JPH0367294B2 - - Google Patents

Abstract

1. A thermal relay comprising : a first case (2") in which are disposed current monitoring bi-metal strips (3 to 5) adapted to communicate their movements to a link (9) and a second removable case (2') associated with the first one so that the link may communicate to a normally closed safety switch (45), placed inside, a work position in which the switch is open, characterized in that this switch (45), a movement transmission device (77) and a thermal compensation device (19) are disposed in said second case (2') having a small width ("q") measured in the direction of movement of the link (9) and having on several faces (80, 61, 64, 110) access windows (85, 84, 83, 109, 116) which are closed by dividing walls (72, 63, 86, 76) belonging to the first case (2").

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention comprises a first case provided with a current monitoring bimetallic piece whose motion is transmitted to the link, and a removable second case combined with the first case. and a link transmitting motion to a normally closed safety switch disposed within the second case that opens when in the actuated position.

Such relays are widely used in the electrical field to protect motors in combination with contactors placed between the motor and the power supply network.

If these thermal relays are formed of two removable mating parts, a first case with a bimetallic piece and a second case with a safety switch, the relays are provided with a similar switch case. Depending on the output of the motor, it is very easy to combine with various bimetal piece cases.

Such a combination becomes easier the higher the power of the motor, and at the same time the volume of the case becomes larger, so that the various mechanical parts installed between the link transmitting the deformation of the bimetallic piece and the safety switch are Individual placement becomes easy.

On the other hand, difficulties arise when it is necessary to make thermal relays as compact as possible so that their volume matches the volume of modern contactors used in thermal relays. Modern contactor volumes today are close to 100 cm ³ for motors of about 2-3 KW.

This difficulty is essentially due to the relative importance of employing normal manufacturing crossovers also when the case has a small volume and the volume of the associated parts, as well as the relative importance of employing normal manufacturing crossovers when the case has a small volume and the current monitoring bimetallic piece. and the possibility of heat exchange between the temperature-compensating bimetallic piece and the temperature-compensating bimetallic piece.

This difficulty can be largely avoided by using a monitoring bimetallic piece case separate from the switch case in which the compensating bimetallic piece is housed, but to improve compactness and ease of installation, It is necessary to adopt measures compatible with current operation, protection against external factors and good electrical insulation.

The object of the invention is to provide an installation compatible with continuous installation, using two removable cases in which measures are taken to require a volume close to or less than the volume of the associated contactor. The object of the present invention is to provide a thermal relay capable of maintaining excellent coordination between the movable parts of the device, electrical insulation comparable to that of a contactor, and sufficient protection against the surrounding environment.

For example, the following thermal relay is already known from US Pat. No. 3,315,054. The general construction is the same as that described above, but the arrangement of the movable members does not significantly reduce the size of the movable members themselves, and one window for introducing these movable members into the interior of the switch case. This makes it difficult to attach movable parts. Furthermore, all the adjustment members of a thermal relay are not provided on the same top side, to the extent that space must be left for mounting the adjustment members between the relay and the equipment adjacent to the relay. This will indirectly increase the space.

The thermal relay of the present invention includes a safety switch, a motion transmission device, and a thermal compensation device in a second case, and the second case has a small width “q” measured in the direction of movement of the link, and The first case is characterized by having mounting windows on several sides that are closed by the partition wall of the first case.

Hereinafter, the present invention will be explained based on the drawings. The thermal relay 1 of the present invention has a circuit shown in FIG. Provides protection function to M. The auxiliary contact 95 is
It is also operated by this electromagnet. This thermal relay has power input terminals 100, 101, 102 connected to corresponding terminals of the contactor, and power terminals 103, 104, 105 connected to the motor.
It has Heaters 3', 4', 5' are provided between these input terminals and output terminals, and these heaters cause deformation of the bimetal pieces 3, 4, 5 arranged in the vicinity thereof. These heaters also form part of a bimetallic piece. The safety switch 57, which is normally closed,
When the bimetallic piece reaches a certain temperature, it is opened by the action of the bimetallic piece. This constant temperature is reached after a time that depends on the previous temperature of the bimetallic piece and the magnitude of the current flowing through the heater.

