5. Note that the following will explain the case where the rotating drum 21 is rotated in the forward direction.

In Figures 7A and 7B, two

vibration dampers

24a, 24b are provided in the front-to-rear direction of the outer tub 11 along the axis of the outer tub 11 (corresponding to the rotation axis Az) in the lower right part of the lower right region of the outer tub 11. The outer tub 11 can be divided into a front region and a rear region in the axial direction, with the center line Cc of the outer tub 11 shown in Figure 7B as the boundary. The right front vibration damper 24a is attached to the front region of the outer tub 11, and similarly the right rear vibration damper 24b is attached to the rear region of the outer tub 11.

The

vibration dampers

24a, 24b are attached in the same manner to the attachment parts (outer tank side attachment parts) 11a, 11b of the

vibration dampers

24a, 24b to the outer tank 11, and to the attachment parts (casing side attachment parts) 1a, 1b of the

vibration dampers

24a, 24b to the housing 1. In other words, the

vibration dampers

24a, 24b are attached in a state where they can oscillate mainly in response to vibrations in the left-right and up-down directions.

Specifically, the mounting

parts

11a, 11b of the outer tub 11 and the mounting

parts

1a, 1b of the housing 1 are provided with a pair of flanges extending in a direction perpendicular to the axis of the outer tub 11, which sandwich both ends of the

vibration dampers

24a, 24b. Both ends of the

vibration dampers

24a, 24b are sandwiched between the pair of flanges and fixed in place by inserting bolts.

This allows the

vibration dampers

24a, 24b to swing about the bolt in response to vibrations on a plane perpendicular to the axis of the outer tub 11. The mounting angle of the right front vibration damper 24a relative to the horizontal is "θa", and the mounting angle of the right rear vibration damper 24b is "θb", with the relationship set to "θa < θb". These mounting angles are appropriately selected depending on the direction and magnitude of the vibrations, mainly in the left-right and up-down directions.

Similarly, in Figures 7A and 7B, two

vibration dampers

24c, 24d are provided in the front-rear direction along the axis of the outer tub 11 (corresponding to the rotation axis Az) in the lower left part of the lower left region of the outer tub 11. As shown in Figure 7B, the left rear vibration damper 24c is attached to the rear region of the outer tub 11, and the left front vibration damper 24d is attached to the front region of the outer tub 11, with the center line Cc of the outer tub 11 as the boundary in the axial direction.

The mounting portion (outer tank side mounting portion) 11c of the left rear vibration damper 24c to the outer tank 11 and the mounting portion (casing side mounting portion) 1c of the left rear vibration damper 24c to the housing 1 are attached in the same manner as the

vibration dampers

24a and 24b described above. In other words, the left rear vibration damper 24c is attached in a state where it can oscillate mainly in response to vibrations in the left-right and up-down directions.

Specifically, the mounting part 11c of the outer tub 11 and the mounting part 1c of the housing 1 are provided with a pair of flanges extending in a direction perpendicular to the axis of the outer tub 11, which sandwich both ends of the vibration damper 24c. Both ends of the left rear vibration damper 24c are sandwiched between the pair of flanges and fixed in place by inserting bolts.

This allows the vibration damper 24c to swing around the bolt in response to vibrations on a plane perpendicular to the axis of the outer tub 11. The mounting angle of the left rear vibration damper 24c is "θc", and is set to a relationship of "θa < θb < θc". These angles are appropriately selected depending on the direction and magnitude of the vibrations, mainly in the left-right and up-down directions.

Next, the left front vibration damper 24d is attached with its mounting direction rotated 90° relative to the left rear vibration damper 24c. In other words, the mounting portion (outer tub side mounting portion) 11d of the left front vibration damper 24d to the outer tub 11 and the mounting portion (casing side mounting portion) 1d of the left front vibration damper 24d to the housing 1 are attached in a state rotated 90° relative to the mounting portions 11a-11c on the outer tub 11 side of the vibration dampers 24a-24c described above, and the mounting portions 1a-1c on the housing 1 side. In other words, the left front vibration damper 24d is attached in a state where it can swing mainly in response to swinging vibrations in the front-to-rear direction.

