JP2606208Y2 - Wire harness test equipment - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test apparatus for a wire harness (bundled wire) used in various industrial fields, and in particular, an automobile, a vending machine, a communication device, a computer, an industrial machine, and the like. The present invention relates to a test apparatus for shortening the inspection time when determining the conduction / non-conduction of a wire harness used for connection between internal wiring and machines.

[0002]

2. Description of the Related Art As a wire harness test apparatus, there is an apparatus which measures a voltage value due to a voltage drop of a wire harness to be tested, and determines conduction / non-conduction based on the voltage value. The relationship between the measured voltage e due to the voltage drop of the wire harness and the resistance value r of the wire harness is as shown in FIG. 6, and conduction / non-conduction is determined using the voltage Es corresponding to the determination resistance value Rs as a boundary value. That is, as shown in FIG. 5, the wire harness test apparatus 20 arranges a group of switches in which two switching elements 1, 1 are connected in series, and applies a voltage to both ends of each group of switches. By controlling ON / OFF of each switching element 1, for example, a voltage value (measurement voltage) e due to a voltage drop of the connection line circuit under test 30 connected between the terminals OO 'is measured, and this voltage value e is measured. And the voltage Es are compared by a comparator 21. In this comparator 21,
It is determined whether the measured voltage e is higher than the voltage Es, and if it is higher, an "L" signal is output. The output signal from the comparator 21 is input to a discriminating circuit 22 to detect whether the output signal is "H" or "L" at one preset reading timing based on a clock signal CK. ,
When “H”, the connection line circuit under test 30 is in a conductive state,
When it is "L", it is determined to be in a non-conductive (open) state.

[0003]

However, according to the wire harness test apparatus 20, if the capacitance component in the connection line circuit under test 30 is large, erroneous determination of conduction / non-conduction may occur. For example, when the wire harness length is long, the stray capacitance in the connection line circuit under test 30 becomes large, and the rise of the measurement voltage as shown by a curve b in FIG. Becomes gradual. In this case, even when the wire harness 30 is open, when the reading timing (measurement time from the switch setting) is set at t1 or t2 in FIG.
Since the measured voltage e has not reached the voltage Es, it is determined that the state is a conduction state. That is, according to the above-described test apparatus, conduction / non-conduction can be accurately determined when the rise of the measured voltage is fast as shown by the curve a in FIG. 7, but the rise is gradual as shown by the curve b. In some cases, erroneous determination may occur depending on the setting time of the reading timing.

In order to avoid such a phenomenon, the reading timing in the determination circuit 22 should be set sufficiently long (to t3 in the case of the curve b in FIG. 7). However, since the reading timing is set in advance, if it is set to be sufficiently long, if the rising time is short, a wasteful time is generated until the determination, and as a result, it takes a long time until the determination, and as a whole, There is a problem that the inspection time becomes longer.

The present invention has been made in view of the above circumstances, and when conducting / non-conducting of a wire harness having a large stray capacitance is determined, conducting / non-conducting is efficiently performed to shorten the inspection time. An object of the present invention is to provide a wire harness test device that can be designed.

[0006]

In order to achieve the above object, according to the present invention, a connection line circuit under test is connected between terminals, and a voltage value due to a voltage drop of the connection line circuit under test and a desired boundary voltage value are determined. The wire harness testing apparatus for inspecting the conductivity / non-conductivity of the connection line circuit under test by comparison of the above is characterized by the following configuration. In addition to the boundary voltage value, that is, a voltage value that has been determined as a boundary between conduction and non-conductivity in the related art, a second boundary voltage value lower than this voltage value is set, and between the two voltage values. The area to be created is defined as an uncertain area.
Then, it is determined in chronological order whether the voltage value due to the voltage drop is inside or outside the uncertain region set as described above.
There is provided a judging means for making it possible . To the determination of the determination means
That receives a signal indicating that the uncertainty region outside, provided with discriminating means for checking the conductive-non-conducting under test connecting line circuit.

[0007]

According to the present invention, two boundary voltage values to be compared with the voltage value due to the voltage drop of the connection line circuit under test are set to two, and an uncertain area is provided therebetween, so that the voltage value due to the voltage drop is outside the uncertain area. Is checked for conduction / non-conduction of the connection line circuit under test, so that the read timing time can be set by the discriminating means in accordance with the rising state of the voltage value due to the voltage drop, ensuring no wasteful time. Can be determined.

