JP2006331705A - Protector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a protector formed into an easily manufacturable structure and used for cutting off the overcurrent of a motor. <P>SOLUTION: This protector includes: a casing 121 having an opening; first and second electrodes 124-1 and 124-2 mounted in the casing 121; a plate-like bimetal 140 having a first contact 141 and a second contact 142, brought into either of a non-inversion state and an inversion state in response to the temperature of itself, and housed in the casing 121 so that the first contact 141 contacts the first electrode 124-1 and the second contact 142 contacts the second electrode 124-2 in the non-inversion state; and a lid body 160 jointed and fixed to the casing 121 so as to close the opening. The protector is so structured that the lid body 160 has a first pressing part 162 for pressing and fixing the second contact 142 of the bimetal 140 to the second electrode 124-2 in a state jointed and fixed to the casing 121. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a protector that controls current supply to a load to prevent the load from being damaged.

  A battery unit that supplies current to a load, a motor used for a compressor, and the like are provided with a protector for interrupting overcurrent. For example, in a motor used for a compressor or the like, when an internal motor rotor is restrained for some reason or an overload is applied to the motor rotor, an overcurrent is interrupted by a protector, and the overcurrent is prevented. It is possible to prevent the motor from being damaged by the temperature rise due to the current.

  Such a conventional protector (see, for example, Patent Documents 1 to 3) is provided on a bimetal provided so as to be able to perform an inversion on a current path for supplying a current to a load (eg, a motor), and the bimetal. It has a movable contact and a fixed contact, and an electrode provided on the current path corresponding to the movable contact and the fixed contact. The fixed contacts are joined to the electrodes, and electrical connection is always established between the fixed contacts and the electrodes.

The movable contact is normally in contact with the electrode, whereby the current path is conducted and current is supplied to the load. On the other hand, if the amount of current for the load increases for some reason (for example, when the motor rotor is constrained or when an overload is applied to the motor rotor), an increase in the amount of current flowing through the bimetal or The temperature of the bimetal rises due to an increase in the ambient temperature around the bimetal due to heat generated by the load itself (for example, a motor). When the temperature of the bimetal becomes equal to or higher than a predetermined temperature (operation temperature), the bimetal is inverted, the movable contact is separated from the electrode, and the current path is cut. For this reason, no current is supplied to the load, and the load is prevented from being damaged by a further temperature rise. Thereafter, when the temperature of the bimetal drops and becomes equal to or lower than a predetermined temperature (recovery temperature), the bimetal again enters a non-inverted state, the movable contact contacts the electrode, and the current path becomes conductive.
JP-A-10-308150 JP 2000-166181 A JP 2003-328939 A

  However, when the above-described conventional protector is manufactured, a process of welding the fixed contact provided on the bimetal to the electrode is necessary, which takes time and increases the cost. Further, in order to invert the bimetal in the non-inverted state at a predetermined temperature, it is necessary to form the non-inverted bimetal into a certain shape. However, the forming operation is time-consuming. For this reason, it has been desired to facilitate its manufacture.

  Then, an object of this invention is to provide the protector used as the structure which can be manufactured easily.

  The protector according to the present invention includes a housing having an opening, first and second electrodes provided in the housing, a first contact, and a second contact, and the protector according to its temperature In the casing, the first contact is in contact with the first electrode and the second contact is in contact with the second electrode in the non-inversion state. And a lid that is bonded and fixed to the casing so as to close the opening, and the lid is bonded and fixed to the casing. A first pressing portion that presses and fixes the second contact to the second electrode, and the second pressing of the second contact by the first pressing portion when the bimetal is in an inverted state; The first contact is separated from the first electrode while maintaining contact with the electrode. A configuration in which the way.

  With such a configuration, the non-inverted bimetal is accommodated in the housing such that the first contact abuts on the first electrode and the second contact abuts on the second electrode. When the lid is joined and fixed to the casing so as to close the cover, the second contact is pressed and fixed to the second electrode by the first pressing portion. Instead, the second contact can be fixed to the second contact.

