JP2010111295A - Abnormality diagnostic device for on-vehicle communication line - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform the diagnosis for the abnormality of each branch circuit of a branch-connected two-wire type CAN communication circuit. <P>SOLUTION: An abnormality diagnostic device for an on-vehicle communication line includes a branch circuit for inspection connector-connected to each branch circuit of a CAN communication line, a branch connection circuit having a joint circuit for connecting the branch circuit, a disconnection means for disconnecting each branch circuit from the joint circuit, an electric potential measuring means for measuring the electric potential of the branch circuit disconnected by the disconnection means, a connection means for connecting the electric potential measuring means to the branch circuit, and an abnormality determination means connected to the electric potential measuring means to perform the abnormality determination by the measured electric potential. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an in-vehicle communication line abnormality diagnosis device, and more particularly, when an abnormality diagnosis of a CAN communication circuit mounted on an automobile is performed, the abnormality diagnosis circuit can be easily separated from another branch-connected circuit for diagnosis. To do.

  2. Description of the Related Art A two-wire multiplex communication line whose protocol is CAN is widely used as a communication line mounted on an automobile. The CAN communication line is composed of a twisted pair electric wire obtained by twisting and combining a high line (hereinafter abbreviated as H line) and a low line (hereinafter abbreviated as L line). Are connected to electronic components such as a communication network inside the automobile.

  Conventionally, failure diagnosis of a CAN communication line is performed by connecting a diagnosis connector to a branch line branched from a trunk line of the CAN communication line via a joint connector, etc., and connecting the diagnosis connector to a diagnosis apparatus of an external tool. By communicating with each node device connected to the line, the node device in which an abnormality has occurred or the communication line that is disconnected is identified.

However, if an abnormality occurs due to a short in the CAN communication line, a communication abnormality occurs in the entire CAN communication circuit. Therefore, in the failure diagnosis by the diagnosis apparatus, the abnormality occurs in a node or in a branch connection. Which of the CAN communication lines is out of which CAN communication line has an abnormality, whether an abnormality has occurred in the H line of the CAN communication line, or an abnormality has occurred in the L line I can't specify.
Therefore, it is necessary to inspect each communication line one by one using a tester or the like in order to specify a failure location and a failure mode, and there is a problem that workability is poor and work takes time.

JP-A-2004-252963 (Patent Document 1) has been proposed as a failure diagnosis method for this type of CAN communication line. In Patent Document 1, a resistance value between an H line and an L line of a CAN communication line is measured, and an abnormal part is specified by a combination of the measurement result and an abnormal code stored in advance.
In the failure diagnosis method of Patent Document 1, it is possible to detect a case where a CAN communication line main line is disconnected, a branch line connected to a connector connected to a diagnosis device is disconnected, or a short circuit occurs between the H line and the L line. In addition, it is impossible to detect a short circuit to the battery power line of the H line and the L line of each CAN communication line or a short circuit to the ground.

Moreover, in the failure detection method of Unexamined-Japanese-Patent No. 2006-191404 (patent document 2), each potential of the H line and the L line of the CAN communication line is measured, and whether or not a short has occurred based on the measurement result. Is detected.
In this Patent Document 2, it is possible to detect a short circuit to the battery power supply and a short circuit to the ground of the H line and L line that could not be detected in Patent Document 1, but when a short circuit occurs between the H line and the L line. Has a problem that cannot be detected.

JP 2004-252963 A JP 2006-191404 A

As described above, in the conventionally proposed CAN communication line failure detection method, the abnormality that can be detected is limited. Therefore, even if an abnormality occurs, there is a problem that the abnormality occurrence location and the abnormality occurrence mode cannot be specified. . In addition, when many branch lines (branch circuits) are branched and connected via joint connectors, each branch line is disconnected from the other branch lines, and the abnormality diagnosis for each branch line is not efficient. There is a problem that takes time and labor.
In addition, when connecting to an external tool diagnosis device at the time of abnormality diagnosis, there is a problem that abnormality diagnosis cannot be performed easily.

  The present invention is intended to solve the above problem, and when a two-wire CAN communication line having an H line and an L line is branched and connected via a joint connector or the like, without being connected to a diagnosis apparatus, It is an object of the present invention to make it possible to easily separate each branch line so that abnormality diagnosis can be performed efficiently, and to easily diagnose an abnormality occurrence location and abnormality occurrence mode.

