JPH09153326A - Thermal type overload relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal type overload relay wherein dimensional accuracy of an adjust screw does not affect setting accuracy of operation temperature and a loosening locking process of the adjust screw is improved. SOLUTION: A thermal type overload relay 1 is equipped with a switching mechanism 2 having a sheet-shaped body 3. This sheet-shaped body 3 is formed into a rectangular shape using a thin, flat sheet-shaped spring plate material, and its lower side end part is attached by caulking to a beam-shaped body 71 in one body with a pressing body 75 while its upper side end part is formed to have dimensions which make it possible to stand opposite to a tip end part of an adjust screw 72. A position of the sheet-shaped body 3 standing opposite to the tip end part of the adjust screw 72 is a circular arc part formed into a circular arc which becomes recessed toward the tip end part of the adjust screw 72. The switching mechanism 2 is adapted such that a projecting side face of the circular arc part of the sheet-shaped body 3 makes contact with a cam face of an eccentric cam 992 possessed by an adjusting dial 99.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal overload relay provided with a bimetal device that is bent by being heated by a heating body through which an electric current to be detected is passed, and finely adjusts the operating current value. The present invention relates to a structure improved so as to easily reduce dimensional accuracy required for an adjusting screw and prevent loosening thereof.

[0002]

2. Description of the Related Art A device to be detected, which is installed in multi-phase and single-phase electric lines, detects one of the electric currents flowing in the electric line when the electric current value becomes excessive and outputs a signal. BACKGROUND OF THE INVENTION It is well known that thermal overload relays are widely used, which are equipped with a bimetal device that is heated by a heating element through which an electric current is passed to perform a bending operation.

A conventional example of this type of thermal overload relay is shown in FIG.
2, it demonstrates using FIG. Here, FIG. 12 is a front view showing a conventional thermal overload relay without a lid, and FIG. 13 is a partial detailed view of FIG.
13A is a detailed view of a P portion of FIG. 12, and FIG. 13B is a sectional view taken along line AA in FIG. FIG.
Reference numeral 2 shows a conventional single-phase to three-phase thermal overload relay in a normal operation state. 12 and 13,
9 is a storage having two sets of main bimetal device 8, shifter 93, opening / closing mechanism 7, reversing mechanism 6, contact mechanism 5, adjusting dial 99, case 921 and a lid not shown. It is a thermal overload relay provided with a container 92.

Each of the main bimetal devices 8 is formed in a strip shape by using a flat bimetal plate, one end of which is a heat receiving portion 81 held in a case 921, and an electric insulating layer is provided around the heat receiving portion 81. And a heating body 82 made of a heating wire wound through the heating element. The heating body 82 is supplied with the current flowing through the electric path, and Joule heat is generated in an amount according to the current value. The temperature receiving portion 81 is heated by receiving the Joule heat generated from the heating body 82, and performs a bending operation according to the temperature according to the property of the bimetal plate. The end portion on the opposite side to the fixed one end of the temperature receiving portion 81 is a free end, and this free end is the temperature receiving portion 81.
The higher the temperature becomes, the higher the temperature becomes, and it is installed so as to be displaced in the right direction in FIG. The free ends of the temperature receiving portions 81 of both main bimetal devices 8 are connected to the shifter 93. The shifter 93 is movably supported by a guide groove 922 for the shifter 93 formed in the case 921. An end portion 93a of the shifter 93 on the right end side in FIG. Accordingly, the movement operation in the horizontal direction in FIG. 12 is performed.

The opening / closing mechanism 7 includes a beam-shaped body 71, an adjusting screw 72 screwed and mounted near one end of the beam-shaped body 71, a release lever 73, a compensating bimetal device 74, and a pressing body. And 75. Beam-shaped body 71
Is a through hole 711 formed near the center of the
It is rotatably supported by the case 921 by being inserted into and attached to the round pin 923 fixed to the case 921. A female screw 713 for inserting the adjusting screw 72 is formed at one end of the beam-shaped body 71. The pressing body 75 is formed by using a thin flat plate-shaped spring plate material, and is fixed by caulking to the female screw 713 side of the through hole 711 of the beam-shaped body 71, and the tip end portion of the adjusting screw 72 is dialed. It plays a role of pressing against the cam surface of an eccentric cam 992 described later.

In this case, a headless screw is used as the adjusting screw 72. When the screwing amount of the adjusting screw 72 is determined, the adjusting screw 72 is prevented from loosening and the thermal overload relay 9 is prevented. In order to keep the operating current value of (1) stable for a long time according to the set value, a locking agent 721 made of synthetic resin is applied between the beam-shaped body 71 and the same. The release lever 73 is
A round pin 71 fixed to the other end of the beam-shaped body 71
It is inserted into 2 and is rotatably supported. The compensating bimetal device 74 is formed in a strip shape by using a flat bimetal plate, and the release lever 73 is formed in the vicinity of a substantially central portion thereof.
It is stuck to. This compensating bimetal device 74 is
The lower end 74 a in FIG. 12 is the end 9 of the shifter 93.
3a, and the upper end in FIG. 12 is sized so as to face the pressed portion 6a of the reversing operation mechanism 6. Then, the compensating bimetal device 74 is fixed to the beam-shaped body 71 such that the end portion 74a thereof is displaced in the right direction in FIG. 12 as the temperature thereof becomes higher.

