JP7538181B2 - Method and device for inspecting electrical continuity of assembled electric wires - Google Patents

Description

The present invention relates to a method and device for inspecting electrical continuity of an assembled electric wire.

The various sets of electric wires mounted on a vehicle, i.e., wire harnesses, must electrically connect numerous electrical components arranged in various locations on the vehicle to ensure power supply paths and signal transmission paths. For this reason, it is necessary to arrange and bundle together, for example, several hundred electric wires so that each passes through a predetermined path, and to configure the wires so that terminals attached to the ends of the wires can be attached to predetermined locations of a specified connector, or to attach an exterior material such as tape to the outside of the bundle of wires for protection. For this reason, such wire harnesses generally have very complex shapes and structures.

On the other hand, parts manufacturers that manufacture wire harnesses must conduct continuity tests to ensure that each wire harness is constructed according to the design specifications before delivering it to the vehicle manufacturer, and only deliver products that pass the tests to the vehicle manufacturer.

For example, the method of testing continuity of a wire harness in Patent Document 1 uses a simple configuration to ensure that continuity testing can be performed without problems even when unnecessary circuits are present in a system in which multiple wire harnesses are connected.

JP 2007-212249 A

Wire harnesses generally have complex structures and shapes. In addition, parts manufacturers that manufacture wire harnesses must use common manufacturing facilities to manufacture various types of wire harnesses, each of which is managed under a different part number. For example, they must manufacture different types of wire harnesses depending on the type, grade, destination, and presence or absence of various options of the vehicle.

Therefore, there is a possibility that defective wire harnesses may be manufactured due to various reasons. For example, the terminals of multiple electric wires may be swapped and installed in different connector positions. Also, one or more electric wire terminals may be manufactured without being installed in the intended connector positions. Also, one or more electric wire terminals may be installed in the wrong connector positions. Even if the wire harnesses are physically connected, they may be manufactured without the intended circuits being electrically connected due to poor contact or broken wires. Furthermore, wire harnesses contain many circuits that are only used in specific cases, such as options, so that they can be standardized across multiple part numbers, and these circuits also need to be inspected.

Therefore, parts manufacturers perform continuity tests on all electrical circuits in wire harnesses to prevent the shipment of defective wire harnesses. Specifically, they check whether each combination of numerous terminals is electrically conductive and verify whether these match the design specifications.

However, as the structure of a wire harness becomes more complex and the number of terminals increases, the number of processes required to perform a continuity test also increases, so it takes a long time even when the test is performed automatically using a computer. For example, when performing a continuity test on a wire harness with 500 terminals, it is necessary to check the continuity/non-continuity of each combination of one terminal selected in turn from the 500 terminals and the other 499 terminals, and to repeat this process for all terminals. In other words, since 499 continuity tests are performed repeatedly for each of the 500 terminals, it is difficult to complete the work in a short time. Moreover, it is expected that the time required will become even longer in the future as the number of terminals increases.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a method and device for inspecting electrical continuity of assembled electric wires that can easily shorten the time required for an overall electrical continuity inspection even when the total number of terminals in a wire harness is large.

The above object of the present invention is achieved by the following configuration:

A method for inspecting electrical connection between a plurality of terminals of a wire harness formed by assembling a plurality of electric wires, comprising the steps of:
Among all the terminals of the wire harness to be inspected, all the terminals that are to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
If no electrical continuity is detected in the measurement result, a terminal other than the first point is selected from the selected joint group as a new first point;
Fixing the potential of the new first point to the first potential;
applying a second potential different from the first potential to all terminals except the new first point;
detecting potentials appearing at all terminals except the new first point, and taking the combination of the potentials as a new measurement result;
When the new measurement result detects continuity in the joint group to which the new first point belongs, an error is notified about non-continuity of the first point.
Method for testing electrical wire continuity.
A method for inspecting electrical connection between a plurality of terminals of a wire harness formed by assembling a plurality of electric wires, comprising the steps of:
Among all the terminals of the wire harness to be inspected, all the terminals that are to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
based on the measurement result, when continuity is detected within the joint group to which the first point belongs and continuity is detected at one point outside the joint group to which the first point belongs, an error is notified about a wiring error at one point.
Method for testing electrical wire continuity.

