RU2172995C1 - Stepless power regulator - Google Patents

Abstract

FIELD: electrical engineering; bimetal temperature controllers. SUBSTANCE: device is designed to keep temperature of electric heating appliances within desired limits and can be used for stationary and portable ovens. As distinct from known regulators, proposed one has its supporting member mounting angle piece with different additional and different fixed and movable contact members. Stepless adjustment screw carries cam with different stop engageable with mentioned movable contact member. Bimetal compensating plate is screwed to insulator in overhanging position, its loose end abutting against upper plate of regulator for bending towards sensing member. EFFECT: enhanced reliability, operating stability, and electric safety of regulator. 2 dwg

Description

 The invention relates to thermoregulating bimetallic devices designed to limit a given temperature in electric heaters, and can be used in stationary and portable electric stoves.

 Known designs of temperature control devices and thermal switches of instantaneous operation, where the main elements are a movable spring contact and thermal bimetal acting on it (ed. St. N 1767565, H 01 H 37/54, 1992).

 The disadvantage of this device is its low sensitivity when installed in household electric stoves.

 Known temperature regulator containing a fixed contact, a sensing element made in the form of a plate of thermobimetallic material, a support element made in the form of a bracket with a hole in which the adjusting mechanism in the form of a smooth adjustment screw and an emphasis of insulating material, a plate with a tongue, contact holder with movable contact, made in the form of an elastic plate connected to the tongue of the plate, and the plate, support element, fixed contact and the sensing element are cantilevered len on the insulator, and the free ends of the sensitive element and the plate are interconnected using parts made of insulating material, in addition, the sensitive element and the plate have contact leads (French patent N 2577069, CL H 01 H 37/20, 1986). This patent is accepted as an analogue.

 In the known invention, a decrease in inertia and an increase in sensitivity when used in electric stoves are provided. For this, the sensing element is provided in the middle part with a spiral made of a material with high electrical resistance, one end of which is connected to a fixed contact, and the other end with the output of the sensitive element, the supporting element is equipped with a mounting bracket, mounted on the side bends of the supporting element, and in the shelf of this bracket a hole is made through which a smooth adjustment screw is passed, in addition, an emphasis of insulating material is installed on the tongue of the plate, in the elastic plate of the contact holder is made П-о different groove forming the tongue of the contact, it is resiliently curved towards the fixed contact and passed through a hole formed in the tongue plate, which is passed through the U-shaped groove in the elastic plate contact carrier. See RF patent N 2115971. This patent is adopted as a prototype.

Disadvantages:
- when the ambient temperature rises from heating devices and other heat emitters, the sensitive element heats up and turns off the device, not withstanding the specified temperature regime;
- since the phase does not turn off, in the event of a breakdown under voltage there will be a heating device, which is unacceptable.

The technical result - improving the reliability, stability of the power controller and its safety, is achieved by the fact that in the well-known stepless power controller:
- a square with an additional post with insulators and a contact consisting of a fixed contact part and a movable contact part is fixed on the support element;
- a cam with an emphasis interacting with the movable contact part is installed on the smooth adjustment screw;
- a bimetallic compensation plate is fixed on the insulator.

 In FIG. 1 - power regulator, general view, enlarged.

 In FIG. 2 - power regulator, top view, increased.

 The power regulator consists of insulators 1 and 2. On the insulators, a sensing element 4 in the form of a plate of thermo-bimetallic material, a top plate 5 with a tongue 16, a plate 6 with a fixed contact part 7, contact 8, a spiral 23, a support element in the form of a bracket 9. The upper plate 5 is connected to the contact terminal 10. The sensing element 4 is connected to the contact terminal 11. The free end of the sensing element and the end of the upper plate 5 are connected by a piece of insulating material 12. On the contact holder 13 the movable contact part 14 is displaced. The contact holder 13 is made in the form of an elastic plate with a groove and is connected by the tongue 15 to the end of the tongue 16 of the upper plate 5. The tongue 15 is located in the middle of the contact holder 13. The contact holder 13 together with the upper plate 5 form a spring system that provides instantaneous closing and opening of contact parts 7.14.

