JP6373031B2 - Shield structure - Google Patents

Description

The present invention, for example, relates to a wire harness used to connect a between electronic devices to be mounted on a vehicle or the like, high-voltage wire over harness for electrically connecting the shield each other through that will be particularly routed in a vehicle or the like It relates to a shield structure .

  In general, it is known that electromagnetic noise due to high-frequency current is generated from a wire harness (electric wire) that supplies a motor driving current of a hybrid vehicle. In order to shield this electromagnetic noise and prevent noise from being superimposed on signal lines of ECU (Electric Control Unit) etc., harnesses equipped with various shields and shield connectors are used between electrical and electronic equipment. It is connected to the.

Patent Document 1 describes an example of a shield connector that can prevent noise due to current distribution bias generated in a shield shell. Shield connector according to Patent Document 1 has a conductive inner chromatography shield shell housing a housing for holding the terminal fitting and an outer over shield shell conductive housing the inner chromatography shield shell. The outer over shield shell includes a rectangular tube-like shell body has a fixing portion having a inside annular wall which is formed along the circumferential direction of the shell main body, inner over its inner surface an annular wall The shield shell is formed so as to overlap densely over the entire outer surface of the shell body.

  In the shield connector configured as described above, a current flows between the inner shield shell and the outer shield shell through the annular wall of the outer shield shell covering the inner shield shell. The annular wall has a sufficient surface area to electrically connect the inner shield shell and the outer shield shell with a large contact area, thereby preventing uneven current distribution on the surfaces of the inner shield shell and the outer shield shell. It is supposed to be possible.

JP 2009-301930 A

  However, when the shape of the outer shield shell is a rectangular tube shape, the distance to the wire or terminal for transmitting signals and power differs between the corner portion of the shield shell wall and the center portion of the shield shell wall. The distribution is biased. In Patent Document 1, such an uneven current distribution cannot be eliminated.

  On the other hand, by making the shape of the outer housing also cylindrical, it becomes possible to eliminate the above-described bias in current distribution. However, since high-voltage harnesses used for electric vehicles and hybrid vehicles are mainly two-pole or three-pole, the shape of the shield connector for the high-voltage harness often has to be a square shape. When trying to make the shape of the shield connector for such a high voltage harness into a cylindrical shape, there arises a problem that the size of the connector must be increased.

  Further, since the current density also increases at the connection portion with the casing and the mating connector to which the shield connector is connected, there is a problem that the current distribution is uneven and the shield performance is deteriorated. Furthermore, in the shield connector described in Patent Document 1, since the shield shell has a two-layer structure of an inner shield shell and an outer shield shell and an annular wall is required to electrically connect both shield shells, As a result, there will be a problem that the cost increases and the cost increases.

The present invention has been made to solve the above-described problems, and can provide a shield structure that can reduce noise caused by uneven distribution of current flowing in the shield and can be realized at a low cost with a small number of components. Objective.

In order to solve the above problems, a first aspect of the shield structure of the present invention is a shield structure that electrically connects shields through which a wire harness passes, and an inner housing that houses one or more of the wire harnesses; A shield shell covering the outer periphery of the inner housing; a shield connecting portion provided on one end side of the inner housing and electrically connected to the shield shell; and provided on the other end side of the inner housing. A flange portion electrically connected to the shield shell, and a connection portion provided on the flange portion and electrically connected to a predetermined housing, wherein the shield connection portion and the connection portion are the wires Each of the one or more wire harnesses in a cross section of the inner housing perpendicular to the axial direction of the harness. The positioning of the current center position relative to the weighted average current centroid position for each current value, the shield connecting portion is provided to be electrically connected to the other shield part, the shield connecting portion and the connection Two or more portions are provided, and the shield connection portion has the current center-of-gravity position under the condition that a central angle formed by a straight line connecting the current center-of-gravity position and each shield connection portion on the cross section is equal. And an average value of linear distances between the shield connecting portions and the shield shells are arranged at the respective positions of the shield shell, and the connecting portions pass through the current center of gravity position and the shield connecting portions, respectively. The two or more planes parallel to the axis and the flange portion are arranged on two or more straight lines intersecting each other.

