Classifications

• • D—TEXTILES; PAPER
  • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
  • D06F—LAUNDERING, DRYING, IRONING, PRESSING OR FOLDING TEXTILE ARTICLES
  • D06F37/00—Details specific to washing machines covered by groups D06F21/00 - D06F25/00
  • D06F37/20—Mountings, e.g. resilient mountings, for the rotary receptacle, motor, tub or casing; Preventing or damping vibrations

Definitions

• the invention relates to a damper, in particular for washing machines with a spin cycle.
• DE 22 04 325 C2 discloses a drum-type washing machine with struts or friction dampers for damping the vibrations of the washing unit. These each have a housing with a plunger slidably guided therein. To determine the insertion depth of the plunger, the plunger is hollow with a permanent magnet. Arranged in front of the housing of the damper in the direction of extension of the tappet is an annular coil which surrounds the tappet and is capable of detecting the position of the permanent magnet in the annular coil.
• the known device makes it possible to determine a specific predetermined critical insertion depth of the ram and to interrupt the spin cycle, for example, due to particularly strong vibrations. The result is therefore only digital. A disadvantage of this arrangement is that the position of the plunger cannot be determined continuously.
• the coil arranged upstream of the housing makes the overall arrangement longer. Another disadvantage is that it is not possible to determine the payload of the washing unit, since, due to the high static friction between the friction lining and the housing, the insertion depth is not a measure of the payload.
• the invention has for its object to provide a damper with a housing and a plunger slidably guided therein, in which the insertion depth of the plunger into the housing is as simple as possible can be determined and from this the insertion force acting on the ram can be determined.
• the object is solved by the features of claim 1.
• the essence of the invention is that a measuring element is connected to the housing and the plunger, the relative position of which is determined by electrical interaction, the plunger having an essentially frictionless idle stroke over part of the insertion depth. This enables e.g. B. to measure the weight of dry laundry and water at rest and / or to detect dynamic imbalances during operation.
• Fig. 1 is a drum washing machine in a schematic representation in
• FIG. 2 shows a drum washing machine according to FIG. 1 in front view
• Fig. 3 is a drum washing machine in a schematic representation in
• FIG. 4 shows a drum washing machine according to FIG. 3 in front view
• 5 shows a longitudinal section of a spring strut according to a first embodiment
• Fig. 6 shows a longitudinal section of a shock absorber according to a second
• FIG. 7 shows a longitudinal section of a friction damper according to a first embodiment
• FIG. 8 shows a longitudinal section of a friction damper according to a second embodiment
• FIG. 10 shows a longitudinal section of a friction damper according to a fourth embodiment which has been slightly modified compared to FIG. 9,
• FIG. 11 shows a longitudinal section of a friction damper according to a fifth embodiment which has been slightly modified compared to FIG.
• Trornmelwaschmasch ne with horizontal drum axis 1 has a vibratory washing unit 2 with a drive motor 3 which drives a washing drum, not shown in detail, via a belt drive 4.
• Other components connected to the washing unit 2, for example a gear, are not shown for the sake of simplicity.
• the oscillating washing unit 2 is supported by two spring struts 5 described in more detail below in relation to a machine frame 7 standing on the floor 6 and forming a base frame.
• a washing machine housing 8 surrounding the washing unit 2 is supported with respect to the machine frame 7 and connected to it. The input and removal of laundry takes place through a flap 10 arranged on an end face 9 of the washing unit 2.
• Each strut 5 has a tubular housing 11 with a central longitudinal axis 12, in which a plunger 13 is displaceably guided coaxially is.
• a stop 14 is fastened in the region of the free end of the plunger 13.
• a prestressed helical compression spring 15 surrounding the section of the plunger 13 located outside the housing 11 is supported with respect to the stop 14 on the one hand and the end of the housing 11 on the plunger outlet side, on the other hand, so that the plunger 13 counteracts the force of the spring 15 into the housing 11 can be inserted.