In the circuit shown in FIG.
3 is coupled in series to the safety switch 57 via terminals 92, 91, 70, 71, and to the + of the power supply.
It is coupled between the pole and the - pole. switch 94
Auxiliary contact 95 coupled in parallel to switch 9
energizes the electromagnet when 4 stops working.

In abnormal conditions such as overheating of the motor, when the bimetallic piece reaches a very high temperature, switch 57 opens and the electromagnet is deenergized and opens power switches 96, 97, 98, cutting off power to the motor. do.

The operation of the thermal relay 1, the selection of the constant operating mode, the regulation of the nominal current of the motor and the setting of the relay in industry are provided by a number of elements shown in FIG. 1b. According to this figure, this relay has an external case 2;
It can be seen that two connected cases 2' and 2'' are used.

Inside the case 2″ are bimetal pieces 3, 4, 5,
Those heaters and corresponding terminals 100, 101,
102, 103, 105, 105, and a motion transmission link 9 which receives the deformation of these bimetallic pieces to the push rods 6, 7, 8.

The container 2' includes a safety switch 57, related terminals 70, 71, and components to be described later. One end 10 of the link inserted into the case 2' through the opening 11 of the case 2'' and the opening 12 of the case 2'' is connected to the point 1 of the one end 17' of the lever 17.
End 1 of lever 14 rotatably attached to 5
3, and the other end 17'' of the lever 17 is
It is rotatably mounted at point 18 on case 2'.

These two levers 14 and 17 form a movement transmission mechanism 77 that transmits the movement of the link to the dead center crossing device 30. To transmit this movement, lever 1
4 point 24 is the contact point 23 of the ambient temperature compensator 19
requires contact with. The contact point 23 is formed by the end of a bimetallic piece 22 fixed to the frame 20 which pivots about a pivot 21.

Between the frame 20 and a point 26 on the case 2',
A spring 25 fixed to the frame 20 transmits a clockwise torque to this frame. This torque causes the fixed end 27 of the bimetallic piece 22 to act on the cam 28 of the current regulator 65. The current adjustment device further includes an adjustment member 29 connected to the cam and drives a current scale 62.

The dead point crossing device 30 includes a locking lever 31
It is equipped with This lever moves around the bin 32 so that the first contact surface 59 in the region 33
It oscillates between a stable resting position R in which it contacts the stopper 58, and two operating positions _T1 or _T2 , which will be described later.

A spring 34 tensioned between a first locking point 34' of the lever 31 and a second locking point 34'' located at one end 16 of the lever 14 is such that the spring axes 34' and 34'' are aligned with the pivot 32. A dead center effect is applied when passing through the axis of .

The second contact surface 35 of the region 33 is located at each position T ₁ , T ₂
Under the action of the spring 34, a stop provided by the end 37 of the operating mode selection device 36 can be touched. The operating mode selection device 36 is formed, for example, by a cylindrical rod 38. This cylindrical rod can slide and rotate within the opening of the case 2' so as to place the stud 43 of the case 2' in one of the ends of the groove 42 extending axially and tangentially on its surface. can.
The cylindrical rod is further acted upon by a return spring 41. Spring 41 returns end 37 to position M.
The end 37 can be brought to position A by the user pushing and rotating the top 40 of the cylindrical rod 38.

The lever 31 has a hammer 44. This hammer separates the movable contact 48 and the fixed contact 49 of the safety switch 57 for each position T ₁ , T ₂ . For this reason, the hammer 44 is
opposite one end 46' of the. The lever 46 has a movable contact 48, and the other end 46'' of the lever has a movable contact 48.
It is rotatably provided at a point 47 on the case 2'.
Therefore, as explained below, lever 46
and contacts 48 and 49 form a variable resistance torque switch indicated at 45. The lever 46 is actually integral with a first end 50'' of a tension spring 50, which has a second end fixed to the movable part 51 of the position adjustment device 78. In one mode of operation, in which the end 37 of the cylindrical rod 38 is in position A, when the movement of the bimetallic pieces 3, 4, 5 is transmitted to the link 9, the transmission 77 is pushed to the left and follows the path of travel D. After moving over , it contacts the end 23 of the bimetallic piece 22. The deflection of the lever 14 about point 24 forms a linear array of points 34', 32, 34''. This linear arrangement immediately causes a sharp clockwise rotation of the lever 31. This rotation of the lever causes the hammer 4
4 collides with lever 46 and opens switch 57.

