JP6572006B2 - Ground connection device for vehicle - Google Patents

Description

  The present invention relates to a vehicle ground connection device.

  In a vehicle, in general, between the output terminal of the power supply unit composed of an alternator, a battery, etc., and the power input terminal of various electrical components mounted on this vehicle is routed to each part on the vehicle body The power supply power is supplied to the electrical component by connecting via the wired harness. Further, when the power supply is actually supplied, it is also necessary to connect a ground in order to secure a path through which a current flows from the electrical component toward the power supply unit.

  With respect to the ground connection between the output of the power supply unit and the electrical component, for example, as disclosed in Patent Document 1, it is possible to connect using a vehicle body that is a conductor such as metal. However, when the vehicle body is formed of a non-metallic material such as resin, the vehicle body cannot be used as a ground. Further, as shown in Patent Document 2, a dedicated ground wire is incorporated in a wire harness, and the ground connection is used to realize the ground connection between the output of the power supply unit and the electrical component. is there.

JP 2006-290153 A JP 2007-250286 A

  When the vehicle body is used as a ground as in Patent Document 1, since the current can freely flow through various parts of the vehicle body, the disconnection of the ground system is very unlikely to occur. On the other hand, when using a wire harness in which a ground wire is incorporated as in Patent Document 2, a malfunction may occur in the wire harness for some reason, and the ground wire may be disconnected.

  If this ground wire is disconnected, the power supply current does not flow in all electrical components connected to the downstream side of the disconnected location, so that all these operations stop and a large-scale failure occurs on the vehicle. .

  Therefore, although it is desirable to use the vehicle body as the ground, for example, when the vehicle body is resin-molded, the vehicle body ground cannot be used. Therefore, it is essential to take measures against the disconnection of the ground wire. Therefore, it is conceivable to prepare a conductive special grounding member in place of the ground wire and form a closed loop shape portion at one or a plurality of locations on the grounding member. That is, the closed loop shape portion branches from a certain point to form a plurality of different current paths, so that the current paths can be made redundant.

  For example, even if a failure occurs in the grounding member due to an impact applied from the outside, and a part of the closed loop shape portion is disconnected and the loop is opened, the remaining part of the loop is routed. Since an electric current flows through, the grounding member as a whole can maintain a function of flowing an electric current. Therefore, if such a grounding member is used for the ground path, it is possible to secure a ground-side power supply current path for the electrical component even if a disconnection occurs.

  However, if the weight and cost of the parts are taken into consideration, the cross-sectional area of the conductor constituting the ground wiring member cannot be increased more than necessary. In other words, the cross-sectional area of the conductor constituting each part of the ground wiring member is determined to the extent that the entire ground wiring member allows the maximum value of the current flowing to the ground of the vehicle.

  As described above, when the ground wiring member is used, even if a part of the ground wiring member is disconnected, a current path on the ground side can be secured, so that power supply to each electrical component can be continued. However, when a disconnection occurs in a part of the grounding member, a larger current flows in the remaining current path than in the case where there is no disconnection. Since there is no special margin in the cross-sectional area of the conductor that forms this current path, an excessive current flows compared to the capability of the conductor. As a result, abnormal heat generation due to Joule heat occurs in the ground wiring member itself, and the ground wiring member may be melted or fired. Therefore, it is necessary to detect the occurrence of disconnection even when the ground wiring member is used.

  Further, when the grounding member is disconnected, the disconnected part comes into contact with a metal body (floating from the ground) in the vicinity thereof, and electric leakage is likely to occur. In that case, electrical noise is generated due to electric leakage, and various electrical components mounted on the vehicle may malfunction due to the influence of the electrical noise.

  The present invention has been made in view of the above situation, and an object thereof is to provide a vehicle ground connection device capable of detecting the occurrence of partial disconnection of a conductor in a ground path on a vehicle. To do.