In the case shown in FIG. 12, the reversing operation mechanism 6 has a shape and structure that is already well known by using a thin flat plate-shaped spring plate material, and the pressed portion 6a is provided in the vicinity of its central portion. Has been formed. The reversing mechanism 6 is shown in FIG.
Two support points are provided at positions in the upper and lower sides of the two, and both support points are supported by the case 921. In the reversing operation mechanism 6 having such a structure, the pressed portion 6a is pressed from the right side in FIG. 12 by the upper end portion of the compensating bimetal device 74, and the pressing degree exceeds the preset pressing value. Then, the well-known inversion operation is performed. The upper end portion of the reversing operation mechanism 6 in FIG. 12 performs a rapid left-right movement operation in FIG. 12 along with the reversing operation of the reversing operation mechanism 6.

In the case shown in FIG. 12, the contact mechanism 5
Has fixed contacts 51, 53, movable contacts 52, 54, and a slider 55, and the fixed contacts 51, 53 and the movable contacts 52, 54 are held by the case 921. , 54 are in contact with the slider 55. Then, the fixed contact 51 and the movable contact 52 make 1
A contact point is formed, and the fixed contact point 53 and the movable contact point 1b
It constitutes a contact. The slider 55 is a case 921.
The slider 55 is movably supported by a guide groove (not shown) for the slider 55, and is connected to the upper end of the reversing mechanism 6 at the right end in FIG. 12 of the slider 55. As a result, the slider 55 performs the left-right movement operation in FIG. 12 along with the left-right movement operation of the upper end of the reversing operation mechanism 6. In the contact mechanism 5, when the slider 55 is pushed to the left by the reversing operation mechanism 6 (the state shown in FIG. 12), the 1a contact is opened and the 1b contact is closed. Further, when the slider 55 is pushed to the right by the reversing operation mechanism 6, contrary to the above, the 1a contact is closed and the 1b contact is opened.

The adjusting dial 99 has a dial portion 991 rotatably held at a side end portion of the case 921 and an eccentric cam 992 which is a position adjusting portion. The eccentric cam 992 has an adjusting screw 7 which the opening / closing mechanism 7 has on its cam surface.
The distal end portion of No. 2 is configured to abut, and the interval length L ₉₉ between the central axis X of the dial 99 and the distal end portion of the adjusting screw 72 is changed by rotating the dial 99 [ 13 (b)]. In the thermal overload relay 9, by rotating the dial portion 991 of the dial 99 from the outside to change the interval length L ₉₉ and change the position of the end portion 74a of the compensating bimetal device 74, the operating value can be changed. It is possible to adjust a certain operating current value.

Since the conventional thermal overload relay 9 is constructed as described above, when it is used for a three-phase three-wire type electric line, for example, any two electric wires of the electric line are When used for a single-phase two-wire type electric line, one of the electric lines of the electric line is connected to the terminal of the thermal overload relay 9 to which the heating body 82 of the main bimetal device 8 is connected. . When the value of the current flowing in the electric path is small, the degree of bending of the temperature receiving portion 81 is small, and therefore the degree to which the pressed portion 6a of the reversing operation mechanism 6 is pressed via the opening / closing mechanism 7 is small. The operating mechanism 6 is in the state shown in FIG. Therefore, the slider 55 of the contact mechanism 5 is pushed to the left by the reversing operation mechanism 6, and the thermal overload relay 9 is in a normal operating state.

When the value of the current flowing through the electric path increases and reaches the operating current value of the thermal overload relay 9, a current having this operating current value is passed through the heating element 82, so that the temperature receiving portion 81 Is greatly curved. As a result, the end portion 74a of the compensating bimetal device 74 of the opening / closing mechanism 7 is largely displaced in the right direction by the end portion 93a of the shifter 93. Then, the release lever 73, to which the compensating bimetal device 74 is fixed, rotates counterclockwise in FIG. 12 with the portion inserted into the round pin 712 as the rotation center. As a result, the upper end of the compensating bimetal device 74 strongly presses the pressed portion 6a of the reversing operation mechanism 6 (in FIG. 12, the compensating bimetal device 74 in this state).
Is indicated by a chain double-dashed line).

As a result, the reversing operation mechanism 6 performs a reversing operation and its upper end portion instantaneously moves to the right, the slider 55 of the contact mechanism 5 is switched to the state of being pushed to the right, and the 1a contact is closed. Then, the 1b contact is opened, and the thermal overload relay 9 is activated. Often 1b
Since the contact is connected to an exciting coil such as an electromagnetic switch installed in the electric circuit in which the thermal overload relay 9 is installed, and the 1a contact is connected to an alarm device, the thermal overload relay 9
When is activated, the electromagnetic switch immediately cuts off the electric circuit, safety measures are taken for the electric circuit and the load device connected to the electric circuit, and an alarm is issued.

