JP2018034748A - Structure for electrically connecting on-board electrical article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure for electrically connecting on-board electrical articles that can reduce radio noise generated by a noise loop formed in a vehicle without providing a noise filter.SOLUTION: A structure for electrically connecting on-board electrical articles includes: a harness 40 for electrically connecting a first electrical article 20 and a second electrical article 30 which are mounted on a vehicle; and a bus bar 50 for flowing a feedback current to the first electrical article from the second electrical article. At least two loops 80a, 80b of which electric field becomes an antiphase are formed by crossing the harness with the bus bar.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electrical connection structure for in-vehicle electrical components.

  Conventionally, many electric components such as a generator, an inverter, and a battery are mounted on a vehicle, and these on-vehicle electric components are electrically connected by a harness (for example, Patent Document 1). FIG. 3 is a configuration explanatory view showing an electrical connection structure 110 of a conventional in-vehicle electrical component. In the electrical connection structure 110, the battery 120 as the first electrical component, the load 130 as the second electrical component, the harness 140 that electrically connects the battery 120 and the load 130, the battery 120, and the load There are provided GND harnesses 151 and 152 for connecting 130 housings and the vehicle body.

In the electrical connection structure 110 shown in FIG. 3, the battery 120, the harness 140, the load 120, the GND harnesses 151 and 152, and the vehicle body form one loop through which current flows. When a current flows through this loop, electromagnetic noise that causes radio noise is generated. The electromagnetic noise increases as the loop area S ₀ surrounded by the alternate long and short dash line increases, and the influence is reduced as the distance from the radio antenna mounted on the vehicle increases.

  Specifically, the scalar quantity of the electric field E, which is generated by the current flowing through the loop and becomes electromagnetic noise, is calculated by the following Equation 1. In Equation 1, i represents the loop current, f represents the frequency component of the current, S represents the loop area, and r represents the distance from the center of the loop to the object receiving the noise.

JP 2006-273315 A

  With respect to radio noise, in Patent Document 1, radio noise is reduced by separately providing a noise filter circuit for reducing noise in a drive circuit for electrical components. However, a noise loop formed in a vehicle including a harness and a vehicle body is used. The generated radio noise is not considered.

  Moreover, if a large number of noise filters and noise filter circuits are added to reduce radio noise, the electrical components will be increased in size and cost.

  The present invention has been made in view of the above problems, and provides an electrical connection structure for in-vehicle electrical components that can reduce radio noise generated by a noise loop formed in a vehicle without providing a noise filter. With the goal.

  In order to achieve the above object, an electrical connection structure for an in-vehicle electrical component according to claim 1 includes a harness for electrically connecting a first electrical component and a second electrical component mounted on a vehicle; A bus bar for flowing a feedback current from two electrical components to the first electrical component, and the harness and the bus bar intersect each other to form at least two loops in which the electric fields are in opposite phases. To do.

  According to this configuration, when current flows in the order of the first electrical component, the harness, the second electrical component, and the bus bar, electromagnetic noise (that is, the electric field E) is generated in each of the two loops formed by intersecting the harness and the bus bar. ) Occurs. The two loops have a relationship in which noises are canceled with each other with respect to the radio antenna because the electric field E has an opposite phase. Thereby, the radio noise by the noise loop formed in the whole vehicle can be reduced.

  According to a second aspect of the present invention, in the electrical connection structure for in-vehicle electrical components according to the first aspect, the loop includes a first loop and a radio antenna mounted on the vehicle from the first loop. And a second loop having an electric field in an opposite phase, wherein the loop area of the second loop is larger than the loop area of the first loop. To do.

  According to this configuration, since the magnitude of the electric field serving as electromagnetic noise is proportional to the loop area S and inversely proportional to the distance r between the loop and the radio antenna, as described in Equation 1, the distance from the radio antenna is increased. By enlarging the loop area of the second loop at a certain position, it is possible to approximate the magnitude of the electric field due to the first loop and the magnitude of the electric field due to the second loop having the opposite phase. Thereby, the noise cancellation effect by the first loop and the second loop can be enhanced.

  According to a third aspect of the present invention, in the electrical connection structure for on-vehicle electrical components according to the second aspect, the bus bar extends in a straight line, and the harness extends in a curved shape intersecting the bus bar. It is characterized by doing.

  According to this configuration, since the harness having a higher degree of freedom than the bus bar is curved, the installation is easy.

  According to the electrical connection structure for in-vehicle electrical components according to the present invention, radio noise generated by a noise loop formed in a vehicle can be reduced without providing a noise filter.

The perspective view which shows the electrical connection structure of the vehicle-mounted electrical equipment which is one Embodiment of this invention. The perspective view which shows the example of a change of the electrical connection structure of vehicle-mounted electrical equipment. Structure explanatory drawing which shows the electrical connection structure of the conventional vehicle-mounted electrical equipment.