According to another aspect of the shield structure of the present invention, the inner housing includes two or more wire harnesses including the wire harness having a current direction in one direction and the wire harness having a current direction opposite to the one direction. When the wire harness having the current direction opposite to that of the wire harness is equidistant from all the wire harnesses having one direction of current, the current center of gravity position is The current center of gravity position is determined from the wire harness excluding the wire harness in the reverse direction, and when the wire harness in the reverse direction is in a position where the current direction is not equidistant from the wire harness in the one direction. A wire harness having a reverse direction of the current and a wire having a single direction of the current adjacent to the wire harness. Characterized in that it is determined from the wire harness by removing all pairs of the harness as a set.

ADVANTAGE OF THE INVENTION According to this invention, the noise which arises by the bias | inclination of the electric current distribution which flows into a shield can be reduced, and the shield structure which can be implement | achieved at low cost with few parts count can be provided.

It is a perspective view of the shield structure concerning a 1st embodiment of the present invention. It is a front view of the shield structure concerning a 2nd embodiment of the present invention. It is a front view of the shield structure used for the confirmation test. It is a table | surface which shows the result of a confirmation test. It is a front view of the shield structure concerning a 3rd embodiment of the present invention. It is the front view and top view of a shield structure concerning a 4th embodiment of the present invention.

A shield structure according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. Each component having the same function is denoted by the same reference numeral for simplification of illustration and description. In the shield structure, there is a bias in the distribution of current flowing in the shield part due to differences in its shape, the position of the connection part with the connection destination housing, the position of the shield connection part for connecting to the shield part of the connection partner , etc. As a result, there is a problem that noise is generated due to the uneven current distribution. The shield structure of the present invention is configured to suppress the generation of noise due to such a bias in the current distribution in the shield portion.

(First embodiment)
A shield structure according to a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a perspective view of the shield structure 100 of the present embodiment. The shield structure 100 according to the present embodiment includes an inner housing 110 whose end face that accommodates the wire harness (covered electric wire) 10 has a substantially square shape, a shield shell 120 that covers the outer periphery of the inner housing 110, and one end of the inner housing 110. A shield connection portion 130 provided and electrically connected to the shield shell 120 and a flange portion 140 provided on the other end side of the inner housing 110 are provided.

  In the embodiment shown in FIG. 1, only one wire harness 10 is accommodated in the inner housing 110. However, the present invention is not limited to this, and two or more wire harnesses may be accommodated in the inner housing 110. Further, the flange portion 140 is provided with a connection portion 141 for electrically connecting to a connection destination housing (not shown).

Shield structure 100 is intended to be used by connecting one end of the inner housing 110 to shield connecting portion 130 is provided on the connection destination, the shield connecting portion 130 is electrically connected to the shield portion of the connection partner The In addition, the flange portion 140 is electrically connected to the shield shell 120 and is electrically connected to the connection destination housing via the connection portion 141.

In the shield structure 100 of the present embodiment, only one shield connection part 130 is provided, and the arrangement position thereof is determined as follows. In the cross section of the inner housing 110 perpendicular to the axial direction of the wire harness 10, the shield connecting portion 130 is located at a position where the linear distance between the shield shell 120 disposed on the outer periphery of the inner housing 110 and the center position 10 a of the current flowing through the wire harness 10 is the shortest. Is provided. Moreover, the connection part 141 provided in the flange part 140 is good to arrange | position on the straight line through which the plane parallel to the axis | shaft of the wire harness 10 and the flange part 140 cross | intersect the current center position 10a and the shield connection part 130.

  In FIG. 1, only one wire harness 10 is accommodated in the inner housing 110. However, when two or more wire harnesses 10 are accommodated, the current center positions of the two or more wire harnesses 10 are set to respective currents. The position weighted and averaged by the value is the current center position 10a. Hereinafter, the current center position 10a obtained by the weighted average as described above is referred to as a current center-of-gravity position including the current center position when the number of the wire harness 10 is one. The shield connecting portion 130 is preferably provided at a position where the distance between the current center of gravity position 10a and the shield shell 120 on the cross section is the shortest, and further passes through the current center position 10a and the shield connecting portion 130 and is parallel to the axis of the wire harness 10. It is preferable to provide the connecting portion 141 on a straight line where the flat surface and the flange portion 140 intersect.

In the shield structure 100 according to the present embodiment, the noise connection noise is obtained by disposing the shield connection part 130 having a high shield current density and the connection part 141 with the casing at a position close to the center of the current that flows through the current and becomes a noise radiation source. It is possible to more effectively reduce the occurrence of. That is, the shield connection part 130 where the shield current concentrates is arranged at a position on the shield shell 120 located at the shortest distance from the current center of gravity position 10a where the strongest magnetic field is generated, and the connection part 141 where the shield current concentrates is also the current. By arranging at a position close to the gravity center position 10a, radiation noise from the wire harness 10 can be effectively suppressed.