Since the temperature receiving portion 81 constituting the main bimetal device 8 is heated not only by the heating body 82 but also by the room temperature in which the thermal overload relay 9 is installed, the temperature receiving portion 81 is not heated as it is. The operating current value of the overload relay 9 is affected by the room temperature value. This is compensated for by the compensating bimetal device 74, and the temperature of the compensating bimetal device 74 is almost equal to room temperature. Therefore, as the room temperature rises, the end portion 74a of the compensating bimetal device 74 is increased.
Is displaced to the right. This compensation bimetal device 74
Due to the displacement of the end portion 74a according to the room temperature, the influence of the room temperature value on the operating current value is canceled in the thermal overload relay 9. Further, the adjusting screw 72 is for adjusting so that the error of the operating current value due to variations in the manufacturing dimensions, the mounting dimensions, the displacement amount, etc. of the above-mentioned various parts constituting the thermal overload relay 9 is minimized. It is a part provided. The adjustment of the operating current value is performed by the beam-shaped body 7
Since the adjustment screw 72 is screwed into the screw 713 at one end of the No. 1, the gap length L ₇₂ between the opening / closing mechanism 7 and the cam surface of the eccentric cam 992 is adjusted (see (b) of FIG. 13). It is done by doing. This adjustment is often
The test is performed after the assembly of the thermal overload relay 9 is completed. Therefore, the case 9 of the thermal overload relay 9
21 is provided with an adjusting screw 7 at a portion facing the adjusting screw 72.
Through hole 9 having a shape and dimensions into which a tool (for example, a screwdriver) used for the screwing operation of 2 can be inserted.
24 is generally formed.

[0014]

In the thermal overload relay according to the prior art described above, for example, the thermal overload relay 9, even if the components used have some variations, the setting of the operating current value is required. Although it is possible to provide a product that can accommodate the error within the allowable error and can compensate the room temperature fluctuation, there are still the following problems. That is, (1) if there is a gap between the adjusting screw 72 and the female screw 713, the female screw 713
The angle formed by the adjusting screw 72 with respect to the central axis line of No. 2 and the position of the central axis line of the adjusting screw 72 may change due to vibration or the like. The change of the angle and the position of the central axis means that the contact point Q (see FIG. 13) between the cam surface of the eccentric cam 992 of the dial 99 and the tip of the adjusting screw 72 is deviated. This means that since the cam surface has an arc shape, the distance L ₇₂ between the opening / closing mechanism 7 and the cam surface of the eccentric cam 992 changes, and the set value of the operating current of the thermal overload relay is changed. Will change. Further, the shape of the tip of the adjusting screw 72 is, for example,
In the case where the eccentric cam 992 is formed in the shape of an inclined surface (which means that the tip end portion of the adjusting screw 72 is formed as a plane having an angle with respect to the central axis that is not 90 degrees). Since the surface is arcuate, the interval length L ₇₂ may not change linearly with respect to the turning angle of the adjusting screw 72 (it will have hysteresis, dead zone, etc.). In this case, the adjusting screw 72
When the operation current value is adjusted by using, an undesired error occurs in the set value of the operation current value.
In order to deal with the above, it is necessary to adopt a special adjustment screw 72 having an external thread with high dimensional accuracy or an accurate spherical tip shape. There was Although the use of the special adjustment screw 72 can reduce the amount of setting error of the operating current value described above, the use of a general-purpose screw makes the adjustment screw 72 itself expensive to manufacture. At the same time, since the general-purpose screw must be purchased and stored separately from the general-purpose screw, the management cost increases, which also causes the manufacturing cost of the thermal overload relay 9 to be high. Further, (2) it is necessary to apply the lock agent 721 to the adjusting screw 72 as described above in order to stably maintain the interval length L ₇₂ for a long period of time. Agent 721
Is required and an application confirmation step for confirming that the lock agent 721 is applied in a predetermined manner, which causes the manufacturing cost of the thermal overload relay 9 to be expensive. It was

The present invention has been made in view of the above-mentioned problems of the prior art, and a first object thereof is a thermal type in which the dimensional accuracy of the adjusting screw does not affect the operating temperature setting accuracy. A second object of the present invention is to provide an overload relay, and a second object thereof is to provide a thermal overload relay having an improved adjustment screw locking process.

[0016]

According to the present invention, the above-mentioned first
The purpose of 1) is that the main bimetal device is heated by a heating body through which an electric current to be detected is passed to perform a bending operation, and the bending degree of the main bimetal device via an opening / closing mechanism. And a contact mechanism that is opened and / or closed in accordance with the reversing operation of the reversing operation mechanism, and one end of the opening / closing mechanism. And an adjusting dial for adjusting the current value when the reversing operation mechanism performs the reversing operation, and the opening / closing mechanism is rotatably supported near the central portion. A beam-shaped body and an adjusting screw that is mounted near one end of the beam-shaped body and abuts on an adjusting portion of the dial, and the main bimetal device is bent at the other end of the beam-shaped body. To catch the movement Yes, the main bimetal device is largely curved by the current in the overcurrent state being passed through the heating body, and the reversing operation mechanism is strongly pressed by the opening / closing mechanism to the largely curved main bimetal device to perform the reversing operation. In the thermal overload relay in which the contact mechanism is opened and / or closed by the switch mechanism, the opening / closing mechanism includes a plate-like body held by a beam-like body, and the adjusting screw abuts on one side surface of the plate-like body. At the same time, the adjustment part of the dial is achieved by being brought into contact with the other side surface of the plate-shaped body.

