JP5061304B2 - Water level detector - Google Patents

Description

  The present invention relates to a water level detection device that detects the water level in a tub when washing or rinsing in a washing machine or the like.

  Conventionally, this type of water level detection apparatus is configured as shown in FIGS. Hereinafter, the configuration will be described. FIG. 6 is a cross-sectional view of a conventional water level detection device. FIG. 7 is a perspective view of a conventional bobbin unit.

  As shown in FIG. 7, the coil 4 is formed by winding the coated copper wire 3 on the bobbin winding frame 2 of the resin bobbin unit 1, and the coil 4 and the capacitor 6 are formed on the back side of the bobbin base 5 of the bobbin unit 1. The connection terminal portions 7 were collected at one place and electrically connected by solder at the solder portion 8. Moreover, the attachment part 9 was provided in the right and left so that a hand might come out from the lower surface of the bobbin winding frame 2, and the attachment part 9 had the through-hole 10. In FIG.

  As shown in FIG. 6, the through case 10 of the mounting portion 9 of the bobbin unit 1 is inserted into the boss 12 provided inside the upper case 11 made of resin, and the upper case is formed by heat caulking or cold caulking at the caulking portion 13. 11, the bobbin unit 1 was fixed. Further, a rubber diaphragm 15 is installed in the lower case 14, and a movable core 17 having magnetism is attached via a connection plate 16. Reference numeral 18 denotes a spring.

  In the above configuration, when the diaphragm 15 is deflected by the pressure from the outside, the connection plate 16 attached to the diaphragm 15 rises, and the movable core 17 having magnetism approaches the coil 4 so that the inductance of the coil 4 changes, and the oscillation circuit The water level is detected by changing the oscillation frequency (not shown) and detecting this oscillation frequency (see, for example, Patent Document 1).

JP-A-1-320098

  However, in the configuration of such a conventional water level detection device, the mounting portion is formed so as to reach the bottom surface of the bobbin winding frame, so that when the bobbin is molded, the mounting portion is completely horizontal due to variations during molding. It causes warping rather than becoming. When the bobbin unit is fixed to the upper case due to the warping of the mounting part, it is caulked or cold while the stress is applied to the mounting part in order to force the mounting part to fit into the upper case surface. It will be caulked. As a result, due to fluctuations in the ambient temperature, the mounting part moves up and down due to the stress accumulated in the mounting part, the position of the bobbin unit moves up and down, and the coil inductance changes due to fluctuations in the ambient temperature. There was a problem that it would end up.

  In addition, when inserting the connector into the connection terminal, there is a risk that the stress applied to the connection terminal will be transmitted as it is to the caulking part of the mounting part of the bobbin unit, resulting in weakening the fixing force of the bobbin unit, resulting in a durable surface. There was a problem of anxiety.

  The present invention solves the above-mentioned conventional problems, and even if the ambient temperature changes, the bobbin unit does not move up and down, the coil inductance is constant and the oscillation frequency is stable, and the detection accuracy is high. It is an object of the present invention to provide a water level detection device that realizes a strong mounting portion without transmitting stress at the time of connector insertion to the caulking portion of the mounting portion.

  In order to solve the above-described conventional problems, the water level detection device of the present invention is configured to electrically connect at least one capacitor inserted in a bobbin base and a coil in which a coated copper wire is wound around a bobbin winding frame at a terminal connection part. A bobbin unit constituting a resonance circuit or an LC oscillation circuit, a movable core, a diaphragm joined to the movable core via a connecting plate, an upper case forming an exterior, and a lower case, and a pressure change In the variable reactance (frequency) type water level detection device for detecting the water level of a washing machine or the like by the movement of the movable core in conjunction with the displacement of the diaphragm deformed by the change of the positional relationship with the coil, the bobbin At least one flat surface portion is provided on the pedestal, and the flat surface portion is in contact with and fixed to the inner surface of the upper surface of the upper case.