The shield structure 100 of the present embodiment does not require special parts for reducing noise, and the shield connection part 130 and the connection part 141 are suitably arranged in consideration of the position of the electric wire that is a noise radiation source. Therefore, the structure is excellent in noise shielding performance and easy to manufacture at low cost.

(Second Embodiment)
A shield structure according to a second embodiment of the present invention will be described with reference to FIG. FIG. 2 is a front view of the shield structure 200 of the present embodiment. The shield structure 200 according to the present embodiment includes a plurality of shield connection portions 230 for electrically connecting to the shield portion of the connection partner, and a plurality of connection portions 241 for electrically connecting to the housing of the connection destination. Have. In the shield structure 200 shown in FIG. 2, four shield connection portions 230 and four connection portions 241 are provided.

  The four shield connecting portions 230 are such that the shield shell 220 intersects the four straight lines having the same central angle from the current center of gravity position 10a of the wire harness 10 in the cross section of the inner housing 210 perpendicular to the axial direction of the wire harness 10. Arranged at the position of the point. In addition, the four shield connection portions 230 are positioned so that the average value of the linear distances between the current gravity center position 10a and each of the four shield connection portions 230 is minimized. Here, the central angle is an angle formed by two straight lines connecting the current center-of-gravity position 10a and the two shield connecting portions 230 adjacent in the circumferential direction. When four shield connection portions 230 are provided, the central angle is 90 ° (= 360 ° / 4).

  The four connecting portions 241 provided in the flange portion 240 pass through each of the current gravity center position 10a and the four shield connecting portions 230, and the four planes parallel to the axis of the wire harness 10 and the flange portion 140 intersect. They should be placed on each of the two straight lines. In FIG. 2, only one wire harness 10 is stored in the inner housing 210, but two or more wire harnesses 10 may be stored.

In the shield structure 200 of the present embodiment, the same effects as those of the shield structure 100 of the first embodiment can be obtained. In addition, the shield connecting portion 230 and the connecting portion 241 where the shield current is concentrated are arranged at the current center of gravity position as described above. By evenly arranging a plurality of elements 10a at the center, the bias of the shield current can be minimized, and the noise caused by the bias of the shield current can be minimized.

Test results for confirming the effect of reducing noise in the shield structures 100 and 200 of the first embodiment and the second embodiment will be described below. Here, it was confirmed how the shield performance is affected by the installation position of the connection portion 141 (241) with the connection destination casing provided in the flange portion 140 (240) of the shield structure 100 (200). . This test result for the installation position of the connection part 141 (241) can be similarly applied to the installation position of the shield connection part 130 (230) having the same shielding effect against noise. The shield structure 20 used for the confirmation test is shown in FIG.

  In this confirmation test, an absorption clamp method was employed as a noise measurement method, and a test was performed using an absorption clamp KT-10 manufactured by Kyoritsu Electronics. In addition, a spectrum analyzer (R3132 manufactured by Advantest) was used to output the measurement noise waveform, and the measurement frequency was set to 10 to 100 MHz. A 1.25 sq coated copper wire was used as the signal line. The shield shell 120 (220) was made of tin-plated copper and having a thickness of 1 mm, and was produced by bending. The dimension of the shield shell 120 (220) was 25 mm long × 75 mm wide × 50 mm deep, and the dimension of the flange 140 (240) was 75 mm long × 125 mm wide × 5 mm deep.

The shield structure 20 used in this confirmation test has 12 pieces in advance in the flange portion 140 (240) as candidates for the installation position of the connection portion 141 (241) used for connection to the housing (made of aluminum) as shown in FIG. Through-holes 21-1 to 12 are provided. In the confirmation test, the twelve through holes 21-1 to 12-12 are appropriately selected and used for the connecting portion 141 (241).