Since the tip of the adjusting screw is in contact with the plate-like body, the angle formed by the adjusting screw with respect to the central axis of the female screw for inserting the adjusting screw and the central axis of the adjusting screw Even if displacement of the tip of the adjusting screw in the direction of arrow R shown in FIG. 3B, which will be described later, occurs due to changes in the position due to vibrations, etc., the gap between the opening / closing mechanism and the adjusting unit of the dial. Length [L ₂ shown in FIG. 3 (b). ] Does not change. Further, since the tip of the adjusting screw comes into contact with the plate-shaped body, even if the tip of the adjusting screw is formed in a sloped shape, the turning angle of the adjusting screw is On the other hand, the interval length can change linearly.

Further, according to the second object of the present invention, 2) the main bimetal device which is heated by a heating body through which an electric current to be detected is passed to perform a bending operation. A reversing operation mechanism that is pressed according to the bending degree of the main bimetal device via the opening / closing mechanism and that performs a reversing operation according to the pressing degree, and is opened and / or closed according to the reversing operation of the reversing operation mechanism. The opening / closing mechanism has a contact mechanism that adjusts the position of one end of the opening / closing mechanism, and an adjustment dial for adjusting the current value when the reversing operation mechanism performs the reversing operation. The beam-shaped body includes a beam-shaped body rotatably supported in the vicinity of a substantially central portion, and an adjusting screw mounted near one end of the beam-shaped body and abutting an adjusting portion of a dial. At the other end of the It receives the bending operation of the immetal device, and the main bimetal device is greatly bent by the current in the overcurrent state being passed through the heating body, and it is strongly pressed by the opening and closing mechanism to the heavily curved main bimetal device. In a thermal overload relay in which the contact mechanism is opened and / or closed by the reversing operation of the reversing mechanism, the switching mechanism is provided with a loosening prevention structure by press fitting the adjusting screw. To be done.

Since the opening / closing mechanism is provided with the loosening prevention structure due to the press-fitting of the adjusting screw, it is not necessary to use the locking agent as in the conventional example in order to prevent the loosening of the adjusting screw. 3) According to the third aspect, in the means described in the second aspect, the loosening prevention structure of the adjusting screw provided in the opening / closing mechanism is formed in the beam-shaped body for mounting the adjusting screw, and the adjusting screw is provided. This is achieved by a configuration having a female thread having a thread diameter smaller than the thread diameter of the male thread of the screw and a slit that partially removes this female thread in the radial direction and reaches the end face of the beam-shaped body. .

Thus, when the adjusting screw is inserted into the female screw, the width of the slit is widened, so that the width of the slit is widened between the female screw and the adjusting screw. The reaction force generated by this is added. A frictional force corresponding to this reaction force acts between the female screw and the male screw of the adjusting screw. 4) According to the fourth aspect, in the means described in the second aspect, the loosening prevention structure of the adjusting screw provided in the opening / closing mechanism is a triangle or a polygon formed in the mounting portion of the adjusting screw of the beam-shaped body. And a female screw having a smaller screw diameter than the male screw of the adjusting screw, which is formed on the inner diameter side of the through hole for mounting the adjusting screw. To be done.

Thus, when the adjusting screw is inserted into the female screw, the distance between the opposite sides of the triangular or polygonal through hole formed in the mounting portion of the adjusting screw of the beam-shaped body is increased. Therefore, the reaction force generated due to the widening of the slit interval is applied between the female screw and the adjusting screw. A frictional force corresponding to this reaction force acts between the female screw and the male screw of the adjusting screw. 5) According to the fifth aspect, in the means described in the third or fourth aspect, the adjusting screw included in the loosening prevention structure for the adjusting screw included in the opening / closing mechanism is a female screw into which the adjusting screw is inserted. This can be achieved by using a material that is softer than the beam-shaped body of the portion to be formed.

Thus, in the step of inserting the adjusting screw into the female screw, the male screw formed on the adjusting screw is cut by the female screw. As a result, the thread shape of the male thread formed on the adjusting screw can be made almost the same as the thread shape of the female thread. Furthermore, 6) According to claim 6, the above items 2 to 5
In the means described in any of the above items, the adjustment screw provided in the opening / closing mechanism has a male screw thread whose tip portion is smaller than the screw diameter of the female screw, and has a maximum male screw diameter of the female screw. This is achieved by having a taper screw having a diameter larger than the diameter.

Thus, even if the screw formed in the beam-like body for mounting the adjusting screw has a female screw having a smaller screw diameter than the maximum screw diameter of the male screw of the adjusting screw, The screw can be easily inserted into the female screw.

[0024]

Embodiments of the present invention will be described below in detail with reference to the drawings. In the following description of this section, the same parts as those of the conventional thermal overload relay shown in FIGS. 12 and 13 are designated by the same reference numerals, and the description thereof will be omitted. In addition, in the figures used for the description of this section,
Regarding the reference numerals given in FIGS. 12 and 13, only representative reference numerals are shown.