In order to achieve the above-described object, the vehicle ground connection device according to the present invention is characterized by the following (1) to ( 6 ).
(1) a conductive grounding member connected between a ground electrode of a power supply unit mounted on a vehicle and a ground electrode of an electrical component mounted on the vehicle;
One or more voltage sensors for measuring the potential difference between the potential and the reference potential at the point of the specific portion of the front Symbol grounding wiring member,
Based on the measurement value obtained by the measurement of the voltage sensor , at least an abnormality identification unit for identifying the presence or absence of abnormality,
Equipped with a,
The ground wiring member includes an annular loop portion, and a connecting portion that connects between the first portion and the second portion different from each other on the loop portion so as to divide the loop portion into two parts,
In the vicinity of the first part, in the vicinity of the second part, in the vicinity of the third part located on the first divided part on one side of the connecting part in the loop part, and on the first divided part The first voltage sensor, the second voltage sensor, the third voltage sensor, each of which measures a potential difference from the reference point potential in the vicinity of a fourth part different from the third part located in the middle. The voltage sensor and the fourth voltage sensor are connected;
A ground electrode of the power supply unit is connected to a fifth part located in the middle of the second divided region on the other side of the coupling unit in the loop unit,
The abnormality identifying unit identifies presence / absence of abnormality based on only four measurement values obtained by measurement of the first to fourth voltage sensors, and a part on the current path where the disconnection has occurred Automatically identify
A vehicle ground connection device.
(2) Ground electrodes of the electrical components different from each other are connected to the vicinity of the first part, the vicinity of the second part, the vicinity of the third part, and the vicinity of the fourth part, respectively .
The vehicle earth connection device according to (1) above, wherein
( 3 ) The abnormality identification unit identifies whether or not an abnormality has occurred based on a difference between a reference value of the voltage sensor in a state where there is no abnormality and an actual measurement value obtained by measurement of the voltage sensor .
The vehicle earth connection device according to (1) above, wherein
( 4 ) The abnormality identification unit outputs a predetermined warning by at least one of display and sound when the occurrence of disconnection in the ground wiring member is detected.
The vehicle earth connection device according to (1) above, wherein
( 5 ) The abnormality identifying unit automatically restricts the power supply from the power supply unit when the occurrence of the disconnection in the ground wiring member is detected.
The vehicle earth connection device according to (1) above, wherein
( 6 ) It further comprises a backup ground wiring member that forms a backup current path in the vicinity of the current path of the ground wiring member,
The abnormality identification unit automatically switches from the current path on the ground wiring member to the current path of the backup ground wiring member when the occurrence of disconnection in the ground wiring member is detected.
The vehicle earth connection device according to (1) above, wherein

According to the vehicle ground connection device having the above configurations (1) and (2) , when the disconnection occurs in a part of the grounding member, the abnormality identification unit can automatically detect the disconnection. That is, when a disconnection occurs, a change occurs in a path through which a current flows on the ground wiring member, so that a current distribution state changes. Further, the voltage drop on each path also changes with the change of current, and the potential on each path changes. Therefore, the change status of the measurement values of the voltage sensor is measured voltage, it can identify the presence or absence of disconnection.
Furthermore, according to the above (1) and the vehicle ground connection device configured as (2), the disconnection in any of the plurality of current paths on previous SL grounding wiring member occurs, in the earth wiring member on Since a significant change appears in the potential at the point where a plurality of current paths intersect, the disconnection can be easily identified by detecting the potential in the vicinity of this point.
Furthermore, according to the vehicle ground connection device having the configurations (1) and (2), the disconnection point can be automatically specified. That is, when the current path changes due to disconnection, a change in the measured value accompanying the change in the current path occurs at each of a plurality of locations. In addition, the state of change in the measurement values at a plurality of locations is affected by the difference between the locations where the disconnection has occurred. Therefore, a disconnection location can be specified based on a plurality of measurement values measured at each of the plurality of locations.
According to the vehicle ground connection device having the configuration ( 3 ), it is possible to easily identify whether or not an abnormality has occurred. That is, when disconnection occurs, abnormality is the current path changes compared with the state without a change appears in the measured value of the voltage. Therefore, for example, the reference value of the voltage sensor in a state where there is no abnormality is compared with the actual measurement value obtained by the measurement of the voltage sensor , and if these differences are greater than or equal to a predetermined value, it is considered that a disconnection has occurred be able to.
According to the vehicle ground connection device having the above configuration ( 4 ), it is possible to warn a user or the like when a disconnection occurs, so that an inspection or inspection can be performed before a problem occurs due to an excessive current. The user can be prompted to perform repair work.
According to the vehicle ground connection device having the above configuration ( 5 ), the power supply is automatically limited in the event of a disconnection, so that the current flowing through each part on the ground wiring member is prevented from becoming excessive. Can prevent abnormal heat generation.
According to the vehicle ground connection device having the above configuration ( 6 ), when a disconnection occurs, the problem path is switched to the current path on the backup ground routing member, so that the current flowing through each part becomes excessive. Can prevent abnormal heat generation.

  According to the vehicle ground connection device of the present invention, the ground connection can be realized even when the vehicle body ground cannot be used, such as when the vehicle body is resin-molded, and even when the conductor is partially disconnected in the ground path. Since it can be detected, abnormal heat generation can be prevented.

  The present invention has been briefly described above. Further, the details of the present invention will be further clarified by reading through a mode for carrying out the invention described below (hereinafter referred to as “embodiment”) with reference to the accompanying drawings. .

FIG. 1 is a plan view showing a layout (1) of main components on a vehicle on which the vehicle earth connection device of the embodiment of the present invention is mounted. FIG. 2 is a plan view showing a layout (2) of main components on the vehicle on which the vehicle earth connection device of the embodiment of the present invention is mounted. 3 (A) and 3 (B) are plan views showing a configuration example of the ground wiring member, FIG. 3 (A) is a state without disconnection, and FIG. 3 (B) is a specific example of the disconnection state. Show. FIG. 4 is a plan view showing a layout of main components on the vehicle on which the grounding member is mounted. FIG. 5 is a block diagram showing a configuration example (1) of the electric circuit of the vehicle earth connection device according to the embodiment of the present invention. FIG. 6 is a block diagram showing a configuration example (2) of the electric circuit of the vehicle ground connection device according to the embodiment of the present invention. FIG. 7A and FIG. 7B are plan views showing specific examples of measured values of respective parts in a normal state and a disconnected state, respectively. FIG. 8 is a plan view showing a preliminary ground wiring member and a positional relationship between the preliminary ground wiring member and the ground wiring member. FIG. 9: is a block diagram which shows the structural example (3) of the electric circuit of the earth connection apparatus for vehicles in embodiment of this invention. FIG. 10 is a plan view showing a situation when the current path is switched to the spare earth wiring member.