The position adjustment device 78 comprises an elastically deformable U-shaped member 53 having a fixed leg 55 integral with the case 2' and a movable leg 52 with a movable part 51. The position of the movable leg 52 is determined by screwing the leg 52 onto the leg 52.
It can be adjusted by means of an adjustment screw in contact with 5. Movement of the movable part 51 changes the torque applied to the lever 46 by the spring 50.

The purpose of this adjusting device 78 is that when the stop 37 is in position A and the lever 31 is in position _T2 (this corresponds to the automatic re-closing of the switch), the spring 50 causes the lever to The torque applied to the hammer 46 is slightly greater than the opposite torque applied to the hammer 44 by the spring 34 to provide an erratic characteristic to the opening of the switch. In this case, as soon as the bimetallic piece has cooled down, the lever 31 returns to its rest position R and the switch 57 closes.

If the bimetallic piece is sufficiently heated and the end 37 is previously set in position M, the transmission 7
The clockwise rotation of the lever 31 caused by 7 ends when the contact surface 35 contacts the end 37.

The lever 31 in position _T1 opens the switch 57 and holds it stably in this position. This is due to the fact that the torque applied to spring 34 is greater than the torque applied by spring 50. This adjustment of the torque value is based on a change in the slope of the two springs. After the bimetallic piece has cooled sufficiently, the thermal relay must be reset to manually close switch 57 again. This reset, which can be accomplished by a separate manual reset member, can also be accomplished by pushing button 40 axially to the left in FIG. 1b.

The thermal relay can further include a member 73 for optionally opening the switch 57 through the action of the lever 46. The switch is opened when a movement in direction B by the user is transmitted to member 73.

The various operations and interactions described above are
The basic operation diagram is shown in FIG. 1a. In Figure 1a, the same numbers are used for the same parts and devices as in Figure 1b.

The thermal relay 1 uses a first case 2''. According to FIG. 8a, this first case 2''
is divided into adjacent compartments 3a, 4a, and 5a, and each compartment is provided with bimetallic pieces 3, 4, and 5, respectively. These bimetallic pieces are
It cooperates with link 9 which moves RR′. two parallel walls 74, 76 transverse to the compartment;
A housing 87 having a small width "q" (approximately 11 mm) is provided between the bottom portion 72 and the external partition wall 86. This housing has a central plane PP' parallel to the wall and perpendicular to the plane RR'. The wall portion 76 is elastically deformable in the direction of width “q”.

As can be seen from the plan view in FIG. 8b, the outer surface 88 of the case 2'' adjoining the compartment is closed by a lid 89 which also closes the lateral inlet 99 of the housing 87.

This insulating lid includes a connecting terminal 100 penetrating the lid,
101 and 102. These connection terminals. It is guided by grommets 101a, 102a, 103a, and other connection terminals 103, 1
04,105.

For purposes described below, two openings 106,1
07 is provided on the external partition wall 86 and located approximately within the plane PP' (see FIGS. 8a and 8b). The housing 87 accommodates the second case 2' between the two parallel opposing surfaces 63 and 108 of the partitions 74, 76. The function of the second case 2' has been described above. The second plane shown as a cross section of plane PP′
According to figure a, it can be seen that the interior of the case 2' is divided into two separate spaces 66 and 67 by an internal partition wall 75. Each of these spaces communicates with the upper space 68 and is a surface on which the link 9 moves.
It is provided in a region L adjacent to RR'.

The space 66 is, on the one hand, located at the bottom 80 of the case 2'.
It leads to the outside through a lower opening 85 and, on the other hand, through a side window 83 opened in the same plane as the contact surface 61 for cooperating with the surface 63 of the wall 74. (See Figures 4 and 8b).

On the one hand, the space 67 opens to the outside through a side window 109 which is open in the same plane as the side surface 110, and on the other hand, it is connected to the outside through a window 84 which opens into the face 61 of the case 2' and occupies the entire width of the space 68. This leads to the outside (see Figures 2a, 4 and 5). Furthermore, the window 116 and the opposite window 83 opening in the surface 64 allow movement of the pivot frame 60.

These windows and openings provide spaces 66, 67, 6 for providing the elements described in FIG. 1b.
It borders on 8.

