JP5590699B2 - Current detector assembly structure - Google Patents

Description

  The present invention relates to an assembly structure of a current detection device that can be attached to a bus bar without sacrificing accuracy and has high mass productivity.

  2. Description of the Related Art Conventionally, a current detection device for detecting a current value flowing between a battery and a vehicle electrical component by detecting a magnetic flux generated from a current flowing in a harness connected to a battery terminal is known. The current detection device is attached to a part of the vehicle using a jig such as a bracket. And the said harness is inserted in the detection hole of this electric current detector, and magnetic flux is detected in the part.

  However, in the conventional current detection device, since it is necessary to use separate parts such as a bracket in order to attach the current detector to the vehicle, the number of parts is increased and the configuration is complicated. Furthermore, since it is necessary to pass a flexible harness through the detection hole, it is necessary to enlarge the detection hole from the viewpoint of workability. For this reason, it has been difficult to reduce the size of the current detection device.

  Therefore, a vehicle current detection device has been proposed that is downsized, improves assembly workability, and has a simple configuration (see, for example, Patent Document 1). As shown in FIG. 7, the current detection device has a battery terminal 101 connected to one end 201 of a bus bar 200 with a screw 102 and a current detector 300 supported by the bus bar 200. Further, the other end 202 of the bus bar 200 is connected by a screw 402 and a terminal 401 that bites an end of a harness 400 connected to a vehicle electrical component (not shown).

  Further, as shown in FIG. 8, a core 302 is fixed to the current detector 300 so as to surround a detection hole 304 through which the bus bar 200 penetrates in a detector body 301 made of synthetic resin. Hall elements 303 are mounted so as to be positioned between both ends of 302. As a result, the vehicle current detection device can be easily configured, can be miniaturized, and can further improve the assembly workability.

JP 2001-272422 A

  However, the conventional current detection device has the following disadvantages. That is, as described above, in order to install a magnetic core for collecting magnetic flux, it is necessary to provide a core having a hole through which the bus bar is inserted and to insert the bus bar through the hole. Further, if the shape of the bus bar is complicated, it is difficult to insert the bus bar into the hole, so that the magnetic core becomes large because the hole needs to be formed larger.

  The present invention has been made in view of the above-described circumstances, and an object of the present invention is to provide a simple structure, easy assembly, and a current detection device assembly structure suitable for downsizing the current detection device. Is to provide.

In order to achieve the above-described object, the assembly structure of the current detection device according to the present invention is characterized by the following (1) to ( 2 ).
(1) Bus bar,
A sensor body for detecting magnetism generated from the bus bar, and calculating a value of a current flowing through the bus bar based on the detected magnetism;
A housing having a sensor chamber for housing the sensor body, and a lower surface facing one surface of the bus bar;
A magnetic shield body mounted on the housing such that the sensor body and the bus bar are located inside;
With
The housing is formed with a first protrusion protruding downward from a fixed base protruding downward from the lower surface of the housing,
The bus bar has a notch formed at a location facing the fixed base when the bus bar and the magnetic shield are assembled to the housing.
The magnetic shield is formed with a hole that is penetrated by the first protrusion when the bus bar and the magnetic shield are assembled to the housing.
When the bus bar and the magnetic shield are assembled to the housing, the first convex portion passes through the notch of the bus bar and passes through the hole of the magnetic shield, and the bus bar and the When the magnetic shield is assembled, the magnetic shield supported by the fixing base is melted when the tip of the first convex portion is thermally fused to the hole of the magnetic shield and then solidified. Prevent you from getting out of the
about.
(2) In the assembly structure of the current detection device having the configuration of (1 ) above,
The housing is provided with a second protrusion protruding downward from the lower surface of the housing,
The bus bar is formed with a hole that is penetrated by the second protrusion when the bus bar and the magnetic shield are assembled to the housing.
A tip of the second convex portion penetrating the hole of the bus bar is thermally welded to the hole;
about.

