JP2004319208A - Calibration method for bent pressure tester of safety valve for sealed type secondary battery, and bent pressure tester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a calibration technique of a bent pressure tester for accurately measuring a bent pressure of a valve element of rubber to be incorporated into a safety valve for a sealed type secondary battery. <P>SOLUTION: A relief valve 80 with a metal-made spring 81 and with an operation pressure is preset thereto is held to a holding unit 40, when a bent pressure tester 30 of a safety valve for a sealed type secondary battery 10 is calibrated. A pressure stepup rate of a pressure in a gas line due to a pressure stepup unit 60 is regulated by regulating a pressure stepup rate regulation unit 70 so that the pressure of the gas line 50, measured by a measuring means 51 when it is detected that a gas is relieved from an exhaust opening 82 of the relief valve 80 by a bent detecting means 53, expresses the operation pressure of the relief valve 80. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for calibrating a vent pressure tester of a safety valve for a sealed secondary battery and a vent pressure tester.
[0002]
[Prior art]
As a reusable battery, a sealed secondary battery is widely used. When the sealed secondary battery is exposed to high temperatures due to abnormal current charging or reverse charging due to misuse, or disposal of the battery after use, the electrolytic solution inside the outer can becomes chemically reactive. May generate abnormal gas. The pressure inside the outer can rises due to abnormal gas generation. In order to prevent damage to the outer can caused by this pressure rise, the sealed secondary battery is provided with a return-type safety valve that discharges the gas inside the outer can to the outside according to the pressure rise inside the outer can. ing.
[0003]
This type of safety valve is a sealing plate that is hermetically attached to the opening of the outer can and has a vent hole, a terminal cap that is attached to the sealing plate and has a vent hole, a sealing plate and a terminal cap. And a rubber valve body made of polymer rubber or the like which is arranged in a compressed state so as to cover the gas vent hole (see, for example, Patent Document 1).
[0004]
When the pressure inside the outer can rises above a certain value, the rubber valve body of the safety valve is compressed and a vent hole is opened, and the gas inside the outer can is released to the outside through the vent hole through the vent hole. Is done. When the pressure inside the outer can falls below a certain value due to gas release, the rubber valve body expands by its own elastic force and automatically returns to a state in which the gas vent hole is closed. Such an action of the safety valve prevents breakage of the outer can due to pressure rise. The safety valve is, for example, 2.94 to 3.92 MPa (30 to 40 kgf / cm). ² ) Designed to operate in the pressure range. The rubber valve body is, for example, a rectangular parallelepiped having a size of about 2 mm to 6 mm. There are also trapezoidal and cylindrical rubber valves.
[0005]
In order to confirm the function of the safety valve for a sealed secondary battery having a rubber valve body, a vent pressure which is a pressure at which the safety valve operates, a hold pressure after a predetermined time (for example, 5 seconds) after venting, and Has been tested. This test is performed not only by the manufacturer of the sealed secondary battery but also by the component manufacturer that supplies the rubber valve body, and is performed using a vent pressure tester owned by the manufacturer and the component manufacturer. Has been done.
[0006]
[Patent Document 1]
JP-A-2002-63885
[0007]
[Problems to be solved by the invention]
Prior to the above test, the rubber valve body component maker first supplies the manufactured rubber valve body to the battery manufacturer, and the battery manufacturer attaches the rubber valve body to the sealing plate and the terminal cap. Have the safety valve manufactured by incorporating it in the middle. The battery manufacturer further measures the vent pressure and the hold pressure of the manufactured safety valve using a vent pressure tester owned by the battery manufacturer, and gives the measured value. The component manufacturer uses the safety valve priced by the battery manufacturer as a master safety valve to calibrate the vent pressure tester owned by the component manufacturer. Specifically, a master safety valve is attached to the vent pressure tester, and the master safety valve is vented at the vent pressure that is priced, and the pressurizing speed and the supply air flow rate are adjusted so as to exhibit the valued hold pressure. I have. After the calibration of the vent pressure tester based on the master safety valve is completed, the component maker confirms the vent pressure performance by performing the above test on the rubber valve body manufactured thereafter.
[0008]
The reasons why component manufacturers calibrate their vent pressure testers are as follows. For the vent pressure, the peak value is measured, and for the hold pressure, the value after a lapse of a set time from the vent is measured. It varies depending on the difference in capacity. Therefore, in order to match the vent pressure tester of the battery manufacturer with the vent pressure tester of the component manufacturer of the rubber valve body, the component manufacturer calibrates the vent pressure tester based on the master safety valve. I have.
[0009]
However, in the rubber valve element incorporated in the master safety valve, the rubber material itself shows a change in hardness over time, and since a compressive load is constantly applied, stress distortion is not reduced. For this reason, the vent pressure and the hold pressure of the master safety valve change with time, and the value of the master safety valve cannot be trusted for a long time. In addition, since the hardness of the rubber valve body changes depending on the temperature range to be used, the vent pressure and the hold pressure also change depending on the difference in temperature between the price and the test.
[0010]
Therefore, there is a problem that even if the vent pressure tester of the component maker is calibrated, the reproducibility is poor and the accuracy is low. In addition, each time a prototype is made to change the material or shape of the rubber valve, the battery manufacturer must provide a master safety valve, and it takes a relatively long time to evaluate the performance of the prototype. There is a problem that it takes.