  Moreover, the protector which concerns on this invention is a structure with which the said cover body has a 2nd press part which presses the predetermined site | part between the said 1st contact and the said 2nd contact of the said bimetal which will be in a non-inversion state It can be.

  With such a configuration, when the lid is bonded and fixed to the housing so as to close the opening, the predetermined portion between the first and second contacts of the bimetal that is housed in the housing and is in a non-inverted state Is pressed by the second pressing portion, it is possible to adjust the degree of bimetal forming in a non-inverted state. The temperature at which the bimetal is changed from the non-inverted state to the inverted state can be adjusted according to the degree of the pressing against the bimetal by the second pressing portion.

  Further, in the protector according to the present invention, the casing has a plurality of first locking portions formed at a joint portion with the lid, and the lid is connected to the plurality of first locking portions. Each of the plurality of first locking portions and the corresponding one of the plurality of second locking portions are locked with each other. Thereby, it can be set as the structure by which the said cover body is joined and fixed to the said housing | casing.

  With such a configuration, the lid body is joined and fixed to the housing by locking each of the plurality of first locking portions and the corresponding one of the plurality of second locking portions to each other. Thus, the joining and fixing work of the lid body to the housing can be easily performed.

  In the protector according to the present invention, the bimetal may have a shape that is point-symmetric with respect to a midpoint of a line segment that connects the first contact and the second contact.

  With such a configuration, when the bimetal is accommodated in the housing, the operator does not need to consider the direction of the bimetal, and the work can be facilitated.

  In the protector according to the present invention, the first contact and the second contact may have a metal plating layer.

  The protector according to the present invention includes a housing having an opening, first and second electrodes provided in the housing, a first contact, and a second contact, and the protector according to its temperature The first contact is in contact with the first electrode in the non-inversion state, and the second contact is in the non-inversion state and the inversion state. A plate-like bimetal housed in the housing so as to be fixed to the electrode, and a lid joined and fixed to the housing so as to close the opening, and the lid is in a non-inverted state. A pressing portion that presses a predetermined portion between the first contact and the second contact of the bimetal, and when the bimetal changes from a non-inverted state pressed by the pressing portion to an inverted state. A configuration in which the first contact is separated from the first electrode; That.

  With such a configuration, the first contact contacts the first electrode and the second contact is fixed to the second electrode in a state where the lid is bonded and fixed to the housing so as to close the opening. Since a predetermined portion between the first contact and the second contact of the non-inverted bimetal is pressed by the pressing portion, when the lid is joined and fixed to the housing containing the bimetal. The degree of forming of the bimetal can be adjusted. The temperature at which the bimetal is turned from the non-inverted state to the inverted state can be adjusted according to the degree of pressing of the bimetal against the bimetal.

  Moreover, the protector which concerns on this invention can be set as the structure by which the said press part presses the center site | part of the said 1st contact and the said 2nd contact of the said bimetal.

  With such a configuration, since the central portion of the first contact and the second contact is pressed, bimetal forming can be performed more effectively.

  Moreover, the protector which concerns on this invention can be set as the structure from which the said press part becomes a protrusion which protrudes from the inner surface of the said cover body.

  With such a configuration, it is possible to easily change the degree of bimetal pressing by changing the height of the protrusion serving as the pressing portion.

  According to the protector according to the present invention, when the lid is bonded and fixed to the casing, a predetermined part of the bimetal is pressed down, so that the second contact (fixed contact) of the bimetal and the second electrode are welded. Therefore, it is possible to easily adjust the degree of bimetal forming, and to manufacture the bimetal easily.

  FIG. 1 is an exploded perspective view of a protector according to an embodiment of the present invention, and FIG. 2 is an assembled perspective view of the best mode for carrying out the present invention. 3A is a top view of the protector, FIG. 3B is a bottom view, FIG. 3C is a first side view, and FIG. 3D is a second side view 2 of the protector. Show. 3A is a cross-sectional view taken along the line XX ′ in FIG. 3A, and FIG. 4A shows a normal state (energized state) of the protector, and FIG. 3A is a cross-sectional view taken along the line XX ′ in FIG. FIG. 4B shows a state when the temperature of the protector rises (current interruption state).

