JPH0980080A - Magnetic core protective structure for current detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a small and lightweight current sensor in which the magnetic core is not buried in molding resin, an appropriate current detecting state is ensured and the bus bar is protected against damage due to backlash while reducing the manufacturing cost. SOLUTION: The magnetic core protective structure for current detector comprises a magnetic core 29 having a space 31 for passing bus bar secured to the board 27 of a current detector 21, and a nonmagnetic wedge protector 35 secured to the outer circumference of a bus bar 33 and clamping the bus bar 33 by vertical and lateral tapered outer surfaces 37a, 37b thereof. The tapered outer surfaces 37a, 37b of protector 35 are abutted against the opening of space 31 for passing bus bar and then the bus bar 33 is inserted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic core protection structure for a current detecting device using a non-contact type current detecting means, and is particularly suitable for use in an electrical junction box used for vehicle wiring. .

[0002]

2. Description of the Related Art Some electric connection boxes mounted on vehicles have a current detection device (current sensor) built therein. Figure 7
Is a perspective view of an electric junction box having a built-in current sensor, and FIG. 8 is an enlarged view of the current sensor. A current sensor 3 is attached to the bottom of the electric junction box 1, and a bus bar 5 penetrates the current sensor 3. As shown in FIG. 8, the current sensor 3 is
An outer shell is formed by the case 7, and the magnetic core 9 is provided in the case 7.
Is installed inside. The bus bar 5 will be inserted into the through space of the magnetic core 9. Also, the magnetic core 9
The molding resin 11 with which the case 7 is filled is embedded integrally with the case 7. As a result, the magnetic core 9 is positioned relative to the bus bar 5, ensures an appropriate current detection state, and is protected from damage due to rattling of the bus bar 5.

In this current sensor 3, the magnetic field generated by the current flowing through the bus bar 5 is collected in the magnetic core 9, and the strength of this magnetic field is detected as a voltage through a magneto-electric conversion element such as a Hall element, whereby the bus bar is detected. The current flowing through 5 is detected.

According to such a current sensor 3, as compared with a device which directly detects a current flowing through the bus bar 5 by a resistance, energy loss due to a voltage drop, restriction of a current carrying capacity due to an allowable current of the resistance, and heat generated by the resistance. It was possible to eliminate the error in the detected current value due to.

[0005]

However, in the above-mentioned current sensor 3, the magnetic core 9 is provided in the case 7, and the magnetic core 9 is protected by the molding resin 11 with which the case 7 is embedded in the case 7. Therefore, there is a problem that the size of the entire current sensor 3 is enlarged, the weight is increased, and further, the manufacturing cost is increased. This means that in today's vehicles in which electrical components are diversified, the detected current becomes large, and the larger magnetic core 9
It became more prominent in the current sensor 3 which had to be buried. The present invention has been made in view of the above situation, and a proper current detection state can be secured without burying a magnetic core in a molding resin, and a current detection device capable of preventing damage due to rattling of a bus bar. An object of the present invention is to provide a magnetic core protection structure to reduce the size of a current sensor, reduce its weight, and reduce its manufacturing cost.

[0006]

In order to achieve the above object, the structure of the magnetic core protection structure of the current detecting device according to the present invention comprises a magnetic core fixed to the substrate of the current detecting device and having a bus bar penetrating space, A wedge-shaped protector made of a non-magnetic material and fixed to the outer periphery of the busbar and sandwiching the busbar between the upper and lower outer surfaces and the left and right outer surfaces respectively having tapered surfaces, and the tapered surface of the protector is brought into contact with the opening of the busbar penetrating space. The bus bar is inserted into the bus bar penetrating space. When the busbar is inserted into the busbar penetrating space of the magnetic core so that the front end face of the protector is on the front side and the protector fixed to the outer periphery of the busbar reaches the busbar penetrating space, the taper surface on the top, bottom, left, and right of the protector Comes into contact with the opening of the bus bar penetrating space, whereby the bus bar is positioned and held at the center of the bus bar penetrating space via the protective device.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a magnetic core protection structure for a current detecting device according to the present invention will be described in detail below with reference to the drawings. 1 is an exploded perspective view showing a magnetic core protection structure of a current detection device according to the present invention, FIG. 2 is a perspective view of a protector used in the magnetic core protection structure of FIG. 1, and FIG. 3 is a process of inserting a bus bar into the magnetic core. FIG. The current sensor unit (current sensor) 21 has a current sensor unit 2
3, the current sensor unit 23 includes a plurality of electronic components 25 for forming an amplifier circuit for the detected current, etc.
It is configured by mounting in 7. A magnetic core 29 is fixedly mounted on the substrate 27, and the magnetic core 29 has a bus bar penetrating space 31. The magnetic core 29 is not buried in the molding resin material as in the conventional case, but remains exposed.