In order to solve the above problems, the present invention provides:
An apparatus for performing an abnormality diagnosis for each branch circuit of a two-wire CAN communication line that is branched and connected to a plurality of nodes,
A branch circuit for inspection that is connected to the branch circuit by a connector, and a branch connection circuit having a joint circuit that connects these branch circuits;
Separating means for separating each branch circuit from the joint circuit;
A potential measuring means for measuring the potential of the branch circuit separated by the separating means;
Connecting means for connecting the potential measuring means and the branch circuit;
An abnormality determining means connected to the potential measuring means and performing an abnormality determination from the measured potential;
An in-vehicle communication line abnormality diagnosis device is provided.

Specifically, in the abnormality diagnosis device of the present invention, a case housing a substrate is fixed to a vehicle panel, and the separation means and / or the connection means can be operated by an operation unit provided on the panel. Yes.
That is, it is configured to be able to easily perform abnormality diagnosis by fixing to a vehicle panel without connecting to a diagnosis device of an external tool via a diagnosis connector at the time of abnormality diagnosis.

The panel is composed of an instrument panel or a center console, and is housed and fixed inside the instrument panel or center console.
The operation unit is arranged on an operation switch arrangement unit provided on the instrument panel or the center console, and the abnormality determination unit is connected to a display unit including an indicator or a display provided on the instrument panel or the center console. The determination result is preferably displayed on the display means.

  As described above, when the abnormality diagnosis device is housed and fixed in the instrument panel or the center console, there is no need to provide an operation switch or a display unit unique to the abnormality diagnosis device, and the air conditioner operation device assembled in the center panel module, Since operation switches and display units such as an audio operation device and a car navigation operation device can be used for an abnormality diagnosis device, the number of parts can be reduced and the cost can be reduced.

Furthermore, it is preferable that an opening for the separating member for operating the separating means and an insertion opening for the short pin constituting the connecting means are provided facing an opening / closing lid provided on the instrument panel or the center console.
With this configuration, when it is considered that an abnormality has occurred in the CAN communication line, an occupant can easily perform an abnormality diagnosis operation. In particular, if a branch circuit in which an abnormality has occurred can be identified, the branch circuit can be separated and connected manually by an occupant, and an abnormality diagnosis can be performed easily and quickly.

The abnormality diagnosis device of the present invention includes a connection connector connected to a connector to which each branch circuit of a CAN communication line connected to the node is connected;
Branch having a branch circuit connected to the connection connector and connected to the High line and Low line of each branch circuit connected to the node, and a joint circuit connected to each High line and Low line of the branch circuit With connection circuit,
The separation means is provided for each of the High line and Low line of each branch circuit, and the potentials of the High line and Low line of the separated branch circuit are respectively measured by the potential measurement means.

The separating means is provided to separate the H line and the L line of the branch circuit for abnormality diagnosis from the H line joint circuit and the L line joint circuit, respectively.
Alternatively, the separating means disconnects the H line and L line of other branch circuits that are not diagnosed for abnormality from the joint circuit unit, and connects only the H line and L line of the branch circuit that is diagnosed for abnormality to the joint circuit.

Specifically, as the separating means, a relay is provided in each branch circuit.
By turning on / off the relays connected to the H line and L line of each branch circuit, the H line and L line of the branch circuit to be diagnosed for abnormality are disconnected from the joint circuit, or other branch circuits that are not diagnosed for abnormality are jointed. It can be disconnected from the circuit and connected to the branch connection circuit after diagnosis.
If the relay is used as the separating means, the branch circuit for automatically diagnosing an abnormality by the control of a microcomputer or the like can be separated from the joint circuit, and the man-hour at the time of abnormality inspection can be reduced.

Alternatively, the separating means includes a pair of terminals having elastic contacts that are brought into contact with the H line and the L line of each branch circuit, respectively, and an insulating pin is inserted between the elastic contacts to separate the insulating pin. It is good also as a structure connected by pulling out.
Preferably, terminals for elastic connection of the respective branch circuits are arranged in parallel, and a separating member is provided in which insulating pins inserted between the pair of elastic conductor terminals are projected in parallel from the lower surface of the mounting plate portion on which the terminals are mounted. It is preferable.
As described above, when the separating means composed of the insulating pins is used, electronic components such as relays are not required, and the number of components can be reduced and the cost can be reduced.