a switch circuit for fixing a potential of a terminal selected from the wire harness to be inspected at a predetermined potential;
a potential application unit capable of applying a predetermined test potential to each terminal of the wire harness;
a potential detection unit that detects a difference in potential between each terminal of the wire harness;
an inspection control unit that controls the switch circuit, the potential application unit, and the potential detection unit in accordance with a design specification that is specified based on a product number of the wire harness,
The inspection control unit is
Among all the terminals of the wire harness, all the terminals to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
If no electrical continuity is detected in the measurement result, a terminal other than the first point is selected from the selected joint group as a new first point;
Fixing the potential of the new first point to the first potential;
applying a second potential different from the first potential to all terminals except the new first point;
detecting potentials appearing at all terminals except the new first point, and taking the combination of the potentials as a new measurement result;
When the new measurement result detects continuity in the joint group to which the new first point belongs, an error is notified about non-continuity of the first point.
Continuity inspection device for assembled electric wires.
a switch circuit for fixing a potential of a terminal selected from the wire harness to be inspected at a predetermined potential;
a potential application unit capable of applying a predetermined test potential to each terminal of the wire harness;
a potential detection unit that detects a difference in potential between each terminal of the wire harness;
an inspection control unit that controls the switch circuit, the potential application unit, and the potential detection unit in accordance with a design specification that is specified based on a product number of the wire harness,
The inspection control unit is
Among all the terminals of the wire harness, all the terminals to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
based on the measurement result, when continuity is detected within the joint group to which the first point belongs and continuity is detected at one point outside the joint group to which the first point belongs, an error is notified about a wiring error at one point.
Continuity inspection device for assembled electric wires.

The method and device for inspecting electrical continuity of assembled electric wires according to the present invention make it easy to shorten the time required for the entire electrical continuity inspection, even when the number of terminals in the entire wire harness is large. In other words, the number of times that electrical continuity inspections are repeated is significantly reduced, so the time required for the entire inspection can be shortened. In addition, if the inspection result is a failure, it is also possible to determine where the problem is occurring in the wire harness.

The present invention has been briefly described above. The details of the present invention will become clearer by reading the following description of the embodiment of the invention (hereinafter referred to as "embodiment") with reference to the attached drawings.

FIG. 1 is an electric circuit diagram showing the circuit configuration of a simplified model of a wire harness. FIG. 2 is an electric circuit diagram showing the parts belonging to each of a plurality of joint groups. FIG. 3 is a schematic diagram showing the relationship between a plurality of joint groups and the terminals belonging to the groups. FIG. 4 is a block diagram showing an example of the configuration of a continuity inspection device. FIG. 5 is a flowchart showing an outline of the operation procedure of the continuity inspection device. FIG. 6 is a flow chart showing the details of S12 in FIG. FIG. 7 is a flow chart showing the details of S13 in FIG. FIG. 8 is a flow chart showing the details of S14 in FIG.

Specific embodiments of the present invention are described below with reference to the drawings.

<Example of wire harness to be inspected>
FIG. 1 is an electric circuit diagram showing the circuit configuration of a simplified model of a wire harness.

The wire harness shown in FIG. 1 has three mutually independent electric circuits C1, C2, and C3. Each of the electric circuits C1, C2, and C3 has one or more electric wires and terminals attached to the ends of each electric wire. In addition, the electric wires of each of the electric circuits C1, C2, and C3 branch out midway and are connected to multiple terminals.

In the example shown in FIG. 1, terminals T11, T21, T31, and T41 are connected to the ends of the wires of electric circuit C1. Terminals T12, T22, T32, and T42 are connected to the ends of the wires of electric circuit C2. Terminals T13, T23, T33, and T43 are connected to the ends of the wires of electric circuit C3.

Note that the portion of the electrical circuit C3 in Figure 1 shown by the dashed line may be connected or left unconnected depending on the specifications of the wire harness. In a wire harness where this circuit is unconnected, terminal T44 is not connected to electrical circuit C3. Similarly, terminal T34 in Figure 1 is also unconnected and is not connected to electrical circuit C1.

In the wire harness shown in FIG. 1, terminals T11, T12, and T13 are each arranged and fixed in a space (cavity) at a predetermined position in the housing of connector CN1. Terminals T21, T22, and T23 are each arranged and fixed in a space at a predetermined position in the housing of connector CN2. Terminals T31, T32, and T33 are each arranged and fixed in a space at a predetermined position in the housing of connector CN3. Terminals T41, T42, T43, and T44 are each arranged and fixed in a space at a predetermined position in the housing of connector CN3.

When conducting a continuity test on the wire harness shown in Figure 1, if the product is normal, there will be electrical continuity between the terminals T11, T21, T31, and T41. There will also be electrical continuity between the terminals T12, T22, T32, and T42. There will also be electrical continuity between the terminals T13, T23, T33, and T43. For terminal combinations other than those mentioned above, there will be no electrical continuity in any section.

