KR101130785B1 - A magnet friction damper for a drum type washing machine - Google Patents

Abstract

PURPOSE: A magnet friction damper for a drum washing machine is provided to offer excellent damper control efficiency by reducing an impact phenomenon through an electromagnetic force. CONSTITUTION: A first and a second solenoid are respectively installed at the inside of a cylinder. A first or a third core(161-163) are respectively arranged at the bottom of the first solenoid, between the first and the second solenoid, and the upper side of the second solenoid. A first or a third metal bearings(171-173) are arranged between the outer circumference of the first core and the inner circumference of the third core. An elastic member is installed between the cylinder and a load unit.

Description

Magnet friction damper for drum washing machine {A Magnet Friction Damper for a drum type washing machine}

The present invention relates to a damper for effectively reducing vibration and shock generated during the rotational operation of a drum washing machine. Compared with a damper filled with a conventional magnetic fluid, the structure is simple, excellent in assembly, and improved in durability. Magnet friction damper.

There are many types of washing machines, but recently, the demand for a drum washing machine having excellent noise characteristics and excellent laundry entanglement or washing effect is increasing.

In such a drum washing machine, a rotating drum rotates about a horizontal axis, and an irregular shock or vibration is applied to a tub located outside the drum due to the contents being slid to one side during an initial operation or a mode switching process.

Noise and vibration due to the rotational imbalance of the laundry causes a lot of inconvenience to the neighbors living in the same apartment house, especially the noise and vibration is amplified at night.

In order to prevent the vibration impact of the drum washing machine and the noise thereof, the conventional drum washing machine prevents this by installing various types of dampers under the tub in which the drum is embedded. Such a drum washing machine damper is a hydraulic damper or friction. Dampers are mainly adopted and used.

In Patent No. 10-1048092, "Damp Washer Damper" (2011.07.08), the rubber inside the guide member 8 sliding up and down by the rod member 4 reciprocating inside the damper housing 2 Disclosed is a damper structure for a drum washing machine which provides a friction damping force to the rod member 4 by a frictional force by providing a frictional member 6 made of felt.

In Patent No. 10-0479108, "Damper Assembly of Drum Washing Machine" (2005.03.29), when a shock is applied in a direction different from the axial direction of the cylinder 52 and the piston 54, the piston and the cylinder collide with each other, causing vibration or noise. The shock absorbing member 60 is provided below the damping members 58 and 59, which are spaced apart on the outer circumferential surface of the piston so as to prevent occurrence thereof.

In Patent No. 10-0517610, "Damper assembly of a drum washing machine" (September 28, 2005), a coil 78 is formed on the outer peripheral surface of the upper end of the piston 64 reciprocating inside the cylinder 62, and on the outer diameter side thereof. Disclosed is a structure in which the damping pad is attached to the movable member 74 to be slidably mounted, and the first and second permanent magnets are provided on opposite surfaces of the movable member and the piston. Such a patent regulates the repulsive force by not supplying current to the coil when the axial displacement of the moving member is smaller than the predetermined interval, and when the interval is greater than the set interval, by supplying a current higher than the set value to the coil to repulse between permanent magnets. To increase the damping force.

Patent No. 10-0732151 "Pallet Valve Separation MAL Damper for Self-Securing" (2007.06.25) relates to a damper that can obtain damping force by increasing the apparent viscosity of the magnetic fluid by using the magnetic fluid and the solenoid coil. In particular, in order to solve a problem in which a narrow portion of magnetic flux is generated by a piston band formed on an outer circumferential surface of a conventional flux ring, the structure of a piston valve separate type MAL damper is installed on a hollow rod located on an upper side of a piston valve. It is about.

These conventional techniques are common in that damping force is provided by using a damping member made of a felt or rubber material with strong friction force on the outer circumferential surface of the rod or piston reciprocating, and the material is deformed in the damping member by repeated friction force and temperature rise. There is a disadvantage that the risk of damage is high.

In addition, in the case of Patent No. 10-0517610, which simultaneously uses a friction member and a permanent magnet, a physical damping pad is basically employed as a main damping means, and there is a problem that it is not easy to precisely control the repulsive force applied to the permanent magnet. .

The MR damper using magnetic fluid is easy to control in that it controls the damping force of the hollow rod by controlling the magnetic flux density of the magnetic force line using magnetic fluid and solenoid coil, but the compression chamber and the tension chamber of the cylinder tube are easy to control. There is a problem that the manufacturing cost is too expensive in that the expensive magnetic fluid fluid is driven in a full state, and the internal structure is somewhat complicated.

As a supplement to the problems of the prior arts, a magnetic fluid fluid friction damper having a solenoid disposed inside the cylinder and filling a magnetic fluid between the cylinder rod and the solenoid has been proposed.