  In this way, by providing a flat part for mounting on the extension line of the bobbin pedestal part, there is no need to forcibly adapt to the surface of the upper case when fixing it to the upper case, eliminating the warping of the mounting flat part during molding. Can be fixed without accumulating, and the bobbin unit does not move up and down even when the ambient temperature changes, and the coil inductance is constant and the oscillation frequency is stabilized, thereby increasing the detection accuracy.

  The water level detection device of the present invention has high detection accuracy because the bobbin unit does not move up and down even when the ambient temperature changes, and the oscillation frequency is stable and the coil frequency is constant. Stress, that is, stress that attempts to break a portion that has been caulked by heat or cold, is reduced by the lever principle with a protrusion in the vicinity of the connection terminal portion, and a strong mounting portion can be realized.

Sectional drawing of the washing machine provided with the water level detection apparatus in embodiment of this invention Sectional view of the water level detector of the washing machine The principal part exploded perspective view of the water level detection apparatus of the washing machine Main part exploded block diagram of water level detection device of the washing machine Cross-sectional view of the main part showing the assembly method of the water level detection device of the washing machine Sectional view of a conventional water level detection device A perspective view of a conventional bobbin unit

  According to a first aspect of the present invention, there is provided a bobbin unit comprising an LC resonance circuit or an LC oscillation circuit in which at least one capacitor inserted in a bobbin pedestal and a coil having a coated copper wire wound around a bobbin winding frame are electrically connected at a terminal connection portion. And a movable core, a diaphragm joined to the movable core via a connection plate, an upper case forming an exterior, and a lower case, and in conjunction with the displacement of the diaphragm deformed by a change in pressure In the variable reactance type water level detection device that detects the water level of a washing machine or the like by changing the positional relationship with the coil by moving the movable core, the upper surface of the upper case is provided with at least one plane portion on the bobbin base The flat part is brought into contact with and fixed to the inner part, and the flat part for mounting is provided on the extension line of the bobbin pedestal part, so that the flat part of the mounting part at the time of molding is counteracted. When fixing to the upper case, it is not necessary to forcibly adapt to the surface of the upper case, it can be fixed without accumulating stress, and the coil does not move up and down even if the ambient temperature changes. The detection accuracy can be increased by stabilizing the oscillation frequency and stabilizing the oscillation frequency.

  In the second invention, in particular, a hole is provided in the vicinity of the coil center of the flat portion of the bobbin pedestal of the first invention, and the hole is passed through a boss provided on the inner surface of the upper surface of the upper case. Alternatively, the bobbin unit can be fixed to the upper case in a simple, strong, and reliable manner by abutting and fixing by heat caulking.

  In particular, the third invention provides a projection at a position facing the flat portion of the bobbin pedestal of the first or second invention, and when the connection terminal is inserted into the opening provided in the upper case, the projection Is inserted at the same time along the opening, and the bobbin unit can be positioned by inserting the connection terminal part of the bobbin unit into the opening provided in the upper case at an angle. Stress, that is, stress that attempts to break a portion that has been caulked by heat or cold, is reduced by the lever principle with a protrusion in the vicinity of the connection terminal portion, and a strong mounting portion can be realized.

(Embodiment 1)
About this Embodiment, the water level detection apparatus for detecting the water level used at the time of washing and rinsing of a washing machine is described.

  1 is a cross-sectional view of a washing machine provided with a water level detection device according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of the water level detection device of the washing machine, and FIG. 3 is an exploded view of a main part of the water level detection device of the washing machine. FIG. 4 is an exploded block diagram of the main part of the water level detection device of the washing machine, and FIG. 5 is a cross-sectional view of the main part showing an assembling method of the water level detection device of the washing machine.