However, due to defects in the manufacturing process, the configuration of the wire harness that is actually manufactured may differ from the design data shown in Figure 1. For example, the terminals may be installed in the wrong positions inside the housings of the connectors CN1 to CN4. The positions of multiple terminals may also be mixed up. Furthermore, circuits that need to be connected may be left unwired due to poor connections or broken wires.

Parts manufacturers need to detect all of the above defects in the wire harnesses they manufacture through continuity tests. Therefore, when conducting a continuity test using the standard method, the presence or absence of continuity is checked for each combination of all terminals. In other words, when conducting a continuity test on the wire harness in Figure 1, since there are a total of (13 x 14 = 182) possible combinations of two each of the 14 terminals T11-T13, T21-T23, T31-T34, and T41-T44, the continuity test needs to be repeated 156 times while sequentially changing the target locations.

In addition, an actual wire harness has a much more complicated configuration than the model in Figure 1, and may have, for example, about 30 circuits and a total of about 500 terminals. In that case, the number of times that the continuity test is repeated increases to 499 x 500 (= 249,500). As a result, the time required for the continuity test becomes extremely long.

<Explanation of the Joint Group>
On the other hand, the continuity test device 100 of the present embodiment utilizes the concept of a "joint group" in order to reduce the number of times the test is repeated. This "joint group" refers to a grouping of all of a plurality of terminals that are to be connected to each other in the design specifications of the wire harness to be tested. Each terminal of the wire harness to be tested is assigned to one of the joint groups.

Figure 2 is an electrical circuit diagram showing the parts that belong to each of the multiple joint groups.

Figure 2 shows the state in which the parts belonging to each of the multiple joint groups JG1, JG2, and JG3, and the unused circuits, are extracted from the model of the wire harness shown in Figure 1. In Figure 2, circuits belonging to the same joint group are shown with solid lines, and circuits belonging to different joint groups are shown with dashed lines.

As shown in FIG. 2, the circuit of the first joint group JG1, which is included in the same wire harness as FIG. 1, includes terminals T11, T21, T31, and T41. Therefore, terminals T11, T21, T31, and T41 are assigned to the joint group JG1.

The circuit of the second joint group JG2 includes terminals T12, T22, T32, and T42. Therefore, terminals T12, T22, T32, and T42 are assigned to joint group JG2.

The circuit of the third joint group JG3 includes terminals T13, T23, T33, and T43. Therefore, terminals T13, T23, T33, and T43 are assigned to joint group JG3. In addition, terminals T34 and terminal 44 are assigned as free circuits.

<Relationship between joint groups and terminals>
FIG. 3 is a schematic diagram showing the relationship between a plurality of joint groups and the terminals belonging to the groups.
Each component of the wire harness shown in Fig. 1 can be divided into joint groups as shown in Fig. 2. Therefore, as shown in Fig. 3, the correspondence between each joint group JG1 to JG3 and the terminals assigned to each group can be specified.

<Outline of procedure for inspecting electrical wire continuity>
The procedure for carrying out the method for inspecting electrical continuity of an electric wire assembly according to this embodiment is outlined below.
(S01) Among all the terminals of the wire harness to be inspected, all of the multiple terminals that should be connected to each other in the design specifications are assigned to the same joint group, and multiple joint groups JG1 to JG3 are formed for the wire harness, for example, as shown in FIGS. 2 and 3.
(S02) One joint group is selected in sequence from the multiple joint groups JG1 to JG3.
(S03) One terminal is selected from the selected joint group as a first point P1.
(S04) The potential of the first point is fixed at a first potential, and a second potential different from the first potential is applied (via resistors) to all terminals except the first point.
(S05) The potentials appearing at the respective positions of all terminals except the first point are detected, and the combination of the potentials is taken as the measurement result, and the continuity state of each circuit is checked based on the relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs. The above-mentioned processes from (S02) onwards are repeated.

For example, if joint group JG1 is selected in the wire harness shown in FIG. 1, one of terminals T11, T21, T31, and T41 belonging to this group can be selected as the first point P1. Then, the presence or absence of continuity between this first point P1 and all terminals of all joint groups other than it is checked simultaneously in a single process.

If there is continuity between the first point P1 and a terminal in the same joint group, it is normal, and if there is continuity between the first point P1 and a terminal outside the joint group, it is abnormal. Also, if there is no continuity between the first point P1 and a terminal in the same joint group, it is abnormal, and if there is no continuity between the first point P1 and a terminal outside the joint group, it is normal.

<Configuration of the continuity inspection device>
4 is a block diagram showing an example of the configuration of the continuity inspection device 100. The continuity inspection device 100 can be used to carry out the electric wire assembly continuity inspection method of the present embodiment.