FIG. 7 is a partial longitudinal cross-sectional view of a conventional magnetic fluid fluid friction damper 10, in which a pair of solenoids 21 and 22 are disposed inside a cylinder 11, and a metal core (upper and lower side of each solenoid) is disposed. 17a, 17b, and 17c are disposed, and the magnetic fluid 23 is filled in the space between the solenoids 21 and 22 and the outer circumferential surface of the rod 12.

This conventional magnetic fluid fluid friction damper 10 has an advantage in that it can be easily controlled by varying the friction viscosity of the fluid shock of the magnitude exceeding the damping force of the spring, but the magnetic fluid fluid filled therein as shown In order to prevent the leakage and to maintain the airtight a plurality of O-ring 15, the oil seal 16 and the rod guides (13a, 13b) must be assembled, there was a disadvantage in that the assembly is poor. In addition, since the O-ring sheet for coupling the O-ring 15 must be separately grooved in the cores 17a, 17b, and 17c, processing costs increase and disadvantageously, the structure is unfavorable to integrally produce each component.

In particular, the conventional magnetic fluid fluid friction damper 10 has to fill the magnetic fluid in the gap between the solenoid (21, 22) and the rod 12, the filling process is not so simple, a separate injection device for the filling is required Moreover, there was a problem that it is not easy to accurately fill the quantification.

Therefore, it is possible to alleviate the shock transmitted to the damper by using the magnetic flux density caused by the electromagnetic force, but by simplifying the overall structure and reducing the assembly process or manufacturing cost by eliminating the use of the magnetic fluid which complicates the sealing or sealing structure. Development of a friction damper in a structure has been called for.

Registered Patent No. 10-1048092 "Damp Washer Damper" (2011.07.08) Patent No. 10-0479108 "Damper Assembly of Drum Washing Machine" (2005.03.29) Patent No. 10-0517610 "Damper Assembly of Drum Washing Machine" (2005.09.28) Registered Patent No. 10-0732151 "Pallet Valve Separated MR Damper for Securing Self" (2007.06.25)

In the present invention, by omitting the magnetic fluid fluid used in the conventional fluid friction damper structure, instead of applying a plurality of metal bearings in combination with the core, the damping efficiency is maintained as it is, while maintaining a complex sealing structure to prevent leakage of fluid. It is aimed at eliminating and thus improving the assembly and durability of the product.

In order to solve the above technical problem, in the present invention, in order to reduce the vibration and noise generated in the drum washing machine, the cylinder is mounted between the drum tub and the inner wall of the washing machine cabinet, the cylinder having a hollow inside, and one end of the cylinder First and second spaced up and down spaced inside the cylinder consisting of a rod drawn into the interior and the other end extending to the outside of the cylinder, a bobbin penetrated by the central portion and a solenoid coil wound around the bobbin many times. A solenoid, first to third cores disposed between the lower end of the first solenoid and the first and second solenoids and the upper end of the second solenoid, respectively, the outer circumferential surface of the rod and the first to third cores First to third metal bearings mounted between the inner circumferential surface of the, and comprises a spring mounted between the cylinder and the rod Proposes a drum magnetic friction damper for washing machines, characterized in that the.

Here, it is preferable to form a heat dissipation grease layer in the gap between the bobbin and the outer circumferential surface of the rod.

On the other hand, the lower end of the first core and the upper end of the third core to be provided with a rod guide fixedly coupled to the inner diameter of the cylinder, and an oilless bearing mounted between the inner peripheral surface of the rod guide and the outer peripheral surface of the rod, respectively Can be.

According to the present invention, the spring mounted between the cylinder and the rod firstly alleviates the shock transmitted from the rotating drum, and the damping control efficiency is excellent because the secondary shock is alleviated by the electromagnetic force generated by the solenoid, the core and the metal bearing combination. Do.

In particular, unlike a friction damper using a magnetic fluid, it is economical because it does not use expensive magnetic fluids, and it is easy to assemble since the leakage preventing structures such as various O-rings and oil seals required for the use of magnetic fluids are unnecessary. This has the advantage of being improved and durable.

1 is a side view showing the appearance of the present invention.
Figure 2 is a longitudinal cross-sectional view of Figure 1 according to an embodiment of the present invention.
Figure 3 is a longitudinal sectional view of Figure 1 according to another embodiment of the present invention.
Figure 4 is a longitudinal sectional view of the solenoid, core and metal bearing combination of the present invention.
Figure 5 is a graph showing the magnetic force lines and magnetic flux density generated inside the damper of the present invention.
Figure 6 is a graph showing the change in magnetic flux density according to the metal bearing material of the present invention.
7 is a partial longitudinal cross-sectional view of a conventional magnetic fluid fluid friction damper.