  The protector 100 shown in these drawings is provided, for example, on a current path for a load in the battery unit, and controls the current supply to the load. The protector 100 includes a base 120, a bimetal disc 140, and a cover 160 that is a lid (see FIGS. 1 and 2).

  The base 120 is formed, for example, by resin molding (insert molding) in which two metal plates arranged on a straight line are inserted, and one metal plate protrudes from one end of a resin case body 121 (housing). A first external connection terminal 123-1 serving as a portion and a first electrode 124-1 serving as a portion in the case body 121 subsequent thereto are configured. Further, the other metal plate constitutes a second external connection terminal 123-2 that is a portion protruding from the other end of the case body 121 and a second electrode 124-2 that is a portion in the case body 121 that follows. The case body 121 has a recess that opens to the outside of the surface of the first electrode and the second electrodes 124-1 and 124-2, and a bimetal disc 140 having a structure as described later is accommodated in the recess. In addition, a total of four locking protrusions 122 (first locking portions) are formed at both end portions of each side surface of the case body 121 where the first external connection terminal 123-1 and the second external connection terminal 123-2 do not protrude. ing.

  The bimetal disc 140 is configured by bonding two types of plate-shaped metal pieces having different thermal expansion coefficients, and has conductivity. A first contact 141 is formed at one end of one surface of the bimetal disc 140, and a second contact 142 is formed at the other end of the same surface. The surfaces of the first contact 141 and the second contact 142 are metal plating layers (for example, silver plating layers) that are particularly excellent in conductivity. The bimetal disk 140 has a shape that is point-symmetric with respect to the midpoint O of the line segment L connecting the first contact 141 and the second contact 142 (see FIG. 1).

  In the initial state, the bimetal disc 140 is formed in a curved state (non-inverted state) so that the central portion is raised (see FIG. 4A). When the bimetal disc 140 becomes equal to or higher than a predetermined temperature (operating temperature) due to the difference in the thermal expansion coefficient between the two types of plate-shaped metal pieces, the central portion of the bimetallic disc 140 is curved (reverse state) to the side opposite to the bulge. (See FIG. 4 (b)). The temperature (operating temperature) at which the bimetal disk 140 should transition from the non-inverted state to the inverted state is determined according to the degree of forming. In general, the greater the degree of curvature of the bimetal disc 140 in the non-inverted state, the higher the operating temperature at which the transition to the inverted state is to occur.

  The concave portion of the case body 121 in the base 120 described above has a planar shape that substantially matches the planar shape of the bimetal disc 140. The non-reversed bimetal disc 140 is set in the recess so that the first contact 141 contacts the first electrode 124-1 and the second contact 142 contacts the second electrode 124-2. Is housed in. As described above, the bimetal disk 140 has a shape that is point-symmetric with respect to the midpoint O of the line segment L that connects the first contact 141 and the second contact 142 (see FIG. 1). Therefore, the first contact 141 is in contact with the second electrode 124-2 and the second contact 142 is in contact with the first electrode 124-2 so that the first contact 141 is in contact with the first electrode 124-2. You can also.

  The cover 160 (lid) formed of resin or the like has four stoppers corresponding to both end portions of each side surface of the case body 121 in which the locking projection 122 is formed as described above, and the plate-shaped cover main body 161. 164, and a locking hole 164a (second locking portion) is formed in each locking portion 164. In addition, a first protrusion 162 (first pressing portion) is formed on one end of the surface of the cover body 161 facing the recess of the case body 121, and a second protrusion (second pressing portion) is formed at the center thereof. A pressing portion) is formed.