The continuity inspection device 100 is configured assuming that the wire harness W/H having the configuration shown in FIG. 1 is to be inspected. The configuration of the continuity inspection device 100 is appropriately changed according to the configuration and specifications of the wire harness W/H to be inspected.

The continuity test device 100 in FIG. 4 includes connectors CN01 to CN04, a switch circuit 11, a test voltage generating circuit 12, a voltage detection circuit 13, a control unit 14, a design database 15, a data table 16, and a measurement result storage unit 17.

The connectors CN01 to CN04 of the continuity inspection device 100 can be attached to the connectors CN1 to CN4 of the wire harness W/H, respectively. In addition, the connector CN01 has terminals that can be mated with the terminals T11 to T13 in the connector CN1, the connector CN02 has terminals that can be mated with the terminals T21 to T23 in the connector CN2, the connector CN03 has terminals that can be mated with the terminals T31 to T33 in the connector CN3, and the connector CN04 has terminals that can be mated with the terminals T41 to T44 in the connector CN4.

The test voltage generating circuit 12 can generate a predetermined test voltage VT (for example, a constant DC voltage) used for continuity testing. The test voltage VT generated by the test voltage generating circuit 12 can be applied to all terminals in each of the connectors CN01 to CN04. However, a resistor (not shown) is interposed between the output of the test voltage generating circuit 12 and each terminal in each of the connectors CN01 to CN04. Therefore, for example, if any of the circuits is shorted to ground GND, the potential of the terminal of the corresponding circuit becomes equivalent to ground GND.

The switch circuit 11 can short-circuit one terminal selected from the connectors CN01 to CN04 to ground GND according to the selection signal SEL output by the control unit 14. For example, when one terminal T11 is selected from the joint group JG1 as the first point P1, the terminal T11 in the connector CN1 is short-circuited to ground GND via the connector CN01 and the switch circuit 11, and the potential is fixed.

In this case, unless there is an abnormality in the wire harness, each of the terminals T21, T31, and T41 in the same joint group JG1 will have the same potential as ground GND, and the potential of the test voltage VT will appear at all of the terminals in the different joint groups JG2 and JG3.

The voltage detection circuit 13 can simultaneously identify the high/low potentials present at each of the terminals of the wire harness W/H. In other words, it can distinguish between a state in which each of the multiple terminals is conductive to ground GND and a state in which the test voltage VT is being applied.

The design database 15 holds predefined design data that represents the configurations and specifications of various wire harnesses, including the wire harness W/H to be inspected.

The data table 16 can hold data representing multiple joint groups JG1 to JG3 included in the wire harness W/H to be inspected and each terminal included in each group, for example as shown in FIG. 3. This data can be determined based on the contents of the design database 15.

The measurement result storage unit 17 can store and temporarily hold the data of the results detected by the voltage detection circuit 13 as the measurement result each time each of the multiple joint groups JG1 to JG3 is selected and inspected.

The control unit 14 is configured, for example, with an electronic circuit mainly composed of a microcomputer, and executes a pre-installed program to perform the processing required for the continuity inspection device 100 to perform a specified operation.

Specifically, the control unit 14 obtains the necessary design data from the design database 15 according to the part number of the wire harness W/H to be inspected, creates joint group (J/G) data as shown in FIG. 3, and stores it in the data table 16. The control unit 14 sequentially selects the first point P1 based on the joint group. Furthermore, the control unit 14 uses the selection signal SEL to control the switch circuit 11 to short-circuit the potential of the terminal selected as the first point P1 to ground GND. The test voltage VT is applied to all terminals other than the first point P1 via connectors CN01 to CN04.

The control unit 14 also detects the high/low potential combinations of all terminals other than the first point P1 using the voltage detection circuit 13, and stores the measurement results in the measurement result storage unit 17. The control unit 14 compares the measurement results obtained for all joint groups with the design specifications of the wire harness W/H being inspected, and makes a judgment on the pass/fail of the inspection, etc. A detailed operation will be described later.

<Outline of operation procedure>
Fig. 5 is a flow chart showing an outline of the operation procedure of the continuity inspection device 100. The operation procedure of Fig. 5 will be described below.

The control unit 14 reads the product number information from a tag attached to the wire harness W/H to be inspected, for example, and obtains the design data required for the continuity inspection of the wire harness W/H identified by this product number from the design database 15 (S11). This design data includes information that can identify the connection relationship between all terminals and each circuit, such as the configuration of the wire harness shown in Figure 1.