  Specific embodiments relating to the present invention will be described below with reference to the drawings.

  FIG. 1 shows a layout (1) of main components when a vehicle equipped with the vehicle ground connection device of the embodiment of the present invention is viewed from above. Further, FIG. 2 shows a layout (2) of the vehicle ground connection device having a slightly different configuration from that of FIG. Moreover, the grounding member 10 mounted on the vehicle shown in FIGS. 1 and 2 is shown in FIGS. 3 (A) and 3 (B). FIG. 3A shows a state without disconnection, and FIG. 3B shows a disconnection state. Moreover, the layout of the main components which looked at the vehicle carrying the earth wiring member 10 from upper direction is shown in FIG.

  As shown in FIG. 4, in the vehicle body 13 of this vehicle, a power supply unit 21 is arranged in the engine room 13e. The power supply unit 21 corresponds to a battery, an alternator (generator) or the like mounted on the vehicle, and supplies predetermined DC power supply power to the output.

  As shown in FIG. 4, auxiliary machines 14, 15, 16, and 17 are arranged in the vicinity of the vehicle doors 13a, 13b, 13c, and 13d, respectively. These auxiliary machines 14-17 are electrical components, such as a door lock mechanism and a power window mechanism, for example, and operate | move using the power supply supplied from the vehicle side. Therefore, the positive electrode side terminal of the power supply unit 21 and the auxiliary machines 14 to 17 are electrically connected via a wire harness (not shown). The ground side, that is, the negative side terminal of the power supply unit 21 and the ground side terminals of the auxiliary machines 14 to 17 are electrically connected through a special grounding member 10 that is a conductor. Yes.

  Next, the earth wiring member 10 will be described. For example, as shown in FIG. 4, it is necessary to connect the ground-side terminals of the plurality of auxiliary machines 14 to 17 and the like arranged at various locations on the vehicle body 13 to the negative-side terminal of the power supply unit 21. Therefore, it is necessary to route the conductor forming the ground so as to pass through each part of the vehicle body 13 so that it can be connected to the ground in the vicinity of each of the auxiliary machines 14 to 17. In order to form this ground, in this embodiment, the ground wiring member 10 shown in FIG. 3A is mounted on the vehicle body 13 as shown in FIG.

  As shown in FIG. 3A, the ground wiring member 10 has linear portions 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h connected to each other. The material of the ground wiring member 10 is a conductor such as metal. If necessary, the outside of the ground wiring member 10 is covered with an electrically insulating coating.

  Regarding the cross-sectional shapes of the linear portions 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h, for example, it is assumed to be a thin plate, a circle, an ellipse, or the like. Regarding the cross-sectional areas of the linear portions 10a, 10b, 10c, 10d, 10e, 10f, 10g, and 10h, the maximum value of the current that should be allowed for the grounding wiring member 10 as a whole is based on the resistivity of the material that constitutes the cross-sectional areas. In order to reduce the weight and material cost, it is determined to be as small as possible.

  As shown in FIG. 3A, the linear portions 10b, 10h, 10f, and 10g are connected to each other to form an electrically closed loop. This is one closed loop shape portion 11. Similarly, since the linear portions 10c, 10d, 10e, and 10h are also connected to each other to form an electrically closed loop, the closed loop shape portion 12 is formed. The linear portions 10b, 10c, 10d, 10e, 10f, and 10g are also connected to each other to form an electrically closed loop.

  The reason for providing such closed loop shape portions 11 and 12 is to provide redundancy in the current path. For example, in the state shown in FIG. 3A, current can pass through the linear portion 10g, but in the state shown in FIG. 3B, the current path is blocked at the linear portion 10g because there is a broken portion Px. However, even in the state shown in FIG. 3B where there is a disconnection point Px, the current path from the part P02 to the part P06 can be secured using the linear parts 10b and 10h.

  That is, by providing the closed loop shape portions 11, 12, etc., even if a partial disconnection occurs, other paths can be used, so that the current is not interrupted as a whole of the ground wiring member 10. Can be maintained.

  However, as shown in FIG. 3B, in the state where there is a broken portion Px, the current to be passed through the linear portion 10g also flows through the linear portion 10h. Current flows. That is, an excessive current exceeding the allowable value may flow intensively in the linear portion 10h or the like. Abnormal heat generation occurs due to Joule heat generated by this overcurrent. Moreover, in the disconnection location Px, as shown in FIG. 4, the linear site | part 10g may contact with the vehicle body 13, and an electric leakage may arise. Here, since the vehicle body 13, which is a conductor, is floating from the ground (electrically insulated), electrical noise is generated due to electric leakage, which causes malfunction of electrical components.