According to the assembly structure of the current detection device having the configuration of (1) to ( 2 ), the sensor body and the bus bar can be integrated with a simple configuration, and the current detection device can be easily assembled. Moreover, it is possible to provide a structure for assembling the current detection device suitable for downsizing the current detection device. Also, since the caulking portion made of a metal member is not used to fix the magnetic shield or bus bar to the housing, the shape of the caulking portion is not uniform or broken, or the magnetic hysteresis characteristics are not uniform or The problem of causing deterioration is eliminated, and deterioration in sensitivity of magnetic detection and current detection can be avoided in advance.

  The present invention has been briefly described above. Further, details of the present invention will be further clarified by reading through the modes for carrying out the invention described below with reference to the accompanying drawings.

It is sectional drawing which shows the structure of the electric current detection apparatus which concerns on the 1st Embodiment of this invention. FIG. It is explanatory drawing which shows the assembly method. It is sectional drawing which shows the structure of the electric current detection apparatus which concerns on the 2nd Embodiment of this invention. FIG. It is explanatory drawing which shows the assembly method. It is a front view which shows the conventional electric current detection apparatus. It is the side view.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings.
(First embodiment)
FIG. 1 shows a current detection device 10A according to a first embodiment manufactured by applying an assembly structure of a current detection device according to the present invention. This current detection device 10A is installed in a vehicle. The housing 20, the sensor main body 30, the bus bar 40, and the magnetic shield 50 are provided.

  The housing 20 of the present embodiment is integrally molded with a non-magnetic and non-conductive material such as an appropriate synthetic resin material, and is fixed in order from the end side closer to the battery (right side in FIG. 1). γ, connector connecting portion α, detecting portion β, and fixing portion γ are configured in this order.

  The connector connecting part α is for connecting a connector (not shown) attached to a signal line (not shown). In this embodiment, a room (hereinafter referred to as a connector room 21) surrounded by four standing walls is surrounded by a standing wall. Configure the connector. This signal line is for transmitting an electric signal corresponding to the strength of the magnetic field detected by the magnetic detection element 32 of the detection unit β described later to a control IC unit not shown.

  In the detection unit β, a substrate 31 is installed in a sensor chamber 22 surrounded by walls in four directions, and a magnetic detection element 32 is mounted on the substrate 31. Further, on the lower surface of the detection portion β of the housing 20, a fixed base 23 that protrudes downward and first convex portions 26 and 27 that protrude downward from the fixed base 23 are provided. Although details will be described later, when the bus bar 40 is assembled to the housing 20, the fixing base 23 passes through the notches 45 and 46, and when the magnetic shield is assembled to the housing 20 to which the bus bar 40 is assembled, the first projection The parts 26 and 27 pass through the hole 53.

  When the bus bar 40 is assembled to the housing 20, the fixing portion γ melts the second protrusions 24 and 25 on the lower surface of the housing 20 that protrude from the holes provided in the magnetic shield 50, thereby 40 is fixed. For this reason, on the lower surface of the fixed portion γ of the housing 20, second convex portions 24 and 25 projecting downward are projected.

  The sensor body 30 includes the above-described magnetic detection element 32 that detects the magnetic field generated from the bus bar 40, and calculates the value of the current (I) flowing through the bus bar 40 based on the detected strength of the magnetic field. As described above, the sensor main body 30 of this embodiment has the substrate 31 installed in the sensor chamber 22, and the magnetic detection element 32 is mounted on the substrate 31.

  The magnetic detection element 32 detects a magnetic flux generated around the current (I) with respect to the flow of the current (I) in the bus bar 40 shown in FIG. That is, the magnetic detection element 32 of the present embodiment is arranged in the plane direction (XY plane) for detecting the magnetic flux density of the current (I) flowing through the bus bar 40, and is in the Z direction perpendicular to the plane of the bus bar 40. Magnetic flux is not detected. Thus, the Z direction perpendicular to the XY plane of the bus bar 40 is a direction in which the magnetic detection element 32 does not detect the magnetic flux. For these reasons, the magnetic detection element 32 is open at the top in shape, but this does not adversely affect accurate magnetic detection.