The control unit 14 automatically selects the inspection points to be used in the continuity inspection based on the design data of the wire harness W/H acquired in S11 (S12). Here, it determines how many times to perform the circuit check. This number is the result of adding the number of free circuits to the number of joint groups included in the wire harness W/H to be inspected.

The control unit 14 uses each inspection point (first point P1) selected in S12 to check the continuity of the circuit for each joint group (S13). Here, the continuity check between the first point P1 and each point of all other terminals is performed in a single process.

The control unit 14 compares the results of the electrical continuity measurement performed in S13 with the connection state in the design data acquired in S11 for each terminal of each point, and identifies the presence or absence of a defect (S14).

When the control unit 14 has completed the continuity test for one selected joint group, it returns from S15 to S13 to process the next joint group. Then, when the continuity test for all joint groups is completed, it proceeds to the process from S15 to S16.

The control unit 14 performs a continuity test in S16 on vacant circuits (terminals not used by part number) that are not assigned to any joint group in the configuration of the wire harness W/H to be inspected. When inspecting an empty circuit, a continuity test is performed between one terminal of the empty circuit and all other terminals. The continuity test in S16 makes it possible to find connections between terminals that do not belong to any joint group, such as the connection between terminals T34 and T44 shown at the bottom of Figure 2.

If the result of the continuity test in S16 is that all free circuits are OPEN (open state: no continuity), the control unit 14 proceeds to process S17 to S18, otherwise it proceeds to process S17 to S19.

In S18, the control unit 14 determines that the wire harness W/H being inspected has passed the continuity test, and notifies the administrator of the result by sound or display. In S19, the control unit 14 determines that the wire harness W/H being inspected has failed the continuity test, and notifies the administrator of the result by sound or display.

<Details of "Automatic Inspection Point Selection">
Fig. 6 is a flow chart showing details of S12 in Fig. 5. The operation in Fig. 6 will be described below.
The control unit 14 determines the total number Njg of joint groups based on the design data of the wire harness W/H to be inspected in S21. For example, in the case of the wire harness shown in FIG. 1, since it includes three independent electric circuits C1, C2, and C3, the total number Njg of joint groups is determined to be "3".

The control unit 14 determines one terminal as the first point P1 for each of the multiple joint groups in S22. For example, when selecting and inspecting the joint group JG1 shown in FIG. 2, any one of the terminals T11, T21, T31, and T41 connected to the electrical circuit C1 can be selected as the first point P1.

In addition, when selecting and inspecting joint group JG2, any one of terminals T12, T22, T32, and T42 connected to electrical circuit C2 can be selected as the first point P1.

The control unit 14 recognizes each of the terminals of the free circuits in the wire harness W/H to be inspected that do not belong to any joint group as an inspection point separate from the joint group, and determines the number of such terminals in S23.

<Details of "Inspection point circuit check">
Fig. 7 is a flow chart showing details of S13 in Fig. 5. The operation of Fig. 7 will be described below.
The control unit 14 controls the selection signal SEL in S31 so as to short-circuit one terminal in any one of the joint groups selected in S12, i.e., the first point P1, to the ground GND. As a result, the switch circuit 11 short-circuits only one terminal of the first point P1 to the ground GND in accordance with the selection signal SEL.

The control unit 14 applies the test voltage VT from the output of the test voltage generating circuit 12 to all terminals other than the first point P1 via independent resistors for each of the connectors CN01 to CN04 and each terminal (S32). In practice, the test voltage VT may be constantly applied to all terminals including the first point P1. However, since only the first point P1 is shorted to GND in S31, the potential of the first point P1 is fixed to the potential of ground GND. Also, since there are resistors between the output of the test voltage generating circuit 12 and each terminal, no large current flows from the output of the test voltage generating circuit 12 to the shorted terminal.

The control unit 14 detects the high/low potential of each terminal in the connectors CN01 to CN04 using the voltage detection circuit 13, and stores data representing the combination of high/low potential for each terminal in the measurement result memory unit 17 as a measurement result associated with the selection state of the joint group (S33).

Based on this measurement result, the control unit 14 can check short-circuit points other than the first point P1. That is, all terminals belonging to the same joint group as the currently selected first point P1 are electrically connected to each other within the wire harness according to the design specifications, so each of them will be at a potential that indicates a short-circuit state (a low potential equivalent to ground GND). Also, all terminals belonging to joint groups other than the first point P1 are not electrically connected to each other within the wire harness according to the design specifications, so each of them will be at a potential that indicates an open state (a high potential equivalent to the test voltage VT).

<Details of "Test Data Verification">
Fig. 8 is a flow chart showing details of S14 in Fig. 5. The operation of Fig. 8 will be described below.
The control unit 14 can automatically identify whether or not there is a defect in the actually manufactured wire harness by comparing the design specifications of the wire harness W/H to be inspected with the measurement result data stored in the measurement result storage unit 17 in the circuit check of S13 as shown in Figure 8.

