JPH10206478A - Tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To evaluate durability of a relay accurately by turning the contact of an element having contact on/off repeatedly at a predetermined period and controlling a multiterminal switch to switch connection of a plurality of loads sequentially every predetermined time. SOLUTION: A sample relay 10 is connected with a power supply Va and turned on/off repeatedly by applying a pulse signal at a predetermined period to a power transistor 14. More specifically, at a time t1 when the contact (a) of a multiterminal switch 12 is connected with the sample relay 10, both the power transistor 14 and the contact (a) are turned off and an actual load R1 is not conducted with the power supply Va. At time t2 , the power transistor 14 and the contact 10a of the sample relay 10 are turned on by a pulse signal generated from a timing signal generator 15 and the actual load R1 is lighted. At time t3 , an exciting coil 10b is turned off by the falling of of the pulse signal and the actual load R1 is unlighted. Upon elapsing a time T1 after time t1 , the contact is switched from (a) to (b) by the pulse signal. Subsequently, the operation is repeated and a decision is made whether the relay 10 fails when it is turned on/off by a predetermined times after unlighting the actual loads R1 -R3 .

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 performing a durability test by repeatedly opening and closing contacts of a contact element such as an electromagnetic relay switch.

[0002]

2. Description of the Related Art In an automobile, an electromagnetic relay switch is generally used for the purpose of, for example, switching on / off of a headlight or driving of a drive motor for a power window. In this type of load, the normal current is less than the rated value of the relay switch, but at the moment when the relay switch is switched from the off state to the on state, it far exceeds the rated value of the relay switch. Excessive inrush current (inrush current) flows. Here, when the material of the contact of the relay switch is not appropriate, if the on / off switching is performed frequently, the contact of the relay switch may be melted and welded or melted. Then, when the contacts of the relay switch are welded, the contacts cannot be turned off and the current may continue to flow. . Therefore, it is important to conduct a durability test sufficiently at the design stage of the relay switch and to select a contact material of the relay switch suitable for the load.

[0003] Conventionally, as a test apparatus for performing a durability test by repeatedly turning on and off a contact of a contact element such as a relay switch, for example, there is one as shown in FIG. Here, the power transistor 2 repeats the ON (Ton) / OFF (Toff) operation at a predetermined cycle T1 based on the timing signal output from the timing generator 1, and FIG.
As shown in (a), the relay switch (hereinafter referred to as "test relay") 3 to be subjected to the test is repeatedly turned on and off to the exciting coil 4 a predetermined number of times (for example, about 10,000 times). as a result,
As shown in FIG. 4B, the contact 5 of the test relay 3 performs an on / off operation, and intermittently supplies the current from the power supply 6 to the load 7. In this way, it is determined whether or not the test relay 3 can withstand a predetermined number of repetitive operations, that is, whether or not the load 7 can repeatedly perform the on / off switching operation a predetermined number of times or more. Endurance test.

FIG. 3 shows a test for a relay for supplying power to a vehicle-mounted lamp such as a headlight. The same as the lamp actually used as a headlight etc.
) Is used.

[0005]

When a test of the test relay 3 is performed by connecting an actual load to a circuit as shown in FIG.
Is determined by the operation cycle of the test relay 3 as shown in FIG. Here, generally, since there is a demand for shortening the test time, it is desirable to set the operation cycle T1 of the load 7 as short as possible.

In this case, if the operation cycle T1 of the load 7 is set short, the rest time Toff of the load 7 is also shortened. However, since the load 7 generally generates heat by continuous operation, if the downtime Toff of the load 7 is shortened, the time for cooling the load 7 is reduced. The load 7 generates heat and its temperature gradually rises. When the temperature of the load 7 rises, the electric resistance value of the load 7 increases, so that an inrush current (inrush current) to the load 7 decreases, and an effect such as a decrease in an energizing current occurs. Therefore, there remains a problem that the steady state of the load 7 cannot be maintained and accurate evaluation cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a test apparatus capable of maintaining load characteristics at a steady state and accurately and quickly evaluating the durability of a relay.

[0008]

Means for Solving the Problems In order to solve the above problems,
The present invention provides a test device for performing a durability test by repeatedly turning on and off the contacts of a contact element, a multi-terminal switch that is connected in series to the contact element and sequentially switches and connects the plurality of loads. And timing control means for controlling the drive timing of the contact element and the multi-terminal changeover switch.

The timing control means includes a first timing control function for switching the contact element on and off with a predetermined time period as a cycle, and sequentially switches and connects the plurality of loads at the predetermined time intervals. A second timing control function for controlling the multi-terminal changeover switch.