  The magnetic detection element 32 uses a Hall element utilizing the Hall effect, and outputs an output voltage proportional to the magnetic field density (generated according to the intensity of the current I flowing through the bus bar 40), for example. .

  One end of the bus bar 40 (left end in FIG. 1) is integrally attached to one end of a harness (not shown) for connecting a vehicle electrical component and a battery (both not shown). And the other end (the right end in FIG. 1) is integrally attached to the battery terminal. Further, in the bus bar 40 of the present embodiment, as shown in FIG. 3, holes 43 and 44 through which the second convex portions 24 and 25 are inserted are opened.

  Furthermore, when the part which protruded from the back surface of the bus-bar 40 among the 2nd convex parts 24 and 25 inserted in these holes 43 and 44 is fuse | melted, hole 43,44 so that the fusion | melting part may be folded back to the back surface. After welding to solidify. Therefore, the bus bar 40 is held by the housing 20 from the back side (lower surface side). In addition, between the holes 43 and 44 of the bus bar 40, notches 45 and 46 cut into both sides in the width direction from the outside to the inside in the width direction (the width is narrower than other portions of the bus bar 40. Are provided). The notches 45 and 46 are penetrated by the fixing base 23 when the bus bar 40 is assembled to the housing 20. The notches 45 and 46 are holes provided to allow the fixing base 23 to pass through, but are not limited to the rectangular shape.

  The magnetic shield 50 is formed of an appropriate magnetic material, for example, in the case of the present embodiment, a magnetic body having a spring property, and covers the surroundings of the detection unit β of the housing 20 and the bus bar 40 from the outside. The magnetic shield 50 is shielded from the outside of the magnetic shield 50, and the intensity of the magnetic field propagating through the magnetic shield 50 is amplified.

  The magnetic shield 50 of the present embodiment has a substantially box shape with an upper surface and two opposite side surfaces opened, and the detection unit β of the housing 20 is held from below (outside) the bus bar 20 to detect the housing 20. Locking notches 51 and 52 that are locked to the locking claws 28 and 29 in the housing 20 are provided to be integrally fixed to the part β. A bottom piece 50b sandwiched between the pair of rising pieces 50a of the magnetic shield 50 is provided with a single hole 53 into which the first convex portions 26 and 27 are inserted.

Next, a method for assembling the current detection device 10A according to the present embodiment will be described with reference to FIGS.
(1) First, the magnetic detection element 32 is mounted on the substrate 31.
(2) Next, the substrate 31 is turned upside down so that the magnetic detection element 32 is on the lower surface, and then the substrate 31 is assembled into the sensor chamber 22 of the housing 20 from above.
(3) Thereafter, the bus bar 40 is placed after the housing 20 is turned upside down. At this time, the second convex portions 24 and 25 are inserted into the holes 43 and 44. Further, the fixing base 23 is inserted into the notches 45 and 46. In this way, the lower surface of the housing 20 faces one surface of the bus bar 40.
(4) Next, the magnetic shield 50 is attached so as to sandwich both sides of the housing 20. At this time, the locking notches 51 and 52 of the magnetic shield 50 are fitted to the locking claws 28 and 29 in the housing 20, and the first convex portions 26 and 27 are inserted through the holes 53. As shown in FIG. 1, in the housing 20 in which the first protrusions 26 and 27 are inserted through the holes 53, the fixing base 23 comes into contact with the bottom piece 50b of the magnetic shield 50 and supports the bottom piece 50b.
(5) Finally, the first protrusions 26 and 27 protruding from the hole 53 of the magnetic shield 50 are melted by heat, welded so as to be folded back to the lower surface of the magnetic shield 50, and naturally cooled. Similarly, the 2nd convex parts 24 and 25 which protrude from the holes 43 and 44 of the bus bar 40 are heat-melted, welded so as to be folded back to the lower surface of the bus bar 40, and naturally cooled. Accordingly, the bus bar 40 and the magnetic shield 50 are integrally coupled to the housing 20 by resin welding.