The control unit 14 identifies in S41 whether each of the terminals inside and outside the currently selected joint group is open (open potential equivalent to the test voltage VT), and if this condition is met, proceeds to S42, and if the condition is not met, proceeds to S45.

In S42, the control unit 14 automatically switches the currently selected first point P1 to another terminal position in the same joint group, and performs a circuit check again similar to S13. For example, if the joint group JG1 in FIG. 3 is selected and terminal T11 in the group is initially selected as the first point P1 to perform a circuit check, the first point P1 is changed to one of the other terminals T21, T31, or T41, and then the check is performed again.

In S43, the control unit 14 identifies whether or not there is only one open point detected in the same joint group as the first point P1 in the recheck of S42. If there is only one open point, the process proceeds from S43 to S44, and if there are two or more open points, the process proceeds to S52.

In S44, the control unit 14 determines that the match is "NG" and reports as the inspection result that a minor error has occurred in the wire harness W/H, with one wiring missing.

In S45, the control unit 14 identifies whether or not the circuit check in S13 detected only one open point in the same joint group as the first point P1 and whether or not the rest of the open point matches the design specifications. If this condition is met, the process proceeds from S45 to S44, and if not, the process proceeds to S46.

In S46, the control unit 14 checks whether there is only one short circuit (potential equivalent to ground GND) among the terminals belonging to a joint group other than the first point P1 in the circuit check in S13, and whether the rest of the terminals match the design specifications. If this condition is met, the process proceeds to S47, and if not, the process proceeds to S48.

In S47, the control unit 14 determines that the comparison is "NG" and notifies the user that a minor error, including one miswiring, has occurred in the wire harness W/H as the inspection result.

In S48, the control unit 14 checks whether or not there is only one open point among the terminals belonging to the same joint group as the first point P1 in the circuit check in S13, and whether there is only one short point among the terminals belonging to a different joint group from the first point P1. If this condition is met, proceed to S49, and if not, proceed to S50.

In S49, the control unit 14 determines that the match is "NG" and reports as the inspection result that a minor error has occurred in the wire harness W/H, with one wiring being mixed up.

In S50, the control unit 14 identifies whether or not multiple points within the same joint group as the first point P1 are open in the circuit check in S13, and multiple points outside a different joint group from the first point P1 are short. If this condition is not met, the process proceeds to S51, and if the condition is met, the process proceeds to S52.

In S51, the control unit 14 notifies, as an inspection result, that the matching in the circuit check in the current joint group selection state has been successful.
In S52, the control unit 14 notifies, as an inspection result, that a complex error has occurred in the circuit check in the current joint group selection state.

As described above, the continuity inspection device 100 according to the present embodiment sequentially determines the points to be inspected while taking into account the joint groups when inspecting the continuity of the wire harness W/H, so that the number of times the process is repeated can be significantly reduced. In other words, a continuity inspection can be performed for the entire joint group with only one inspection. This can reduce the time required for the entire continuity inspection. For example, when the continuity inspection is performed according to a general procedure, when the total number of terminals of the wire harness is 500, the continuity inspection between two points needs to be repeated 499 x 500 (= 249500) times, which corresponds to the number of combinations of two points. In the case of the continuity inspection device 100 of FIG. 4, when the number of circuits of the wire harness is 30 and the total number of terminals is 500, the number of times the continuity inspection is repeated can be reduced to the number of joint groups (30). Note that when inspecting multiple types of wire harnesses including vacant circuits that are used/unused depending on the part number, the vacant circuit parts need to be inspected by a process separate from the joint groups, so the number of processes increases by the number of vacant circuits.

In addition, by comparing the inspection data using the procedure shown in Figure 8, it is possible to automatically distinguish between minor errors and complex errors, as well as between types of errors such as no wiring, incorrect wiring, and swapped wiring, in addition to distinguishing between pass and fail for each wire harness. This makes it easier to repair failed wire harnesses and also provides information that is useful for analyzing defects in the manufacturing process.

The present invention is not limited to the above-described embodiment, and can be modified, improved, etc. as appropriate. In addition, the material, shape, size, number, location, etc. of each component in the above-described embodiment are arbitrary as long as they can achieve the present invention, and are not limited.

For example, in the continuity test device 100 shown in FIG. 4, it is assumed that the first point P1 is shorted to ground GND, but the first point P1 may also be shorted to a specified power supply line on which a potential different from the test voltage VT appears.