Further, the timing control means controls the multi-terminal switch so as to sequentially switch and connect the plurality of loads only when the contact element is in an off state.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION

<Structure> FIG. 1 is a circuit diagram showing a test apparatus according to an embodiment of the present invention. This test apparatus is a test apparatus for performing an endurance test by repeatedly turning on and off a contact 10a of an electromagnetic relay switch (test relay) 10 as a contact element for switching a headlight of an automobile. , A plurality (three) of actual loads R1, R2, R
And a multi-terminal switch 12 for sequentially switching and connecting the plurality of actual loads R1 to R3 to the contact 10a of the test relay 10.
And a power transistor 14 connected in series with the exciting coil 10b of the test relay 10 to switch the power supply to the exciting coil 10b, and a timing generator for controlling the drive timing of the multi-terminal switch 12 and the power transistor 14. (Timing control means) 15.

Here, as the actual loads R1 to R3, the same ones as the lamps actually used as headlights are used in order to carry out the test under the conditions according to the actual use as much as possible. One end of each of the actual loads R1 to R3 is grounded, and the other end is connected to the switching contacts a, b, and c of the multi-terminal switch 12, respectively.

The multi-terminal changeover switch 12 includes actual loads R1 to R1.
It has a three-terminal switching structure having three switching contacts a, b, and c corresponding to the number of R3. For example, a large-capacity three electromagnetic relay switch having high durability is installed in parallel by the test relay 10. Is used. Note that the multi-terminal switch 12 is switched at the time when no current flows under the control of the timing generator 15 as described later.
This prevents the influence of the inrush current as in the test relay 10. This prevents a situation in which the multi-terminal switch 12 is deteriorated earlier than the test relay 10.

As the power transistor 14, an NPN type bipolar transistor is used, the emitter is grounded, and the collector is connected to the exciting coil 10b of the test relay 10.

The timing generator 15 includes a ROM, a RAM,
An ASIC circuit having a CPU and a CPU, a general microcomputer chip, and the like are used, and a pulse signal having a predetermined period T1 (FIG. 2A) as shown in the timing chart of FIG.
) To the base of the power transistor 14 to repeatedly switch the test relay 10 on and off, and a second timing control function (switching control of the multi-terminal switch 12 every time T1). FIG. 2 (b)
(C) and (d)). In particular, the switching control of the multi-terminal switch 12 in the second timing control function is performed only when the test relay 10 is turned off by the first timing control function.
The duty ratio (Ton / Toff) of the pulse signal input to the base of the power transistor 14 by the first timing control function is appropriately determined according to the characteristics of the test relay 10 and the characteristics of the actual loads R1 to R3. Can be set.

<Operation> The operation of the test apparatus having the above configuration will be described. First, after connecting the power supply Va to the test relay 10 as shown in FIG. 1, the multi-terminal switch 12 is switched every time T1 by the second timing control function.
The first timing control function supplies a pulse signal having a period T1 to the power transistor 14 to repeatedly switch the test relay 10 on and off. The first timing control function starts operation with a delay of a predetermined time Td (<Toff) from the start of operation of the second timing control function.

That is, at time t1 in FIG.
(FIG. 2B). At this time, the power transistor 14 remains off (FIG. 2 (a)). Therefore, since the contact 10a of the test relay 10 is off, the switching contact a of the multi-terminal switch 12 and the first actual load R1 Is not conducting with respect to the power supply Va (FIG. 2).
(E)).

Next, at time t2, which is delayed by td from time t1, the power transistor 14 is turned on based on the pulse signal from the timing generator 15, and the power transistor 14 is turned on with the conduction of the exciting coil 10b of the test relay 10. The contact 10a of the test relay 10 is turned on (FIG. 2A). As a result, the current from the power supply Va flows into the switching contact a of the multi-terminal selector switch 12 that is already in the on state, and the light as the first actual load R1 is turned on and turned on (FIG. 2D). ).

A time t after a time Ton further from the time t2
In 3, the power transistor 14 is turned off as the pulse signal from the timing generator 15 falls, and the current of the exciting coil 10b of the test relay 10 stops flowing. Therefore, the exciting coil 10b of the test relay 10 is turned off. (FIG. 2A). As a result, the power supply to the multi-terminal switch 12 is stopped, so that the first actual load R1
Is turned off (FIG. 2E).