That is, if the voltage value due to the voltage drop is outside the uncertain area during the read timing time, it is immediately determined whether the voltage is conductive or non-conductive. The conduction / non-conduction may be determined at the subsequent read timing time.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to FIGS. FIG. 1 is a simplified equivalent circuit diagram of a wire harness test apparatus 10 according to the present invention,
A switch group in which two switching elements 1, 1 are connected in series is arranged in an array. Terminals are provided between the switching elements 1 and 1 of each switch group, and a voltage V is applied to both ends of each switch group via a standard resistor Rm for generating a measured voltage. Therefore, if the switching elements 1a and 1b are turned on and the other switching elements are turned off, the measured voltage e due to the voltage drop of the connection line circuit under test 30 connected between the terminals OO 'is X.
Appear at the point. The wiring harness 30 to be tested is connected to each terminal, and the on / off of each switching element 1 is sequentially controlled (scan switching) to sequentially connect the connection wiring circuit under test 30 connected between each terminal. To be inspected. The voltage V is divided by resistors R1, R2, and R3, so that a first boundary voltage value Eu is generated at a point Y and a second boundary voltage value El is generated at a point Z.

The first boundary voltage value Eu is a voltage corresponding to the voltage value Es shown in the conventional example, and is the discrimination resistance value Rs shown in FIG.
Is the voltage corresponding to The second boundary voltage value El is set lower than the first boundary voltage value Eu, and an uncertain region is set between the first boundary voltage value Eu and the second boundary voltage value El (FIG. 2). If this second boundary voltage value El is too low,
The fixed area becomes wider, and will be described in a flowchart described later.
As a result, it takes time to judge whether conductive or nonconductive.
May be. Therefore, the second boundary voltage value El
The value is, specifically, the measurement standard for the connection line circuit under test.
After connecting the maximum stray capacitance and applying voltage for a certain period of time
It is preferably equal to a voltage value that stabilizes the voltage.

The first comparator 11a is connected so that a measurement voltage e at the point X and a first boundary voltage value Eu at the point Y are input to its input side. It is determined whether the measured voltage e due to the voltage drop of the line circuit 30 is larger than the first boundary voltage value Eu, and if it is higher, an "L" signal is output. The second comparator 11b has on its input side a measured voltage e at point X and a second boundary voltage value E at point Z.
l, and the comparator 11b determines whether the measured voltage e due to the voltage drop of the connection line circuit under test 30 is greater than the second boundary voltage value El,
If it is larger, an "L" signal is output.

The output signal of each of the comparators 11a and 11b is XO
An R (exclusive or) circuit is input to the output side of this XOR circuit.
Since the "L" signal is output in the same case, the "H" signal is output when the measured voltage e is within the uncertain region, and the "L" signal is output when the measured voltage e is outside the uncertain region. Therefore, each comparator 1
The XOR circuit that inputs the output signals 1a and 11b constitutes a determination circuit 12 that determines whether the measured voltage e is inside or outside the uncertain region and outputs an uncertain signal.

The uncertain signal output from the XOR circuit is input to the determination circuit 13, and the output of the second comparator 11b is input to the determination circuit 13 as a determination signal. The clock signal CK is input to the discrimination circuit 13, and in a plurality of read timing times set based on the clock signal CK, the conduction / non-conduction of the connection line circuit 30 under test is determined from the uncertain signal and the discrimination signal. An inspection is performed.

The procedure of the inspection in the discriminating circuit 13 will be described with reference to the flowchart of FIG. First, scan switch setting (step 101) is performed by on / off control of each switching element 1, and O-
A voltage is applied between the O 'terminals, and a measured voltage e is generated at the resistance r of the connection-target circuit 30 under test. The elapsed time T from the setting of the switch is calculated by counting the clock signal CK, and the first reading timing time is set after a fixed time (Ti time) has elapsed. After the elapse of the Ti time from the switch setting, the clock signal CK starts counting again, and after the elapse of the Ts time, the second read timing time is set, and thereafter, the read timing time is set every Ts time ( Step 102 and Step 110). That is, first, switch setting (Step 1)
01), it is determined whether or not the Ti time has elapsed (step 102).
The discrimination signal from 1b and the uncertain signal from the decision circuit 12 are read (step 103).

Subsequently, it is determined whether or not the uncertain signal is "L" (step 104). If the uncertain signal is "L", the measured voltage e is out of the uncertain region. It is determined whether or not the determination signal read at 103 is "H" (step 105). If the determination signal is "H", it is determined that the connection line circuit under test 30 is in the conductive state, and the process of having conduction is performed. (Step 106). In step 105, if the determination signal read in step 103 is "L", it is determined that the connection line circuit under test 30 is in a non-conductive state, and an opening process is performed (step 107).