Here, the features of the electric wire assembly continuity inspection method and the electric wire assembly continuity inspection device according to the above-mentioned embodiment of the present invention will be briefly summarized and listed in the following [1] to [5].
[1] A method for inspecting electrical connection between a plurality of terminals of a wire harness formed by assembling a plurality of electric wires, comprising:
Among all the terminals of the wire harness to be inspected, all the terminals that are to be connected to each other in the design specification are assigned to the same joint group;
A plurality of joint groups (JG1 to JG3) are formed for the wire harness (see FIGS. 2 and 3),
Sequentially selecting one joint group from the plurality of joint groups (S13, S15);
Select one terminal from the selected joint group as a first point (P1) (S22);
The potential of the first point is fixed to a first potential (the potential of ground GND) (S31);
A second potential (test voltage VT) different from the first potential is applied to all terminals except the first point (S32);
The potentials appearing at the respective positions of all the terminals except the first point are detected, and the combination of the potentials is determined as the measurement result (S33).
The electrical continuity of each circuit is compared based on the relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs (S14, S41 to S52);
Method for testing electrical wire continuity.

According to the method for inspecting the electrical continuity of an assembled electric wire as described above in [1], when inspecting the electrical continuity of a wire harness W/H, the points to be inspected are determined sequentially taking into account the joint groups, so the number of times the process is repeated can be significantly reduced. In other words, a single inspection can be performed to inspect the electrical continuity of an entire joint group, so the number of repetitions is reduced and the time required for the inspection is shortened.

[2] When no electrical continuity is detected in the measurement result, a terminal other than the first point is selected as a new first point from the selected joint group (S41, S42);
Fixing the potential of the new first point to the first potential;
applying a second potential different from the first potential to all terminals except the new first point;
detecting potentials appearing at all terminals except the new first point, and taking the combination of the potentials as a new measurement result;
When continuity in the joint group to which the new first point belongs is detected in the new measurement result (S43), an error is notified about non-continuity of the first point (S44).
The method for inspecting electrical continuity of an electric wire assembly according to the above [1].

According to the method for inspecting the electrical continuity of an assembled electric wire as described above in [2], even if the terminal of the first point P1 selected initially is not connected within the selected joint group, the electrical continuity inspection can be continued by changing the first point P1 to another terminal position. In addition, a non-conductivity error can be automatically detected for the first point P1 that was not connected.

[3] Based on the measurement result, when continuity is detected within the joint group to which the first point belongs and continuity is detected at one point other than the joint group to which the first point belongs (S45, S46), an error is notified about a wiring error at one point (S47).
The method for inspecting electrical continuity of an assembled electric wire according to the above [1] or [2].

The method for inspecting electrical wire continuity as described above in [3] can automatically detect that there is one terminal among terminals other than the currently selected joint group that is erroneously connected to a circuit within the group.

[4] Based on the measurement result, when a non-continuity at one point is detected within the joint group to which the first point belongs and a continuity at one point is detected outside the joint group to which the first point belongs (S48), an error is notified about a wiring misalignment at one point (S49).
The method for inspecting electrical continuity of an assembled electric wire according to any one of [1] to [3] above.

According to the method for inspecting the electrical continuity of an assembled electric wire as described above in [4], if the position of two terminals of the wire harness being inspected is incorrectly inserted across the inside and outside of a joint group, the type of error can be automatically detected.

[5] A switch circuit (11) that fixes a potential of a terminal (a first point P1) selected from a wire harness (W/H) to be inspected at a predetermined potential;
a potential application unit (test voltage generation circuit 12) capable of applying a predetermined test potential to each terminal of the wire harness;
a potential detection unit (voltage detection circuit 13) that detects a difference in potential between each terminal of the wire harness;
an inspection control unit (control unit 14) that controls the switch circuit, the potential application unit, and the potential detection unit in accordance with a design specification that is specified based on a product number of the wire harness;
The inspection control unit is
Among all the terminals of the wire harness, all the terminals to be connected to each other in the design specification are assigned to the same joint group;
A plurality of joint groups (JG1 to JG3) are formed for the wire harness,
Sequentially selecting one joint group from the plurality of joint groups (S13, S15);
Select one terminal from the selected joint group as a first point (S22);
The potential of the first point is fixed to a first potential (S31);
A second potential different from the first potential is applied to all terminals except the first point (S32);
The potentials appearing at the respective positions of all the terminals except the first point are detected, and the combination of the potentials is determined as the measurement result (S33).
The electrical continuity of each circuit is compared based on the relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs (S14, S41 to S52);
An electric wire assembly continuity inspection device (continuity inspection device 100).

