JPH0320965A - Judging method of welded part in lead-acid battery - Google Patents

Abstract

PURPOSE:To simply, adequately judge whether welding is satisfactory or not by deciding on the basis of the surface temperature data on a welded lead member part measured immediately after resistance welding. CONSTITUTION:A lead member lug 1 and a partition wall 3 in a lead-acid battery are welded by resistance welding. The surface temperature in the welded part measured immediately after welding with a touch sensor 2a and a temperature measuring unit 2 is compared with the surface temperature before welding. By referring the difference between both temperatures to the reference value, whether welding is satisfactory or not is simply and adequately judged.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for determining welds in lead-acid batteries. [Prior Art] Conventionally, in manufacturing monoblock button storage batteries, when connecting the cells housed in each cell chamber in series, the ear members extending from adjacent cells are connected through holes in the partition wall. They are placed in opposing contact with each other or above a partition wall, and a resistance welding gun is applied to both outer surfaces of the parts and electricity is applied under pressure to perform resistance welding on the contact surfaces. Therefore, in order to judge whether or not the welded part of the resistance welded lead member is well welded, the resistance of the welded part can be electrically measured or a certain stress can be applied to the welded part. The method used was to measure strength mechanically. [Problems to be Solved by the Invention] In the former case, the above-mentioned conventional determination method cannot determine whether the lead is melted or attached in a crimped state from the measurement of electrical resistance.

This is because even in the crimped state it exhibits the same electrical resistance value as in the molten state. Therefore, if you miss something that is crimped, the V will increase over time while the battery is in use.
! ．． Acid may seep into the weld and eventually break. Mechanical measurements of the latter tend to produce high torque values even when only the outer circumferential surface of the weld is welded. Therefore, even if the inside is not welded, it tends to be judged as a good product. [Means for Solving the Problems] The present invention provides a method for determining resistance welds in lead-acid batteries, which eliminates the above-mentioned conventional inconveniences and makes it possible to more appropriately determine the quality of the battery. This method is characterized by measuring the surface temperature of the welded lead members immediately after performing resistance welding between the lead members to be welded in a lead-acid battery. [Function] It has been found that when the welded parts are well welded, the surface temperature is within a predetermined range. Based on this, the surface temperature is measured and whether it is within the predetermined temperature range. For example, it can be determined that the welded part has good resistance welding, and if the surface temperature is low or high temperature that does not fall within the specified range, it can be determined that there is insufficient welding or excessive welding. Appropriate pass/fail judgments can be made. In this case, measurements must be made at a certain point immediately after resistance welding, and generally within one minute. In addition, the temperature of the lead parts to be welded before welding may change due to seasonal changes, etc., so measure the temperature before welding and find the difference between the measured temperature and the surface temperature measured after resistance welding. , it can be determined that good resistance welding is achieved only within a certain range of temperature differences. [Example] An example of the present invention will be described below. In the manufacturing process of general monoblock lead-acid batteries, a group of electrode plates (cells) are housed in each of the plurality of cell chambers in the monoblock battery case, and when these are connected in series, their mutual On the l side or the other side of each adjacent cell,
Lead members of opposite polarity to be welded to each other rising upward from the straps of the plate group on both sides through holes through each partition wall, generally with the ear members facing each other, in this state a pair of resistance welding Pressure is applied from the outside of both ears with a gun, and the inner surfaces of the opposing ears are pressed against each other inside the through hole, and in this state, current is applied at a predetermined current density to resistance weld the mutual ears. This resistance welding operation is well known, but when performing such resistance welding, there are cases where the resistance welding of the ear member is done poorly, when it is done well, or when excessive welding is performed due to excessive melting. It was found that the surface temperatures of the ears welded together immediately after each weld were different. In other words, we have been carrying out such surface temperature measurements, inspection and analysis of welded parts for many years using various types of W.
As a result of many attempts to manufacture E ponds, I have found that if the surface temperature of the ears after resistance welding between the ears is within a certain range, the resistance welding will be performed satisfactorily. It has been found that if the temperature is lower than this range, there will be poor welding, and if the temperature is higher than that range, there will be a tendency for excessive welding to occur due to sparks etc. and voids inside. Based on this knowledge, the present invention proposes a determination method in which the surface temperature of the welded ear is measured immediately after resistance welding is performed at room temperature, and if the temperature is within a predetermined temperature range, If good welding is obtained and the specified temperature is not reached, welding defects are recognized, and if the specified temperature is exceeded, it can be determined that excessive welding has been performed. The temperature measuring means in this case is, for example, a touch sensor type temperature measuring device. This temperature measuring device only needs to place its temperature sensing element on the surface of the ear. Other measuring instruments that use non-contact methods, such as infrared rays, can be used to instantly measure the surface temperature. It is necessary to measure the surface temperature immediately after the completion of resistance welding, and it is preferable to measure it at a certain point. Normally, measurements are taken immediately after welding is completed, within a few seconds, but generally within one minute is sufficient. Furthermore, it is preferable to measure the surface temperature of the ear at a fixed location. For example, as shown in FIGS. The peripheral surface portion 1b or both surface portions 1a thereof
, Ib. In the drawing, 2 is a temperature measuring device, 2a
shows the touch sensor derived from this. The temperature during resistance welding changes depending on the diameter of the hole 4 provided in the partition wall 3 of the storage battery case. Generally, as the diameter of the hole 4 provided in the partition wall 3 becomes larger, the amount of heat generated also increases, so the determination temperature becomes higher. Therefore, each time the diameter of each hole changes, the standard for determining whether the temperature is good or bad changes. It is a good idea to collect data on the relationship between the quality of the welding and the quality of the welding, and to determine the criteria for each storage battery based on this data.
Additionally, the surface temperature of the weld may change depending on the season, such as winter or summer. The reason for this is that the temperatures of the parts to be welded before welding are different. Therefore, it is preferable to set determination reference temperatures for summer and winter, respectively. As a modification of the present invention, the temperature of the member before welding is measured, the surface temperature is measured after welding, the difference between these temperatures is determined, and based on the data measured in advance, it is possible to determine whether the weld is good or bad based on the range of temperature rise. It is also possible to make a determination as follows. Next, specific examples will be explained. When the temperature of the ears to be welded together was measured at room temperature, it was approximately 20°C.