After that, that is, from time t1 to time T
At time t4 when 1 has elapsed, the timing generator 15
The multi-terminal changeover switch 12 switches from the switching contact a to the switching contact b based on the output from the switch (FIGS. 2B and 2C).
At this time, since the contact 10a of the test relay 10 is off,
The switching contacts a and b and the actual loads R1 and R2 of the multi-terminal switch 12 are not electrically connected to the power supply Va (FIG. 2).
(E)). Thereafter, the same operation is repeated for the second and third real loads R2 and R3, and it is checked whether the actual loads R1 to R3 are correctly turned on and off a predetermined number of times. It is determined whether a failure occurs when the on / off operation is performed. Note that the actual loads R1 to R3
The turning on and off may be confirmed afterwards by using a recorder or the like to electronically record.

As described above, the test is proceeding while sequentially switching the plurality of switching contacts a to c. Thus, while realizing the time T1 as the cycle of the test relay 10, each actual load R
The energization cycle T2 of 1 to R3 can be increased to T2 = 3 × T1 as compared with the related art. That is, while the suspension period of the actual loads R1 to R3 is Toff in the related art, the suspension period T3 of each of the actual loads R1 to R3 is greatly extended to T3 = T2−Ton = 2 × T1 + Toff in this embodiment. be able to. As a result, the load can be returned to the steady state while the test cycle period remains at T1, and the evaluation of the relay can always be performed correctly.

Switching of the actual loads R1 to R3 is
Since the execution is always performed only when the test relay 10 is turned off, the actual loads R1 to R3 can be switched in a non-energized state. Therefore, unlike the test relay 10, it is possible to prevent the influence of the rush current of each of the actual loads R1 to R3, so that it is possible to prevent occurrence of an arc or the like, and to prevent erroneous detection of a test result due to a change in characteristics. Also, the multi-terminal switch 12 is faster than the test relay 10.
2 is prevented from deteriorating.

<Modifications> (1) In the above embodiment, a relay test for a lamp such as a headlight has been described. However, in addition to the above, what kind of actual condition such as a motor such as a power window or a blower or an actuator for a door lock is used. It is needless to say that the present invention can be applied to a test of a contact element for a load.

(2) In the above embodiment, three actual loads R1, R2, and R3 are used. However, the number is not limited to the above. By increasing the length further, the length becomes longer, and sufficient time required for cooling the load can be secured. Even in this case, the test can be performed with the operation time of the contact element kept at the minimum required.

[0025]

According to the first aspect of the present invention, when performing the durability test by repeatedly turning on and off the contacts of the contact element by the timing control means at a predetermined period, the multi-terminal changeover switch is also operated. Since it is controlled so as to sequentially switch and connect a plurality of loads every predetermined time,
Each operating cycle of the individual load is longer than the operating cycle of the contact element. Here, since the load energization time is only during the operation time of the contact element, the pause time of each load increases, so even if the operation cycle of the contact element is reduced to shorten the test time, Sufficient time required for cooling the load can be secured, and the test environment conditions can be stabilized.

According to the second aspect of the present invention, the multi-terminal switch is switched when the contact element connected in series to the multi-terminal switch is always turned off. It is possible to prevent an inrush current from flowing at the time of switching, and to prevent a situation in which the multi-terminal switch is deteriorated before the contact element.

[Brief description of the drawings]

FIG. 1 is a circuit diagram showing a test apparatus according to an embodiment of the present invention.

FIG. 2 is a timing chart showing an operation of the test apparatus according to one embodiment of the present invention.

FIG. 3 is a circuit diagram showing a conventional test apparatus.

FIG. 4 is a timing chart showing the operation of a conventional test apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Test relay 10a Contact 10b Excitation coil 12 Multi-terminal switch 14 Power transistor 15 Timing generator R1, R2, R3 Actual load a, b, c Switching contact

Claims (2)

[Claims] 1. A test apparatus for performing a durability test by repeatedly turning on and off a contact of a contact element, comprising: a plurality of loads; a plurality of loads connected in series to the contact element to sequentially switch and connect the plurality of loads; A terminal changeover switch, and timing control means for controlling drive timing of the contact element and the multi-terminal changeover switch, wherein the timing control means switches on and off of the contact element at predetermined time intervals. 1. A test apparatus, comprising: a timing control function of claim 1; and a second timing control function of controlling the multi-terminal changeover switch so as to sequentially switch and connect the plurality of loads at every predetermined time. 2. The test apparatus according to claim 1, wherein the timing control means controls the multi-terminal switch so as to sequentially switch and connect the plurality of loads only when the contact element is in an off state. A test device characterized by controlling.