  As described above, the H line and the L line of each branch circuit for diagnosing an abnormality are branched and connected by using an electrical separation means using a relay or a mechanical separation means for inserting / removing an insulation pin. It can be easily separated from the H line and L line of the branch circuit. In addition, when an abnormality is diagnosed in another branch circuit, a relay can be connected or an insulation pin can be removed to easily connect to a connection circuit. In this way, by providing separation means, even if a large number of branch circuits are connected, it is possible to diagnose the abnormality for each branch circuit by turning the relay on and off sequentially or by inserting and removing the insulation pins. It can be done easily.

In the branch connection circuit, when disconnecting the branch circuit to be diagnosed from the joint circuit, the connection means for switching connection is provided in order to connect the branch circuit to the potential measuring means.
In order to select the H line and L line of the branch circuit and connect to the potential measuring means, the changeover connection means, for example, is provided with a changeover switch, and the changeover switch switches the H line and L line to be connected. . The changeover switch is preferably controlled by a microcomputer or the like. Alternatively, the H line and the L line may be connected to a microcomputer without providing a changeover switch, and automatic connection switching may be performed inside the microcomputer.
When controlled by the microcomputer in this way, the branch circuit for automatically diagnosing the abnormality can be switched, and the branch circuits connected to all the nodes can be diagnosed sequentially.

  When the changeover switch is provided, specifically, the contact portion at the tip of the inspection H line circuit connected to the H line of each branch circuit is arranged in parallel, and similarly, the inspection L line circuit connected to the L line The contact portions at the front end are arranged in parallel, and the movable contacts of the H line change switch and the L line change switch are sequentially brought into contact with these contact portions for switching.

On the other hand, when the branch circuit to be diagnosed is connected to the joint circuit and the other branch circuit is disconnected from the joint circuit, the joint circuit is connected to the potential measuring means via the connection means including the circuit opening / closing connection means. ing.
The circuit opening / closing connection means may be a relay, or the circuit may be opened / closed by inserting / removing a short pin between contacts provided in the connection circuit.
When the short pin is inserted between the contacts and conducted, electronic parts such as a microcomputer and a changeover switch become unnecessary, and the number of parts can be reduced and the cost can be reduced.

  The H line and L line whose potential is measured by the potential measuring means via the switching means or the circuit switching connection means are connected to the test resistance circuit, respectively, and the potential of the test resistance circuit is set. It is preferable that the potentials of the H line and the L line are individually measured by the potential measuring means. As a result, abnormality determination can be performed for each branch circuit, and abnormality determination of the H line and L line of the branch circuit can be performed individually.

The test resistor circuit includes at least three test resistors connected in series to a circuit connecting a DC power source and a ground, and the H line is interposed between a pair of test resistors provided on the power source side. On the other hand, the L line is connected between a pair of the inspection resistors provided on the ground side,
The potential measuring device is connected to the inspection resistor connected to the H line and the L line,
It is preferable that the potential detected by the potential measuring device is compared with a potential range stored in advance in the abnormality determination unit so that a short-circuit occurrence mode occurring in the H line and the L line can be specified and determined. .

  The abnormality diagnosis device of the present invention is provided with the circuit, and if necessary, houses a board on which electronic components such as the relay, microcomputer, and changeover switch are mounted inside the case and is connected to the circuit provided on the board. The substrate is provided with the potential measuring device and an arithmetic processing unit serving as an abnormality determining means connected to the potential measuring device.

  As described above, the abnormality diagnosis device according to the present invention can easily separate each branch circuit for each branch circuit when performing abnormality diagnosis of a CAN communication line forming a plurality of two-wire multiplex communication circuits connected in a branched manner. Abnormal diagnosis is possible. Further, in the branch circuit for diagnosing abnormality, the H line and the L line of the CAN communication line can be individually diagnosed, and it is the H line that is abnormal in the branched CAN communication line. Or L line can be specified.