Therefore, according to the in-vehicle current detection device 10A according to the present embodiment, the magnetic shield 50 is provided, and external adverse electromagnetic effects can be suppressed, and accurate current detection can be performed.
For example, depending on the vehicle system to which the in-vehicle current detection device 10A according to the present embodiment is applied, a magnetic field is generated around the Hall element used as the magnetic detection element 32, or a relay or a motor is installed nearby. In such a case, there is a possibility that accurate magnetic detection cannot be performed due to the magnetic field generated there. Moreover, the influence of geomagnetism and high-voltage electric wires can also be considered as environmental influences during vehicle travel. However, according to the current detection apparatus 10A according to the present embodiment, the magnetic shield 50 is provided, and the magnetic shield 50 effectively prevents the sensor output from greatly fluctuating due to these effects.

  By the way, for example, in the case of a current detection device (current sensor) manufactured by temporarily fastening the magnetic shield 50 by means such as caulking, a big problem that magnetic distortion is likely to occur has occurred. However, by melting and solidifying the first convex portions 26 and 27 and the second convex portions 24 and 25 that are a part of the synthetic resin housing, the convex portions are fixed in holes that pass therethrough. In the current detection device 10A according to the first embodiment, such a magnetostriction does not occur (or is reduced as much as possible), and a highly reliable current sensor can be realized.

Therefore, according to the assembly structure of the current detection device 10A in the vehicle according to the present embodiment, a metal material (magnetic material) is not used for fixing the magnetic shield 50 and the bus bar 40 to the housing 20, so that the conventional caulking is performed. This eliminates the occurrence of magnetostriction due to the above, and improves the accuracy of magnetic detection and current detection, thereby forming a highly reliable current detection device.
Further, in the present embodiment, the first protrusions 26 and 27 and the second protrusions 24 and 25 of the housing 20 have holes 43 and 44 and notches 45 and 46 of the bus bar 40 and holes 53 of the magnetic shield 50, respectively. Since these members can be positioned through these holes so as to coincide with each other, the assembly work can be performed quickly. As a result, assembly is easy with a simple configuration, and the current detection device can be downsized. In addition, the occurrence of magnetostriction can be prevented.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals to avoid redundant description.

  The difference between the current detection device 10 </ b> B of the present embodiment and the current detection device 10 </ b> A of the first embodiment is that the members corresponding to the first convex portions of the first embodiment are mainly located at both ends of the housing 20. The projection piece 20 </ b> A extends toward the base, and the projection piece 20 </ b> A is located outside the bottom piece 50 b of the magnetic shield 50 when the projection piece 20 </ b> A is attached to the housing 20. Further, the magnetic sensation chamber 60 is opened in the lower surface of the housing 20, and the sensor body 30 is fixed in the sensor chamber 60 by the spacer 70 covering the opening of the sensor chamber 60. The configuration using the spacer 70 can be applied to the first embodiment.

  The spacer 70 is provided with a support protrusion 72 and a positioning protrusion 73 on one surface of the base 71, and is supported by the housing 20 and the bus bar 40 so that the support protrusion 72 supports the lower surface of the substrate 31 in a line contact state. The positioning projection 73 is in contact with the side surface of the substrate 31 to prevent the positional deviation and the vibration of the substrate 31.