The space 66 mainly accommodates the components of the conduction device 77 and the components of the thermal compensation device 19, the space 67 mainly accommodates the components of the switch device 45 and a part of its adjustment device 78, and the space 68 mainly accommodates the components of the switching device 45 and a part of its adjustment device 78. It mainly accommodates 30 members and 65 members of the current adjustment device. According to FIG. 2a, and optionally FIGS. 3, 4 and 5, the axes of rotation or rotation of all pivots or hinges of the levers used are
It can be seen that it is approximately located at PP'. shaft
XX' is the axis of the pivot 18, axis YY' is the axis of the joint 15, axis TT' is the axis of the pivot 21,
It can be seen that VV' has the axis of pivot 47, and axis ZZ' has the axis of pivot 32.

The pivots 18, 32, 47 have U-shaped recesses 18
a, 18b; 32a, 32b; 47a, 47b. These recesses support the blades of the corresponding movable parts (see especially FIG. 3).
On the other hand, the frame 20 includes studs 21a and 21b.
It is rotatably mounted on the top by its cheek portion 20'. This method of blade rotation provides very low friction and ease of installation. On the other hand, the greater friction occurring on studs 21a and 21b of shaft TT' is easily overcome by the torque applied to cam 28 during manual current adjustment. axis of joint 15
YY' is also parallel to the other axes.

The part of the adjustment device 78 of the switch 45 that is not provided in the space 67 passes through the window 109.
It protrudes from the outside of case 2'. These parts are
A first conductive member 70a that is fixed to the case 2' and has a terminal 70 for connecting to the fixed contact 49 and is integral with the U-shaped member 53 and contacts the lever 46 of the movable contact 48 for connecting to the terminal 71. and the second conductive member 71a.

The part of the adjusting device that extends outside the case 2' is a U-shaped member 53 in which the screw 54 engages, so that if the removable case 2' has not yet been assembled with the case 2'', the above-mentioned It is extremely easy to adjust the torque on-site.

Conductors 70a and 7 extending parallel to bottom 80
1a passes through each opening 106, 107 of the partition wall 86 when the two cases are assembled.

The current setting member 29, the operation mode (M or A) selection member 40, and the member 73 for arbitrarily opening the switch are inserted into the parallel axes II' and JJ by passing through the upper wall 113 of the case 2'. ′、
KK' or around these axes. The upper wall 113 is located opposite the bottom part 80 and includes an upper adjustment surface 7 on which, for example, a current scale 62 is provided.
It has 9. These axes I, J, K are planes
It is located almost within PP′. When the case 2' is engaged in the housing 87 of the case 2'' in the F direction,
Recess 114 in surface 61 extending parallel to bottom 80
allows the end of the projecting link 9 to be located opposite the window 83 which also forms the opening 12 of FIG. 1b (see FIGS. 3, 5 and 8b). To combine the two cases, remove the screws from terminals 70 and 71 of conductors 70a and 71a.

Contact surface 61 of case 2'' to surface 63 of case 2'
This contact is possible because the wall 76 is resilient. Surface 108 of wall 76 is deflected toward surface 64 of case 2' (see arrow C in FIG. 8a).

The lid 89 disposed in the F direction is connected to the housing 87
and is held in place by contacting surface 112 while closing the compartment (see Figure 8b).

The reduction in volume of the case 2' is mainly due to the respective arrangement of the parts in the various spaces and the lightness of the walls due to the large number of windows and openings which also facilitate the installation.

One or more partition walls 86 of bimetallic case 2″
The electrical insulation of the terminals 70, 71, which is formed or completed when the two cases are assembled by the This can also be done by protection for the surroundings provided by other parts of the case 2'', such as.

[Brief explanation of drawings]