The busbar penetrating space 31 formed in the magnetic core 29 is opened with an area sufficiently larger than the tip end surface of the busbar 33. On the other hand, a protector 35 made of a non-magnetic material is integrally fixed to the bus bar 33 inserted into the magnetic core 29 by molding or the like. The protector 35 is preferably made of an elastic material such as soft resin or rubber. The protector 35 is formed in a wedge shape, and the bus bar 33 is penetrated through the front end surface and the rear end surface facing each other.
In the protector 35, upper, lower, left and right outer surfaces sandwiching the penetrated bus bar 33 are tapered surfaces 37a and 37b, respectively. The tapered surfaces 37a and 37b are tapered surfaces in a direction in which the thickness in the up-down direction and the thickness in the left-right direction become thicker toward the rear end surface.

The area of the front end face of the protector 35 is equal to that of the magnetic core 29.
Is formed smaller than the opening area of the bus bar penetrating space 31. The area of the rear end surface of the protector 35 is formed larger than the opening area of the bus bar penetrating space 31 of the magnetic core 29.

In the magnetic core protection structure having the magnetic core 29 and the protector 35 thus formed, FIG.
As shown in (b), the bus bar 33 is inserted into the bus bar penetrating space 31 of the magnetic core 29 so that the front end surface of the protector 35 faces the front side. When the protector 35 reaches the busbar penetrating space 31, the busbar 33 inserted into the busbar penetrating space 31 has tapered surfaces 3 on the upper, lower, left, and right sides of the protector 35.
7a and 37b abut on the opening of the bus bar penetrating space 31. As a result, the bus bar 33 is positioned and held in the central portion of the bus bar penetrating space 31 while being in contact with the bus bar 33 via the protector 35.

According to the magnetic core protection structure thus constructed, the bus bar 33 integrally formed with the wedge-shaped protector 35 is inserted into and held by the magnetic core 29 exposed without being filled with the molding resin. Since it is decided that the bus bar 3 is contacted with the protector 35 in contact with the magnetic core 29,
Since 3 is positioned in the center of the bus bar penetrating space 31 and the bus bar 33 is held in the bus bar penetrating space 31 via the protector 35, damage due to rattling of the bus bar 33 in the bus bar penetrating space 31 is prevented. be able to.

Further, according to the magnetic core protection structure constructed as described above, the relative position between the magnetic core 29 and the bus bar 33 can always be kept constant even when the current sensor is vibrated. At this time, by making the protector 35 an elastic material, it is possible to effectively absorb the rattling between the two due to vibration and reduce the impact.

Therefore, even if the magnetic core 29 is not embedded in the molding resin, an appropriate current detection state is ensured and the bus bar 33 is provided.
It is possible to prevent damage due to rattling of the
It is possible to reduce the size and weight of the current sensor and reduce the manufacturing cost.

Next, another embodiment of the magnetic core protection structure according to the present invention will be described with reference to FIGS. 4 is an exploded perspective view showing a magnetic core protection structure of a current detection device according to another embodiment, FIG. 5 is a perspective view of a protector used in the magnetic core protection structure of FIG. 4, and FIG. 6 is a bus bar to the magnetic core. It is explanatory drawing which shows the insertion process of. In the magnetic core protection structure according to this embodiment, like the magnetic core protection structure described above,
The magnetic core 29 is mounted on the substrate 27 in an exposed state. A protector 41 made of a non-magnetic material is attached to the bus bar penetrating space 31 of the magnetic core 29. The protector 41 is made of an elastic material such as soft resin or rubber so that it can be press-fitted into the bus bar penetrating space 31. The protector 41 is formed in substantially the same shape as the bus bar penetrating space 31. That is, the protector 41 includes the bus bar penetrating space 3 of the magnetic core 29.
It is attached in close contact with 1.

Locking portions 43 are provided on the front edge and the rear edge of the protector 41 so as to project from the magnetic core 29 when the protector 41 is mounted in the bus bar penetrating space 31. The protector 41 is retained in the bus bar penetrating space 31 by being locked to the front surface and the rear surface. Further, the protector 41 is formed with a bus bar insertion hole 45 penetrating the front end face and the rear end face. In the bus bar insertion hole 45, the upper inner wall surface and the lower inner wall surface that sandwich the inserted bus bar 33 between the upper and lower sides are tapered surfaces 47. The tapered surface 47 is a tapered surface whose opening area gradually becomes smaller in the insertion direction of the bus bar 33. That is, the bus bar insertion hole 45 is formed in the protective device 4
On the inlet side which is opened at the rear end face of the first bus bar 33, the opening is larger than the front end face of the bus bar 33 so that the bus bar 33 can be easily inserted. On the other hand, the exit side of the bus bar insertion hole 45 is opened with an area equal to or slightly smaller than the tip end surface of the bus bar 33.