Next, a method for assembling the current detection device 10B according to the present embodiment will be described with reference to FIGS.
(1) First, the magnetic detection element 32 is mounted on the substrate 31.
(2) Next, the substrate 31 is assembled to the sensor chamber 60 of the housing 20 via the spacer 70 with the housing 20 turned over so that the magnetic detection element 32 faces the lower surface of the sensor chamber 22.
(3) Thereafter, the bus bar 40 is placed with the housing 20 turned upside down. At this time, the holes 43 and 44 are fitted into the second convex portions 24 and 25 of the housing 20.
(4) Next, the magnetic shield 50 is attached so as to sandwich both sides of the housing 20. At this time, the locking notches 51 and 52 formed in the magnetic shield 50 are engaged with the locking claws 28 and 29 in the housing 20.
(5) Finally, the second protrusions 24 and 25 protruding from the holes 43 and 44 of the bus bar 40 are heat-melted and welded so as to be folded back to the lower surface of the bus bar 40, and downward toward both ends of the housing 20. The projecting piece 20A extended in this manner is melted and bent toward the bottom piece 50 so as to cover the outer surface near the corner where the bottom piece 50b of the magnetic shield 50 and the two rising pieces 50a are continuous. As a result, the melted protruding piece 20 </ b> A is solidified so that the protruding piece 20 </ b> A has a shape that prevents the magnetic shield 50 from coming out of the housing 20, so that the bus bar 40 and the magnetic shield 50 are integrally coupled to the housing 20. The

  Therefore, according to the assembly structure of the in-vehicle current detection device 10C according to the present embodiment, a metal material (magnetic material) is not used for fixing the magnetic shield 50 and the bus bar 40 to the housing 20, so that the conventional caulking is performed. This eliminates the occurrence of magnetostriction due to the above, and improves the accuracy of magnetic detection and current detection, thereby forming a highly reliable electric current detector.

  Further, according to the present embodiment using the spacer 70, even if the vehicle receives a large impact and the bus bar 40 connected to the battery terminal vibrates, the sensor body 30 is located on the bus bar 40 and the spacer 70. It is fixed and does not cause displacement or displacement with respect to the bus bar 40. Therefore, the impact does not affect the current detection accuracy of the current sensor.

  Also in this embodiment, each member can be positioned through these holes so that the second protrusions 24 and 25 and the holes 43 and 44 of the housing 20 coincide with each other. Can be done quickly. As a result, assembly is easy with a simple configuration, and the current detection device can be downsized. In addition, no magnetostriction occurs.

  Note that the current detection device of the present invention is not limited to application as a part of a system in a vehicle as in these embodiments, and can detect current in various fields as long as it has a bus bar. Application as a device is possible.

10A, 10B, 10C Current detection device 20 Housing 21 Connector chamber 22, 60 Sensor chamber 23 Fixing base 24, 25 Second convex portion 26, 27 First convex portion 30 Sensor body 31 Substrate 32 Magnetic detection element 40 Bus bar 41, 42, 43, 44, 53 Hole 45, 46 Notch 50 Magnetic shield α Connector coupling part β Detection part γ Fixed part

Claims (2)

A bus bar,
A sensor body for detecting magnetism generated from the bus bar, and calculating a value of a current flowing through the bus bar based on the detected magnetism;
A housing having a sensor chamber for housing the sensor body, and a lower surface facing one surface of the bus bar;
A magnetic shield body mounted on the housing such that the sensor body and the bus bar are located inside;
With
The housing is formed with a first protrusion protruding downward from a fixed base protruding downward from the lower surface of the housing,
The bus bar has a notch formed at a location facing the fixed base when the bus bar and the magnetic shield are assembled to the housing.
The magnetic shield is formed with a hole that is penetrated by the first protrusion when the bus bar and the magnetic shield are assembled to the housing.
When the bus bar and the magnetic shield are assembled to the housing, the first convex portion passes through the notch of the bus bar and passes through the hole of the magnetic shield, and the bus bar and the When the magnetic shield is assembled, the magnetic shield supported by the fixing base is melted when the tip of the first convex portion is thermally fused to the hole of the magnetic shield and then solidified. Prevent you from getting out of the
An assembly structure of a current detection device characterized by that. The housing is provided with a second protrusion protruding downward from the lower surface of the housing,
The bus bar is formed with a hole that is penetrated by the second protrusion when the bus bar and the magnetic shield are assembled to the housing.
A tip of the second convex portion penetrating the hole of the bus bar is thermally welded to the hole;
The assembly structure of the current detection device according to claim 1 .

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