• an elastic link 16 is provided at the free end of the plunger 13, which has a bearing 17 connected to the washing unit 2, which is braced with the plunger 13 via elastic blocks 18. In the same way, the free end of the housing 11 is articulated on the machine frame 7.
• the drum washing machine according to FIGS. 3 and 4 differs from that according to FIGS. 1 and 2 in that the washing unit 2 is suspended from the machine housing 8 by means of helical tension springs 19.
• the Tension springs 19 are attached to eyes 20 on the one hand, which are attached in the upper area of the washing unit 2. On the other hand, they are suspended from eyelets 21 which are formed on the cover plate 22 of the washing machine housing 8.
• two friction dampers 23, which are described in more detail below, are attached in the center in the longitudinal direction and are connected to the machine frame 7.
• Each friction damper 23 has a cylindrical housing 24 with a central longitudinal axis 25, in which a plunger 26 is slidably guided coaxially.
• a damping housing 28 is formed therein.
• a friction-damping covering 29 is fastened therein, which lies against the plunger 26 on the circumferential side.
• the plunger 26 has at its free end a joint bushing 30 as a linkage element, by means of which the friction damper 23 is attached to a bearing 36 on the washing unit 2 in such a way that the friction damper 23 about a pivot axis 32 relative to the washing unit 2 is pivotable, which runs parallel to the drum axis 1.
• the pivot axis 35 of which, like the pivot axis 32, intersects the central longitudinal axis 25 perpendicularly. With this joint sleeve 34, the friction damper 23 is attached to a bearing 31 on the machine frame 7 so that the pivot axis 35 also runs parallel to the drum axis 1.
• a damping piston 38 is provided which has an annular groove 39 which is delimited in the longitudinal direction by annular stops 40, 41 which are integral with the damping piston 38 are trained.
• a ring-cylindrical damping ring 42 is arranged, which has an annular groove 43 on the outer circumference side, in which a friction damping coating 44 is provided.
• the damping ring 42 can be displaced in the annular groove 39 approximately without friction relative to the damping piston 38.
• the friction-damping lining 44 abuts the inside 45 of the housing 11.
• the friction-damping coating 44 can consist of a lubricant-impregnated, foamed, closed-cell polyurethane.
• an annular-cylindrical guide bushing 47 is provided, which is connected to the housing 11 via beads 48.
• the plunger 13 is guided in the guide bushing 47.
• the guide bushing 47 has a guide tube 50 protruding counter to the insertion direction 49 and formed in one piece with the guide bushing 47, which is surrounded by an annular cylindrical stop 51, against which the helical compression spring 15 on its Insert direction 49 end is supported.
• the strut 5 has a tappet position measuring device for detecting the insertion depth T of the tappet 13 in the housing 11.
• the measuring device has an annular-cylindrical sensor 52 which is fastened to the end of the damping piston 38 lying in the insertion direction 49 coaxially to the central longitudinal axis 12.
• the encoder 52 is made of metal, in particular iron or another ferritic material.
• the housing 11 consists of a magnetically permeable, in particular non-metallic material.
• the measuring device also has a coil unit 53 which, in the case shown in FIG. 5, consists of two coils 54 and 55 connected in series. The coils 54, 55 are connected to an evaluation unit 57 via electrical connecting lines 56.
• the spools- Unit 53 can in particular consist of one or two coils arranged adjacent to one another and surrounding the housing 11 in a ring-cylindrical manner.
• the coil unit 53 extends in the longitudinal direction, in particular at least over the length that is covered by the encoder 52 at the maximum insertion depth T of the plunger 13.
• the measuring device is a so-called inductive displacement transducer.
• the inductance is changed by inserting the encoder 52 into the interior of the coil 54.
• the inductance of the coil 54 is evaluated on a quarter bridge which is generally known in electrical engineering.
• the advantage of this arrangement is the completely simple structure. It is disadvantageous that changes in the insertion depth T are proportional to the change in inductance only in a narrow area around the operating point of a given insertion depth T.
• the measuring device is a so-called differential choke.
• An electrical signal is applied to the connecting lines 56 or tapped from them.
