JPS5846508Y2 - Thermal relay with phase loss protection - Google Patents

Description

[Detailed description of the invention] As shown in Fig. 1, a conventional thermal relay with phase loss protection includes a plurality of mounting brackets b1. b2. b3
The base ends of the plurality of bimetals C1, C2, and C3 are fixed to the base ends of the bimetals C1, C2, and C3, and the bimetals C1, C2, and C3 are arranged in parallel to each other,
Heater d1 attached to each of the above-mentioned bimetals C1, C2, and C3. d2. terminals e1.d3 each having one end fixed to the case a; e2゜ Connect to C3 and connect the other ends of the heaters (L, dz, and da to terminals f1, f2, and f3 attached to case a, and connect each bimetal C
A pair of drive rods g and g' are disposed in the case a so as to be slidable in the longitudinal direction so as to be substantially perpendicular to each other at the free ends of the bimetals C1, C2, and C3, respectively.
Contact piece h1. that contacts the high expansion side side surface of the free end of C3. h
2. Contact piece i1. ti2. i3 is integrally protruded from one side edge of the drive rod g', and the intermediate part of the drive piece j whose base end is pivotally supported on the tip of the drive rod g is pivoted by the drive rod g' to drive the drive piece j. A switch k is disposed in the case a, which is substantially orthogonal to the rods g and g', and which is operated by movement of the tip of the drive piece j over a certain amount.

However, the heater d1. d2. When d3 is inserted and connected in series to each phase wiring of a three-phase distribution line, and an overcurrent of a certain level or more flows through each phase wiring, each bimetal C1, C2 ° C3
is bent over a certain level, and the contact piece h1. of the drive rod g is bent. h2. h3 is in contact with the high expansion side side surface of each free end of each bimetal C1, C2, C3, and the contact piece i1. i2.
With i3 in contact with the low-expansion side surfaces of each bimetal C1, C2, and C3, drive rod g.

g' are moved together by the bending of the free ends of each of the bimetals C1, C2, and C3, and the tip of the drive piece j moves beyond a certain amount, causing the switch to operate.

Next, when an open-phase accident occurs in a three-phase distribution line, the free end of the bimetal corresponding to the phase wire with the open phase does not bend at all, and the free end of the bimetal corresponding to the phase wire without the open phase bends.

At this time, the contact piece of the drive rod g comes into contact with the high-expansion side side surface of the free end of the bimetal corresponding to the phase-fixing line where the phase is missing, and the drive rod g does not move, and the phase-fixing line where the phase is not open is connected. Only the drive rod g' moves due to the deflection of the corresponding bimetal, and the drive piece j
The base end of is pivotally supported by the drive rod g, and the middle part of the drive piece j is pivotally supported by the drive rod g', so the amount of movement of the tip of the drive piece j is greater than the amount of movement of the drive rod g'. , the switch is operated quickly.

However, the contact piece h1 of the drive rod g is attached to the high expansion side side surface of the free end of each bimetal C1, C2, C3. h2. h3, and the contact pieces i, i2 . In order to abut i3, the distance between the free ends of each bimetal C1, C2, C3 must be set to a predetermined value,
Conventional thermal relays with phase loss protection include mounting brackets, b2. By adjusting the attachment position of b3 to case a, or by plastically deforming bimetals C1, C2, and C3, the distance between the free ends of each bimetal C1, C2, and C3 is adjusted to a predetermined value. Because I was doing
There is a drawback that this adjustment work is complicated.

The present invention is intended to eliminate the above-mentioned drawbacks of the conventional technology, and an embodiment of the present invention will be described below with reference to the drawings. 1 is a case, 2a, 2b, and 2C are a plurality of bimetals, and their base ends are connected to the case. 1, mounting brackets 3a, 3b,
3C and are arranged parallel to each other.

4a, 4b, 4C are heaters attached to each bimetal 2a, 2b, 2C, one end of which is connected to terminals 5a, 5b, 5C attached to case 1, and the other end is connected to a terminal attached to case 1. 5a.