This makes resistance welding a poor welding condition, a welding condition and an over-welding condition, and in each case, measure the surface temperature of the welded ear in many 'specific kinds'! The battery was repeatedly used to determine the condition of the welded part of this storage battery and the corresponding surface temperature. As a result, we obtained the following criteria. In other words, the respective welding states are shown in Figure 2 (^) (B) and Figure 3 (^).
(B), as shown in Figure 4 (^) (B), the temperature measuring device 2
The touch sensor 2a derived from
As a result of measuring by applying it to the surface of a, the surface temperature was 40 to 70.
℃ range, it was determined that the weld was a good weld where both ears 1 and 1 completely melted together, as shown in Figure 3 (^) (B). If the surface temperature does not reach 40℃,
As shown in Figure 2 (A) and (B), the pressure contact surface of ear 1.1 was in a crimped state, and insufficient welding was observed. Surface temperature is 7
It was found that when the temperature exceeds 0° C., excessive melting occurs, and cavities are observed inside as shown in FIGS. 4(A) and 4(B), resulting in excessive welding.

Therefore, based on the above data, it was possible to judge whether the resistance welded part was good or bad according to the above criteria in the production of this particular type of lead-acid battery. In the manufacture of lead-acid batteries, the surface temperature of the welded lead parts was measured after resistance welding the lead parts that were to be resistance welded together. Based on this, it is possible to properly judge whether the product is good or bad, and the judgment work is simple.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 (8) is a cross-sectional view showing an example of implementing the present invention
Figure 1 (B) is a front view seen from the first side, Figure 2 (^
), Fig. 3 (^) and Fig. 4 (8) are cutaway views of the welded states, Fig. 2 (B), Fig. 3 CB) and Fig. 4 (
B) shows a cross-sectional view of each weld. 1...Ear 1a...Central surface part 1b...
・Surrounding part 2: Temperature measuring device 2a...Touch sensor

Claims (1)

[Scope of Claims] 1. A method for determining a welded part in a lead-acid battery, which comprises measuring the surface temperature of the welded lead members immediately after performing resistance welding between the lead members to be welded in the lead-acid battery. 2. The lead member to be welded is an ear member connecting cells of a monoblock storage battery, and the temperature is measured by applying a temperature sensing element to the surface of the ear member immediately after resistance welding. Judgment method. 3. The method for determining a welded portion in a lead-acid battery according to claim 1 or 2, wherein the determination criterion is the difference between the measured temperature before welding and the surface temperature after welding of the lead member to be welded.