In the magnetic core protection structure having the magnetic core 29 and the protector 41 formed as described above, FIG.
As shown in (b), the bus bar 33 is inserted into the protector 41 mounted on the magnetic core 29. The bus bar 33 that is inserted into the protective equipment 41 is guided through the opening on the inlet side, which is largely opened, and is inserted into the protective equipment 41. At this time, the bus bar 33 penetrating the opening on the outlet side of the protector 41 is positioned at the center of the bus bar penetrating space 31 and held by the magnetic core 29 via the protector 41.

According to the magnetic core protection structure constructed as described above, since the protector 41 is attached to the magnetic core 29 which is exposed without being filled with the molding resin, the bus bar 33 is attached to the magnetic core 29. In the inserted state, the bus bar 33 is positioned at the center of the bus bar penetrating space 31, and the bus bar 33 and the bus bar penetrating space 31 are in contact with each other via the protector 41. Therefore, the bus bar penetrating space 3
It is possible to prevent damage due to rattling of the bus bar 33 in the inside 1.

According to this magnetic core protection structure,
Since the protector 41 made of an elastic material plays a role as a cushioning material, it is possible to reduce the impact due to the rattling of the bus bar 33, and to absorb the error due to the manufacturing accuracy and the mounting accuracy.

Therefore, even if the magnetic core 29 is not embedded in the molding resin, an appropriate current detection state can be secured and the bus bar 33 can be secured.
It is possible to prevent damage due to rattling of the
It is possible to reduce the size and weight of the current sensor and reduce the manufacturing cost.

[0020]

As described above in detail, according to the magnetic core protection structure of the current detecting device of the present invention, a wedge-shaped protector is provided on the exposed magnetic core without being filled with the molding resin. Since the bus bar provided with is inserted and the bus bar is brought into contact with the bus bar penetrating space through this protector, the bus bar is positioned and held at the center of the bus bar penetrating space while the protector is in contact with the magnetic core. It is possible to prevent damage due to rattling of the bus bar in the through space. Therefore, without embedding the magnetic core in the mold resin, it is possible to secure an appropriate current detection state and prevent damage due to rattling of the bus bar. As a result, downsizing and weight saving of the current sensor and reduction of manufacturing cost can be achieved. Can be achieved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a magnetic core protection structure of a current detection device according to the present invention.

FIG. 2 is a perspective view of a protector used in the magnetic core protection structure of FIG.

FIG. 3 is an explanatory diagram showing a process of inserting a bus bar into a magnetic core.

FIG. 4 is an exploded perspective view showing a magnetic core protection structure of a current detection device according to another embodiment.

5 is a perspective view of a protector used in the magnetic core protection structure of FIG. 4. FIG.

FIG. 6 is an explanatory diagram showing a process of inserting the bus bar into the magnetic core.

FIG. 7 is a perspective view of an electrical junction box having a built-in current sensor.

FIG. 8 is an enlarged view of a current sensor.

[Explanation of symbols]

 21 Current Sensor (Current Detector) 27 Substrate 29 Magnetic Core 31 Busbar Penetration Space 33 Busbar 35, 41 Protective Equipment 37a, 37b, 47 Tapered Surface 45 Busbar Insertion Hole

Claims (3)

[Claims] 1. A magnetic core fixed to a substrate of a current detecting device and having a bus bar penetrating space, and a wedge-shaped non-magnetic material fixed to the outer periphery of the bus bar and having upper and lower outer surfaces and left and right outer surfaces sandwiching the bus bar are tapered surfaces. A magnetic core protection structure for a current detecting device, comprising: a protector, wherein a tapered surface of the protector is brought into contact with an opening of the busbar penetrating space to insert the busbar into the busbar penetrating space. 2. A magnetic core fixed to a substrate of a current detecting device and having a bus bar penetrating space, and a bus bar insertion hole which is made of a non-magnetic material and is mounted in the bus bar penetrating space of the magnetic core and through which the bus bar is inserted. And a protector having an upper inner wall surface and a lower inner wall surface of the bus bar insertion hole sandwiching the bus bar in the thickness direction, which are formed by tapered surfaces narrowing in the bus bar insertion direction, and are mounted in the bus bar penetration space of the magnetic core. A magnetic core protection structure for a current detecting device, wherein the bus bar is inserted in a state in which the bus bar is in close contact with the tapered surface of the protector. 3. The magnetic core protection structure for a current detecting device according to claim 1, wherein the protector is made of an elastic material.