• By moving the encoder 52 in the interior of the coils 54, 55, their inductance is changed. Over approximately 80% of the length of the coils 54, 55 there is essentially a linear relationship between a change in the insertion depth T and the inductance.
• the evaluation of the insertion depth T via the change in inductance presupposes that the transmitter 52 consists of a ferromagnetic material, for example iron / steel. If an evaluation of the input thrust depth occurs via an eddy current effect, then the encoder 52 should consist of a non-ferromagnetic, but electrically conductive material, for example aluminum.
• the washing unit 2 is first loaded with laundry.
• the plunger 13 sinks into the housing 11 from the initial position shown in FIG. 5, so that the insertion depth T is increased.
• the plunger 13 is pushed in essentially free of static friction over a range ⁇ T until the damping ring 42 comes into abutment with the stop 41.
• the plunger 13 thus has an idle stroke.
• the change ⁇ T in the insertion depth T is substantially proportional to the insertion force acting on the tappet 13, so that the weight of the laundry loaded is measured by measuring the change ⁇ T in the insertion depth T of the spring struts 5 of the washing machine can.
• the insertion force can be calculated via the spring constant of the spring 15 and the change ⁇ T.
• the evaluation unit 57 determines the payload mass of the washing unit 2 and any imbalance that may be present.
• the washing unit 2 vibrates, the amplitude of which is so great, that the damping ring 42 alternately in hit with the stops 40 and 41, so that the movement of the plunger 13 is damped by the friction-damping coating 44.
• the amplitude of the vibrations can be determined at any time by measuring the insertion depth T. If the amplitudes of the vibrations become too large, the spin speed can be reduced or the spin process can be stopped based on signals from the evaluation unit 57. It is possible in the drum washing machine described in the introduction to provide only one of the spring struts 5 with a tappet position measuring device. The other spring strut 5 can be designed in a commercial manner.
• a second embodiment of the spring strut 5 ' is described below with reference to FIG. 6. Identical parts are given the same reference numerals as for the strut 5 according to the first embodiment, to the description of which reference is hereby made. Structurally different, but functionally similar parts are given the same reference numerals with a prime.
• the central difference compared to the first embodiment is that the damping ring 42 'cannot be displaced relative to the damping piston 38' essentially without force, as in the first embodiment.
• the stops 40' and 41 ' are provided coaxially to the central longitudinal axis 12 ring-cylindrical, pre-tensioned compression springs 58 and 59, respectively.
• the compression springs 58, 59 have an influence on the function described in the context of the first exemplary embodiment, in that not only the helical compression spring 15 but also the compression spring 59 when the plunger 13 is inserted slightly are compressed, which is to be taken into account when determining the mass of the washing unit 2 from the insertion depth T by the evaluation unit 57.
• a guide piston 61 is formed which has two annular guide webs 62, 63 which are offset longitudinally with respect to one another and formed in one piece therewith, between which an annular groove 64 is formed.
• the guide webs 62, 63 bear in a leading manner on the inner wall 65 of the housing 24.
• a ring-cylindrical damping ring 66 is provided, which has a lining ring groove 67 along the outer circumference, in which the friction damping lining 29 is arranged, which rests rubbing against the inner wall 65.
• the friction damping covering 29 consists of foamed plastic or felt impregnated with lubricant.
• the guide piston 61 can be displaced relative to the damping ring 66 in the region of the longitudinal extent of the annular groove 64, essentially without static friction.
• a bead 68 At the end of the housing 24 lying counter to the insertion direction 60, this is provided with a bead 68 so that the plunger 26 can be pulled out of it.
• the plunger 26 and the guide piston 61 are made in one piece from plastic.
• the housing 24 consists of a non-metallic material, in particular plastic, or of a magnetically permeable metal.
• the plunger position measuring device has an annular cylindrical sensor 69 arranged at the end of the plunger 26 lying in the insertion direction 60 coaxially to the central longitudinal axis 25.
• a coil unit 70 with two coils 71, 72 arranged adjacent to one another and surrounding the housing 24 in a ring-cylindrical manner, which are electrically conductively connected to an evaluation unit 74 via connecting lines 73.