Embodiment 1; FIG. 1 is a front view showing a thermal overload relay according to an embodiment of the present invention corresponding to claim 1 without a lid, and FIG. It is the perspective view which shows the principal part of the opening / closing mechanism shown in FIG. 3 is a partial detailed view of FIG. 1, FIG. 3A is a detailed view of a main part of the opening / closing mechanism, and FIG. 3B is a detailed view of FIG. 13 of the thermal overload relay shown in FIG. It is a detailed view of the site | part corresponding to (b). FIG. 4 is a perspective view of the S portion in FIG. 1 to 4, reference numeral 1 denotes a thermal overload relay in which the switching mechanism 2 is used instead of the switching mechanism 7 in the conventional thermal overload relay 9 shown in FIGS. 12 and 13. Is.

The opening / closing mechanism 2 includes a plate-shaped body 3 in addition to the opening / closing mechanism 7 according to the conventional example. Plate 3
Is formed in a strip shape using a thin flat plate-shaped spring plate material, for example, and the lower end in FIG. 1 is caulked integrally with the beam body 71 with the pressing body 75, and the upper side in FIG. The end portion is formed in such a size that it can face the tip portion of the adjusting screw 72. A portion of the plate-shaped body 3 facing the tip end portion of the adjusting screw 72 is an arcuate portion 31 formed in an arcuate shape that is concave toward the tip end portion of the adjusting screw 72. Thus, the opening / closing mechanism 2 is configured to contact the cam surface of the eccentric cam 992 of the adjustment dial 99 on the convex surface of the arcuate portion 31 of the plate-shaped body 3.

The embodiment shown in FIGS. 1 to 4 has the above-mentioned configuration, so that the tip end portion of the adjusting screw 72 has the tip portion as already described in the item (1) of the means for solving the problem. It is in contact with one side surface of the plate-like body 3. As a result, for example, the angle formed by the adjusting screw 72 with respect to the central axis of the female screw 713 and the position of the central axis of the adjusting screw 72 are changed due to some cause during use of the thermal overload relay 1. However, depending on the displacement of the tip portion of the adjusting screw 72 in the direction of the arrow R shown in FIG.
_It is possible to keep ₂ unchanged. Further, as two, even when the tip end portion of the adjusting screw 72 is irregularly shaped such as being formed in a slope shape, the interval length L ₂ is almost equal to the turning angle of the adjusting screw 72. It can be changed linearly. Then, even if the tip position of the adjusting screw 72 changes as described above, the eccentric cam 992 of the dial 99 is provided.
The contact point Q ₃ between the cam surface of No. 3 and the other side surface of the plate-like body 3 [see (b) of FIG. 3] can be kept unchanged.

Thus, in the thermal overload relay 1, even if the adjusting screw 72 has some dimensional error, the operating current set value will not change due to vibration or the like. Therefore, the change in the interval length L ₂ with respect to the turning angle of the adjusting screw 72 does not have hysteresis or dead zone. This makes it possible to use an inexpensive general-purpose screw as the adjusting screw 72.
Therefore, the management cost for storage etc. can be reduced.

In the above description of the first embodiment, the arcuate portion 31 is formed at the portion of the plate-like member 3 facing the adjusting screw 72, but the present invention is not limited to this.
For example, it may be flat. And then
When the plate-shaped body at the portion facing the adjusting screw 72 is formed into a flat plate shape, the flat plate-shaped portion may be formed so as to be substantially parallel to the beam-shaped body 71 at the portion where the female screw 713 is formed. This is preferable from the viewpoint of stabilizing the interval length L ₂ .

In the above description of the first embodiment, one end of the plate-like body 3 is crimped to the beam-like body 71 integrally with the pressing body 75, but the present invention is not limited to this. For example, the pressing body 75 may be fixed to the beam-shaped body 71 at an appropriate portion other than the portion where the pushing body 75 is caulked. Embodiment 2; FIG. 5 is a front view showing a thermal overload relay according to an embodiment of the present invention corresponding to claims 1 to 3 without a lid. 6 is a perspective view showing a main part of the opening / closing mechanism in the assembled state shown in FIG. 5, and FIG.
It is the perspective view which shows the principal part of the opening / closing mechanism shown in FIG. 5 in a disassembled state. 5 to 7, the same parts as those of the thermal overload relay according to the embodiment of the present invention corresponding to claim 1 shown in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof will be omitted. 5 to 7, 1A is a thermal type overload relay in which the switching mechanism 2 is used instead of the switching mechanism 2 in the thermal type overload relay 1 according to the present invention shown in FIGS. 1 to 4. Is.

The opening / closing mechanism 2A is different from the above-described opening / closing mechanism 2 according to the present invention in that the opening / closing mechanism 7 used in the opening / closing mechanism 2 is replaced by a beam-shaped body 41.
I am trying to use. The beam-shaped body 41 has a thread diameter smaller than that of the male thread of the adjusting screw 72 as a female thread for inserting the adjusting screw 72 with respect to the beam-shaped body 71 employed in the opening / closing mechanism 2 described above. In addition to replacing with the female screw 42, a part of the threaded portion of the female screw 42 is removed in the radial direction to form a slit 43 reaching the end face 41a of the beam-shaped body 41. That is,
In the opening / closing mechanism 2A, the loosening prevention structure of the adjusting screw 72 is composed of the female screw 42 and the slit 43.