Specifically, the mounting part 11d of the outer tub 11 and the mounting part 1d of the housing 1 are provided with a pair of flanges extending in the axial direction of the outer tub 11 that sandwich both ends of the vibration damper 24d. Both ends of the vibration damper 24d are sandwiched between the pair of flanges and fixed by inserting a bolt. This allows the left front vibration damper 24d to swing around the bolt in response to the swaying vibration on a plane along the axis of the outer tub 11.

Here, the mounting portion 11d on the outer tub 11 side and the mounting portion 1d on the housing 1 side are positioned as follows. As shown in FIG. 7B, the mounting portion 11d of the outer tub 11 is positioned closer to the clothing insertion opening 11op in the front area of the outer tub 11, and the mounting portion 1d of the housing 1 is positioned farther away from the clothing insertion opening 11op of the outer tub 11 than the mounting portion 11d. At this time, the mounting angle of the left front vibration damper 24d is "θd", and this angle is appropriately selected depending on the direction and magnitude of the vibration in the front-rear direction.

As explained in Figures 5 and 6, in the resonance mode of the outer tub 11's forward/rearward vibration, the upper right and lower left parts of the outer tub 11 swing and vibrate greatly. Therefore, the left front vibration damper 24d, which is inclined in the forward/rearward direction along the axis of the outer tub 11, can provide sufficient damping force to the swinging motion of the outer tub 11 and suppress forward/rearward vibration by being placed at the lower left rather than the lower right of the outer tub 11.

Next, we will explain the effect of vibration transmission to the installation floor due to the arrangement of the vibration dampers 24a to 24d shown in Figures 7A and 7B. Note that the damping performance of the vibration dampers 24a to 24d is the same regardless of the arrangement position.

As shown in Figure 3, at rotation speeds higher than the resonance range of the outer tub 11, the resonance range of the housing 1 (e.g., 450 r/min) exists, so the force transmitted to the installation floor increases, and then as the rotation speed increases, the force transmitted to the installation floor decreases and the vibration converges. In the high rotation speed range, the vibration of the outer tub 11 tends to converge to a constant value regardless of the arrangement of the vibration dampers 24a to 24d. For this reason, the vibration transmitted from the outer tub 11 to the installation floor depends on the damping performance of the vibration dampers 24a to 24d24, and converges to the same value regardless of the arrangement of the vibration dampers 24a to 24d.

Therefore, by using the arrangement of the vibration dampers 24a to 24d2 described in this embodiment, vibrations in the front-back direction as well as the up-down and left-right directions of the outer tank 11 can be effectively suppressed, and vibrations transmitted to the installation floor can also be effectively suppressed.

Next, the positioning of the left front vibration damper 24d, which is inclined in the front-rear direction along the axis of the outer tub 11, will be described. In this embodiment, since the electric motor 22 is provided at the rear of the outer tub 11, the center of gravity 11g is described as being located at the rear of the center line Cc of the outer tub 11. Generally, the electric motor 22 is located on the opposite side of the clothes insertion opening 11op of the outer tub 11, as shown in FIG. 2.

The oscillating vibration of the outer tub 11 is greater at positions farther away from the center of gravity 11g (closer to the clothing insertion opening), so the oscillating vibration is greater at the front than at the rear of the outer tub 11. Furthermore, when the clothes are biased towards the front of the rotating drum 21 (closer to the clothing insertion opening), the moment arm with respect to the center of rotation of the oscillating vibration is larger and the oscillating vibration is greater than when the clothes are biased towards the rear (closer to the electric motor) under the same conditions, so it is better to attach the attachment part 11d to the outer tub 11 at the front (closer to the clothing insertion opening).

Figures 8A and 8B show the relative positions of the outer tub 11 and the left front vibration damper 24d. We will explain the cases where the attachment part 11d is closer to the clothes insertion opening 11op relative to the center of gravity 11g of the outer tub 11, the cases where the attachment part 11d is closer to the center of gravity 11g of the outer tub 11, and the cases where it is located nearby.

As shown in FIG. 8A, when the mounting part 11d is provided close to the clothing insertion opening 11op, the stroke dx of the left front vibration damper 24d increases according to the magnitude of the oscillating vibration of the outer tub 11, and the damping performance is exerted, so that the oscillating vibration of the outer tub 11 can be effectively suppressed.