  In the state shown in FIG. 4, the tip portion P01 of the linear portion 10a of the ground wiring member 10 is connected to the negative electrode side terminal of the power supply unit 21. Further, the ground side terminals of the auxiliary machines 14, 15, 16, and 17 are electrically connected to the ground wiring member 10 in the vicinity of the parts P03, P04, P06, and P05, respectively.

  Next, voltage and current measurement will be described. In the vehicle ground connection device of the present invention, it is necessary to measure at least one of voltage and current at one or a plurality of locations on the ground wiring member 10 to obtain a measured value. Therefore, the configuration shown in FIG. 1 and the configuration shown in FIG. 2 are conceivable as specific examples of the vehicle ground connection device.

  Hereinafter, a configuration example in the case of measuring a voltage will be described. In the configuration shown in FIG. 1, four voltage sensors 23, 24, 25, and 26 are provided.

  The voltage sensor 23 measures the potential difference between the potential (Vpr) of the wiring 18 connected to the positive terminal of the power supply unit 21 and the ground potential (Ve01) near the portion P03 on the ground wiring member 10. Part P03 is a point where the current paths of the linear parts 10b and 10c intersect with the current path of the linear part 10h.

  The voltage sensor 24 measures the potential difference between the potential (Vpr) of the wiring 18 connected to the positive terminal of the power supply unit 21 and the ground potential (Ve02) near the portion P04 on the ground wiring member 10. The part P04 is a point at an angle where the current path of the linear part 10c and the current path of the linear part 10d intersect.

  The voltage sensor 25 measures a potential difference between the potential (Vpr) of the wiring 18 connected to the positive terminal of the power supply unit 21 and the ground potential (Ve03) near the portion P05 on the ground wiring member 10. The part P05 is a point at the corner where the current path of the linear part 10d and the current path of the linear part 10e intersect.

  The voltage sensor 26 measures the potential difference between the potential (Vpr) of the wiring 18 connected to the positive terminal of the power supply unit 21 and the ground potential (Ve04) near the portion P06 on the ground wiring member 10. Part P06 is a point where the current paths of the linear parts 10e and 10f intersect the current path of the linear part 10h.

  At a point where a plurality of current paths intersect, the influence when a disconnection occurs in any of the current paths surely appears as a change in potential. Therefore, by measuring the potential difference at each point where the path intersects as shown in FIG. 1, a measurement value that can be used to identify the presence or absence of disconnection is obtained.

  Hereinafter, a configuration example in the case of measuring current will be described. In the configuration shown in FIG. 2, seven current sensors 31, 32, 33, 34, 35, 36, and 37 are provided.

  The current sensor 31 is connected in a state where the current passing through the linear portion 10a on the ground wiring member 10 can be measured. Similarly, the current sensors 32 to 37 are connected in a state in which current passing through the linear portions 10b, 10c, 10d, 10e, 10g, and 10h can be measured.

  That is, the current sensor 31 measures the current of the linear portion 10a after all the currents passing through the ground wiring member 10 have joined together. Further, the current sensor 32 measures a current downstream of the part P03 where the current of the linear part 10c and the current of the linear part 10h merge and upstream of the part P02. Similarly, the current sensor 33 measures the current flowing between the parts P04 and P03. The current sensor 34 measures the current flowing between the parts P04 and P05. The current sensor 35 measures the current flowing through the linear portion 10e on the upstream side of the portion P06 where the path branches. The current sensor 36 measures the current flowing through the linear portion 10g after branching at the portion P06. The current sensor 37 measures the current flowing through the linear portion 10h between the portions P06 and P03.

  Before and after the location where branching or aggregation (merging) of a plurality of current paths occurs, the effect of disconnection in any of the current paths appears as a change in current. Therefore, as shown in FIG. 2, by measuring the current at each of the upstream and downstream points where the branching or gathering of the path occurs, a measurement value that can be used to identify the presence or absence of disconnection can be obtained.

Hereinafter, a configuration example of the electric circuit of the vehicle ground connection device will be described.
First, a configuration for measuring a voltage will be described. FIG. 5 shows a configuration example (1) of the electric circuit of the vehicle ground connection device according to the embodiment of the present invention. That is, when four voltage sensors 23 to 26 are used as shown in FIG. 1, an electric circuit of the vehicle ground connection device is configured as shown in FIG.

  The vehicle ground connection device shown in FIG. 5 includes a power supply unit 21, a disconnection identification unit 22, voltage sensors 23 to 26, a power supply restriction unit 27, a warning output unit 28, and a reference value table TB1.

  As described above, the voltage sensor 23 measures the potential difference between the potential Vpr appearing on the wiring 18 and the ground potential Ve01 at the site P03. Then, a signal V01 proportional to the measured value of the potential difference is output.

