JPS5826438Y2 - centrifugal force switch - Google Patents

Description

[Detailed description of the invention] Recently, relatively high-capacity split-phase starting single-phase motors have come into widespread use, and the contact capacity of the centrifugal force switch that opens the starting winding when the starting of the motor is completed. There is a strong demand for improvement.

Moreover, due to the miniaturization of the motor itself or its load equipment,
The actual situation is that the dimensions of centrifugal force switches cannot be increased despite the increase in contact capacity.

In response to such demands, the present invention aims to provide a large-capacity, small-sized centrifugal force switch.

The centrifugal force switch of the present invention consists of an opening/closing contact part C provided on the electric equipment body and a co-rotating part R attached to the motor rotating shaft S.

At opening/closing contact part t, F2, 11-' base made of material, 2, 3
are the fixed contacts 3,
3, the base end is fixed to the base 1, and the terminal hole 2A
, 2A.

Reference numeral 4 denotes a lever consisting of a semi-circular arc-shaped operating part 4A surrounding the electric motor rotation axis S and a base 4B, 5 a support plate, and 6 equipped with movable contacts 7, 7 at the tip, respectively, along the operating part 4A of the lever 4. It is a movable contact plate made of an elastic metal plate that is separated from an extending semicircular arc portion 6A and a bent base portion 6B.

The base 4B of the lever 4 is pivotally supported by engaging the groove 4C at its tip with the groove 5A at the tip of the support plate 5, and is supported by the bent base 6B of the movable contact plate 6 into the gate-shaped rising portion 5B of the support plate 5.
is constantly being pushed.

Next, in the reaching part R, 8 is a slider that freely moves the motor rotation shaft S, and an annular part 8A that opposes and separates from the semicircular arc-shaped operating part 4A of the lever 4 of the first opening/closing contact part C. has.

Reference numeral 9 denotes a support base having a hole 9A in the center into which the electric motor rotating shaft S is press-fitted, and reference numeral 10 represents an actuating piece 11 whose one end is pivotally supported on the support base 9.
It is also a centrifugal force actuator that flies open against the tension spring 12 in response to an increase in the rotational speed of the motor shaft S, and drives the slider 8 rightward in FIG.

Next, we will discuss the operation.

When the electric motor is stopped, the slider 8 moves to the left in FIG. 1 under the action of the tension spring 12, and its annular portion 8A moves the lever
Then, the movable contact plate 6 is pressed, and the movable contact 7 is closed with the fixed contact 3 (see Figure 4).

The centrifugal force actuator 10 gradually flies open against the tension spring 12, and as soon as it reaches a predetermined rotational speed and passes the dead center of the tension spring 12, it rapidly pulls the slider 8 toward the right in FIG. .

After the slider 8 moves a minute distance and generates acceleration, the pressure on the lever 4 and the movable contact plate 6 is released, and the lever 4 and the movable contact plate 6 move as shown in FIG. 1 due to the elasticity of the latter. It rotates counterclockwise to rapidly open contacts 3 and 7, cutting off the power to the starting winding of the motor.

That is, if the relative positions of the rotating part R and the opening/closing contact part C are properly determined, after the slider 8 starts to move rapidly, both contacts 3.7 are rapidly opened, resulting in the state shown in FIG. 4A. The breaking ability of the contact can be improved.

Therefore, as shown in Fig. 3, the conventional switch of this type has the following characteristics.
On the base 1, there is a terminal plate 2' having a fixed contact 3' and a terminal screw hole, and a movable contact plate 6' made of an elastic metal plate having a movable contact 7' at the free end and having a terminal screw hole. was provided, and the base end 4'D of the semicircular arc portion of the lever 4' was opposed to the back surface of the movable contact 7'.

Therefore, as shown in FIG. 5, the distance Ll' from the pivot point of the lever 4' to the contacts 3' and 7' is The ratio was large, and it was not possible to make the contact gap G' large relative to the stroke l of the slider 8.

In contrast, the present invention has a lever 4 as shown in FIG.
The distance L1 from the pivot point of the lever 4 to the contact points 3 and 7 is approximately equal to the distance L2 from the pivot point of the lever 4 to the driving point of the slider 8, and therefore the stroke l of the slider 8 is Even if they are the same, the contact gap G can be made extremely large.

In addition, when opening and closing, the movable contact 7 is connected to the bent base 6B of the movable contact plate 6.
Since the fixed contacts 3 each move circularly around the fixed part of the terminal plate 2 to the base 1, both contacts 7
, 3, the wiping action is performed.

Compared to conventional models, the free ends of the lever and movable contact plate are shaped into semicircular arcs and are cleverly arranged to surround the motor rotating shaft, so the space required is the same, and the movement and stroke of the slider are equal. In both cases, the contact has two points of contact, which improves the breaking speed of the contact, increases the gap when it opens, and improves welding resistance due to the wiping action between both contacts. Since the plate extends widely from the base and both contacts are in flowing air, the current capacity and durability of the contacts are greatly improved, such as excellent heat dissipation.
This is a distant relative of the intended purpose for small, high-capacity electric motors.

[Brief explanation of the drawing]

Figure 1 is a front view of the present invention, Figure 2 shows the opening/closing contact part,
A is a front view of the central longitudinal section, the opening is a partially cutaway right side view, C is a bottom view, Figure 3 shows the opening/closing contact part of the conventional type, A is a front view of the central longitudinal section, and the opening is a partially cutaway right side view. Figures 4 and 5 are diagrams explaining the operation of the present invention and the conventional one, respectively. ). S: Motor rotating shaft, C: Opening/closing contact part, R: Rotating part, 1;
Base, 2; Terminal board, 3; Fixed contact, 4; Lever, 4A;
Semi-circular arc-shaped operating portion, 4B; base, 5; support plate, 6; movable contact plate, 6A; semi-circular arc-shaped portion, 6B; bent base, 7; movable contact, 8; slider, 8A; annular portion.

Claims (1)

[Scope of utility model registration request] A semicircular arc-shaped operation part that is rapidly driven by a slider that moves quickly at a predetermined rotational speed of a rotating part attached to the electric motor rotating shaft, is provided on the electric equipment body, and surrounds the rotating shaft. A movable contact plate made of an elastic metal plate that pivotally supports the base end of the lever and extends along the operating part of the lever has movable contacts at both ends of a semicircular arc, and two terminals protrude from the base. A movable contact that moves in a circle around the bent base of the movable contact plate and a fixed contact that moves in a circle around the fixed part of the terminal plate are brought into contact with each other by a wiping action. Centrifugal force switch with opening/closing contact parts that can be separated.