Connected to 6b and 6C.

7a, 7b, and 7C are adjustment screws with the same length,
They are screwed through screw holes at the free ends of each bimetal 2a, 2b, 2C.

8, 8' are a pair of drive rods, which are connected to each bimetal 2
A, 2b, 2C is disposed in the case 1 so as to slide perpendicularly to the free end of each bimetal, and one side edge of the drive rod 8 has a free end of each bimetal 2a, 2b, 2C. Adjustment screws 7a, 7b, 7C protruding from the high expansion side of the end
Contact pieces 8 a , 8 b , 8 C that abut against the base ends of the bimetal rods 8 a , 8 b , and 8 C are protrudingly provided on one side edge of the drive rod 8 ′.
Adjustment screws 7a, 7b protrude from the low expansion side surfaces of the free ends of 2b, 2C.

Contact pieces 8'a, 8'b, 8' that contact the tip of 7C
C is provided protrudingly.

9 is a drive piece that is perpendicular to the tips of the drive rods 8 and 8';
Its base end is pivoted to the tip of the drive rod 8, and its intermediate portion abuts or pivots to the tip of the drive member 8'.

A switch 10 is disposed within the case 1 and is operated by movement of the tip of the drive piece 9 over a certain amount.

Thus, in the present invention, the adjustment screws 7a having the same length,
7b, 7C for each bimetal/L/2 a, 2b, 2
To adjust the amount of protrusion from the high expansion side side surface of the bimetal at the proximal end of each adjustment screw even if the spacing between the free ends of each bimetal varies when the through screw is inserted into the screw hole at the free end of c. The distance between the base ends of each adjustment screw can be adjusted to a predetermined value, and each contact piece of the drive rod 8 can be brought into contact with the base end of each adjustment screw, and the distance between each adjustment screw can be adjusted to a predetermined value. Since the lengths of the drive rod 8' are the same, by setting the distance between the base ends of each adjustment screw to a predetermined value, the distance between the tips of each adjustment screw can be similarly adjusted to a predetermined value. Each contact piece can be brought into contact with the tip of each adjustment screw, which has the effect of providing a thermal relay with open-phase protection that is easy to assemble and adjust.

[Brief explanation of drawings]

Fig. 1 shows a conventional thermal relay with open-phase protection, Fig. 1 A is an internal side view, Fig. 1 opening is a sectional view taken along the line X-X of the above, and Figs. FIG. 2 is an internal side view, and FIG. 3 is a sectional view taken along the line Y--Y in the same embodiment. 1 is the case, 2a, 2b, 2C are bimetal, 3a, 3
b, 3C are mounting brackets, 4a, 4b, 4C are heaters, 7a, 7b, 7C are adjustment screws, 8, 8' are drive rods, 8a, 8b. 8C, 8'a, 8'b, and 8'C are contact pieces, 9 is a drive piece, and 10 is a switch.

Claims (1)

[Scope of utility model registration request] A plurality of bimetals 2a, 2b, 2C heated by heaters 4a, 4b, 4C are fixed to mounting brackets 3a, 3b, 3C whose base ends are fixed in case 1, and are arranged parallel to each other. Adjustment screws 7a, 7b, and 7C having the same length are screwed through the free ends of each bimetal, and a pair of drive rods 8 and 8' are perpendicular to the free ends of each bimetal. Contact pieces ga and 8b are arranged to slide in a direction perpendicular to each bimetal and come into contact with the base end of each adjustment screw.
, 8C are provided on the sliding rod 8, and contact pieces 8'a, 8'b, and s'c are formed on the driving rod 8' to abut the tips of the respective adjustment screws,
The base end of a drive piece 9 disposed perpendicularly to the tips of the drive rods 8 and 8' is pivoted to the tip of the drive rod 8, and the intermediate part of the drive piece 9 is pivoted to the tip of the drive rod 8'. A switch 1 that comes into contact with the drive piece 9 and operates as a result of movement of the tip of the drive piece 9 beyond a certain level.
Phase loss protection thermal relay with 0 arranged in case 1