  Similarly, the voltage sensor 24 measures the potential difference between the potential Vpr appearing on the wiring 18 and the ground potential Ve02 at the site P04. Then, a signal V02 proportional to the measured value of the potential difference is output. Voltage sensor 25 measures a potential difference between potential Vpr appearing on wiring 18 and ground potential Ve03 at portion P05. Then, a signal V03 proportional to the measured value of the potential difference is output. Voltage sensor 26 measures the potential difference between potential Vpr appearing on wiring 18 and ground potential Ve04 at portion P06. And the signal V04 proportional to the measured value of this potential difference is output.

  The disconnection identification unit 22 can be configured by a digital circuit such as a microcomputer, or can be configured by an analog circuit. This disconnection identifying unit 22 identifies the presence or absence of disconnection by comparing each of the signals V01 to V04 output from the voltage sensors 23 to 26 with each reference value held on the reference value table TB1.

  For example, the reference value of the voltage when the signals V01 to V04 are normal is held in the reference value table TB1. The disconnection identification unit 22 considers that there is a disconnection when at least one difference between the voltage of each of the signals V01 to V04 and the reference value is greater than or equal to a predetermined value, and is normal when all the differences are less than the predetermined value. I reckon.

  Further, when a disconnection occurs, the disconnection identification unit 22 can identify the location where the disconnection occurs. That is, since the current path changes depending on the presence or absence of disconnection, the voltage drop amount in each of the linear portions 10a to 10h also varies accordingly. Therefore, it is possible to identify the occurrence location of disconnection based on a plurality of combinations of differences from the normal values of the signals V01 to V04.

  When the disconnection identifying unit 22 detects the occurrence of the disconnection, the warning output unit 28 notifies the user of the occurrence of the disconnection by, for example, displaying a lamp such as lighting or blinking or outputting an alarm sound. As a result, it is possible to prevent the disconnection from being left and to prevent a fire or the like from being generated due to abnormal heat generation. In addition, when the disconnection identification unit 22 identifies the occurrence location of the disconnection, the warning output unit 28 notifies the user of the occurrence location by display.

  The power supply restriction unit 27 controls the power supply unit 21 and restricts the power supply from the power supply unit 21 when the disconnection identification unit 22 detects the occurrence of the disconnection. For example, by suppressing the maximum value of the current supplied from the power supply unit 21 more than usual, an increase in temperature in the ground wiring member 10 when disconnection occurs can be suppressed.

  In the configuration shown in FIG. 5, it is assumed that the outputs of the four voltage sensors 23 to 26 are intensively monitored by one disconnection identification unit 22, but a more simplified configuration is adopted. Is also possible. For example, an analog comparator or a digital comparator is connected to the output of one voltage sensor 23, and the presence or absence of disconnection can be identified based on the result of comparing the signal V01 with a predetermined threshold value. In that case, one voltage sensor 23 and an analog comparator or a digital comparator can be integrated to constitute the main part of the vehicle ground connection device.

  Next, a configuration for measuring current will be described. FIG. 6 shows a configuration example (2) of the electric circuit of the vehicle ground connection device according to the embodiment of the present invention. That is, when seven current sensors 31 to 37 are used as shown in FIG. 2, an electric circuit of the vehicle ground connection device is configured as shown in FIG.

  The vehicle ground connection device shown in FIG. 6 includes a power supply unit 21, a disconnection identification unit 22B, current sensors 31 to 37, a power supply restriction unit 27, a warning output unit 28, and a reference value table TB2.

  Current sensors 31, 32, 33, 34, 35, 36, and 37 measure currents flowing through the linear portions 10a, 10b, 10c, 10d, 10e, 10g, and 10h, respectively. The current sensors 31, 32, 33, 34, 35, 36, and 37 output signals i01, i02, i03, i04, i05, i06, and i07 that are proportional to the current values of the measurement results, respectively.

  The disconnection identification unit 22B can be configured by a digital circuit such as a microcomputer, or can be configured by an analog circuit. The disconnection identification unit 22B identifies the presence or absence of occurrence of disconnection by comparing each of the signals i01 to i07 output from the current sensors 31 to 37 with each reference value held on the reference value table TB2.

  For example, the reference value of current when the signals i01 to i07 are normal is held in the reference value table TB2. Then, the disconnection identification unit 22B considers that there is a disconnection when at least one difference between the currents of the signals i01 to i07 and the reference value is greater than or equal to a predetermined value, and is normal when all the differences are less than the predetermined value. I reckon.

  Further, when a disconnection occurs, the disconnection identification unit 22B can identify the occurrence location of the disconnection. That is, since the current path changes depending on the presence or absence of disconnection, the magnitude of the current in each of the linear portions 10a to 10h also varies accordingly. Therefore, the occurrence location of the disconnection can be specified based on a plurality of combinations of differences from the normal values of the signals i01 to i07.

  When the disconnection identifying unit 22B detects the occurrence of the disconnection, the warning output unit 28 notifies the user of the occurrence of the disconnection by, for example, a lamp lighting or flashing display or an alarm sound output. As a result, it is possible to prevent the wire from being left undisturbed and to prevent abnormal heat generation. Further, when the disconnection identifying unit 22B identifies the occurrence location of the disconnection, the warning output unit 28 notifies the user of the occurrence location by display.

