JPH0226474Y2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Field of Industrial Application The present invention relates to a water injection and dehydration device that performs rinsing by dehydrating water while injecting water into a dehydration tank.

(B) Prior art It is important for this type of device to allow water to penetrate well into the laundry in the dehydration tank, and for this purpose, the dehydration tank is rotated intermittently, and water can be effectively absorbed when the dehydration tank rotates at low speed or when it is stopped. That's what I do. If you want to stop the induction motor that rotates the dehydration tank simply by a power outage,
As shown by the dashed line in FIG. 3, the time required for one rotation and stop becomes long, so the dehydration work is time-consuming. Therefore, DC power is applied to the main winding or auxiliary winding of the induction motor that rotates the dehydration tank.
Some attempt to apply electrical braking to the motor to bring it to a quick stop. This is shown by the dotted line in FIG.

Comparing the characteristics of the dashed-dotted line and the dotted line, there is not much difference in the state of decrease in rotational speed until a certain period of time after power cutoff and DC braking.

According to Japanese Patent Application Laid-Open No. 57-106385, the motor is allowed to rotate inertia for about one second before applying braking, and then DC power is applied to both the main and auxiliary windings. However, for one second, only the same characteristics as applying electric braking immediately can be obtained, and furthermore, during braking except for this one second, direct current is applied to both windings, causing significant heat generation.
In reality, even if direct current is applied to the main winding, the braking effect will be small, so adding direct current to this main winding will only promote heat generation and is not a good idea.

(c) Purpose of the invention The purpose of the invention is to obtain efficient braking characteristics that suppress heat generation in the windings by applying DC braking after a certain period of time has elapsed.

(d) Structure of the invention The invention uses AC power and DC power selectively applied to the induction motor that rotates the dehydration tank.
This water injection and dewatering device performs rinsing by injecting water while rotating the dehydration tank intermittently, and is characterized in that the DC power is applied after a certain period of time after the AC power is turned off. Therefore, as shown by the solid line in Figure 3, there is no difference in braking characteristics from the braking characteristic when DC power is applied from the beginning (dotted line), and dehydration work can be carried out smoothly, and the braking characteristics can be maintained even if DC power is applied only for a certain period of time. It is possible to suppress heat generation in the windings by delaying the

(E) Example To explain the following based on the drawings, in Fig. 1A, 1 is an AC power source, and 2 is a water injection means that rotates a centrifugal dewatering tank (not shown) that is continuously injected with water during water injection and dehydration. 3 and 4 are the main windings and auxiliary windings of the motor, and 5 is a starting capacitor.

The dehydration timer has a display around it that shows the time for continuous rotation of the dehydration tank and a display for the number of times the dehydration tank is intermittently rotated.The time and number of times can be adjusted by manually operating the knob. is set.

Reference numeral 6 denotes the first switch of the dehydration timer, which is continuously closed during a set time and a set number of times. 7 is a second switch, 8 is a changeover type third switch, and these switches 6, 7, and 8 are connected to the AC power source 1 and the motor 2.
connected in series between.

A diode 9 is connected in parallel to the second switch 7 as a DC converting means, and when the second switch 7 is open, DC power can be applied to the motor 2.
A switching contact a of the third switch 8 is connected to the main winding 3 of the motor 2, and a switching contact b is connected to the auxiliary winding 4.

FIG. 1B shows another embodiment in which the second switch 7 and the diode 9 are removed, and the diode 9 is connected in series between the switching contact b and the auxiliary winding 4.

The opening and closing states of the switches 6, 7, and 8 during water injection and dehydration are shown in the time charts in Figure 2 A and B. FIGS. 2A and 2B are time charts of the embodiments shown in FIGS. 1A and 1B, respectively. In addition, water is continuously poured into the dehydration tank at a rate of about 10 per minute during the set time.

In Figure 2, while the first switch 6 is closed, rinsing by water injection and dehydration is performed a maximum of five times and a minimum of three times. is closed, and the switching contact a of the third switch 8 is closed. In this way, AC power is applied to the motor 2 from the main winding 3 side at approximately 1400 r.pm.
Rotate clockwise to dehydrate the clothes in the dehydration tank and dilute the detergent solution in the clothes. This dewatering time _t1 is about 50 seconds, after which the switching contact a of the third switch 8 is released and the power to the motor 2 is cut off. This first power-off time _t2 is about 15 seconds, and the dehydration tank is decelerated to about 700 rpm, for example, as if braking was applied due to the resistance between the load (clothing) and the water injection.
Further, the second switch 7 is released during this first power-off time _t2 . After this first power outage time _t2 , the switching contact b of the third switch 8 is closed, and this time DC power is applied to the motor 2 from the auxiliary winding 4 side, and the dehydration tank, which was slowed down during the power outage, is Make it stop. This braking time t ₃ is about 15 seconds, after which switching contact b is opened to constitute a second de-energization time t ₄ of about 40 seconds. Then, the water injection and dehydration cycle is completed once during the above time period _t1 to _t4 , and is repeated several times depending on the setting of the timer knob.

In the case of FIG. 2B, the time chart of the second switch 7 in FIG. 2A is omitted.

As a result of such operation, in this example, braking characteristics as shown by the solid line in FIG. 3 were obtained. In other words, the characteristics are almost the same as those with direct current braking added from the beginning. Therefore, the dehydration work can proceed smoothly, and heat generation in the winding 5 during the first power-off time _t2 can be suppressed. Also, the overall power consumption is reduced.

(f) Effects of the invention The present invention can provide an economical water injection and dewatering device with a long lifespan, which can suppress heat generation in the windings and reduce power consumption while obtaining efficient braking characteristics.

[Brief explanation of the drawing]

Figures 1A and 2B are electrical circuit diagrams of each embodiment of the water injection and dewatering device according to the present invention, and Figures 2A and 2B are the electrical circuit diagrams of Figure 1A and 2B.
The time chart corresponding to B and FIG. 3 are braking characteristic diagrams. 2...Induction motor, 8...Third switch, 9...Diode.

Claims (1)

[Scope of utility model registration request] In the case where the dehydration tank is intermittently rotated by a capacitor run type induction motor in which a main winding and an auxiliary winding are connected via a capacitor, and water is poured into the dehydration tank for rinsing, the main winding is A switch a connected to the wire side and closed when the dehydration tank rotates, a switch b connected to the auxiliary winding side and closed after predetermined braking by water injection after switch a is opened, and this closed switch b A water injection and dewatering device characterized by comprising: a DC power supply connected to an auxiliary winding side through a DC power supply.