Since the embodiment shown in FIGS. 5 to 7 has the above-mentioned configuration, the second aspect of the means for solving the problems (2)
As already described in Section (3), when the adjusting screw 72 is to be inserted into the female screw 42, the female screw 42
Since the screw diameter of the slit 43 is smaller than the screw diameter of the male screw of the adjusting screw 72, the width of the slit 43 can be expanded in the direction of arrow T in FIG. As a result, a reaction force generated by expanding the width of the slit 43 is applied between the female screw 42 and the adjusting screw 72, and a frictional force corresponding to this reaction force is applied to the female screw 42 and the adjusting screw 72. Will be added between and. This frictional force can prevent the adjusting screw 72 from loosening due to vibration or the like, so that the locking agent 721 required in the conventional example can be eliminated. Then, this frictional force is applied to the female screw 42 and the adjusting screw 72.
Since the force is automatically generated by inserting, the step of confirming the frictional force is unnecessary. Opening / closing mechanism 2A
In the thermal overload relay 1A using the above, the manufacturing cost can be reduced because the lock agent 721 and the application confirmation step thereof are not required.

Embodiment 3; FIG. 8 is a perspective view showing an essential part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention corresponding to claims 1, 2 and 4. 9
FIG. 9 is a plan view showing a main part of the beam-shaped body shown in FIG. 8. 8 and 9, the same parts as those of the thermal overload relay according to the embodiment of the present invention corresponding to claim 1 shown in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted. 8 and 9, 2B is a beam-shaped member 44 instead of the beam-shaped member 41 for the opening / closing mechanism 2A used in the thermal overload relay 1A according to the present invention shown in FIGS. It is an opening / closing mechanism adapted to use the opening / closing mechanism 4B using. The beam-shaped body 44 is formed by forming a rectangular through hole 45 in place of the slit 43 at the portion where the female screw 42 is formed in the beam-shaped body 41 employed in the above-described opening / closing mechanism 2A. It was done. That is, in the opening / closing mechanism 2B, the loosening prevention structure for the adjusting screw 72 is configured by the female screw 42 and the through hole 45.

Since the embodiment shown in FIGS. 8 and 9 has the above-mentioned configuration, the second aspect of the means for solving the problems (2)
As already described in Section (4), when the adjusting screw 72 is to be inserted into the female screw 42, the female screw 42
Since the screw diameter of the through hole 45 is smaller than the screw diameter of the male screw of the adjusting screw 72, the through hole 45 can extend the opposite side distance L ₄₅ . As a result, the female screw 42 and the adjusting screw 72
Since the opposite side distance L ₄₅ is widened between and, a reaction force generated in the portion where the through hole 45 of the beam-shaped body 44 is formed is applied, and a frictional force corresponding to this reaction force is generated by the female screw 4
2 and the adjusting screw 72. With this frictional force, it is possible to obtain the same action and effect as in the case of the second embodiment described above.

In the above description of the third embodiment, the through hole formed in the beam-like member 44 of the opening / closing mechanism 2B is the rectangular through hole 45, but the through hole is not limited to this. For example, the shape of the through hole may be a square, a triangle, or a pentagon or more polygon. In the above description of the third embodiment, the through hole formed in the beam-shaped body 44 of the opening / closing mechanism 2B is the through hole 45 having a rounded corner. However, the invention is not limited to this. It is not limited to this, and may be, for example, a through hole provided with a notch at the corner. By providing the notch at the corner, the value of the reaction force generated when the opposite side distance L ₄₅ is expanded can be reduced, and the adjusting screw 72 can be reduced.
The torque value required for inserting the female screw 42 into the female screw 42 can be reduced.

Embodiment 4; FIG. 10 is a perspective view showing an essential part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention in an exploded state. 10, the same parts as those of the thermal overload relay according to the embodiment of the present invention corresponding to claim 1 shown in FIGS. 1 to 4 are designated by the same reference numerals, and the description thereof will be omitted. FIG.
0, 4C is an opening / closing mechanism 4A used in the thermal overload relay 1A according to the present invention shown in FIGS.
On the other hand, the opening / closing mechanism uses the adjusting screw 46 instead of the adjusting screw 72. The adjusting screw 46 is different from the adjusting screw 72 used in the opening / closing mechanism 4A described above.
As the material, a material softer than the material of the beam-shaped body 41 is used. And then
For the material of the adjusting screw 46, for example, when the material of the beam-shaped body 41 is soft iron, a known free-cutting brass material or synthetic resin material can be adopted. When adopting a soft iron material, it is possible to use the beam-like body 41 made of iron material in which at least the portion where the female screw 42 is formed is subjected to hardening treatment such as quenching treatment.