  The power supply restriction unit 27 controls the power supply unit 21 to restrict the power supply from the power supply unit 21 when the disconnection identification unit 22B detects the occurrence of the disconnection. For example, by suppressing the maximum value of the current supplied from the power supply unit 21 more than usual, an increase in temperature in the ground wiring member 10 when disconnection occurs can be suppressed.

  Specific examples of measured values of the respective parts in the configuration shown in FIG. 1 are shown in FIGS. 7 (A) and 7 (B). FIG. 7A shows the measurement value in the normal state, and FIG. 7B shows the measurement value in the disconnection state.

In the example shown in FIG. 7A, the measured values are as follows.
Voltage sensor 23 (potential difference of “Vpr−Ve01”): 11.9 [V]
Voltage sensor 24 (potential difference of “Vpr−Ve02”): 11.6 [V]
Voltage sensor 25 (potential difference of “Vpr−Ve03”): 11.6 [V]
Voltage sensor 26 (potential difference of “Vpr−Ve04”): 11.9 [V]

In the example shown in FIG. 7B, the measured values are as follows.
Voltage sensor 23 (potential difference of “Vpr−Ve01”): 11.7 [V]
Voltage sensor 24 (potential difference of “Vpr−Ve02”): 11.3 [V]
Voltage sensor 25 (potential difference of “Vpr−Ve03”): 11.3 [V]
Voltage sensor 26 (potential difference of “Vpr−Ve04”): 11.4 [V]

That is, in the example shown in FIG. 7B, since there is a broken portion Px as shown in FIG. 3B, the current path of the linear portion 10g is blocked. Therefore, compared to the example shown in FIG. 7A, the current flowing through the linear portions 10h and 10b is increased, and the voltage drop between the portions P03 and P02, the voltage drop between the portions P06 and P03, and the portions P05 and P03. The voltage drop between each increases. As a result, in the state of FIG. 7B, the measured value is reduced as follows compared to the normal state.
Change in measured value of voltage sensor 23: -0.2 [V]
Change in measured value of voltage sensor 24: -0.3 [V]
Change in measured value of voltage sensor 25: -0.3 [V]
Change in measured value of voltage sensor 26: -0.5 [V]

  The disconnection identification unit 22 shown in FIG. 5 identifies the presence or absence of a disconnection based on the change in the measurement value as described above, and further identifies the location where the disconnection occurs. For example, as reference values of the voltage sensors 23, 24, 25, and 26, 11.9 [V], 11.6 [V], 11.6 [V], and 11.9 [V] are reference values. A case is assumed in which 0.3 [V] is employed as the threshold value for the change in the measured value with respect to these reference values, registered in the table TB1. In that case, the disconnection identifying unit 22 recognizes that the measured value of the voltage sensor 24, the measured value of the voltage sensor 25, and the measured value of the voltage sensor 26 are abnormal in the state of FIG. Therefore, it is identified as “disconnected”. Moreover, the disconnection identification part 22 recognizes that the location of the linear site | parts 10f and 10g is disconnected from the magnitude relationship in the combination of the change of the measured value of the voltage sensors 23-26.

  Next, a modified example will be described. In this modification, in addition to the above-described ground wiring member 10, a spare ground wiring member 50 shown in FIG. 8 is used. FIG. 8 shows a positional relationship between the auxiliary grounding member 50 and the grounding wiring member 10. Further, FIG. 10 shows a situation where the current path is switched to the backup ground wiring member 50.

  In other words, when a disconnection occurs in part on the ground wiring member 10, the influence of the disconnection is eliminated or alleviated by switching the current path to a path that passes through the nearby spare ground wiring member 50. Can do.

  8 includes a linear portion 51 extending in the front-rear direction of the vehicle body 13 and linear portions 52, 53, 54, and 55 extending in the left-right direction of the vehicle body 13. The auxiliary ground wiring member 50 illustrated in FIG. The linear portions 51, 52, 53, 54, and 55 are made of a conductor and are electrically connected to each other. Further, the linear portion 51 is disposed in the vicinity of the center in the left-right direction of the vehicle body 13, the linear portions 52 and 53 are disposed in parallel near the linear portion 10h, and the linear portions 54 and 55 are disposed in the linear portion 10d. It is arranged in parallel in the vicinity.

  When a disconnection occurs in the linear portion 10g of the grounding member 10, as shown in FIG. 10, the linear portion 52 and the linear portion 10h are electrically connected, and the linear portion 51 and the power source are connected. By connecting the negative electrode side terminal of the part 21, a new current path that does not pass through the disconnection point Px can be secured. Therefore, it is possible to prevent an overcurrent from flowing through the ground wiring member 10 and to prevent abnormal heat generation.