Hereinafter, with reference to the accompanying drawings, the configuration and operation principle of the present invention will be described in detail. Figure 1 is a side view showing the appearance of the present invention, Figure 2 is a longitudinal sectional view of Figure 1 according to an embodiment of the present invention.

As shown, the magnet friction damper 100 for a drum washing machine of the present invention (hereinafter, simply referred to as a magnet friction damper for convenience of description) has a cylinder 110 in which a hollow space is provided and an inside of the cylinder 110. It includes a rod 120 for reciprocating linear motion in the hollow space of the spring and the spring 140 to give an elastic force during the reciprocating motion of the rod 120.

The cylinder 110 is a hollow cylindrical cylinder, the air vent hole (110a) is formed on the outer circumferential surface and the stroke chamber (110b) for the reciprocating linear motion of the rod 120 is provided in the hollow portion therein.

Magnet friction damper 100 of the present invention is installed in the drum washing machine in a state as shown, specifically, the upper end is a hinge joint not shown in the tub (tub) including a drum (not shown) of the washing machine therein The lower end is coupled to the inner bottom surface of the outer housing of the washing machine by a hinge joint.

To this end, end bolts 121 and 111 are formed at the ends of the rod 120 and the cylinder 110 to be coupled to the hinge joints, respectively.

The rod 120 is a kind of piston that linearly reciprocates up and down in the stroke chamber 110b inside the cylinder 110 and has a rod shape having a circular cross section, and a snap ring 122 is mounted on an outer circumferential surface of the upper end.

An end bolt 121 for coupling with a hinge joint (not shown) is formed at a lower end of the rod 120, and a spring sheet locking jaw 123 protrudes from an outer circumferential surface thereof.

A coil spring 140 is mounted between the cylinder 110 and the rod 120 to absorb shock when the laundry is rotated. The spring 140 is mounted and supported on the spring sheet 141 supported by the spring seat catching jaw 123 of the rod 120.

When an unbalanced vibration occurs due to the rotation of the laundry inside the drum washing machine, the spring 140 primarily relieves the impact. That is, when an impact is transmitted to the tub surrounding the drum due to the rotation of the laundry, such an impact is transmitted to the cylinder 110 as it is, and the cylinder 110 descends by the transmitted shock, thereby reducing the elastic force of the spring 140. The vibration width is alleviated.

As shown in FIG. 4, a means for providing a vibration damping force separate from the spring 140 is provided inside the cylinder 110. Specifically, a pair of solenoid coils 151 and 152 and a plurality of agents are provided. First to third cores (or yokes 161, 162, 163) are provided inside the cylinder 110.

The solenoid coils 151 and 152 and the first to third cores 161, 162 and 163 form a coupling unit with the metal bearings 171 to 173, which will be described later, to provide frictional force due to electromagnetic force to the rod 120.

In the present invention, a combination of a solenoid coil and a bobbin is simply defined as a solenoid. A pair of solenoids are arranged spaced apart up and down on the inner diameter side of the cylinder 110, the first solenoid is composed of a bobbin 151a located below and a solenoid coil 151 wound a plurality of times on the bobbin 151. The second solenoid includes a bobbin 152a positioned at an upper portion and a solenoid coil 152 wound a plurality of times on the bobbin 152a.

The first core 161 is disposed at the lower end of the first solenoid, the second core 162 is disposed between the first and second solenoids, the third core 163 is the second It is placed on top of the solenoid.

Central portions of the first and second bobbins 151a and 152a are penetrated and open to allow the rod 120 to enter and exit. That is, when the rod 120 reciprocates up and down by an impact transmitted from the drum of the washing machine, the rod 120 passes through the center portions of the first and second bobbins 151a and 152a.

The inner circumferential surfaces of the first and second bobbins 151a and 152a and the outer circumferential surfaces of the rod 120 inserted into the inner diameters of the bobbins 151a and 152a preferably form a constant gap so as not to contact each other. In order to smoothly operate the metal bearings 171 to 173 which will be described later, it is preferable to form the heat dissipation grease layers 133a and 133b.

First to third metal bearings 171, 172, and 173 are provided between the first to third cores 161 to 163 and the outer circumferential surface of the rod 120 in descending order. Preferably, the upper and lower widths of the first to third metal bearings 171 to 173 are the same as those of the corresponding cores.

The metal bearings 171 to 173 are formed of an iron-based metal material as the electromagnetic force lines are formed by the first and second solenoid coils 151 and 152, and the magnetic flux density generated by the same current is closer to pure iron with less impurities. It is advantageous to increase.

In the present embodiment, the rod 120 is provided in the cylinder 110 more stably by providing separate rod guides 131 and 132 and oilless bearings 135a and 135b respectively above and below the solenoid, core and metal bearing combinations. It allows you to do linear motion.

However, the upper and lower rod guides 131 and 132 and the oilless bearings 135a and 135b are not necessarily required and may be omitted as shown in FIG. 3.

5 is a graph showing the magnetic force lines and the magnetic flux density generated inside the damper of the present invention. When current is applied to the first and second solenoid coils 151 and 152, electromagnetic force lines forming a closed loop are formed between the solenoid coils 151 and 152 and the adjacent cores 161 to 163 and the metal bearings 171 to 173 as shown. do.

As shown, when the rod 120 passes through the metal bearings 171 to 173 in the cylinder 110, the magnetic flux density is affected by the electromagnetic force lines, and the influence of the magnetic flux density causes frictional force on the rod 120. Will be provided.

That is, when the rod 120 tries to reciprocate into the cylinder 110 due to the vibration or shock transmitted to the cylinder 110 and the rod 120, the rod is affected by the friction effect due to the magnetic flux density applied to the rod 120. The vibration damping force is acted on 120).

When the impact force applied to the unit damper by the rotation of the laundry of the drum washing machine is usually in the range of about 50 to 150 N, the vibration corresponding to about 50 N only by the spring 140 in the normal rotation state where the impact by the unbalanced rotation of the laundry is small. When the impact force caused by the imbalance vibration caused by the load of the laundry or the vibration of the abnormal state during the initial rotation and the mode change exceeds the damping force limit 50N of the spring 140 It is desirable that the damping force due to the magnetic flux density is finally exhibited.

Figure 6 is a graph showing the change in magnetic flux density according to the material of the metal bearing of the present invention, the magnetic flux density measured by changing the material of the metal bearings (171 ~ 173) to the kinds of carbon steel S45C, S20C, S10C, STP It shows the size of.

As shown in the drawing, the magnetic flux density (B) is the most preferable when the material of the metal bearing is S10C with respect to the unit magnetic field strength (H).

The combination of the first and second solenoids, the first to third cores (161 to 163) and the first to third metal bearings (171 to 173) are integrally formed by a double injection method after manufacturing the respective components. In this case, the assembly process with the cylinder 110 is much more simplified.

As such, the present invention does not use expensive magnetic fluids at all. Instead, by applying an iron-based metal bearing, vibration or shock can be attenuated using friction damping force caused by electromagnetic field induction.

Therefore, there is an advantage that the components are simplified, the assembly is good and the durability is excellent, and as a result, the production cost of the product can be lowered.

According to the present invention, it is possible to reduce the production cost by eliminating the use of expensive magnetic fluid fluid and to introduce a metal bearing, and to improve the assembly and productivity due to the simplification of the component structure. In addition, it may need to be widely applied to the drum washing machine because it can effectively control the vibration or shock transmitted from the rotating drum by using a combination of the mechanical compression spring and the frictional force by the magnetic force line.

100: magnet friction damper 110: cylinder
110a: vent hall 110b: administrative office
120: rod 121: end bolt
122: snap ring 123: spring seat engaging jaw
131, 132: rod guides 133a, 133b: heat dissipation grease layer
135a, 135b: oilless bearing 140: spring
141: spring seat 151, 152: first and second solenoid coil
151a, 152a: first and second bobbins 161, 161, 163: first to third cores
171,172,173: first to third metal bearings

Claims (3)

It is mounted between the drum tub and the inner wall of the washing machine cabinet to reduce the vibration and noise generated in the drum washing machine,
A cylinder having a hollow portion therein, a rod having one end drawn into the cylinder and the other end extending outward of the cylinder, a bobbin with a central portion penetrated therein, and a solenoid coil wound multiple times on the bobbin; First and second solenoids spaced apart from each other and upper and lower, first to third cores disposed between the lower end of the first solenoid and the first and second solenoids and the upper end of the second solenoid, respectively; And first to third metal bearings mounted between the outer circumferential surface of the rod and the inner circumferential surface of the first to third cores, and a spring mounted between the cylinder and the rod. Damper. The method of claim 1,
A magnet friction damper for a drum washing machine, characterized in that a heat dissipation grease layer is formed in the gap between the bobbin and the outer circumferential surface of the rod. The method according to claim 1 or 2,
The lower end of the first core and the upper end of the third core is provided with a rod guide fixedly coupled to the inner diameter of the cylinder, and an oilless bearing mounted between the inner circumferential surface of the rod guide and the outer circumferential surface of the rod, respectively. Magnet friction damper for drum washing machine.

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