JPH01274076A - Winding checking apparatus - Google Patents

Abstract

PURPOSE:To make it possible to check windings in a short time without cumbersome operation, by connecting a power source to the first winding and the second winding, and releasing the power source from the first and second windings when the voltage across the first winding becomes a specified value. CONSTITUTION:When a switching device 4 is thrown to contact points 41 and 42, a first winding 1 is heated with a current (i). After the voltage is increased to a voltage V0, the switching device is thrown to contact points 43 and 44. The resistances of the windings 1 and 2 are measured with ohmmeters R1 and R2 for a time period T based on the operation of a switch main body 45. The windings are naturally cooled. Thereafter, these steps are sequentially repeated. When the output of a comparator 5c exceeds a specified value DELTAr because, e.g., an output r1 is not decreased even if an output r2 is decreased during these steps, a warning device 5d issues a warning. Then, this hard-disk driving coil under checking is estimated to be a defective product having defective soldering and the like.

Description

[Detailed description of the invention] [Purpose of the invention] (Industrial application field) The present invention relates to a device for inspecting windings.

(Prior Art) After lead wires are soldered to both ends of a coil formed by winding an enameled wire to form a wound layer, the coil is molded with epoxy resin.

Conventionally, when testing the reliability of a coil for a hard disk drive obtained in this way, a power supply is applied to both ends of the coil to heat the coil for, for example, about 20 seconds, and then the coil is naturally cooled for about 20 minutes to heat it. Screening was done by giving cycles sequentially.

(Problem to be solved by the invention) However, with this method, measurements are performed manually, which is troublesome and time-consuming, and in some cases, too much heat is applied to the coil, melting the solder part. There was also the risk of producing defective products.

Therefore, the present invention was made to solve these problems.It can be easily done in a short time, it is less likely to apply too much damage to the windings, it is less likely that the solder parts will melt, and it will not result in the formation of defective products. It is an object of the present invention to provide a winding inspection device that prevents such problems from occurring.

[Structure of the Invention] (Means for Solving the Invention) A winding inspection device of the present invention connects a power source to a first winding and a second winding, and detects the voltage across the first winding. When reaches a predetermined value, the power source is opened from the first and second windings by a switch device, and the first and second resistor sides are connected to these windings and the resistances thereof are measured respectively. Then, after a predetermined period of time has elapsed, the first and second
The first and second ohmmeters are opened from the windings by the switch/device, and the power source is connected to these windings, and the difference between the outputs of the first and second resistance bodies is determined to be a predetermined value. It is characterized in that an alarm is issued by an alarm device when the value exceeds the value.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

In FIG. 1(a), FIG. 1(b), and FIG. 1(C), the winding inspection device of the present invention has a first winding 1 and a second winding
When the voltage across the windings 2, the power supply of the constant current source 3 connected to these windings, and the voltage across the first winding reaches a predetermined value V, the first and second windings The power supply is disconnected from the second winding, and the first and second resistance meters R1 and R2 are connected to these windings to measure their resistances rl and r2, respectively, and after a predetermined time T such as about 20 minutes, a switch device 4 that disconnects the first and second resistance meters from the first and second windings and connects the power source to these windings after the lapse of time; Each output of the resistance meter rl, ri! and an alarm device 5 that issues an alarm when the difference between the two exceeds a predetermined value r or more.

The first winding is a coil for the hard disk drive to be tested, and the voltage across it is measured by the first voltmeter ■1
It is measured by

The second winding is a master coil of good quality that is representative of the characteristics of this hard disk drive coil.

The switch device includes a contact 41 connected to a first winding and one end of a first voltmeter, a contact 42 connected to this contact and connected to one end of a second winding, and a first and a contact 43 connected to the winding of and one end of the first ohmmeter
Based on the signals from the contact 44 connected to the second winding and one end of the second ohmmeter, and the voltmeter 1, the contacts 41 and 42 are turned on to the contacts 43 and 44, and the timer is turned on. 45a
A switch main body 45 has a built-in timer, and after a predetermined time T is set in this timer, a signal S is generated after this time T has elapsed, and based on this signal, the switch body 45 switches the contact from the contact 43.44 to the contact 41.42. It is equipped with

In FIG. 2, the alarm device includes a first display 5a that displays the output r1 of the first ohmmeter, a second display 5b that displays the output r2 of the second ohmmeter, and a second display 5b that displays the output r2 of the second ohmmeter. The comparator 5C compares the input r1 of the display with the input r2 of the first display, and the alarm 5d issues an alarm based on the output of the comparator r.