  In this modification, the configuration shown in FIG. 9 is adopted as the electric circuit of the vehicle ground connection device. In the vehicle ground connection device shown in FIG. 9, the disconnection identifying unit 22 identifies the presence or absence of disconnection based on the signals V01 to V04 output from the voltage sensors 23 to 26, as in the operation in the configuration of FIG. . Furthermore, when there is a disconnection, the location where the disconnection occurs is specified. Then, the current path switching unit 29 is controlled in order to secure a new current path that bypasses the disconnected portion. The current path switching unit 29 electrically connects the ground wiring member 10 and the backup ground wiring member 50 according to the control of the disconnection identification unit 22, for example, as shown in FIG. And the spare earth wiring member 50 are also connected.

  The function of the current path switching unit 29 can be configured using a switch circuit having electrical contacts such as a relay, or can be configured using a semiconductor switch such as a transistor.

  In the vehicular ground connection device shown in FIG. 9, when the disconnection occurs, the current path switching unit 29 switches the current path to a path passing through the backup ground wiring member 50, so that abnormal heat generation can be prevented. Therefore, it is not necessary to limit the power supplied by the power supply unit 21, and the power supply limiting unit 27 shown in FIG. 5 can be omitted.

  As described above, since the ground connection device for a vehicle shown in FIG. 1 uses the ground wiring member 10 having the closed loop shape portions 11 and 12, a partial disconnection occurs on the ground wiring member 10. Even in such a case, it is possible to flow current using the remaining paths.

  Further, in the vehicle ground connection device shown in FIGS. 4 and 5, when a disconnection occurs on the ground wiring member 10, the disconnection identification unit 22 detects the disconnection, and the warning output unit 28 outputs a warning. The user or the like can be notified that the disconnection has occurred. In addition, by using a plurality of voltage sensors or a plurality of current sensors, it is possible to automatically identify the location where the disconnection has occurred.

  In addition, the vehicle ground connection device shown in FIGS. 4 and 5 suppresses abnormal heat generation due to disconnection by limiting power supply from the power supply unit 21 according to an instruction from the power supply limiting unit 27 when disconnection occurs. it can.

  Further, the vehicle ground connection device shown in FIG. 9 can automatically switch the current path to the spare circuit on the spare ground wiring member 50 when a disconnection occurs. Therefore, abnormal heat generation due to disconnection can be suppressed. In addition, it is possible to prevent malfunctions of various electrical components caused by electric leakage from a disconnected portion.

  It is also conceivable that the vehicle earth connection device is configured by combining the voltage sensors 23 to 26 shown in FIG. 1 and the current sensors 31 to 37 shown in FIG. Each circuit such as the disconnection identification unit 22 can be configured by an analog circuit or a digital circuit such as a microcomputer. In addition, various changes can be made as necessary with respect to the relationship between the measured values of the voltage sensors 23 to 26 and the current sensors 31 to 37 and the reference values and threshold values for identifying disconnection.

  In addition, for auxiliary parts of important parts on the vehicle, a spare circuit is prepared on, for example, the ground wiring member 10 or the spare ground wiring member 50 so that the ground can be surely taken even in the case of disconnection. Is desirable. Such a spare circuit may be individually prepared for each auxiliary machine, or may be prepared as a circuit commonly used by a plurality of important auxiliary machines. When a spare circuit is separately prepared for each auxiliary machine, it is easy to identify a disconnection point.

  In addition, as a condition for identifying the presence or absence of disconnection, it is only necessary to identify whether or not the normal value determined by the combination of operating states of each auxiliary machine and the actually measured voltage are shifted by a predetermined amount or more. In addition, if a combination of abnormal locations of a plurality of voltmeter values is registered in the memory as a map in advance, a disconnection location can be easily identified by comparing a plurality of combinations of measured values with the contents of the map. .

  Further, a microcomputer can be incorporated in each of the plurality of sensors, and each sensor can be configured to detect the presence or absence of disconnection. In that case, if the sensors are connected to each other via a communication network, it is possible to exchange information with each other and to perform control for automatically selecting an appropriate spare circuit.

Here, the features of the above-described embodiment of the vehicle ground connection device according to the present invention are summarized and listed in the following [1] to [8], respectively.
[1] A conductive grounding member (10) connected between the ground electrode of the power supply unit (21) mounted on the vehicle (vehicle body 13) and the ground electrode of the electrical component mounted on the vehicle. )When,
One or more measuring devices (voltages) that measure a current flowing through a specific portion of the ground wiring member or a potential difference between a potential (Ve01 to Ve04) of the specific portion of the ground wiring member and a reference point potential (Vpr) Sensors 23 to 26, current sensors 31 to 37),
Based on the measurement value obtained by the measurement of the measuring instrument, at least an abnormality identification unit (disconnection identification unit 22) for identifying presence or absence of abnormality,
A vehicle ground connection device.

[2] When measuring the potential difference with the measuring instrument, the specific part to be measured is determined in the vicinity of a point (P03, P06) where a plurality of current paths intersect on the ground wiring member.
The vehicular ground connection device according to [1] above.