  In addition, it is fixed to the instrument panel or center console of the vehicle, and is always connected to each branch circuit of the CAN communication line connected to the branch. With this configuration, it is not necessary to connect to a diagnostic device of an external tool at the time of abnormality diagnosis, and abnormality diagnosis of CAN communication connection can be easily performed at appropriate times.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a first embodiment.
The abnormality diagnosis apparatus 10 of the present invention is housed and fixed inside an instrument panel 50 of the automobile shown in FIG.

An operation unit 51 on the surface of the instrument panel 50 is provided in parallel with an operation unit 52 of an air conditioner control device and an audio control device (not shown) housed and fixed in the instrument panel 50. An abnormality determination result display means 18 is also provided on the surface of the instrument panel 50.
Further, an operation window portion 54 is provided on the surface of the instrument panel 50. The operation window portion 54 is closed with an opening / closing lid 55, and the opening / closing lid 55 is removed when an abnormality is diagnosed, and a required operation member (not shown) is attached. It can be inserted and removed. When the operation at the time of abnormality diagnosis is performed by electronic control, it is not necessary to attach the operation window 54 and the opening / closing lid 55.

  As shown in FIG. 2, the abnormality diagnosis apparatus 10 includes an H line (High) of a CAN communication line 3 that forms a two-wire multiplex communication circuit that is branched and connected to a plurality of nodes 1 (1A to 1D) mounted on a vehicle. Line) 4 and L line (Low line) 5.

  The terminals THa and TLa connected to the terminals of the H line 4 and the L line 5 of each CAN communication line 3 are inserted and connected to the connector 7, and the connector 7 is fitted and connected to the connection connector 11 provided in the abnormality diagnosis device 10. is doing. The communication lines are terminal-connected without jointing the branch circuit at the fitting portion between the connectors 7 and 11.

  The abnormality diagnosis apparatus 10 is provided with a branch connection circuit 12 connected to the terminals THb and TLb on the connection connector 11 side. That is, the branch communication circuit of the CAN communication line 3 connected to the nodes 1A to 1D is provided in the abnormality diagnosis device 10 to connect the branch circuit, and the abnormality diagnosis device 10 is always connected to the nodes 1A to 1D. Connected to line 3.

The abnormality diagnosis apparatus 10 accommodates a board inside a case, and the connection connector 11 is a connector mounted on the board.
As shown in FIG. 2, the abnormality diagnosis apparatus 10 includes the branch connection circuit 12, the separation means 13, the switching connection means 14, the inspection resistance circuit 15, the potential measuring device 16, the abnormality determination means 17, and the display of the abnormality determination result. The configuration includes the means 18.

The branch connection circuit 12 includes a branch circuit 20 connected to each branch circuit connected to the node 1, and each branch circuit 20 includes an H line 21 and an L line connected to terminals of the H line 4 and the L line 5. 22. A joint circuit 24 that connects the tips of the H lines 21 and a joint circuit 25 that connects the tips of the L lines 22 are provided.
The branch circuit 20 and the joint circuits 24 and 25 including the H line 21 and the L line 22 are made of printed conductors formed on the substrate, and other circuits described later are also made of printed conductors formed on the substrate.

In each of the H line 21 and the L line 22, relays R (R1 to R8) constituting the separating means 13 are mounted and interposed. When the relay R is turned off, the H line 21 and the L line 22 are disconnected from the joint circuits 24 and 25. When the relay R is turned on, the disconnected H line 21 and L line 22 are connected to the joint circuits 24 and 25.
The relay R is automatically controlled by the microcomputer 30 mounted on the board, and the H line 21 and L line 22 of the branch circuit 20 are sequentially disconnected from the joint circuits 24 and 25, and abnormality diagnosis of the CAN communication line 3 connected to the nodes 1A to 1D is performed. Can be performed automatically.

Inspection lines 21 a and 22 a are connected to the H lines 21 and L lines 22 on the opposite side of the joint circuits 24 and 25 with the relay R interposed therebetween.
The contacts 21b provided at the tip of the inspection line 21a of the H line 21 are arranged adjacent to each other at a position where they are switched and connected by the H-side switch 28 of the switching connection means 14.
Similarly, the contacts 22b provided at the tip of the inspection line 22a of the L line 22 are arranged adjacent to each other at a position where they are switched and connected by the L side changeover switch 29.