The result of the confirmation test is shown in FIG. FIG. 4 shows the test results in a table format, and shows the results of 12 tests. 1 to 12 in the column of the position of the connecting portion in FIG. 4 indicate the through holes 21-1 to 12-12, respectively. First, test numbers 1 to 4 are cases where there is one connection portion 141, and are the results of a confirmation test regarding the shield structure 100 of the first embodiment. The test results of test numbers 1 to 4 are results when the through holes 21-1 to 21-4 are selected as the connection portions 141, respectively. As shown in FIG. 4, when the through hole 21-4 having the shortest distance from the current gravity center position 10a is selected as the connecting portion 141, the shield performance is the highest, and the through hole 21-2 having the longest distance from the current gravity center position 10a is selected. When the connection portion 141 is selected, the shielding performance is the lowest. From this, it can be seen that, similarly to the shield structure 100 of the first embodiment, the shield performance can be improved by providing the connection portion 141 at the shortest position from the current gravity center position 10a.

The confirmation tests of test numbers 5 to 12 are results of a confirmation test related to the shield structure 200 of the second embodiment in which a plurality of connection portions 241 are provided. Test numbers 5 to 8 are when there are two connecting portions 241, and test numbers 9 to 12 are when there are three connecting portions 241. Even in the test where the connection portion 241 has two test numbers 5 to 8, when the through holes 21-4 and 21-10 having the shortest average distance from the current center of gravity position 10a are selected as the connection portion 241, the shielding performance is the highest. It has been shown to be higher. From this, it can be seen that the noise can be effectively suppressed by arranging the connection portion 241 where the current flowing through the shield shell 120 is concentrated near the gravity center position 10a of the current serving as the noise source.

Moreover, in the test of test numbers 9-12 in the case of three connection parts 241, the shielding performance of test number 9 in which the connection parts 241 are arranged so as to be biased upward in the drawing of the flange part 240 is the lowest. In this case, since the distribution of the shield current is also biased, it indicates that the noise suppression effect due to the shield current is deteriorated due to the bias of the current distribution. On the other hand, in the test of test number 12 in which the average value of the linear distances from the current gravity center position 10a to each connection portion 241 is the shortest and the three connection portions 241 are evenly distributed around the current gravity center position 10a. The performance is the highest. Thus, as in the shield structure 200 of the second embodiment, the average value of the linear distances between the current gravity center position 10a and each of the three connecting portions 241 is the smallest in the three directions having the same central angle from the current gravity center position 10a. It can be seen that by arranging the connecting portions 241 at the positions, the current distribution of the shield can be made uniform and noise can be effectively suppressed.

(Third embodiment)
A shield structure according to a third embodiment of the present invention will be described with reference to FIG. Figure 5 is a front view of the shield structure 300 of the present embodiment. Shield structure 300 of the present embodiment, similarly to the shield structure 200 of the second embodiment, the shield connecting portion 330 for electrically connecting to the shield portion of the connection destination, and the destination of the electrically to the housing A plurality of connection portions 341 for connection are provided, and the number of shield connection portions 330 and connection portions 341 is four in FIG.

  In the present embodiment, a plurality of wire harnesses are accommodated in the inner housing 310, and a reverse current is passed through some of the wire harnesses. Thus, when the wire harness in which the reverse current flows is housed in the inner housing 310, the radiation noise is canceled out by the reverse current wire harness and the adjacent wire harness. Therefore, the current center-of-gravity position is determined with respect to the remaining wire harnesses excluding the wire harness in which the current is reversed and the wire harness adjacent thereto. When there are multiple wire harnesses with opposite currents, the two adjacent wire harnesses whose current directions are opposite to each other are considered as one set, and the remaining wire harnesses excluding these multiple wire harnesses Thus, the current barycentric position is determined.

  In FIG. 5, three wire harnesses 11, 12, and 13 are housed in the inner housing 310. Among these, the current in the same direction flows in the wire harnesses 11 and 12, and the current in the direction opposite to the current in the wire harnesses 11 and 12 flows in the wire harness 13. Therefore, the current center-of-gravity position 10a is determined for the remaining wire harnesses 11 excluding the adjacent two wire harnesses 12 and 13 whose current directions are opposite to each other. In this case, the current center-of-gravity position is the center of the current flowing through one wire harness 11.

  When the current gravity center position 10a is determined as described above, the straight line in the four directions with the same central angle intersects the shield shell 220 from the current gravity center position 10a on the cross section of the inner housing 310 as in the second embodiment. The four shield connection portions 330 are arranged at the positions of the four points and where the average value of the linear distances between the current gravity center position 10a and each of the four shield connection portions 330 is minimum. In addition, the four connecting portions 341 provided in the flange portion 340 pass through the current gravity center position 10a and the four shield connecting portions 230, and the four planes parallel to the axis of the wire harness 10 and the flange portion 140 intersect. Placed on each of the two straight lines.