On the other hand, as shown in Figure 8B, when the mounting part 11d is provided closer to the center of gravity position 11g, not only is the stroke dx smaller than in Figure 8A, but the left front vibration damper 24d rotates around the mounting part 1d of the housing 1, making it difficult to provide a damping force against the oscillating motion of the outer tub 11, and therefore it is not possible to provide sufficient damping performance compared to the arrangement position in Figure 8A. Of course, it is also possible to suppress the oscillating motion in Figure 8B, so this is merely a relative comparison.

In this way, the mounting portion 11d of the left front vibration damper 24d can be more effectively suppressed by locating it as close as possible to the clothing insertion opening 11op. In this embodiment, the mounting portion 11d of the left front vibration damper 24d is located between near the center of the front area of the outer tub 11 and the clothing insertion opening 11op of the outer tub 11, but most preferably at the clothing insertion opening 11op.

If the left front vibration damper 24d is attached so that the mounting part 11d of the outer tub 11 is at the rear side of the outer tub 11 and the mounting part 1d of the housing 1 is at the front side of the outer tub 11, the left front vibration damper 24d will rotate mainly around the mounting connection part 11d, making it difficult to apply damping force to the oscillating movement. Therefore, it is preferable to attach the left front vibration damper 24d so that the mounting part 11d of the outer tub 11 is at the front side and the mounting part 1d of the housing 1 is at the rear side, as shown in Figures 8A and 8B.

Furthermore, if a configuration is adopted in which a weight is attached to the outer tub 11, the center of gravity 11g of the outer tub 11 may be located in front of the center line Cc of the outer tub 11. In this case, the left front vibration damper 24d shown in FIG. 7B is replaced with the left rear vibration damper 24c, and the left rear vibration damper 24c is replaced with the left front vibration damper 24d. In this case, the inclination direction of the left front vibration damper 24d is also reversed.

Next, we will explain the vibration dampers 24a to 24c that are installed with an inclination in the left-right direction as shown in Figure 7A.

In a plan view of the front of the clothing insertion opening 11op of the outer tub 11, the vibration dampers 24a to 24c are installed with inclinations at angles θa to θc in the left-right direction (the horizontal plane is 0°), which makes it possible to suppress vibrations caused by resonance mainly in the left-right and up-down directions.

Anti-vibration damper 24c is provided on the left side of outer tub 11, and

anti-vibration dampers

24a and 24b are provided on the right side, and are configured to support outer tub 11. As mentioned above, the lower left region of outer tub 11 vibrates more than the lower right region, so it is desirable to make the damping force of anti-vibration damper 24 stronger on the lower left side than on the lower right side.

As explained in Figure 5, when the outer tub 11 is near the rotation speed of the front-to-rear resonance mode, it oscillates along an elliptical vibration locus that slopes upward to the right, so that on the right side of the Y-Y dividing line of the outer tub 11, the vertical vibration is greater than the left-to-right vibration. Therefore, if either one of the attitude angles θa and θb of the

anti-vibration dampers

24a and 24b, which are located on the right side of the Y-Y dividing line of the outer tub 11, is tilted by 45° or more, the vertical vibration can be further suppressed.

The above-described arrangement of the vibration dampers 24 is an example and should not be considered limiting. For example, the front left vibration damper 24d inclined in the front-to-rear direction may be provided with multiple vibration dampers 24d rather than a single one. In addition, the rear left vibration damper 24c may also be installed with an incline in the front-to-rear direction to increase the damping force of vibration in the front-to-rear direction, resulting in a configuration that further suppresses swaying vibration.

In the above embodiment, an example was described in which the rotating drum 21 rotates forward (left), but if the drum 21 rotates in the reverse direction (right), the left-right relationship should be reversed with respect to the arrangement of the vibration dampers in this embodiment, and the left front vibration damper 24d, which suppresses vibrations in the front-to-rear direction, should be placed in the lower right area.

The present invention is not limited to the above-mentioned embodiments, but includes various modified examples. The above-mentioned embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those having all of the configurations described. In addition, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to add, delete, or replace other configurations with respect to the configuration of each embodiment.