FIG. 3 shows an operation flowchart of the switch device 4 and the alarm device 5, and P+ to P5 are each step.

After the switch device is connected to the contacts 41 and 42 at Pl and the first and second windings are heated by the constant current source 3, the voltage v1 of the first winding 1 is set to a predetermined value at R2. It is determined whether the temperature has risen to Va. After that, the voltage Vl
If Va is smaller than a predetermined value, the state remains as it is, and if it is larger, R3 causes the switch device to close contacts 43 and 44.
These windings have resistances r+, r2 across them.
are measured respectively. Next, in R4, it is determined whether the difference between the vA1 and the outputs rl and r2 of the second resistance meter is smaller or larger than a predetermined value Δr. If it is smaller, return to Pl and perform steps P1+P2+P3 above. Repeat P4, and if it is larger, the alarm 5d will issue an alarm at R5.

Next, the operation of the winding inspection device configured as above will be explained.

Figures 4(a) and 4(b) are plots of the inputs rM and r2 of the first and second indicators, respectively, with the time axis as the horizontal axis. When the first winding 1 is heated by the current i and rises to the voltage Va, the contacts 43 and 44 are closed, and the switch body 45 connects the windings 1 and 2 to the resistance for a time T. Cool naturally while measuring with a meter RI 82.

After that, when repeating the above steps sequentially, for example, the output r
If the output rl of the comparator 5C becomes larger than the predetermined value Δr even though the output rl does not decrease even though the output rl decreases, the alarm device 5d emits an alarm. Therefore, it is presumed that the hard disk drive coil to be inspected is defective due to poor soldering or the like.

In the above description, the case where the power source is a constant current source has been described, but the power source is not limited to this, and may be a voltage source.

Further, it is not necessarily necessary that the first winding is a coil for the hard disk drive to be inspected, and that the second winding is a master coil of good quality that represents the characteristics of the hard disk drive coil. The first winding may be a winding to be inspected in an electric machine such as an induction lightning VJ machine, and the second winding may be a master winding thereof.

[Effect 1 of the invention As described above, in the winding inspection device of the present invention, a power supply is connected to the first winding and the second winding, and the voltage at both ends of the second winding reaches a predetermined value. When this happens, the power source is disconnected from the first and second windings by a switch device, and first and second ohmmeters are connected to these S wires to measure their resistances, respectively. After a predetermined time has elapsed, the first and S2 resistance meters are opened from the first and second windings by the switch device, and the power source is connected to these windings, The alarm device issues an alarm when the difference between the outputs of the two resistance meters exceeds a predetermined value, so the inspection can be done in a short time without being complicated, and there is little chance of applying too much heat to the windings, which will melt the solder parts, etc. There are few such incidents, and there is little risk of producing defective products.

[Brief explanation of the drawing]

FIG. 1(a) is a block diagram of the winding inspection device of the present invention, FIG. 1(b) is an explanatory diagram of winding resistance measurement in the winding inspection device of the present invention, and FIG. 1(C) is a block diagram of the winding inspection device of the present invention. An explanatory diagram of the heating of the winding by the power supply in the winding inspection device of the invention, FIG. 2 is a block diagram of the alarm device in the winding inspection device of the invention, and FIG. 3 is a diagram showing the switch device in the winding inspection device of the invention. The flowchart of the alarm device, FIGS. 4(a) and 4(b) are timing charts for explaining the operation of the winding inspection device of the present invention. 1......First winding 2...Second winding 3...Constant current source 4... ...Switch device 5......Alarm device Fig. 1 ((1) '/'''l Fig. 1 (b) Fig. 1 (C) Fig. 2 Fig. 3

Claims (1)

[Claims] (1) A first winding, a second winding, a power supply connected to these windings, and a power source connected to the first winding when the voltage across the first winding reaches a predetermined value. The power source is disconnected from the second winding, and the first and second ohmmeters are connected to these windings to measure their resistances, and after a predetermined period of time, the first and second a switch device that disconnects the first and second ohmmeters from the windings and connects the power source to these windings, and a difference between the outputs of the first and second ohmmeters that exceeds a predetermined value; 1. A winding inspection device comprising: an alarm device that issues an alarm when the winding is over.