[3] When the current is measured by the measuring instrument, the specific part to be measured is located upstream of a location (P02, P03, P06) where a branch or set of current paths occurs on the ground wiring member or Defined on the downstream side,
The vehicular ground connection device according to [1] above.

[4] The abnormality identification unit identifies presence / absence of occurrence of abnormality based on a difference between a reference value of a measurement value in a state where there is no abnormality and an actual measurement value obtained by measurement of the measuring instrument.
The vehicular ground connection device according to [1] above.

[5] A plurality of the measuring instruments (voltage sensors 23 to 26, current sensors 31 to 37) are provided,
A plurality of the measuring instruments are connected to different parts on the ground wiring member,
The abnormality identification unit automatically identifies a site on the current path where a disconnection has occurred, based on a plurality of measurement values obtained by measurement of each of the plurality of measuring instruments.
The vehicular ground connection device according to [1] above.

[6] The abnormality identification unit (disconnection identification unit 22, warning output unit 28) outputs a predetermined warning by at least one of display and sound when the occurrence of the disconnection in the ground wiring member is detected.
The vehicular ground connection device according to [1] above.

[7] The abnormality identification unit (disconnection identification unit 22, power supply restriction unit 27) automatically restricts power supply from the power supply unit when the occurrence of a break in the ground wiring member is detected.
The vehicular ground connection device according to [1] above.

[8] A preliminary ground wiring member (50) that forms a preliminary current path in the vicinity of the current path of the ground wiring member,
When the abnormality identification unit (disconnection identification unit 22, wire path switching unit 29) detects the occurrence of a disconnection in the ground wiring member, the abnormal grounding unit detects the occurrence of the spare ground wiring member from the current path on the ground wiring member. Automatically switch to current path,
The vehicular ground connection device according to [1] above.

DESCRIPTION OF SYMBOLS 10 Grounding member 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h Linear part 11,12 Closed loop shape part 13 Car body 13a, 13b, 13c, 13d Vehicle door 13e Engine room 14,15,16,17 Auxiliary machine 18 Wiring 21 Power supply unit 22, 22B Disconnection identification unit 23, 24, 25, 26 Voltage sensor 27 Power supply limiting unit 28 Warning output unit 29 Current path switching unit 31, 32, 33, 34, 35, 36, 37 Current Sensor 50 Preliminary grounding member 51, 52, 53, 54, 55 Linear part P01, P02, P03, P04, P05, P06, P07 part Px Disconnection part TB1, TB2 Reference value table Vpr potential Ve01, Ve02, Ve03, Ve04 Ground potential V01, V02, V03, V04 Signal i0 1, i02, i03, i04, i05, i06, i07 signals

Claims (6)

A conductive grounding member connected between the ground electrode of the power supply unit mounted on the vehicle and the ground electrode of the electrical component mounted on the vehicle;
One or more voltage sensors for measuring the potential difference between the potential and the reference potential at the point of the specific portion of the front Symbol grounding wiring member,
Based on the measurement value obtained by the measurement of the voltage sensor , at least an abnormality identification unit for identifying the presence or absence of abnormality,
Equipped with a,
The ground wiring member includes an annular loop portion, and a connecting portion that connects between the first portion and the second portion different from each other on the loop portion so as to divide the loop portion into two parts,
In the vicinity of the first part, in the vicinity of the second part, in the vicinity of the third part located on the first divided part on one side of the connecting part in the loop part, and on the first divided part The first voltage sensor, the second voltage sensor, the third voltage sensor, each of which measures a potential difference from the reference point potential in the vicinity of a fourth part different from the third part located in the middle. The voltage sensor and the fourth voltage sensor are connected;
A ground electrode of the power supply unit is connected to a fifth part located in the middle of the second divided region on the other side of the coupling unit in the loop unit,
The abnormality identifying unit identifies presence / absence of abnormality based on only four measurement values obtained by measurement of the first to fourth voltage sensors, and a part on the current path where the disconnection has occurred Automatically identify
A vehicle ground connection device. In the vicinity of the first part, in the vicinity of the second part, in the vicinity of the third part, and in the vicinity of the fourth part, ground electrodes of the electrical components different from each other are connected, respectively .
The vehicle ground connection device according to claim 1. The abnormality identification unit identifies presence or absence of occurrence of abnormality based on a difference between a reference value of the voltage sensor in a state where there is no abnormality and an actual measurement value obtained by measurement of the voltage sensor ,
The vehicle ground connection device according to claim 1. The abnormality identification unit outputs a predetermined warning by at least one of display and sound when the occurrence of disconnection in the ground wiring member is detected.
The vehicle ground connection device according to claim 1. The abnormality identification unit automatically restricts the power supply from the power supply unit when detecting the occurrence of disconnection in the ground wiring member,
The vehicle ground connection device according to claim 1. A preliminary grounding member that forms a preliminary current path in the vicinity of the current path of the grounding member;
The abnormality identification unit automatically switches from the current path on the ground wiring member to the current path of the backup ground wiring member when the occurrence of disconnection in the ground wiring member is detected.
The vehicle ground connection device according to claim 1.

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