According to the electric wire assembly continuity inspection device having the configuration of [5] above, when conducting a continuity inspection of a wire harness W/H, the points to be inspected are determined sequentially taking into account the joint groups, so the number of times the process is repeated can be significantly reduced. In other words, since a continuity inspection can be performed for an entire joint group with just one inspection, the number of repetitions is reduced, and the time required for the inspection is shortened.

REFERENCE SIGNS LIST 11 Switch circuit 12 Test voltage generating circuit 13 Voltage detection circuit 14 Control unit 15 Design database 16 Data table 17 Measurement result storage unit 100 Continuity inspection device C1, C2, C3 Electric circuit CN1, CN2, CN3, CN4 Connector CN01, CN02, CN03, CN04 Connector JG1, JG2, JG3 Joint group P1 First point T11, T12, T13, T21, T22, T23 Terminal T31, T32, T33, T41, T42, T43, T44 Terminal GND Ground VT Test voltage W/H Wire harness

Claims (5)

A method for inspecting electrical connection between a plurality of terminals of a wire harness formed by assembling a plurality of electric wires, comprising the steps of:
Among all the terminals of the wire harness to be inspected, all the terminals that are to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
If no electrical continuity is detected in the measurement result, a terminal other than the first point is selected from the selected joint group as a new first point;
Fixing the potential of the new first point to the first potential;
applying a second potential different from the first potential to all terminals except the new first point;
detecting potentials appearing at all terminals except the new first point, and taking the combination of the potentials as a new measurement result;
When the new measurement result detects continuity in the joint group to which the new first point belongs, an error is notified about non-continuity of the first point.
Method for testing electrical wire continuity. A method for inspecting electrical connection between a plurality of terminals of a wire harness formed by assembling a plurality of electric wires, comprising the steps of:
Among all the terminals of the wire harness to be inspected, all the terminals that are to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all terminals except the first point, and determining the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
based on the measurement result, when continuity is detected within the joint group to which the first point belongs and continuity is detected at one point outside the joint group to which the first point belongs, an error is notified about a wiring error at one point.
Method for testing electrical wire continuity . based on the measurement result, when detecting a non-continuity at one point within the joint group to which the first point belongs and detecting a continuity at one point outside the joint group to which the first point belongs, an error is notified about a wiring misalignment at one point.
The method for inspecting electrical continuity of an electric wire assembly according to claim 1 or 2 . a switch circuit for fixing a potential of a terminal selected from the wire harness to be inspected at a predetermined potential;
a potential application unit capable of applying a predetermined test potential to each terminal of the wire harness;
a potential detection unit that detects a difference in potential between each terminal of the wire harness;
an inspection control unit that controls the switch circuit, the potential application unit, and the potential detection unit in accordance with a design specification that is specified based on a product number of the wire harness,
The inspection control unit is
Among all the terminals of the wire harness, all the terminals to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
If no electrical continuity is detected in the measurement result, a terminal other than the first point is selected from the selected joint group as a new first point;
Fixing the potential of the new first point to the first potential;
applying a second potential different from the first potential to all terminals except the new first point;
detecting potentials appearing at all terminals except the new first point, and taking the combination of the potentials as a new measurement result;
When continuity in the joint group to which the new first point belongs is detected in the new measurement result, an error is notified about non-continuity of the first point.
Continuity inspection device for assembled electric wires. a switch circuit for fixing a potential of a terminal selected from the wire harness to be inspected at a predetermined potential;
a potential application unit capable of applying a predetermined test potential to each terminal of the wire harness;
a potential detection unit that detects a difference in potential between each terminal of the wire harness;
an inspection control unit that controls the switch circuit, the potential application unit, and the potential detection unit in accordance with a design specification that is specified based on a product number of the wire harness,
The inspection control unit is
Among all the terminals of the wire harness, all the terminals to be connected to each other in the design specification are assigned to the same joint group;
forming a plurality of the joint groups for the wire harness;
Sequentially selecting one joint group from the plurality of joint groups;
Selecting one terminal from the selected joint group as a first point;
Fixing the potential of the first point to a first potential;
applying a second potential different from the first potential to all terminals except the first point;
Detecting potentials appearing at the respective positions of all the terminals except the first point, and taking the combination of the potentials as a measurement result;
A continuity state of each circuit is compared based on a relationship between the potential of each terminal in the measurement result and the selection/non-selection of the joint group to which each terminal belongs;
based on the measurement result, when continuity is detected within the joint group to which the first point belongs and continuity is detected at one point outside the joint group to which the first point belongs, an error is notified about a wiring error at one point.
Continuity inspection device for assembled electric wires.

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