The H side changeover switch 28 and the L side changeover switch 29 include movable contact pieces 28b and 29b that rotate with the fixed contacts 28a and 29a as fulcrums. The movable contact pieces 28b and 29b are selectively brought into contact with any one of the adjacent contacts 21b and 22b and connected to the fixed contacts 28a and 29a.
The changeover operation of the changeover switches 28 and 29 is performed by the microcomputer 30 and is interlocked with an on / off operation by a relay.

The fixed contacts 28a and 29a of the changeover switches 28 and 29 are connected to the test resistor circuit 15 and then to the potential measuring device 16, respectively.
The test resistor circuit 15 has three test resistors 34 connected in series to a circuit 33 that connects a DC power supply 31 and a ground 32. The inspection resistor 34 includes a first resistor 34A, a second resistor 34B, and a third resistor 34C from the DC power supply 31 side. The fixed contact 28a of the H-side changeover switch 28 is connected between the first resistor 34A and the second resistor 34B, and the fixed contact 29a of the L-side changeover switch 29 is connected between the second resistor 34B and the third resistor 34C. is doing.

  In this embodiment, a voltage of 12V is supplied from the DC power supply 31, the resistance values of the first and third resistors 34A and 34C are 60Ω, and the resistance value of the second resistor 34B is 120Ω.

The potential measuring device 16 is formed by connecting the inspection H line 21 to the inspection resistance circuit 15 between the first resistor 34A and the second resistor 34B via the H side changeover switch 28. The circuit 40 is connected to measure the potential V1 of the inspection H line 21.
Similarly, an L line 22 for inspection is formed in the potential measuring device 16 by being connected to the inspection resistance circuit 15 between the second resistor 34B and the third resistor 34C via the L side changeover switch 29. A line inspection circuit 41 is connected to measure the potential V2 of the inspection L line 22.

  The abnormality determining means 17 connected to the potential measuring device 16 and transmitting a measurement result stores a table for specifying an abnormal mode according to a potential range measured in advance, and measures the V1 and V2. The abnormal mode is specified according to the value.

  As shown in FIG. 3, the table to be stored is normal, short between H line and L line, short to H power line, short to H line ground, short to L power line, L line A potential determination range in which a short circuit to the ground can be specified is stored. The short-circuit occurrence mode is specified by referring to the stored potential determination range from the potentials V1 and V2 measured by the potential measuring device 16.

Specifically, as shown in the table of FIG. 3, for example, if the measured potential V1 is 9 V and the potential V2 is 3 V, it is determined that the H line and the L line are normal. .
If the potential V1 is 6V and the potential V2 is 6V, it is determined that the H line and the L line are short-circuited.

The abnormality determination means 17 is connected to the abnormality determination result display means 18, and the abnormality determination result display means 18 is provided on the surface of the instrument panel 50 as described above.
The operation unit 51 provided on the surface of the instrument panel 50 controls the operation of the relay R and the microcomputer 30 that controls the operation of the changeover switches 28 and 29 of the connection means.

  The abnormality diagnosis device 10 having the above configuration is connected to the connector 7 connected to the H line 4 and the L line 5 of the CAN communication line 3 connected to the node 1 (1A to 1D). The joint circuits 24 and 25 of the branch connection circuit 12 connected to the connection connector 11 are always connected to the H line 21 and L line 22 of all the branch circuits 20 and are not connected to the changeover switches 28 and 29.

At the time of abnormality diagnosis, the operation means 51 is operated to operate the relay R of the separation means and the changeover switches 28 and 29 of the switching connection means, turn on / off the relay R, and the H lines 21 and L of the branch circuit 20. The line 22 is separated from the joint circuits 24 and 25 in order.
As shown in FIG. 4A, when making an abnormality diagnosis of the branch circuit 20-1 connected to the node 1A, when the relay R of the H line 21 and the L line 22 of the branch circuit 20-1 is turned off, the H The inspection H lines 21 a and 22 a connected to the line 21 and L line 22 are connected to the changeover switches 28 and 29. The H line 21 and L line 22 connected to the node 1A are connected to the inspection H line 40 and L line 41 connected to the inspection resistance circuit 15 by connection with the changeover switches 28 and 29. The potentials of the inspection H line 40 and L line 41 are measured by the connected potential measuring device 16. An abnormality occurrence mode is specified by referring to a table in which the measured potential is stored in the abnormality determination unit 17, and the result is displayed on the abnormality determination result display unit 18.