  FIG. 1 is a perspective view showing an electrical connection structure 10 for an in-vehicle electrical component according to an embodiment of the present invention, and shows a vehicle body 70 and an electrical connection structure 10 disposed on the vehicle body 70. In the illustrated example, a part of the vehicle body 70 is cut away. The electrical connection structure 10 includes a generator 20 that is a first electrical component, a battery 30 that is a second electrical component, a harness 40, a bus bar 50, and a radio antenna 60. The electrical connection structure 10 for in-vehicle electrical components according to the present invention can be suitably used particularly for an electric vehicle such as a hybrid vehicle or an electric vehicle, and is used for a hybrid vehicle in this embodiment.

  The vehicle has a sheet metal body 70, and the vehicle body 12 includes a pair of left and right side sills 71 and 72 extending in the front-rear direction on both sides in the vehicle width direction, and a floor panel 74 installed between the side sills 71 and 72. including.

  The floor panel 74 is a plate-like member constituting the floor surface of the vehicle body 70, and includes a front floor panel 75 positioned in front of the vehicle body 70 and a rear floor panel 76 positioned in the rear of the vehicle body. The front floor panel 75 has a tunnel structure portion 75a that protrudes inward (inside the vehicle) of the vehicle body at the center in the width direction and extends in the front-rear direction of the vehicle.

  An engine room 12 is formed at the front portion of the vehicle body 70. In the engine room 12, an engine (not shown) and a generator 20 driven by the engine are installed. In the example of illustration, the state which accommodated the generator 20 in the housing | casing is shown. In the present embodiment, the generator 20 is constituted by a generator / motor generator that is connected to the output shaft of the engine to assist power and generate power.

  The battery 40 is mounted in a vehicle space 14 formed behind the vehicle and behind a rear seat (not shown). In the example of illustration, the state which accommodated the battery 40 in the housing | casing (battery case) in which the battery accommodation space was formed is shown. The battery 40 is electrically connected to the generator 20 via the harness 50. When the remaining capacity of the battery 40 is insufficient, the generator 20 can be driven by the engine to charge the battery 40. .

  In the present embodiment, the harness 50 is a high-voltage wire harness that connects high-voltage electrical components, and extends from the engine room 12 in which the generator 20 is disposed to the front floor panel 75 below the floor. It extends to the battery 40 through the floor of the rear floor panel 76 and / or under the floor. In the illustrated example, the harness 50 and the bus bar 60 are indicated by solid lines on the floor of the floor panel 75 in order to facilitate understanding of the positional relationship between the harness 50 and the bus bar 60.

  The harness 40 extends in a curved shape so as to bend left and right across the vehicle width direction central portion of the vehicle body 70. In the present embodiment, a front portion that is a part of the harness 40 extends from the generator 20 to the vicinity of one side sill 72 of the vehicle, and further extends in the front-rear direction along the side sill 72. The rear portion of the harness 40 extends from the side of the one side sill 72 to the vicinity of the other side sill 71 across the center in the vehicle width direction, and extends in the front-rear direction along the side sill 71. The rear end is connected to the battery 40.

  The bus bar 50 forms a return current path and is disposed between the battery 40 and the generator 20. The bus bar 50 is made of copper having a resistance lower than that of the vehicle body 70. In the present embodiment, the bus bar 50 is formed in a rod shape and extends substantially linearly in the center in the vehicle width direction. In the present embodiment, the bus bar 50 is disposed below the floor panel 70 and below the harness 50. The bus bar 50 only needs to be arranged so as to function as a path for the feedback current. For example, both ends may not be directly connected to the battery 30 and the generator 20, and the bus bar The structure which connects 50, the battery 30, and the housing | casing of the generator 20 with a GND harness may be sufficient.

  As shown in FIG. 1, the harness 40 and the bus bar 50 intersect each other in a plan view of the installed state. Thus, two loops, that is, a first loop 80a and a second loop 80b are formed on the electric circuit connecting the generator 20 and the battery 40 by the harness 40 and the bus bar 50. The first loop 80a and the second loop 80b are formed so that the directions of the currents flowing in the loops are opposite to each other when the current flows in the electric circuit.

The first loop 80a is located close to the radio antenna 60, the second loop 80b is located farther from the first loop 80a with respect to the radio antenna 60, the loop center of the second loop 80b and the radio antenna 60 distance _{r 2} of is larger than the distance _{r 1} between the loop center and the radio antenna 60 of the first loop 80a. Further, loop area S ₂ of the second loop 80b surrounded by the chain line in FIG. 1 is larger than the loop area S ₁ of the first loop 80a.

  The radio antenna 60 is disposed outside the passenger compartment and receives AM / FM signals. In the illustrated example, the radio antenna 60 is arranged at the rear of the vehicle, but the arrangement position is not limited to this, and may be arranged at the front of the vehicle, for example.

  In the electrical connection structure 10 described above, electromagnetic noise is generated by a loop current caused by a current (noise current) transmitted through the harness 40 and a feedback current flowing through the bus bar 50.

Specifically, when a current that flows in the order of the generator 20, the harness 40, the battery 50, and the bus bar 50 and returns to the generator 20, a current flows in the first loop 80a in the counterclockwise direction of FIG. On the other hand, current flows in the second loop 80b in the clockwise direction in FIG. In this manner, the direction of the current flowing through the first loop 80a and the second loop 80b are opposite, the electric field generated by the first loop 80a (hereinafter, referred to as an electric field E ₁₎ and generated by the second loop 80b electric field (hereinafter, referred to as the field E ₂₎ and is opposite phase direction of the electric field is reversed.