  When the cover 160 is attached to the case body 121 in which the non-inverted bimetal disc 140 is set in the concave portion, the corresponding stop portions 164 of the cover 160 are joined to the both end portions of each side surface of the case body 121, respectively. Each locking projection 122 of 121 fits into the locking hole 164a of the corresponding stopper 164, and each locking projection 122 and the corresponding locking hole 164a are locked together. As a result, the four stoppers 164 sandwich the case body 121 from the side surfaces, and the cover body 161 is fixedly bonded to the case body 121 so as to close the opening of the concave portion in which the bimetal disk 140 in the non-inverted state is set. Is done. In this state, as shown in FIG. 4A, the first protrusion 162 formed on the cover body 161 presses the bimetal disc 140 from the back surface of the second contact 142, thereby causing the second contact 142 to move to the second electrode 124. -2 is pressed and fixed, and the central portion of the first contact 141 and the second contact 142 of the bimetal disk 140 in which the second protrusion 163 formed on the cover body 161 is in a non-inverted state is pressed.

  In the protector 100 having such a structure, normally, as shown in FIG. 4A, the first contact 141 of the bimetal disk 140 contacts the first electrode 124-1, and the second contact 142 is connected to the second electrode. It will be in the state contacted with 124-2. As a result, the first external connection terminal 123-1 following the first electrode 124-1 is electrically connected to the second external connection terminal 123-2 following the second electrode 124-2 via the bimetal disk 140, and the protector. 100 becomes conductive and current is supplied to the load.

  When the overcurrent is supplied to the load for some reason and the overcurrent flows through the bimetal disk 140, the temperature of the bimetal disk 140 rises, and when the temperature reaches the operating temperature determined by the degree of forming of the bimetal disk 140, As shown in FIG. 4B, the bimetal disc 140 transitions to the inverted state, and the first contact 141 is maintained while being in contact with the second electrode 124-2 of the second contact 142 by the first protrusion 162. Is separated from the first electrode 124-1. As a result, the electrical connection between the first external connection terminal 123-1 following the first electrode 124-1 and the second external connection terminal 123-2 following the second electrode 124-2 is broken, and the protector 100 is non-conductive. The current supply to the load is cut off. The interruption of the current supply to the load prevents the load from being damaged.

  According to the protector having the above-described structure, when the cover 160 is assembled to the base 120, the first protrusion 162 of the cover body 161 presses the bimetal disc 140 from the back surface of the second contact 142, and the second contact Since 142 is pressed and fixed to the second electrode 124-2, the second contact 142 can be fixed to the second electrode 124-2 without performing a welding operation or the like as in the prior art.

  Further, when the cover 160 is assembled to the base 120, the center portion between the first contact 141 and the second contact 142 of the bimetal disc 140 in which the second protrusion 163 of the cover body 161 is in a non-inverted state is pressed. Therefore, the degree of forming of the bimetal disc 140 in the non-inverted state can be adjusted. The bimetal disc 140 is initially formed into a predetermined curved shape, but is further pressed by the second protrusion 163 to adjust the degree of forming, whereby the operating temperature (non-inverted) of the bimetal disc 140 is adjusted. Temperature to be changed from the state to the inversion state) is adjusted. As the height of the second protrusion 163 increases, the pressing force of the second protrusion 163 against the bimetal disk 140 increases, so that the curved shape in the initial state of the bimetal disk 140 is returned to a greater extent. Can be lowered.

  Accordingly, it is possible to manufacture various protectors 100 having different operating temperatures by using the cover 160 in which the second protrusions 163 having different heights are formed on the same curved bimetal disc 140. Thereby, various protectors 100 having different operating temperatures can be manufactured more efficiently.

  In the above-described example, the second contact 142 of the bimetal disc 140 is pressed and fixed to the second electrode 124-2 by the first protrusion 162 formed on the cover body 161. Even if the structure is fixed to the second electrode 124-2 by welding or the like, the center portion of the bimetal disc 140 can be pressed by the second protrusion 162 formed on the cover body 161. In this case as well, the degree of forming of the bimetal disc 140 can be adjusted similarly.

  Further, the portion of the bimetal disc 140 pressed by the second protrusion 162 is not limited to the central portion of the first contact 141 and the second contact 142 as described above, but between the first contact 141 and the second contact 142. It can be set at any position.