After the abnormality diagnosis of the branch circuit 20-1 connected to the node 1A is completed, the relay R of the branch circuit 20-1 is turned on, and the branch circuit 20-1 is connected to the joint circuits 24 and 25.
Next, as shown in FIG. 4B, the relay R of the branch circuit 20-2 connected to the node 1B is turned off, and the same process as that of the branch circuit 20-1 is repeated, and the branch circuit 20- connected to the node 1B is repeated. The potentials of the second H line 21 and the L line 22 are measured to determine abnormality.
By repeating this with the node 1C and the node 1D, it is possible to individually diagnose the abnormality of the plurality of CAN communication lines 3 that are branch-connected, and the H line 4 and the L line 5 of the CAN communication line 3 individually. An abnormality can be diagnosed.

  As a result, as shown in the table of FIG. 3, when there is no abnormality in either the H line or the L line of the CAN communication line and an abnormality has occurred in the node, there is a cause of the abnormality in the node. I understand. In addition, when a short circuit occurs in the H line and the L line, the short circuit is a short circuit between the H line and the L line, a short circuit to the power line of the H line, a short circuit to the ground of the H line, Whether it is a short circuit to the power supply line or a short circuit to the ground of the L line can be specified.

5 and 6 show a second embodiment.
The second embodiment uses an insulating pin 60 instead of a relay as means for separating the H line and L line of each branch circuit 20 of the branch connection circuit 12 of the abnormality diagnosis apparatus from the joint circuit.

FIG. 5 shows only the H line 21 of the branch connection circuit 12, and the L line is the same although not shown.
Separated contact portions 21p1 and 21p2 are provided in the middle of the H line 21 of each branch circuit formed on the substrate 61. The elastic terminals 62a and 63a provided with elastic contact parts 62a and 63a facing the contact parts 21p1 and 21p2, respectively, are erected by soldering, and the elastic contact parts 62a and 63a are always in contact to joint the H line 21. The circuit 24 is connected.
An insulating pin 60 made of resin is inserted between the contacted elastic contact portions 62a and 63a to disconnect the H line 21 from the joint circuit 24. After the abnormality diagnosis, the insulating pin 60 is removed, the elastic contact portions 62a and 63a are in contact with each other, and the H line 21 is connected to the joint circuit 24.

An insertion port 71 for the insulating pin 60 is provided in the case 70 of the abnormality diagnosis device.
As shown in FIGS. 6A and 6B, the insertion port 71 of the insulating pin 60 is disposed so as to face the operation window 54 provided on the surface of the instrument panel 50, and the operation window 54 is closed. When the opening / closing lid 55 to be opened is opened, the insertion port 71 is exposed.
Therefore, when the opening / closing lid 55 is opened, the insulating pin 60 is inserted from the insertion port 71 so that the circuits can be separated.
Since other configurations are the same as those of the first embodiment, description thereof is omitted.
Even when the abnormality diagnosis apparatus is accommodated in the center console, an opening / closing lid may be provided on the center console, and the insertion port may be provided at a position facing the opening / closing lid.

FIG. 7 shows a third embodiment of the abnormality diagnosis apparatus of the present invention.
Similarly to the first embodiment, a relay R is interposed in the middle of each H line 21 and L line 22 of the branch circuit 20.
In the third embodiment, the relay R of the branch circuit 20 (H-line 21 and L-line 22 in FIG. 20-1) for diagnosing abnormality is turned on and connected to the joint circuits 24 and 25. The relays R of the other branch circuits 20 (20-2 to 20-4) are turned off and disconnected from the joint circuits 24 and 25. That is, the on / off of the relay is reversed from that of the first embodiment.