Since the embodiment shown in FIG. 10 has the above-described structure, the female screw 42 is formed on the female screw 42 as already described in the paragraphs (2) and (5) of the means for solving the problems. When the adjusting screw 46 is to be inserted, the screw diameter of the female screw 42 is smaller than the screw diameter of the male screw of the adjusting screw 46, but in the process of inserting the adjusting screw 46 into the female screw 42, In the adjusting screw 46 using a material softer than the hardness of the material used at least in the portion where the female screw 42 is formed, the male screw formed in the adjusting screw 46 is cut by the female screw 42. The Rukoto. As a result, the thread shape of the male thread formed on the adjusting screw 46 can be made almost the same as the thread shape of the female thread 42. As a result, the contact area between the male screw formed on the adjusting screw 46 and the female screw 42 is increased in addition to the frictional force due to the widening of the slit 43 according to the second embodiment. Thus, the obtained frictional force can be increased. Then, by such a frictional force, it is possible to obtain the same action and effect as in the case of the second embodiment described above.

Although the opening / closing mechanism 4C has the beam-shaped member 41 as the beam-shaped member in the above description of the fourth embodiment, the present invention is not limited to this.
It may be the beam-shaped body 44. Embodiment 5; FIG. 11 is a perspective view showing an essential part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention in an exploded state. 11, the same parts as those of the thermal overload relay according to the embodiment of the present invention corresponding to claim 1 shown in FIGS. 1 to 4 are denoted by the same reference numerals, and the description thereof will be omitted. In FIG.
4D is an opening / closing mechanism in which an adjusting screw 47 is used instead of the adjusting screw 72 for the opening / closing mechanism 4A used in the thermal overload relay 1A according to the present invention shown in FIGS. 5 to 7. is there. The adjusting screw 47 is the opening / closing mechanism 4A described above.
In comparison with the adjusting screw 72 used in, the tip end portion has a male screw diameter smaller than the female screw 42 and the maximum male screw diameter is larger than the female screw 42. It has a diameter taper screw.

Since the embodiment shown in FIG. 11 has the above-mentioned configuration, the adjustment screw 47 of the adjusting screw 47 is used as already described in the paragraphs (2) and (6) of the means for solving the problems. Although the outer diameter of the maximum diameter male thread is larger than the thread diameter of the female thread 42, the tip portion thereof has the male thread diameter smaller than the thread diameter of the female thread 42. It can be easily inserted into.

In the above description of the fifth embodiment, the opening / closing mechanism 4D has the beam-shaped body 41 as the beam-shaped body, but the present invention is not limited to this.
It may be the beam-shaped body 44. Although the material of the adjusting screw 47 has not been referred to in the description of the fifth embodiment, the material of the adjusting screw 47 can be the material of the adjusting screw 72 or the material of the adjusting screw 46.

In the above description of the second to fifth embodiments, the opening / closing mechanism has the plate-like body 3. However, the opening / closing mechanism is not limited to this, and the adjusting screw 72 and the adjusting screw 4 are not limited thereto.
In cases such as 6 and 47 do not require high dimensional accuracy,
The plate-shaped body 3 may be omitted.

[0042]

According to the present invention, the following effects can be obtained by adopting the structure described in the section for solving the above-mentioned problems. With the configuration according to item (1) of the means for solving the problem, since the tip end portion of the adjusting screw and the adjusting portion of the dial come into contact with the plate-shaped body, the adjusting screw may be slightly different. Even if there is a dimensional error, there is no change in the set value of the operating current due to vibration or the like, and no hysteresis or dead zone when adjusting the interval length L ₂ by the adjusting screw. As a result, the setting accuracy of the operating current value is high,
It is possible to obtain a thermal type overload relay whose operating current value is stable over a long period of time, and an inexpensive general-purpose screw can be used as an adjusting screw. It is possible to reduce the manufacturing cost of the overload relay. In addition, when the adjustment screw is inserted into the female screw, the width of the slit is expanded by adopting the configuration according to the items (2) and (3) of the means for solving the problem. Since the frictional force due to the reaction force is added as a preventive force for preventing the adjustment screw from loosening, it is possible to eliminate the use of the lock agent used in the conventional thermal overload relay. This makes it possible to reduce the manufacturing cost of the thermal overload relay including the coating confirmation step. Further, by adopting the configuration according to the item (4) of the means for solving the problem, friction due to a reaction force generated by expanding the opposite side distance of the through hole when inserting the adjusting screw into the female screw is provided. Since the force is applied as a preventive force for preventing the adjustment screw from loosening, it is possible to eliminate the use of the locking agent used in the conventional thermal overload relay. This makes it possible to reduce the manufacturing cost of the thermal overload relay including the coating confirmation step. Further, by adopting the configuration according to item (5) of the means for solving the problem, when the adjusting screw is inserted into the female screw, the male screw of the adjusting screw is cut by the female screw, Since the screw shapes of the two are almost the same, the frictional force between them increases, so
It is possible to further increase the effect of the term.

By adopting the constitution according to the item (6) in the section of means for solving the problems, the above items
It is possible to easily insert the adjusting screw into the female screw while obtaining the effect of the item.

[Brief description of the drawings]

FIG. 1 is a front view showing a thermal overload relay according to an embodiment of the present invention corresponding to claim 1 without a lid.

FIG. 2 is a perspective view showing a main part of the opening / closing mechanism shown in FIG.

3A and 3B are partial detailed views related to FIG. 1, in which FIG. 3A is a detailed view of a main part of the opening / closing mechanism, and FIG. 3B is a detailed view of an adjusting screw and an eccentric cam.