1...Housing, 1a-1d...Mounting parts of the housing and the vibration damper, 11...Outer tub, 11a-11d...Mounting parts of the outer tub and the vibration damper, 11op...Clothes insertion opening of the outer tub, 21...Rotary drum, 24a-24d...Vibration damper, 100...Drum-type washing machine

Claims

A drum-type washing machine including a housing, an outer tub supported within the housing and capable of storing wash water therein, a rotary drum contained within the outer tub and rotated by an electric motor, and a plurality of vibration dampers connecting a lower portion of the outer tub to a bottom of the housing,
When the drum-type washing machine is installed on an installation floor and the clothes insertion opening of the outer tub is viewed from the front in a plan view, a gravity direction dividing line passing through the center of the clothes insertion opening is virtually set. At least one of the plurality of vibration dampers is
When the rotation direction of the rotating drum during the dehydration operation is counterclockwise, the rotating drum is installed in the area to the left of the dividing line, and when the rotation direction of the rotating drum during the dehydration operation is clockwise, the rotating drum is installed in the area to the right of the dividing line,
Further, the drum-type washing machine is characterized in that an outer-tub side mounting portion between the one vibration damper and the outer tub is positioned closer to the clothing insertion opening when viewed in the axial direction of the outer tub, and a housing side mounting portion between the one vibration damper and the housing is positioned farther from the clothing insertion opening than the outer-tub side mounting portion when viewed in the axial direction of the outer tub.
The drum type washing machine according to claim 1,
A drum-type washing machine, characterized in that, when viewed in the axial direction of the outer tub, the housing-side mounting portion is arranged closer to the center of gravity of the outer tub than the outer tub-side mounting portion.
The drum type washing machine according to claim 1 or 2,
Another vibration damper different from the one vibration damper is installed in an area to the right of the dividing line when the rotation direction of the rotating drum during a dehydration operation is counterclockwise, and is installed in an area to the left of the dividing line when the rotation direction of the rotating drum during a dehydration operation is clockwise,
Furthermore, the other vibration damper is installed between the outer tub side mounting portion with the outer tub and the housing side mounting portion with the housing in a direction perpendicular to the axial direction of the outer tub, and the mounting angle is set to 45° or more.
A drum-type washing machine including a housing, an outer tub supported within the housing and capable of storing wash water therein, a rotary drum contained within the outer tub and rotated by an electric motor, and four vibration dampers connecting a lower portion of the outer tub to a bottom of the housing,
When the drum type washing machine is installed on an installation floor and the clothes insertion opening of the outer tub is viewed from the front in a plan view, a division line in the gravity direction passing through the center of the clothes insertion opening is virtually set,
The four vibration dampers are arranged such that a first vibration damper and a second vibration damper are arranged along the axial direction of the outer tub in the area on the right side of the dividing line, and a third vibration damper and a fourth vibration damper are arranged along the axial direction of the outer tub in the area on the left side of the dividing line, and the first vibration damper and the fourth vibration damper are arranged close to the clothes insertion opening,
When the rotation direction of the rotating drum during the dehydration operation is counterclockwise, an outer-tub side mounting portion between the fourth vibration damper and the outer tub is disposed closer to the clothing insertion opening when viewed in the axial direction of the outer tub, and a housing side mounting portion between the fourth vibration damper and the housing is disposed farther from the clothing insertion opening than the outer-tub side mounting portion when viewed in the axial direction of the outer tub.
the first vibration damper, the second vibration damper, and the third vibration damper are installed between the outer tank side mounting portion with the outer tank and the housing side mounting portion with the housing in a direction perpendicular to the axial direction of the outer tank,
When the rotation direction of the rotating drum during the dehydration operation is clockwise, an outer-tub side mounting portion between the first vibration damper and the outer tub is disposed closer to the clothing insertion opening when viewed in the axial direction of the outer tub, and a housing side mounting portion between the first vibration damper and the housing is disposed farther away from the clothing insertion opening than the outer-tub side mounting portion when viewed in the axial direction of the outer tub.
The second vibration damper, the third vibration damper, and the fourth vibration damper are installed between the outer tank side mounting portion of the outer tank and the housing side mounting portion of the housing in a direction perpendicular to the axial direction of the outer tank.
A drum type washing machine characterized by the above.
The drum type washing machine according to claim 4,
A drum-type washing machine characterized in that, when the rotating drum rotates counterclockwise, the mounting angles of the first vibration damper, the second vibration damper, and the third vibration damper based on the direction perpendicular to the dividing line are each different.