  In FIG. 1, the water receiving tub 19 includes a washing / dehydrating tub 21 in which a rotary blade 20 is rotatably disposed in an inner bottom portion, and is suspended from a washing machine main body 23 by a suspension bar 22. The motor 24 is attached to the bottom of the water receiving tub 19 and is connected to the washing / dehydrating tub 21 or the rotary blade 20 via a V-belt 25 and a speed reducer 26. A liquid balancer 27 enclosing a liquid is fixed to the upper part of the washing and dewatering tank 21. The water supply valve 28 supplies water into the washing / dehydrating tank 21, and the drain valve 29 drains the washing liquid and the rinsing liquid in the washing / dehydrating tank 21. The control device 30 controls the motor 24, the water supply valve 28, the drain valve 29, etc., and sequentially controls a series of steps of washing, rinsing and dehydration. A water level detection hole opened at the lower peripheral surface of the water receiving tank 19 and the water level detecting device 31 are connected by a tube 32, and the water level detecting device 31 has a pressure according to the water level supplied to the water receiving tank 19. The water level is detected by the change.

  2 and 3, a coil 36 is formed by winding a coated copper wire 35 on a bobbin winding frame 34 of a resin bobbin unit 33, and a tin-plated copper product inserted from the side surface of the bobbin pedestal 37 of the bobbin unit 33. The capacitor 39 and the coil 36 installed on the connection terminal 38 and the bobbin pedestal 37 are gathered at one place on the back surface of the bobbin pedestal 37 and are electrically connected by solder at the solder portion 40. Further, two flat portions 41 are provided on the extended line of the bobbin pedestal 37 near the center of the coil 36 at the position facing the connection terminal 38, and through holes 42 are formed in the flat portions 41. Reference numeral 43 denotes a claw-like protrusion provided near the connection terminal 38.

  The flat portion 41 of the bobbin unit 33 is brought into contact with the upper inner surface of the upper case 44 made of resin, and after inserting the through hole 42 into the boss 45 provided in the upper case 44, the top portion of the boss is caulked hot or cold. To the upper case 44. A rubber diaphragm 48 is installed in a resin lower case 47 having a tube insertion port 46, and a magnetic movable core 50 is attached via a connection plate 49. 51 is a spring. Further, the tip of the tube 32 connected to the water receiving tank 19 shown in FIG. 1 is inserted into the tube insertion port 46 of the water level detection device 31.

  In FIG. 4, an LC resonance circuit is constituted by a coil 36 and a capacitor 39, and a water level in the washing and dewatering tub 21 is detected by detecting a signal from the oscillation circuit 52 by a microcomputer. .

  In FIG. 5, the bobbin unit 33 is slanted in the opening 53 formed in the side surface of the upper case 44 together with the claw-shaped protrusion 43 provided near the connection terminal 38 of the bobbin unit 33 and the connection terminal 38. The bobbin unit 33 is tilted toward the upper case 44 so that the protrusion 43 is along the side surface of the opening 53, and the through hole 42 provided in the flat portion 41 is inserted into the boss 45 of the upper case 44. Then, fix the top part by caulking.

  About the water level detection apparatus comprised as mentioned above, the operation | movement, an effect | action, and an effect are demonstrated below.

  In FIG. 1, the operation is described. After the laundry and detergent are put into the washing / dehydrating tub 21, when the operation is started, the water supply valve 28 is opened and water is supplied to a predetermined water level detected by the water level detection device 31. The motor 24 is driven. At this time, the power of the motor 24 is transmitted to the rotary blade 20, and the rotary blade 20 rotates to agitate the laundry, and dirt is removed by friction between the laundry or the washing / dehydrating tub 21 and the rotary blade 20. To do. In the dehydration process, after the washing is completed, the drain valve 29 is opened to drain the water in the washing / dehydrating tub 21, and then the power of the motor 24 is transmitted to the washing / dehydrating tub 21 to rotate it, and centrifugal force is applied to the laundry. This is done by separating the moisture from the laundry.

  The operation will be described with reference to FIGS. 2, 3, 4, and 5. When water is supplied into the washing and dewatering tub 21, the tube 32 is transmitted and pressure is applied from the tube insertion port 46 of the water level detection device 31. When the diaphragm 48 is deflected by an external pressure, the connection plate 49 attached to the diaphragm 48 rises, and the magnetic movable core 50 approaches the coil 36, so that the inductance of the coil 36 changes and the oscillation of the oscillation circuit 52 occurs. The water level is detected by changing the frequency and detecting the oscillation frequency.