 The adjusting mechanism is a smooth adjustment screw 17, an emphasis 18 made of insulating material. The smooth adjustment screw 17 has a left-hand thread. The stop 18 is installed on the tongue 16 and is adjusted so that it constantly interacts with it. The upper plate 5 is passed through the groove 21 in the contact holder 13. The free end of the tongue 16 is made with an opening 22. The tongue 15 of the contact holder 13 is passed through the hole 22 in the free end of the tongue 16 of the upper plate 5.

 A spiral 23 made of a material with high electrical resistance, such as nichrome, is wound on a sensitive element 4 in its middle part. The end 24 of the spiral 23 is connected to the terminal 11. The bracket 9 is provided with a mounting bracket 26 mounted on the side bends 25 of the bracket 9. A screw 17 is passed through the hole 27 in the shelf 28 of the bracket 26.

 A square 19 with insulators 20 is fixed on the supporting element 9, between which a fixed contact part 29 and a movable contact part 30 are fixed. A cam 31 with a protrusion 32 and a recess 36 is mounted on the smooth adjustment screw 17. A bar 33 with a bent end is installed on the insulators 20 .

 A bimetallic compensation plate 34 is cantileverly fixed to the insulator 1 by a screw 3 with a possibility of deflection towards the sensitive element 4. The free end of this plate is aligned with the upper plate 5. Contact parts 30, 29 are connected to the terminals 37, 35.

 By a bracket 26, a power regulator is fixed to the front panel of an electric heating device (e.g., stove), not shown. To the conclusions 10, 11, 37, 35 connect the electrical circuit.

 The power controller operates as follows. In the initial state, the contact parts 7, 14, 29, 30 are open, since the stop 18 of the smooth adjustment screw 17 presses on the tongue 16, which transfers this force to the tongue 15 of the contact holder 13. The contact holder is held in its highest position. At this moment, the contact part 30 is in the recess 36, the contact parts 29, 30 are open, the phase is thus open. The bar 33 holds the cam 31 to the stop 32.

 Turn the screw 17 clockwise, setting the desired heating temperature. The movable contact part 30 during rotation of the cam 31 exits the recess 36, the contact parts 29, 30 are closed. The screw 17 is loosened, the pressure of the stop 18 on the tongue 16 is weakened, the contact holder 13 is lowered, the contact parts 7, 14 are closed. The current flows through the spiral 23, heats it and the sensing element 4.

 Under the influence of heat, the plate 4 bends, through the insulator 12 bends the upper plate 5. The plate 5 pulls the contact holder 13, the contact parts 7, 14 open.

 With increasing ambient temperature from operating heaters on the sensing element 4 there is an additional undesirable deflection, which compensates for the compensation plate 34, abutting the free end against the upper plate 5 and also bending from the ambient temperature.

The proposed power controller allows you to:
- increase the reliability of the work (the average operating time to failure is not less than 6000 hours.);
- increase the electrical safety of the product;
- smooth adjustment of power;
- to increase stability at ambient temperature up to 150 ^o C;
- maintain a range of adjustable powers of 800-2000 watts.

Claims (1)

 A stepless power regulator comprising a fixed contact part, a sensitive element made in the form of a plate of thermobimetallic material, a support element, an adjustment mechanism made in the form of a smooth adjustment screw and an emphasis of insulating material, an upper plate, a contact holder with a movable contact part, the upper plate, the support element, the fixed contact part and the sensor element are cantilevered on the insulator, and the free ends of the sensor element and the upper plate they are interconnected by means of a part made of insulating material, in addition, the sensitive element and the upper plate have contact leads, the sensitive element is equipped with a spiral of material with high electrical resistance in the middle part, the supporting element is equipped with a mounting bracket fixed to the lateral bends of this supporting element , and a hole is made in the shelf of this bracket through which a smooth adjustment screw is passed, characterized in that a square with other isolates is fixed to the support element frame with another fixed contact part and another movable contact part, a cam with a different stop is installed on the smooth adjustment screw with the possibility of interaction of this cam with another movable contact part, while a bimetallic compensation plate is fixed on the insulator with a screw, the free end of which abuts into the upper plate with the possibility of deflection towards the sensitive element.

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