In step 104, when the uncertain signal is "H", the measured voltage e is in the uncertain region, and the elapsed time T from the setting of the switch exceeds the predetermined elapsed time Ta. It is determined whether or not it has been performed (step 108). If the elapsed time T has exceeded the preset elapsed time Ta, the measurement voltage e is within the uncertainty region, but the measurement time is over and the uncertainty processing is performed (step 109). On the other hand, if the elapsed time T has not elapsed the preset elapsed time Ta, it is determined whether or not the time Ts has elapsed from the Ti time which is the first reading timing time (step 110). After the elapse, the process of step 103 is performed. Therefore, according to the process of the above-described flowchart, as shown in FIG. 2, a plurality of reading timings are set for every Ts time in the range of Ti ≦ T ≦ Ta in accordance with the rising state of the measured voltage in the range of Ti ≦ T ≦ Ta. It can be set.

The above-mentioned uncertain processing (step 109)
Is a case where the measured voltage is present in the uncertain region even after the elapse of the Ta time, but the handling differs depending on whether the detection of the conduction state or the detection of the open state is weighted in the wire harness test device. . That is, the uncertainty processing is processed as a non-conducting state in the case of a test that places importance on the conduction state, and the uncertainty processing is processed as a non-opening (conduction) state in the case of a test placing importance on the open state. Further, in the case where the flowchart of FIG. 3 is performed by using a computer, step 110 can be omitted since there is an execution time of the instruction.

The wire harness test apparatus 1 of the above embodiment
According to 0, the read timing time is provided a plurality of times, and the conduction / non-conduction of the connection line circuit under test 30 is determined by the uncertain signal and the determination signal.
Since the non-conductivity can be determined, for example, the one with a fast rise as shown by the curve A in FIG. 2 can be determined by the time Ti which is the first reading timing, and the one with a gradual rise like the curve B , For example, time Ti
Can be determined based on the read timing after a lapse of (4 × Ts). That is, according to the rising state of the measured voltage e due to the voltage drop of the connection line circuit under test 30, the reading timing time is set within the range of Ti ≦ T ≦ Ta, and the determination is performed. A reliable determination can be made.

FIG. 4 shows a wire harness test apparatus according to another embodiment of the present invention, in which the same components as those in the embodiment of FIG. Explaining a different configuration, the wire harness test apparatus 10 of FIG.
The discrimination signal input to the discrimination circuit 13 is supplied to the first comparator 11a.
Output. The inspection procedure is performed in accordance with the flowchart of FIG. 3 similarly to the wire harness test apparatus 10 of FIG.

In each of the above embodiments, each comparator 11
Although the determination circuit 12 is formed by an XOR circuit that inputs the outputs of a and 11b, the circuit is not limited to this, and may be any circuit that can determine whether the measurement voltage e is within or outside the uncertain region. The configuration may be such that the outputs of the comparators 11a and 11b are directly input to the discrimination circuit 13 and logical processing is performed.

[0021]

According to the present invention, the boundary voltage value to be compared with the voltage value due to the voltage drop of the connection line circuit under test is reduced to two,
In the meantime, an uncertainty area is provided, and a signal indicating that the voltage value due to the voltage drop is out of the uncertainty area is checked for conduction / non-conduction of the connection line circuit under test. The reading timing time by the determining means can be set in accordance with the determination, the reliable determination can be performed without wasted time, and the inspection time in the wire harness test apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a simplified equivalent circuit diagram of a wire harness test apparatus according to an embodiment of the present invention.

FIG. 2 is a graph showing a relationship between a measurement time and a measurement voltage in the wire harness test device of the example.

FIG. 3 is a flowchart for explaining an inspection procedure in a determination circuit according to the embodiment.

FIG. 4 is a simplified equivalent circuit diagram of a wire harness test apparatus according to another embodiment of the present invention.

FIG. 5 is a simplified equivalent circuit diagram of a conventional wire harness test device.

FIG. 6 is a graph showing a relationship between a resistance and a voltage of the wire harness.

FIG. 7 is a graph showing a relationship between a measurement time and a measurement voltage in the wire harness test device of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Switching element 10 ... Wire harness test apparatus 11a, 11b ... Comparator 12 ... Judgment circuit (judgment means) 13 ... Judgment circuit (judgment means) 30 ... Connection line circuit under test Eu ... 1st boundary voltage value El ... 2nd Boundary voltage value

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01R 31/02

Claims (1)

(57) [Scope of request for utility model registration] A connection line circuit under test is connected between terminals, and the conduction / non-conduction of the connection line circuit under test is determined by comparing a voltage value caused by a voltage drop of the connection line circuit under test with a desired boundary voltage value. time that the wire harness testing apparatus for testing, a voltage value by the voltage drop, and the boundary voltage value, an uncertainty region within or outside set between the second boundary voltage value lower than the voltage value Determining means for making a determination in a sequential manner; and determining means for receiving a signal indicating that it is outside the uncertainty area determined by the determination means, and testing the conductive / non-conductive state of the connection line circuit under test. A wire harness test device, comprising: