DE1806428A1 - Washing machine - Google Patents

Description

Patent attorneys

₉ ι-Η.01 «(Η.01βΗ) October 31, 1968

HITAOHI, LTD., Tokyo (Japan)

Washing machine

The invention relates to a drum washing machine, and in particular one in which the vibration of the laundry drum during and after the increase in speed of Wa- ^ see on spin is kept small by the fact that the motor is only switched to spin speed when the drum vibrations have been in the permissible range for a predetermined period of time

In the operation of a drum wasohma machine, which has a drum with a horizontal axis or an axis inclined to a predetermined extent and which works according to a program which loads the laundry into the drum, pouring the detergent solution into the drum, slowly rotating the drum for washing and rapid rotation includes at open drain valve to Sohleudern, the drum is looking at and after the increase in speed from slow to fast run very large oscillations similar conditions to maohen when the laundry is unevenly distributed in the drum ·

Such vibrations not only make noise, but also bring with them the danger that vibrating parts can strike on stationary parts, ζ · Β «the housing, are damaged. Therefore, when excessive vibrations occur, one cultivates several times in a row to interrupt the speed increase halfway, the speed to the original slow to decrease, to maintain this slow speed for a predetermined time and then to adjust it back to sole oar speed.

8i- (item 15.885) -Bgnto (O)

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gladly. With this method, however, the probability is that the laundry is in the drum during the rise Sole oar speed evenly distributed around the axis of rotation, so low that often an impermissibly high speed increase Vibration occurs and the transition to sole oar speed only succeeds after repeated increases and decreases in speed. Therefore, the transition from washing speed to sole oar speed can be made do not execute smoothly

It has also been proposed to suppress the generation of the vibrations by working on the one containing the drum Vat attached a large mass

This remedy is quite superficial and passive, because with him technical considerations are only directed towards how economic it is the resulting vibrations can be suppressed? the vibrations themselves, the uneven distribution the Wäsohe arise in the drum, are thereby as inevitable phenomenon accepted · Suppressing the resulting vibrations, however, is not a thorough solution to the problem This means rather to eliminate the cause of the vibrations · Provide an additional mass, this may now for being permanently appropriate or switching itself on and off automatically is, from the point of view of structural simplicity, the Strength and cost are not at all desirable.

The invention is based on the knowledge gained through experiments that the drum vibrations would be extremely small, if the water in the drum was evenly distributed around the rotating shaft of the drum when running slowly, and that the transition from slow running to high running speed would be possible smoothly and without unduly large vibrations, if this requirement is met when increasing the speed «

It is an object of the invention to prevent impermissibly large vibrations during and after the increase in speed from slow running to prevent slipping

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Another object of the invention is to provide a highly sensitive To create a sensor that indicates the right moment for the speed increase from slow to high speed.

Furthermore, the invention is to provide a washing machine which is built so that vibrations that occur when the speed increase Occasionally arise from slow to fast running, are effectively dampened.

Furthermore, it should provide a sensor that indicates the right time for the transition from slow to fast running " and that is cheap.

Further objects and advantages of the invention will become apparent from the following description in conjunction with the drawing. Show it"

Fig. 1 is a front view of a drum washing machine according to the invention, the front wall of which has been removed so that the interior of the machine can be seen;

2 shows a vertical section through the washing machine;

Fig. 3 is an electrical circuit diagram;

Fig. 4 is a diagram of the operations j g

Fig. 5 is a partial view of the vibration sensor;

Fig. 6 is a diagram showing the circuit of the control circuit of the machine;

7a is a partial view of another embodiment of the Vibration sensor;

7b shows an enlarged view of part of the vibration sensor according to FIG. 7a;

Fig. 8 is a diagram of another circuit of the control circuit ;

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180642a

Pig * 9 is a diagram showing the shape of the vibrations of the drum;

Fig. 10 a vibration characteristic diagram

As the drawing reveals, a box-shaped housing 1 is near the upper edge of its side wall inner surfaces provided with support rails 2 and each of these rails with two hemispherical depressions 3 «. In each of these wells is a sliding intermediate piece 5, which has a hemispherical-convex surface and carries a bolt 4 «This extends down through the support rail 2 and is screwed into a spring holder 6 at its lower end. On this is the top end of a helical tension spring? screwed, at the lower end of which a cylindrical tub 8 is anchored in such a way that it hangs freely

On the rear wall of the tub 8 is a storage cylinder 9 arranged, which is passed through an end wall 10 and attached to the tub and which carries two ball bearings in which a drum shaft 12 is mounted · At the inner end of this shaft is a washing drum 14 and on by means of a flange 13 A belt pulley 16 is attached to its outer end by means of a wedge 15.

The drum 14 has in its jacket a number of holes 17 through which the water exits during spinning, and on the inner surface of the shell a number of inwardly projecting plates 18 which are axially parallel through the drum extending bolts 19 are fastened in the drum »

The tub 8 has a front wall 20 which is attached to the tub by means of a seal 21 and in its center one Has an opening for throwing in the laundry · The edge of the opening is through a flexible rubber bellows 22 with the edge 23 of a laundry insertion opening formed in the front wall of the housing 1 24, which is closed by a door 25 made of transparent synthetic resin

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Arms 26 and 27 are welded to the bottom of tub 8, and motors 28 and 29 are attached to their lower ends the shaft 30 of the motor is connected by means of a Peder coupling 31 a large pulley 32 loosely attached; this is with a small pulley of the other motor 28 by one (not shown) V-belt connected «. The shaft 30 carries also a small pulley 33I firmly keyed onto it this is connected by means of a V-belt 34 to the above-mentioned belt pulley 16 fixed on the drum shaft.

The motor 28 is connected to a pump 35 through a belt 36 coupled; this pump is connected to the bottom of the tub 8 and is driven by the motor 28 during the washing process, to circulate the lye in the vat

Friction plates 37 and 38 extend obliquely downward from the tub 8. Supporting springs 39 attached to the housing carry front ones and rear friction bodies 40, 41. Between these, the friction plates 37, 38 are clamped so that they cause the vibrations of vat 8.

Near the top of the housing 1 is a Filling flange 42 to be connected to an external faucet and a magnetically operated one connected to the flange Filling valve 43. The outlet of this valve 43 is through a jacket tube 44 to the tub 8 close to the upper one Edge connected

The solenoid filler valve 43 is pressure sensitive Switch 45 actuated ", which is from the water level in the Bottioh is operated; there is a pipe 46 connected to the bottom of the vat »

With the reference number 47 a timer is denoted * This is built in such a way that, once it has reached the start position, a washing program runs automatically through the interaction of a built-in timer with a program card to be described later. The switch will

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brought into its starting position by a hand-operated button 48

49 is attached to one of the support rails 2 Single vibration sensor denotes j the details of which are off Fig. 5 eraiohtlioho The reference number 50 points to an in a box arranged controller, which the speed of the drum as a function of a signal from the vibration sensor 49 controls. The details of the circuit of the regulator are shown in FIG.

The construction of the visual vibration sensor 49 will now be described in detail recalling Pig. 5 described. The vibration sensor contains a rod 52 which transmits the vibrations which is rigidly attached to an intermediate piece 5 of hemispherical-convex surface. A contact capsule 53 is attached to the lower end of this transmission rod 52. In this capsule there is a movable contact pad of two Return springs 54 is normally held in the center of the capsule. Before the ends of this contact rod a 55, namely in In each case a distance S, there is one stationary on the housing Contact 56 · The movable contact rod 55 and the fixed contacts 56 are through in! Ig. 6 visible lines 57, 58 with connected to the control device.

As Fig. 6 shows, a voltage from a commercially available power source is reduced by a voltage converter 60, rectified and smoothed by a diode 61 and a capacitor 62 and via resistors 63, 67 and 68 given the movable contact rod and the two fixed contacts A capacitor is connected in parallel to the two contacts; a charging voltage of this capacitor 64 becomes on the base of a transistor65 through a resistor 69, led.

When the Iranaistor 65 receives voltage, it becomes the base voltage of a transistor 66 duroh a voltage drop of a

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Resistor 70 increases, whereby the transistor 66 voltage receives and accordingly the excitation coil of a relay 72 is energized. The excitation coil serves as a switch for the im Circuit Diagram in Pig. 3 visible engine 28

A crouch switch 73 is closed by a timer motor 74 when - and only when - the washing program is running s reaches the sole rowing phase.

Next, the operation of the drum washing machine described above will now be explained with reference to the circuit diagram Pig. 3 and the program picture Fig, 4 « %

The reference numerals 73 and 81-87 indicated in FIG. 3 denote cam-controlled switches _f which are actuated by a row of cams arranged on the shaft of a timer motor 89 In the program picture Fig. 4, thick horizontal lines give contact. A door switch, which only makes contact when the door is closed, as well as the cam-controlled switch 81 and a manually operated switch 92 are connected in series with a power source 90. Thus, when the timer is turned to the start position, it closes first the cam switch 81, and a lamp 93 lights up to indicate that the J washing machine is ready for use. In this case, since there is no water in the tub, the pressure-sensitive switch is in the NO position and the cam switch 83 is in the position ^fl a. ^w . As a result, the solenoid-equipped filling valve 43 is operated and filling begins 95 switched on because the cam switch 86 is in the "a" position. The selector switch 94 is provided to enable the V7a sch process from heavy wash to mild wash

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and vice versa can be reversed if it is τοη hand operated. The UinBohalter 95 and another Umsohalter 96 are provided "so that the ratio between the Sauer normal rotation - d« h · forward running of the motor 28 to the duration of the reverse running of the motor can be changed. It can therefore be seen that the motor 28 runs several times forwards or backwards in a predetermined cycle, so the drum 14 looks normal Rotating and / or rotating backwards »which puts the laundry in the drum is circulated and thus washed. During the washing process, the Nookenso holder 87 is in closed position Position is held, the timer motor 89 continues, so that the program is processed *

When the wasoh process is finished, the cam switch 82 is closed and the cam switches 83 and 84 are ^{brewed in the position "b M} , whereby a drain valve 75 is opened so that the wasoh water drains off, and at the same time a microscope holder 76 operatively connected to this drain valve is closed. If The emptying is finished, the hook holder 83 is put into the position ^M a "hereby the solenoid-operated emptying valve 43 is opened and thus the filling begins. When the water in the tub 8 has reached the prescribed level, the pressure-sensitive switch is off moved from the NO position to the NO position | hereby the filling is interrupted. The timer motor and motor 28 continue to run during the period from emptying to filling, and therefore drum 14 continues to rotate at the same speed as it did during washing.

When the rinse has lasted for a predetermined time and is finished, the machine starts spinning. In this case, the cam sensor 73 is closed and the cam switch 87 is opened, while the timer motor is stopped and a voltage is applied to the vibration sensor circuit shown in FIG. At the same time, the Nookensohalter 86 is brought into the position ^M b ″, so that the motor 28

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rotates in the same direction at the same speed as during the washing process

The movement of laundry in the drum will now be described below. Thrown in the drum Wäsohe initially remains at the bottom of the drum, but is then removed from the drum when the drum starts to rotate The panels 18 are lifted up and then fall down from the given height as a result of gravity Do not always distribute the drum in the same way, but sometimes bunch up and at other times a fairly long one Form a layer «. If it forms such a layer and extends over the entire circumference of the drum, it is pretty much the same moderately distributed around the center of the drum

The distribution becomes extremely even, especially when a fairly large amount of laundry is thrown into the drum will; because the Wäsohe is distributed along the circumference of the drum in a ring shape

The distribution of the laundry around the drum center, however, remains not even for a long time, but becomes irregular again every few tenths of a second. The state that the Wäsohe is evenly distributed around the center of the drum, occurs several times in fairly long periods.

Hence, of course, "if the drum rotates fast enough is generated, such a large centrifugal force of the laundry that the laundry is evenly distributed on the drum wall all around remains, the vibration balance of the drum during acceleration and spinning must be small · The invention is characterized in that the question of whether the water is evenly distributed in the drum or not can be sensed the oscillation amplitude with which the vat oscillates is displayed so that the drum then accelerates can be if the heat distribution is even

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- ίο -

This is because, as FIG. 5 shows, it is the movable contact rod 55 with the bolt 5, on which the drum hangs, duroh the vibration transmitting rod 52 is connected, and the fixed contacts 56 are connected to this movable contact rod 55 arranged opposite · Between the movable contact rod and the fixed contacts there is a space S "

With the vibration sensor of the arrangement described, when the drum has a waveform such as that in Pig. 9 shown vibrates and the swing exceeds a predetermined value, the movable contact rod 55 in contact brought to the fixed contact 56 so that it has an on-off on-off-Sohalt of the same timing as that the drum vibrations performs.

In this case, since the capacitor 64 connected in parallel to the movable contact rod 55 and the fixed contacts 56 discharges the charge secured in it through these movable and fixed contacts, the base voltage of the transistor 65 will not rise so high that the transistor becomes active} rather, this transistor remains without voltage, and the relay remains at rest, _{or the like, since no current flows through its excitation coil}

But if the laundry in the drum is distributed relatively evenly around the drum axis, it vibrates Drum only with a small amplitude, and then therefore remain the movable contact rod 55 and the fixed contacts 56 of the Vibration sensor without contact with each other for a certain period of time. As a result, the voltage in capacitor 65 reaches a sufficient level for the transistor to take effect to let, and so this becomes active · Then a current flows through the excitation coil 72 of the relay through the following Transistor 66, and a contact 79 as well as a series of contacts in series with the timer motor 89 are actuated, whereby the motor 28 is switched so that he the

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Drum 14 rotates twice as fast as during the Wasoh process · At the same point in time at which the 'contact 79 is actuated, the timer motor 89 is switched on again, which controls the cam holder bu · A predetermined time after the motor 28 has been switched over the cam switch 85 is brought into the position ^w b ^M , so that the motor 29 is started, and at the same time the cam switch 87 is closed and the cam switch 73 is opened. The contacts 78 and 79 of the relay are returned to the position shown, and the motor 28 is switched to slow speed.

Since the rotation of the motor 28 is transmitted through the overrunning clutch 31 to the shaft of the motor 29, occurs when the Motor 29 is started, the clutch 31 slips, and therefore the drum 14 is rotated by the motor 29.

Therefore, when using a two-pole-four-pole pole-changing Motor for motor 28 and a two-pole motor for motor 29 and with a suitable choice of gear ratio between motors 28 and 29 and the reduction ratio between motor 29 and the drum by the handling described above, the speed of the drum gradually from the washing speed to the sole wheel speed increase.

Now the vibration characteristics of the movable parts, such as the tub, are suspended from the housing by means of four tension springs 7 8, the drum 14 and the motors 28, 29.

The vibrations of the mass system suspended by means of the four springs each consist of a vertical component and in a horizontal plane. Their natural frequency is generally higher in the vertical plane than in the horizontal Because while the natural frequency in the horizontal direction by the distance between the hemispherical-concave surface 3 and the center of gravity of the elastically suspended moving part is determined, is that of the vibrations in the vertical

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Determination by the mass of the elastically suspended movable part and by the spring constant of the four suspension springs given. You feathers must of course have a high degree of hardness, because they have to support the measurement system. In practice, the vibrations have a characteristic as in Fig. 10.

With such a vibration characteristic, if the Vibrations of the drum with the natural frequencies in the horizontal and coincide in the vertical direction, the oscillation amplitude is large, even if the vibrational Power is small, i.e. the laundry is evenly distributed in the drum. Saher is understandable that the time during which the number of vibrations of the drum coincides with the natural frequency, must be as short as possible *

On the other hand, the number of vibrations of the drum coincides substantially with the speed of rotation of the drum. Therefore, how easy to see, a great vibration damping effect is achieved if you select the speed of the drum ao that the mentioned duration of the collapse of the drum vibration number can be kept very short with the natural frequency of the drum in the horizontal and in the vertical plane.

For an explanation, reference is made to Fig. 10. In it, the reference symbols f ^ _{mean the speed during washing, f 2} a mean speed during spinning, f ^ the natural frequency in the horizontal direction and f the natural frequency in the vertical direction. The drum vibrations can be effectively reduced, by choosing the drum speed so that f "" f "and fj do not coincide with f ^ and f.

In other words, if the natural frequency f. in the horizontal position between f ₁ and f _g and the natural frequency f between f ₂ and f ^, the number of vibrations of the drum will instantly pass through the points of these natural frequencies during the acceleration and increase to a higher value before the vibrations of the drum become large can.

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Her invention is now nooh to another Embodiment described. In the invention, it is essential to vibrate the drum 14 and the vats θ bo exactly «ie possible to determine · In particular, the vibration sensor must be accurate in operation, with a long service life and in be cheap to manufacture

In the embodiment according to Jig. 7, a piezoelectric element is used to move one up to the tension springs 7 To bring the propagating vibration into the form of an electrical signal, and a relay is actuated when this electrical signal is less than a predetermined period of time A predetermined value remains, whereupon the Polumsohaltung of the motor 28 is carried out.

In Fig. 7a a print piece 99 is arranged so that it engages via a lever 98 on the bolt 4, and a piezo-electric element is arranged between the pressure piece 99 and the support rail 2. A line 101 goes from the piezo-electric element Element for the Hegler 50 enclosed in a box whose circuit is in Pig. 8 shown. It is such that that electrical signal coming from the piezo-electric element two-way comparison with a reference value is amplified and, if it is greater than this, i.e. if the drum oscillation amplitude is greater than permissible, the relay remains inactive, but that if this is smaller than the reference value, the relay 72 is actuated and the drum is accelerated.

The previous description is based on the case "that the laundry in the drum during washing, which takes place at a slow speed, essentially evenly around the rotating shaft Drum is distributed and that this distribution of the laundry is maintained when accelerating · However, possibly if Also very rarely, the even distribution is disturbed when accelerating. This can be explained by the fact that the laundry, during the slow rotation of the drum close to the drum axis

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et during its duration the centrifugal force lay with the life caused migration to the circumference of the (drum aieh nioht ringium moves radially outwards at the same time, but locally remains clumped

If such uneven distribution when accelerating entry, the vibration of the drum suddenly becomes large and the vibration detection detected by the vibration sensor is far greater than outside with the result that the power supply to the Eelaie 72 is interrupted again · Therefore the Belais contact 96 automatically returned to its original position, and the drum resumes and retains its original low speed at which it was running when it was washed until the oscillation amplitude is smaller than the limit value To form accelerators; it will not develop if , The Wäsohe lies completely against the peripheral wall of the drum · Therefore To avoid such vibrations, you need the cam switch 73 to be kept closed only as long as the acceleration of the drum from the lower one, at the end of the Wasoh process existing speed to the next higher, the intermediate speed, lasts

After washing, the drum is filled for rinsing. If a switch 102 which selects the amount of water is closed is, the filling with copious amounts of water is done for as long as the cam switch 84 is held in position "a" becomes even if the pressure sensitive switch 45 is out of the NO position is switched to the NO position; and therefore rinsing is done with a larger amount of water than washing

At the end there is the spinning Drum speed converted to a higher speed depending on of the swing width of the drum, as described above. The motor 29 is not started when a the spin speed setting switch 103 is open,

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and the drum 14 is driven at a higher speed of the motor 2Θ »to produce a gentle spin»

If, on the other hand, the switch 103 is closed, the drum is driven by the motor 29 at the high final speed, so that a strong centrifugal effect is achieved the drum speed can also be changed by changing the reduction ratio of a reduction gear, for example a belt drive with variable pulleys, i.e. in addition to electrical pole switching.

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ORfGlNAL INSPECTEO

Claims (9)

- 16 claims 1. Drum washing machine with drum drive with lower and at high speed, characterized by a device which senses the vibrations of the drum and which only then switches from low to high speed when the range of drum vibrations at low speed a does not exceed a predetermined value for a predetermined time. 2. Washing machine according to claim 1, characterized in that · including the natural frequencies of the elastically suspended parts of the drum are between the low and the high speed « 3ο washing machine according to claim 1, characterized in that the drum drive for at least three different drum drives. speeds is set up that also these speeds outside the natural frequencies of the resiliently suspended parts including the drum, furthermore that the switching of the lowest to the next higher speed occurs only when the width of the drum vibrations a predetermined time long does not exceed a permissible value, and that the subsequent switchover to higher speed or speeds happens automatically. 4ο washing machine according to claim 3, characterized in that a pole-changing first motor (28) for the two lowest speeds and a second motor (29) to drive the drum intended for the highest speed and the motors are coupled by means of an overrunning clutch (31). 5. Washing machine according to one of claims 1 to 4, wherein the drum and the tub are suspended from a housing by means of tension springs are characterized in that the vibrations 909823/0811 sensing device (49) consists of a rod (52) which is attached to one of the tension springs (7) at its connection (4) with the housing (1) is attached and transmits the vibrations and that the device controlling the speed of the drum is controlled by a signal from an electrical contact (55), which is mechanically activated by the movement of the vibration-transmitting Rod (52) is actuated 6. Washing machine according to one of claims 1 to 4, wherein the drum and the tub are suspended on a housing by means of tension springs, characterized in that the vibration % sensing device includes a piezo-electric element (100), welohes on one of the Tension springs is clamped in the suspension, and that a device is provided which switches on a higher drum speed when the pulse coming from the piezoelectric element falls below a predetermined value 7β washing machine according to claim 6, characterized in that the piezo-electric element between the tension springs the bolt (4) connecting the housing and the housing is clamped « 8. Washing machine according to one of the preceding claims, characterized in that the input " direction reverses an initiated increase in the drum speed if the range of the drum vibrations is inadmissible grows big. 9. Washing machine according to one of the preceding claims, characterized in that the drum drive by a pole-changing Engine. (28) and the pole changing of the motor is done by a relay, which depends on the vibrations the drum is sensed and the drum speed increasing device is actuated at a permissible oscillation range 909823/0811