  Further, by providing two flat portions 41 on the extended line of the bobbin pedestal 37 near the center of the coil 36 of the bobbin unit 33, the lower surface of the coil 36 and the flat portion 41 are in a straight line when resin molding is performed. Even when the flat part 41 can be maintained in a horizontal position, and the flat part 41 can easily come into contact with the upper case 44 without excessive force when the flat part 41 is brought into contact with the inner surface of the upper case 44, residual stress can be reduced. Can be fixed without accumulating.

  As a result, even if the ambient temperature changes, no stress remains on the flat surface portion 41 of the bobbin unit 33, so that the bobbin unit 33 does not move, the inductance of the coil 36 is constant, and the oscillation frequency is stabilized. Detection accuracy is increased.

  Further, in the present embodiment, the fixing method is such that a through hole 42 is provided in the flat portion 41, and the top portion is fixed by hot or cold caulking after inserting the boss 45 of the upper case 44 into the through hole 42. However, the bobbin unit 33 can be fixed to the upper case 44 with ease, strength and reliability.

Further, in the present embodiment, the bobbin unit is placed in the opening 53 formed on the side surface of the upper case 44 together with the claw-like protrusion 43 provided near the connection terminal 38 of the bobbin unit 33 and the connection terminal 38. The bobbin unit 33 can be easily positioned by inserting it while tilting 33. In addition, when the connector of the water level detection device 31 is inserted from the outside, there is a claw-like protrusion 43, so that if the connector is warped in the upward direction of the connection terminal 38 and the connector is to be inserted, the connection terminal 38 is moved downward. The protrusion 43 in the vicinity of the connection terminal 38 serves as a fulcrum, but the stress is reduced by the lever principle. However, by providing the claw-shaped protrusion 43, a force that breaks the caulking portion in inserting and removing the terminal is not applied, and the fixing can be performed more firmly.

  Although the said embodiment described the water level detection apparatus of the washing machine, if it is an electric equipment which has a function which detects the quantity of water and hot water using hot water, it will become equivalent by setting it as equivalent. Needless to say, an effect can be obtained.

  The water level detection device of the present invention has high detection accuracy because the bobbin unit does not move up and down even when the ambient temperature changes, and the oscillation frequency is stable and the coil frequency is constant. Stress, that is, stress that tries to destroy the part that has been crimped by heat or cold, is mitigated by the lever principle with the protrusion near the connection terminal, and a strong mounting part can be realized, so the coil is fixed to the case It can be applied to various devices that are used for electrical connection by inserting connectors or the like.

31 Water level detection device 33 Bobbin unit 34 Bobbin winding frame 35 Coated copper wire 36 Coil 37 Bobbin base 38 Connection terminal 39 Capacitor 41 Plane part 42 Through hole 43 Projection part 44 Upper case 45 Boss 47 Lower case 48 Diaphragm 49 Connection plate 50 Movable core 53 opening

Claims (3)

A bobbin unit that configures an LC resonance circuit or an LC oscillation circuit by electrically connecting at least one capacitor inserted in the bobbin pedestal and a coil in which a coated copper wire is wound around a bobbin winding frame at a terminal connection;
A movable core,
A diaphragm joined to the movable core via a connection plate;
It has an upper case that forms an exterior and a lower case, and the positional relationship with the coil changes as the movable core moves in conjunction with the displacement of the diaphragm that deforms due to a change in pressure. In the variable reactance type water level detection device that detects the water level,
A water level detecting device in which at least one flat portion is provided on the bobbin pedestal, and the flat portion is brought into contact with and fixed to the inner surface of the upper case.   A hole is provided in the vicinity of the coil center of the flat portion of the bobbin pedestal, the hole is passed through a boss provided on the inner surface of the upper surface of the upper case, and the boss head is contacted and fixed by cold or heat caulking. The water level detection device according to claim 1. The projection is provided at a position facing the flat portion of the bobbin pedestal, and when the connection terminal portion is inserted into the opening provided in the upper case, the projection is simultaneously inserted along the opening. Or the water level detection apparatus of 2.

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