In the shield structure 300 of the present embodiment, two adjacent wire harnesses whose current directions are opposite to each other are taken as one set, and the current center-of-gravity position 10a is determined for the remaining wire harnesses excluding these sets of wire harnesses. In addition, by determining the arrangement of the plurality of shield connection portions 330 and the connection portions 341 based on this, the generation of noise can be more effectively reduced.

  If the wire harness with the reverse current direction is equidistant from the other wire harnesses, the current center of gravity position is the same for the wire harness with the same current direction except for the wire harness with the reverse current direction. 10a should be determined. Thereby, the some shield connection part 330 and the connection part 341 can be arrange | positioned in a suitable position, and generation | occurrence | production of noise can be reduced effectively.

(Fourth embodiment)
A shield structure according to a fourth embodiment of the present invention will be described with reference to FIG. FIG. 6 is a front view and a top view of the shield structure 400 of the present embodiment. The shield structure 400 of this embodiment is provided with a locking portion 451 and / or a slit 452 in the shield structure 200 of the second embodiment. By locking the locking portion 451 with the slit 452 of the shield structure 400 on the other side, the two shield structures 400 can be connected.

The locking portion 451 and / or the slit 452 are provided in the inner housing 410. The locking portion 451 has a key shape in which the inner housing 410 protrudes in a protruding shape. A slit 452 is also formed in the inner housing 410. The locking portion 451 can be locked to the slit 452 of the counterpart shield structure 400.

  The positions where the locking portion 451 and the slit 452 are formed are positions where the wire harness 10, the shield connection portion 430, and the connection portion 441 do not overlap in the horizontal direction and the vertical direction. Thereby, it can avoid that the latching | locking part 451 and the slit 452 reduce the noise suppression effect by a shield current, and can prevent deterioration of a shield performance.

In addition, the description in this Embodiment shows an example of the shield structure which concerns on this invention, and is not limited to this. The detailed configuration and detailed operation of the shield structure in the present embodiment can be changed as appropriate without departing from the spirit of the transmitter and the present invention.

10, 11, 12, 13 Wire harness (covered wire)
100, 200, 300, 400 Shield structure 110, 210, 310, 410 Inner housing 120, 220, 320, 420 Shield shell 130, 230, 330, 430 Shield connection part 140, 240, 340, 440 Flange part 141, 241 341, 441 Connection portion 451 Locking portion 452 Slit

Claims (2)

A shield structure that electrically connects shields through which a wire harness passes,
An inner housing that houses one or more of the wire harnesses;
A shield shell covering the outer periphery of the inner housing;
A shield connecting portion provided on one end side of the inner housing and electrically connected to the shield shell;
A flange portion provided on the other end side of the inner housing and electrically connected to the shield shell;
A connecting portion provided on the flange portion and electrically connected to a predetermined housing;
The shield connection part and the connection part are current center-of-gravity positions obtained by weighted averaging the current center positions of the one or more wire harnesses with respective current values in a cross section of the inner housing perpendicular to the axial direction of the wire harness. Positioned based on
The shield connection part is provided so as to be electrically connectable with other shield parts ,
The shield connection part and the connection part are each provided with two or more,
The shield connection portion has the current center of gravity position and each of the shield connection portions under a condition that a central angle formed by a straight line connecting the current center of gravity position and each of the shield connection portions on the cross section is equal. Are arranged at the respective positions of the shield shell where the average value of the straight line distance is minimized,
The connecting portions are disposed on two or more straight lines where the flange portion intersects with two or more planes parallel to the axis of the wire harness passing through the current gravity center position and the shield connecting portion, respectively. Shield structure characterized by that. The inner housing accommodates two or more wire harnesses including the wire harness in which the direction of current is one direction and the wire harness in which the direction of current is opposite to the one direction,
When the wire harness in the direction of the current is in a position equidistant from all the wire harnesses in the direction of the current,
The current center-of-gravity position is determined from the wire harness excluding the wire harness in which the direction of the current is opposite,
When the current direction of the wire harness is in a position where the current direction is not equidistant from the direction of the current wire harness,
The current center-of-gravity position is determined from the wire harness excluding all the sets of a wire harness having a reverse direction of the current and a wire harness having one current direction adjacent to the wire harness as one set. The shield structure according to claim 1 , wherein the shield structure is determined.

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