FIG. 4 is a perspective view of an S portion in FIG.

FIG. 5 is a front view showing a thermal overload relay according to an embodiment of the present invention, which does not include a lid, corresponding to claims 1 to 3;

FIG. 6 is a perspective view showing a main part of the opening / closing mechanism in the assembled state shown in FIG.

FIG. 7 is a perspective view showing an essential part of the opening / closing mechanism shown in FIG. 5 in an exploded state.

FIG. 8 is a perspective view showing a main part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention corresponding to claims 1, 2, and 4.

9 is a plan view showing the main part of the beam-shaped body shown in FIG.

FIG. 10 is a perspective view showing an essential part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention corresponding to claims 1 to 5 in an exploded state.

FIG. 11 is a perspective view of an essential part of an opening / closing mechanism used in a thermal overload relay according to an embodiment of the present invention corresponding to claims 1 to 6 in an exploded state.

FIG. 12 is a front view showing a conventional thermal overload relay without a lid.

FIG. 13 is a partial detailed view of FIG. 12, (a).
Is a detailed view of part P of FIG. 12, and (b) is a view of (a) of FIG.
A-A sectional view in FIG.

[Explanation of symbols]

 1 Thermal Overload Relay 2 Opening / Closing Mechanism 3 Plate-like Body 71 Beam-like Body 72 Adjusting Screw 75 Pushing Body 99 Dial 992 Eccentric Cam

Claims (6)

[Claims] 1. A main bimetal device which is bent by being heated by a heating body to which a current to be detected is passed,
The reversal operation mechanism is pressed through the opening / closing mechanism according to the bending degree of the main bimetal device, and is opened and / or closed according to the reversal operation of the reversal operation mechanism. The contact mechanism has an adjusting unit that adjusts the position of one end of the opening / closing mechanism, and includes an adjusting dial for adjusting the current value when the reversing operation mechanism performs the reversing operation. The beam-shaped body has a beam-shaped body rotatably supported in the vicinity of the central portion, and an adjusting screw mounted near one end of the beam-shaped body and brought into contact with an adjusting portion of the dial. The other end side receives the bending operation of the main bimetal device. When the current in the overcurrent state is passed through the heating element, the main bimetal device is largely bent, and the opening and closing mechanism is provided to the largely bent main bimetal device. Strongly through In a thermal overload relay in which a contact mechanism is opened and / or closed by a reversing operation of a pressurized reversing mechanism, the opening / closing mechanism includes a plate-shaped body held by a beam-shaped body, and an adjusting screw. Is abutted on one side surface of this plate-shaped body,
The thermal overload relay, wherein the adjusting part of the dial is in contact with the other side surface of the plate-shaped body. 2. A main bimetal device that is bent by being heated by a heating body through which an electric current to be detected flows.
The reversal operation mechanism is pressed through the opening / closing mechanism according to the bending degree of the main bimetal device, and is opened and / or closed according to the reversal operation of the reversal operation mechanism. The contact mechanism has an adjusting unit that adjusts the position of one end of the opening / closing mechanism, and includes an adjusting dial for adjusting the current value when the reversing operation mechanism performs the reversing operation. The beam-shaped body has a beam-shaped body rotatably supported in the vicinity of the central portion, and an adjusting screw mounted near one end of the beam-shaped body and brought into contact with an adjusting portion of the dial. The other end side receives the bending operation of the main bimetal device. When the current in the overcurrent state is passed through the heating element, the main bimetal device is largely bent, and the opening and closing mechanism is provided to the largely bent main bimetal device. Strongly through In a thermal type overload relay in which the contact mechanism is opened and / or closed by the reversing operation of the pressurized reversing mechanism, the opening / closing mechanism is provided with a loosening prevention structure by press-fitting the adjusting screw. And thermal overload relay. 3. The thermal overload relay according to claim 2, wherein the loosening prevention structure of the adjusting screw provided in the opening / closing mechanism is formed in a beam-like body for mounting the adjusting screw, and has a function of holding the adjusting screw. A thermal overload relay having a female thread having a thread diameter smaller than the thread diameter of the screw, and a slit that partially removes the female thread in the radial direction and reaches the end face of the beam-shaped body. 4. The thermal overload relay according to claim 2, wherein the loosening prevention structure of the adjusting screw provided in the opening / closing mechanism has a triangular or polygonal through hole formed in the mounting portion of the adjusting screw of the beam-shaped body. And a female screw formed on the inner diameter side of the through hole for mounting the adjusting screw and having a female diameter smaller than the male screw diameter of the adjusting screw. relay. 5. The thermal overload relay according to claim 3 or 4, wherein the adjustment screw included in the loosening prevention structure of the adjustment screw of the opening / closing mechanism has a portion where a female screw into which the adjustment screw is inserted is formed. A thermal overload relay characterized by using a material softer than the beam-shaped body. 6. The thermal overload relay according to any one of claims 3 to 5, wherein the adjusting screw included in the opening / closing mechanism has a male thread diameter smaller than a female thread diameter at a tip portion thereof. A thermal overload relay characterized in that it has a taper screw whose maximum diameter is larger than that of the internal thread.