Since the joint circuits 24 and 25 are connected to the branch circuit 20 for diagnosing abnormality, the joint circuits 24 and 25 are connected to the H line inspection circuit 40 and the L line via the circuit opening / closing connection means 140 provided with relays 80 and 81. The inspection circuit 41 is connected.
This is because the joint circuits 24 and 25 need to be separated from the H line inspection circuit 40 and the L line inspection circuit 41 at the time of non-abnormal diagnosis.
At the time of abnormality diagnosis, if the joint circuits 24 and 25 are connected to the H line inspection circuit 40 and the L line inspection circuit 41 by turning on the relays 80 and 81, one branch circuit 20 connected to the joint circuits 24 and 25 is connected. An abnormality diagnosis of the H line 21 and the L line 22 can be performed.
Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.

8A and 8B show a first modification of the third embodiment.
In the first modification, in order to open and close the connection circuit between the joint circuits 24 and 25 and the H line inspection circuit 40 and the L line inspection circuit 41, the short pin 83 is inserted and removed instead of the relay.
More specifically, terminals 85 and 86 are provided at intervals between the joint circuit 24 and the H line inspection circuit 40, respectively, and a short pin 83 is inserted between the terminals 85 and 86 at the time of abnormality diagnosis. When the non-abnormal diagnosis is made, the short pin 83 is taken out to open the connection circuit.
The short pin 83 can be inserted and removed from the insertion opening directed to the case in the same manner as the insulating pin of the second embodiment.

FIG. 9 shows a second modification of the third embodiment.
In the second modification, the short circuit 83 of the first modification is used to open and close the joint circuit, the H line inspection circuit, and the L line inspection circuit, and, as in FIG. 5 of the second embodiment, branch connection The branch circuit 20 of the circuit 12 and the joint circuit 24 (25) are separated by an insulating pin 60 inserted between a pair of elastic terminals 62 and 63.
In the third embodiment, one branch circuit is connected to the joint circuit, and the other branch circuit is disconnected from the joint circuit by inserting an insulating pin 60.
At the time of abnormality diagnosis, the insulating pin 60 is not inserted at a position corresponding to one branch circuit that is not separated from the joint circuit, and the branch circuit 20 that is separated from the joint circuit by inserting another insulating pin 60 can be simultaneously separated. ing.
As described above, since the short pins and the insulating pins are inserted to separate and connect the circuits, as shown in FIG. 9, the insulating pin insertion port 71 is located at the position where the open / close lid provided on the center console is opened. And an insertion port 90 for a short pin.

  With this configuration, electronic components such as relays and microcomputers are not required, and the number of components can be reduced, resulting in cost reduction.

The present invention is not limited to the above-described embodiment. For example, the potential of the H line of another branch circuit, one H line branched from the L line, and the L line can be directly measured by the potential measuring means without going through the inspection resistance circuit. The occurrence of a short in the H line and the L line can also be specified by measuring.
In addition, various embodiments are included within the scope not departing from the gist of the present invention.

It is drawing which shows the instrument panel of the motor vehicle which accommodates the abnormality diagnosis apparatus of 1st embodiment of this invention. It is a whole block diagram of an abnormality diagnosis apparatus. It is drawing which shows the table referred by an abnormality determination means. (A) (B) is drawing which shows the isolation | separation state of the branch connection circuit at the time of abnormality diagnosis. The abnormality diagnosis apparatus of 2nd embodiment is shown, (A) is a schematic perspective view which shows the principal part, (B) is explanatory drawing of a terminal attachment part. (A) is a top view which shows the arrangement | positioning part of the insertion port of the insulation pin used by 2nd embodiment, (B) is a top view which shows an insertion port. It is a whole block diagram of the abnormality diagnosis apparatus of 3rd embodiment. The 1st modification of 3rd embodiment is shown, (A) is principal part sectional drawing, (B) is a perspective view. It is drawing which shows the 2nd modification of 3rd embodiment.