Although the radio antenna 60 resulting in noise sound radio broadcasting when receiving the electromagnetic noise is mixed in the vicinity of the radio antenna 60, the electric field E ₂ between the electric field E ₁ in the first loop 80a second loop 80b are opposite phase Thus, the electromagnetic noises cancel each other, and as a result, noise noise can be reduced. Here, the reverse phase is not limited to the case where the direction of the electric field is completely reversed, but includes the case where the phase is shifted to such an extent that the electric fields can be canceled out.

At this time, the magnitude of the electromagnetic noise in each of the loops 80a and 80b can be calculated by the above-described equation 1. Since the current i and the frequency component f have a common value in the first loop 80a and the second loop 80b, the ratio of the electric fields E ₁ and E ₂ is (S ₁ / r ₁ ) :( S ₂ / r ₂ ). In this embodiment, the second loop 80b in a position more distant relative to the radio antenna 60 _(i.e., r 2> _{r 1)} is set larger than the loop area _{S 1} of the loop area _{S 2} of the first loop 80a Thus, the values of the electric fields E ₁ and E ₂ can be approximated. Thereby, the cancellation effect of the electromagnetic noise by the 1st loop 80a and the 2nd loop 80b can be heightened.

  A hybrid vehicle tends to have a larger noise current and a larger radio noise than a vehicle having only an internal combustion engine. However, the electrical connection structure 10 according to the present invention is used for the harness 40 constituting the high-voltage electric wire. Thus, radio noise can be appropriately reduced.

The bus bars 50 forming the loops 80a and 80b can be easily connected to and detached from the vehicle, and the installation cost is relatively low. Therefore, the path of the feedback current can be easily formed while suppressing the cost. be able to. Further, since the harness 40 having a higher degree of freedom than the bus bar 50 is curved, the installation is easy, and the loop area S ₁ and S ₂ of each of the loops 80a and 80b can be easily adjusted by the harness 40. Can do.

  Next, a modification of the electrical connection structure 10 will be described with reference to FIG. In the modification, the harness 40 and the bus bar 50 are arranged so as to intersect each other, thereby forming three loops, that is, a first loop 80a, a second loop 80b, and a third loop 80c.

In this electrical connection structure 10, when a current flows through the circuit, a current flows in the counterclockwise direction of FIG. 2 in the third loop 80c, so that electromagnetic noise having substantially the same phase flows in the first loop 80a and the third loop 80c. Occurs, and electromagnetic noise having a phase opposite to those of the second loop 80b is generated. In the vicinity of the radio antenna 60, the electric field _{E 1} and the electric field _{E 3} of the third loop 80c of the first loop 80a, by the electric field _{E 2} in the second loop 80b cancel, radio noise is reduced. It is preferable to set each loop so that the sum of the electric field E ₁ and the electric field E ₃ approximates the value of the electric field E ₂ .

  As shown in the modified example, the electrical connection structure 10 according to the present invention may be one in which three or more loops are formed by the harness 40 and the bus bar 50. When there are three or more loops, in the vicinity of the radio antenna 60, the sum of the electric fields E of the loops in which the electric fields are substantially in phase and the sum of the electric fields E of the loops in which the electric fields are in opposite phases are approximated. As described above, it is preferable to set the loop area S and the distance r from the radio antenna 60 in each loop.

  In addition, this invention is not limited to embodiment mentioned above, A various change is possible in the range which does not deviate from the meaning of invention. For example, in the above-described embodiment, the bus bar 50 extending in a straight line is used, but the bus bar 50 may be extended in a curved line. Moreover, in this embodiment, although the generator 20 and the battery 30 are mentioned as in-vehicle electrical components, it is not restricted to this, What is necessary is just the in-vehicle electrical components which can comprise an electrical circuit using a harness and a bus bar. The configuration may be such that three or more in-vehicle electrical components are arranged on the electric circuit.

10 Electrical connection structure 20 Generator (first electrical component)
30 battery (second electrical component)
40 harness 50 bus bar 60 radio antenna 70 vehicle body 80a first loop 80b second loop

Claims (3)

A harness for electrically connecting the first electrical component and the second electrical component mounted on the vehicle;
A bus bar for flowing a feedback current from the second electrical component to the first electrical component,
An electrical connection structure for in-vehicle electrical components, wherein the harness and the bus bar intersect each other to form at least two loops in which electric fields are in opposite phases to each other. The loop has a first loop and a second loop that is located away from the first loop with respect to a radio antenna mounted on a vehicle, and the first loop and a second loop in which the electric field has an opposite phase;
The electrical connection structure for in-vehicle electrical components according to claim 1, wherein a loop area of the second loop is larger than a loop area of the first loop.   3. The on-vehicle electrical component electrical connection structure according to claim 1, wherein the bus bar extends linearly and the harness extends in a curved shape intersecting the bus bar. 4.

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