• the transmitter 69 and the coil unit 70 reference is made to the description of the transmitter 52 and the coil unit 53 of the spring strut 5 according to the first embodiment.
• the tappet 26 can be inserted essentially without static friction via a change ⁇ T in the insertion depth T which represents an idle stroke, until the web 63 comes into contact with the damping ring 66. If the movement is continued in the same direction, the frictional force between the friction-damping coating 29 and the inner wall 65 must be overcome.
• the friction damper 23 is thus, like the spring strut 5, suitable both for measuring the load quantity of the washing unit 2 and, if appropriate, for unbalance, and for determining the amplitude of the washing unit vibrations in the spin cycle.
• the evaluation unit 74 must also take into account the counterforces exerted on the washing unit 2 by the helical tension springs 19. As with the strut 5 'according to the second embodiment, it is possible to support the damping ring 29 with compression springs 58, 59 against' the webs 62 and 63, respectively, whereby the same effects described there arise.
• the friction damper 23 ' according to a second embodiment is described below with reference to FIG. 8. Identical parts are given the same reference numerals as in the friction damper 23 according to FIG the first embodiment, to the description of which reference is hereby made. Structurally different, but functionally similar parts are given the same reference numerals with a prime.
• the central difference from the first embodiment is the structure of the ram position measuring device. At the end of the housing 24 located in the insertion direction 60, a base 75 is provided connected to the housing 24 via a bead 76.
• a pin 77 which is arranged coaxially to the central longitudinal axis 25 and protrudes counter to the direction of insertion 60, on the free end of which the transmitter 69 'is attached.
• the pin 77 is made of a non-metallic material, such as. B. plastic.
• the encoder 69 ' is surrounded by the material of the pin 77, in particular plastic.
• the guide piston 61 ' has, coaxially to the central longitudinal axis 25, an insertion channel 78 which is open at the end in the insertion direction 60 and which is designed such that the pin 77 with the transmitter 69' in it Inserting the plunger 26 'can be inserted without contact.
• the coil unit 70 ' has two coils 71' and 72 'which are arranged adjacent to one another and which surround the insertion channel 78 in a ring-cylindrical manner and which are arranged adjacent to one another on the guide piston 61'.
• the connecting lines 73 ' are led out of the plunger 26' in the region of its free end in such a way that they do not impair the insertion of the plunger 26 '.
• the transmitter 69 ' is connected in a stationary manner to the housing 24 and the coil unit 70' with the plunger 26 can be inserted into the housing 24.
• the friction damper 23 "according to a third embodiment is described below with reference to FIG. 9. Identical parts are given the same reference numerals as the friction damper 23 according to the first embodiment, to the description of which reference is hereby made. Parts which are different in construction but have the same function are given the same reference numerals with two raised lines.
• the housing 24 ′′ the end of which in the insertion direction 60 is closed by a base 79, has a stop collar 80 at the end opposite the insertion direction 60, to which an annular cylindrical receiving section 81 is attached Locking lugs 82 having locking arms 83 connects.
• the damping ring 66 “is slidably arranged in the annular space 84 formed between the receiving section 81 and the tappet 26".
• the damping ring 66 "lies on the inner circumference of the receiving section 81, essentially free of sliding friction, on the outer circumference. On the inside, the damping ring 66" has the friction damping lining 29, which rests frictionally on the tappet 26 ".
• the receiving section 81 is closed by a ring-cylindrical cover 85 with latching openings 86, into which the latching lugs 82 engage in a locking manner, on the inside of the cover 85 pointing in the direction of insertion 60 and on the inside pointing in the opposite direction to the direction of insertion 60 Stops 87 and 88 are provided on the inside of the stop collar 80.
• the plunger 26 ′′ has a friction section 89 made of metal, in particular steel, which is in contact with the lining 29.
• the plunger 26 ′′ has an encoder support section 91 connected to the section 89 and made of a non-metallic
• the material, especially plastic, is manufactured.
• the transmitter 69 is arranged in the region of the end of the section 91 in the insertion direction 60.