Explanation of symbols

1 (1A to 1D) Node 3 CAN communication line 4 H line (High line)
5 L line (Low line)
DESCRIPTION OF SYMBOLS 7 Connector 10 Abnormality diagnosis apparatus 11 Connection connector 12 Branch connection circuit 13 Separation means 14 Switching connection means 15 Inspection resistance circuit 16 Potential measuring device 17 Abnormality determination means 18 Abnormality determination result display means 20 Branch circuit 21 H line 22 L line 24 H-line joint circuit 25 L-line joint circuit 28 H-side switch 29 L-side switch 50 Instrument panel

Claims (10)

An apparatus for performing an abnormality diagnosis for each branch circuit of a two-wire CAN communication line that is branched and connected to a plurality of nodes,
A branch circuit for inspection that is connected to the branch circuit by a connector, and a branch connection circuit having a joint circuit that connects these branch circuits;
Separating means for separating each branch circuit from the joint circuit;
A potential measuring means for measuring the potential of the branch circuit separated by the separating means;
Connecting means for connecting the potential measuring means and the branch circuit;
An abnormality determining means connected to the potential measuring means and performing an abnormality determination from the measured potential;
An in-vehicle communication line abnormality diagnosis device comprising:   The in-vehicle communication line abnormality diagnosis device according to claim 1, wherein the separation unit and / or the connection unit can be operated by an operation unit fixed to a panel of the vehicle and provided on the panel. The panel is composed of an instrument panel or a center console, and is housed and fixed inside the instrument panel or center console.
The operation unit is arranged on an operation switch arrangement unit provided on the instrument panel or the center console, and the abnormality determination unit is connected to a display unit including an indicator or a display provided on the instrument panel or the center console. The abnormality diagnosis device for an in-vehicle communication line according to claim 2, wherein the determination result is displayed on the display means. The in-vehicle communication line according to claim 3, wherein an insertion port of a separation member of the separation unit and an insertion port of a short pin of the connection unit are provided facing an opening / closing lid provided on the instrument panel or the center console. Abnormality diagnosis device. A board-mounted connection connector connected to a connector to which each branch circuit of the CAN communication line branch-connected to the node is connected;
Branch having a branch circuit connected to the connection connector and connected to the High line and Low line of each branch circuit connected to the node, and a joint circuit connected to each High line and Low line of the branch circuit With connection circuit,
2. The apparatus according to claim 1, wherein the separation means is provided for each of the High line and Low line of each branch circuit, and the potential measurement means measures the potentials of the High line and Low line of the separated branch circuit. Item 5. The abnormality diagnosis device for an in-vehicle communication line according to any one of items 4 to 6.   The on-vehicle communication line abnormality diagnosis device according to any one of claims 1 to 5, wherein the separation unit includes a relay provided in a high line and a low line of each branch circuit.   The separating means includes a pair of terminals having elastic contacts that are brought into contact with the High line and the Low line of each branch circuit, and the separating member including an insulating pin inserted and removed between the terminals. The abnormality diagnosis device for an in-vehicle communication line according to claim 4 or 5. A switching connection means comprising a changeover switch for connecting each of the High line and Low line of the branch circuit to be diagnosed by the separation means separated from the joint circuit with the potential measurement means or a microcomputer having an automatic switching function; ,
Circuit opening / closing connection means for separating the branch circuit other than the abnormality diagnosis target from the joint circuit, connecting only the branch circuit targeted for abnormality diagnosis to the joint circuit, and connecting the joint circuit to the potential measurement means. The on-vehicle communication line abnormality diagnosis device according to any one of claims 5 to 7, further comprising:   6. The circuit opening / closing connection means is configured such that a relay is interposed in a circuit connecting the junction circuit and the potential measurement means, or the short pin is inserted / removed between contacts provided in the circuit. An in-vehicle communication line abnormality diagnosis device according to claim 1. The connection circuit connected to the branch circuit to be subjected to the abnormality diagnosis is connected to a test resistor circuit, and the potential of the test resistor circuit is measured by the potential measuring means,
The inspection resistance circuit includes at least three inspection resistors connected in series to a circuit connecting a DC power supply and the ground, and the High line is interposed between a pair of the inspection resistors provided on the power supply side. On the other hand, the Low line is connected between a pair of the inspection resistors provided on the ground side, and the connection part of the High line and the Low line is connected to the potential measuring means,
The abnormality that occurs in the High line and the Low line is specified and determined from the potential detected by the potential measuring unit with reference to a potential range stored in advance in the abnormality determination unit. 10. The abnormality diagnosis device for a vehicle-mounted communication line according to any one of 9 above.

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