FIG. 1a is a diagram of a thermal relay schematically showing the various functions of the device and how they work together; FIG. 1b is a diagram of an embodiment of the thermal relay of FIG. 1a; , a diagram that simply shows the various parts in one and the same plane for clarity of operation,
Fig. 2a is a diagram showing a removable case housing the switch in a cross section of the central plane PP', with movable parts removed to clearly show the arrangement of each space. A diagram showing the exterior of the switch case seen from the front of Figure 2a, No. 2
Figure c is a diagram showing the exterior of the switch case seen from the rear side of Figure 2a, Figure 3 is a sectional view of the switch case similar to Figure 2a but showing the movable parts;
Figure 4 is a cross-sectional view on the SS' plane of Figure 3;
The figures are a cross-sectional view at the fold plane QQ' of Fig. 3, Fig. 6 is a simplified perspective view of the two cases of the assembled thermal relay, and Fig. 7 is a thermal relay for the motor and contactor.・Relay wiring diagram, Figure 8a is a side view of a thermal relay with a bimetallic piece for current monitoring, Figure 8b is a side view of a thermal relay with a bimetallic piece for current monitoring.
FIG. 3 is a plan view of the thermal relay shown in FIG. Explanation of the symbols of the main parts, 2'...Second case,
2″...First case, 3, 4, 5...Bimetal piece, 3a, 4a, 5a...Compartment, 9...Link,
14, 17, 20, 30, 46... lever, 19
...Heat compensator, 29,40,73...Adjustment member, 30...Dead point crossing device, 45,57...Safety switch, 54...Adjustment screw, 61,64,8
0,110...face, 63,72,76,86...
Partition wall, 66, 67, 68... Space, 70, 71
... Connection terminal, 76 ... Elastic partition wall, 77 ... Operation transmission device, 79 ... Adjustment surface, 83, 84, 8
5,109,116... window, 87... housing, 89... lid, 99... entrance section.

Claims (1)

[Claims] 1. A first case provided with a current monitoring bimetallic piece whose motion is transmitted to the link, and a removable second case combined with this first case.
a thermal relay comprising a case, the link transmitting motion to a normally closed safety switch disposed within the second case that opens when in the actuated position, the safety switch 45 and a motion transmission device; 77 and the thermal compensator 19 in the second case 2'.
The second case has a small width "q" measured in the direction of movement of the link 9, and has partition walls 72, 63, 8 of the first case 2''.
Mounting windows 85, 8 closed by 6, 76
4, 83, 109, 116 as several faces 80, 6
1,64,110. 2. A patent characterized in that the second case 2' is pressed against the surface 63 of the first case 2'' and in the direction C of the link 9 by the elastic partition wall 76 of the first case 2''. A thermal relay according to claim 1. 3 The motion transmission device 77, the heat compensation device 1
9. Dead point crossing device 30 and the safety switch 4
5 has levers 14, 17, 20, 3, respectively.
0 and 46 rotation axes YY′, XX′, TT′, ZZ′,
The small width "q" is obtained by the parallel arrangement of VV', and all these pivot axes are aligned with the central plane of the second case 2' perpendicular to the direction of movement of the link 9.
PP′, and the rotation axes XX′, ZZ′ and
3. The thermal relay according to claim 1, wherein the pivot of VV' uses a blade and a recess. 4. The first region L of the second case 2' adjacent to the motion surface RR' of the link 9 comprises two adjacent spaces 66, 67, in which the motion transfer device 77 and the heat A compensating device 19 is provided in each space, the safety switch 45 is provided in the other space, and the dead point crossing device 30 is provided in a third space that communicates with the two spaces and is further away from the plane of motion. A thermal relay according to any one of claims 1 to 3, characterized in that: 5. An adjustment surface 79 that partitions the third space and is opposite to the motion surface RR' adjusts the trip current and selects one of the two modes A and M for resetting the safety switch 45; It has three adjusting members 29, 40, 73 for arbitrarily operating the safety switch 45, and their movement axes I, J, K are arranged substantially in the central plane PP' and parallel to each other. A thermal relay according to claim 4, characterized in that: 6. The safety switches 45, 57 are located approximately within the central plane PP', and between this central plane and the link 9.
Thermal according to any one of claims 1 to 5, characterized in that the thermal conductor is connected to two connection terminals 70 and 71 provided on a connection surface 110 perpendicular to the motion plane RR' of the ·relay. 7. The thermal switch according to claim 6, characterized in that the adjustment screw 54 of the safety switch 45 can be attached to the outer surface 110.
relay. The compartments 3a, 4a, 5a of the first case 2'', in which the bimetallic pieces 3, 4, 5 for operating the links 9 of 8 are provided, are covered with a removable lid 89.
It is characterized in that the lid forms an inlet part 99 of the housing 87 of the first case adapted to accommodate the second case 2', and that this housing is partitioned, in particular, by an elastic partition wall 76. A thermal relay according to any one of claims 1 to 7.