• the housing 24 is made of a non-metallic material, in particular of plastic.
• the friction damper 23 '"according to FIG. 10 according to a fourth embodiment differs from that according to FIG. 9 only in that not a separate encoder is attached to the tappet 26'" but that the edge of the tappet 26 'is used as the encoder 69' " "serves, that is, their end located in the housing interior 90.
• the friction damper 23 "" according to a fifth embodiment is described below with reference to FIGS. 11 and 12.
• the structure is similar to the friction damper 23 'shown in FIG. 8, to the description of which reference is hereby made.
• Identical parts are given the same reference numerals as in the friction damper 23 'according to the second embodiment.
• Structurally different, but functionally similar parts are given the same reference numerals with four prime lines.
• the plunger 26 ' has in the region of its end on the inside of the housing an annular cylindrical wall 92, in which radially outwardly extending latching recesses 93 are provided.
• the radially protruding, ring-shaped guide web 63 is provided at the end of the wall 92 in the insertion direction 60.
• the guide piston 61 “" has essentially the shape of an annular cylindrical sleeve, at the end of which, opposite the insertion direction 60, radially outwardly projecting locking lugs 94 are provided, which are in locked engagement with the locking recesses 93 ,
• the radially outwardly projecting guide web 62 is provided at the end of the guide piston 61 "" in the insertion direction 60, the annular groove 64 being delimited in the axial direction by the guide webs 62 and 63.
• two compression springs 95 and 96 are arranged between the damping ring 66 and the guide web 63 on the one hand and the damping ring 66 and the guide web 62 on the other hand, which ensure that the damping ring 66 is arranged approximately centrally between the two webs 62 and 63.
• a cylindrical ring 97 which is designed as a transmitter 69 "" and is fixed in a corresponding annular groove 98 on the inside of the guide piston 61 "”.
• the ring 97 is made of metal, in particular aluminum.
• the cylindrical pin 77 which is made of metal, in particular iron, carries the coil unit 70 "", which is attached to the surface of the pin 77.
• the ordered coil 71 ' in particular made of copper wire.
• the coil 71 ' is insulated from the pin 77 by a thin plastic layer 102, the individual windings of the coil 71' also being insulated from one another.
• a spacer 99 projecting radially with respect to the pin 77 and the coil unit 70 "" is provided, which has a round cross section, with the spacer 99 and the inner wall 100 of the guide piston 61 "" there is a game.
• the spacer 99 ensures that the coil 71 'does not come into contact with the transmitter 69 "". This is of particular importance if transverse forces act on the friction damper 23 "" or the pin 77 warps.
• the connecting line 73 "" is led from the end of the coil 71 'lying in the insertion direction 60 through the base 75 to a plug 101, from which a connection to the evaluation unit 74 can be established.
• An advantage of this arrangement is that the housing 24 can be selected from the metal tappet position measuring device without disadvantage.

Landscapes

• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Fluid-Damping Devices (AREA)
• Main Body Construction Of Washing Machines And Laundry Dryers (AREA)
• A Measuring Device Byusing Mechanical Method (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Vibration Dampers (AREA)
• Spinning Or Twisting Of Yarns (AREA)
• Buildings Adapted To Withstand Abnormal External Influences (AREA)

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• 2000
  • 2000-09-21 DE DE10046712A patent/DE10046712A1/de not_active Withdrawn
  • 2000-09-22 TR TR2002/00877T patent/TR200200877T2/xx unknown
  • 2000-09-22 AT AT00971282T patent/ATE260355T1/de not_active IP Right Cessation
  • 2000-09-22 ES ES00971282T patent/ES2214325T3/es not_active Expired - Lifetime
  • 2000-09-22 WO PCT/EP2000/009282 patent/WO2001027375A1/fr active IP Right Grant
  • 2000-09-22 EP EP00971282A patent/EP1220961B1/fr not_active Expired - Lifetime
  • 2000-09-22 DE DE50005453T patent/DE50005453D1/de not_active Expired - Lifetime

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