  Further, according to the protector 100 described above, the locking projections 122 formed at both end portions of each side surface of the case body 121 and the locking holes 164a formed in the corresponding locking portions 164 of the cover 160 are locked together. As a result, the base 120 (case body 121) and the cover 160 are joined and fixed, so that the assembly work of the base 120 and the cover 160 is facilitated. Conventionally, the base 120 and the cover 160 are also joined by ultrasonic waves. However, in this case, the temperature of the bimetal disc 140 accommodated in the base 120 rises and it is difficult to adjust the operating temperature of the bimetal disc 140. May be. However, in the protector 100 having the above-described structure, there is no thermal influence on the bimetal disk 140 when the base 120 and the cover 160 are joined.

  Further, according to the protector 100 described above, since the bimetal disc 140 has a shape that is point-symmetric with respect to the midpoint of the line segment connecting the first contact 141 and the second contact, the bimetal disc 140 is It becomes possible to set in the concave portion of the case body 121 without worrying about the direction, and the work becomes easy.

  As described above, the protector according to the present invention has a structure that can be easily manufactured, and is useful as a protector that controls the current supply to the load to prevent the load from being damaged.

It is a disassembled perspective view of a protector. It is an assembly perspective view of a protector. It is the top view, bottom view, and side view of a protector. It is sectional drawing of a protector.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Protector 120 Base 121 Case body 122 Locking protrusion 123-1 1st external connection terminal 123-2 2nd external connection terminal 124-1 1st electrode 124-2 2nd electrode 140 Bimetal disk 141 1st contact 142 2nd contact 160 Cover 161 Cover Body 162 First Projection 163 Second Projection 164 Stopping Section 164a Locking Hole

Claims (8)

A housing having an opening;
First and second electrodes provided in the housing;
A first contact and a second contact, which are in a non-inversion state or an inversion state according to their own temperature, and in the non-inversion state, the first contact contacts the first electrode. A plate-shaped bimetal housed in the housing so that the second contact is in contact with the second electrode,
A lid that is bonded and fixed to the housing so as to close the opening;
The lid body has a first pressing portion that presses and fixes the second contact point of the bimetal to the second electrode in a state of being bonded and fixed to the housing.
The first contact is separated from the first electrode while the state where the first pressing portion is in contact with the second electrode of the second contact is maintained when the bimetal is reversed. A protector characterized by doing so.   The said cover body has a 2nd press part which presses the predetermined site | part between the said 1st contact of the said bimetal which will be in a non-inversion state, and a said 2nd contact. Protector. The housing includes a plurality of first locking portions formed at a joint portion with the lid,
The lid body has a plurality of second locking portions formed at sites corresponding to the plurality of first locking portions,
Each of the plurality of first locking portions and a corresponding one of the plurality of second locking portions are locked to each other, whereby the lid body is bonded and fixed to the housing. The protector according to claim 1 or 2.   The protector according to any one of claims 1 to 3, wherein the bimetal has a shape that is point-symmetric with respect to a midpoint of a line segment that connects the first contact and the second contact. .   The protector according to any one of claims 1 to 4, wherein the first contact and the second contact have a metal plating layer. A housing having an opening;
First and second electrodes provided in the housing;
A first contact and a second contact, which are in a non-inversion state or an inversion state according to their own temperature, and in the non-inversion state, the first contact contacts the first electrode. A plate-like bimetal housed in the housing so that the second contact is fixed to the second electrode in the non-inverted state and the inverted state,
A lid that is bonded and fixed to the housing so as to close the opening;
The lid has a pressing portion that presses a predetermined portion between the first contact and the second contact of the bimetal that is in a non-inverted state,
The protector characterized in that the first contact is separated from the first electrode when the bimetal pressed by the pressing portion changes from a non-inverted state to an inverted state.   The protector according to claim 6, wherein the pressing portion presses a central portion between the first contact and the second contact of the bimetal. The protector according to claim 6 or 7, wherein the pressing portion is a protrusion protruding from an inner surface of the lid.

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