[0011]
For this reason, both the battery manufacturer and the component manufacturer of the rubber valve body can easily achieve consistency of the vent pressure tester owned by each of them, so that the vent pressure performance of the rubber valve body can be accurately and accurately. There is a need for a method of calibrating a vent pressure tester that can be quickly confirmed.
[0012]
The present invention has been made to satisfy such a demand, and an object of the present invention is to provide a vent pressure capable of accurately measuring a vent pressure of a rubber valve element incorporated in a safety valve for a sealed secondary battery. An object of the present invention is to provide a tester calibration technique.
[0013]
[Means for Solving the Problems]
The object of the present invention is achieved by the following means.
[0014]
(1) A sealed secondary battery in which a rubber valve body is arranged between a sealing plate having a gas vent hole and a terminal cap having a vent hole in a compressed state so as to cover the gas vent hole. A vent pressure tester that measures a vent pressure at which a safety valve for the valve operates.
Holding means for detachably holding the safety valve including the rubber valve body in an airtight state,
A closed gas line communicating with the vent hole of the held safety valve;
Measuring means for measuring the pressure of the gas line,
Pressure increasing means for increasing the pressure of the gas line,
Pressure increasing speed adjusting means for adjusting the pressure increasing speed of the gas line pressure by the pressure increasing means,
Vent detection means for detecting that the safety valve has been activated, and a method of calibrating a vent pressure tester including:
The relief valve having a metal spring and an operating pressure set in advance is held by the holding means, and when the vent detection means detects that the gas has been relieved from the exhaust port of the relief valve, the measurement means The pressure increasing rate adjusting means is adjusted to adjust the pressure increasing rate of the gas line pressure by the pressure increasing means such that the measured pressure of the gas line indicates the operating pressure of the relief valve. This is a method for calibrating a vent pressure tester of a safety valve for a sealed secondary battery.
[0015]
(2) The vent pressure tester further includes a supply flow rate adjusting means for adjusting a flow rate of the gas supplied from the pressure increasing means to the gas line,
The pressure of the gas line measured by the measuring means at the time when the vent detecting means detects that the gas has been relieved from the exhaust port of the relief valve so as to exhibit the operating pressure of the relief valve, The vent pressure tester for a safety valve for a sealed secondary battery according to (1), wherein the flow rate of the gas supplied to the gas line by the supply flow rate adjusting means is adjusted by adjusting the supply flow rate adjusting means. This is the calibration method.
[0016]
(3) The closed type according to (1), wherein the holding means is capable of holding a safety valve in which the rubber valve body is temporarily installed or a safety valve in which the rubber valve body is installed. This is a method for calibrating the vent pressure tester of the secondary battery safety valve.
[0017]
(4) A sealed secondary battery in which a rubber valve element is arranged in a compressed state so as to cover the gas vent hole between a sealing plate having a gas vent hole and a terminal cap having a vent hole. A vent pressure tester that measures a vent pressure at which a safety valve for the valve operates.
Holding means for detachably holding the safety valve including the rubber valve body in an airtight state,
A closed gas line communicating with the vent hole of the held safety valve;
Measuring means for measuring the pressure of the gas line,
Pressure increasing means for increasing the pressure of the gas line,
Pressure increasing speed adjusting means for adjusting the pressure increasing speed of the gas line pressure by the pressure increasing means,
Vent detection means for detecting that the safety valve has been activated,
When calibrating a vent pressure tester, the relief valve is held by the holding means in place of the safety valve, and includes a metal spring and a relief valve whose operating pressure is preset.
The pressure of the gas line measured by the measuring means when the vent detecting means detects that the gas has been relieved from the exhaust port of the relief valve held by the holding means in place of the safety valve is the relief pressure. A vent for a safety valve for a sealed secondary battery, wherein the pressure increasing speed adjusting means is adjusted so as to exhibit the operating pressure of the valve, and a pressure increasing speed of the gas line pressure by the pressure increasing means is adjusted. It is a pressure tester.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
FIGS. 1A and 1B are schematic configuration diagrams showing a vent pressure tester 30 of a safety valve 10 for a sealed secondary battery according to an embodiment of the present invention, and FIG. FIG. 1B is a schematic configuration diagram illustrating a state in which a test for measuring a hold pressure is being performed, and FIG. 1B is a schematic configuration diagram illustrating a state in which the vent pressure tester 30 is being calibrated. FIG. 2 is a sectional view showing a holding unit 40 for detachably holding the safety valve 10 having a rubber valve body 15 in an airtight state. FIG. 3 is a metal spring used when calibrating the vent pressure tester 30. FIG. 4 is a cross-sectional view showing a relief valve 80 provided with 81, and FIG. 4 is a diagram showing an example of measurement of vent pressure and hold pressure of a safety valve 10 provided with a rubber valve body 15. 5 (A) and 5 (B) are cross-sectional views showing a safety valve 10 for a sealed secondary battery provided with a rubber valve body 15, and FIG. 6 is a sectional view showing the safety valve 10 shown in FIG. It is sectional drawing which shows the state assembled in the outer can 20 of FIG.
[0020]
First, a safety valve 10 for a sealed secondary battery will be described with reference to FIGS. The safety valve 10 for a sealed secondary battery is airtightly attached to an opening 21 of an outer can 20 and has a sealing plate 12 with a gas vent hole 11 opened, and is attached to the sealing plate 12 and has a ventilation hole 13 opened. And a rubber valve body 15 made of an elastic member and arranged between the sealing plate 12 and the terminal cap 14 in a compressed state so as to cover the gas vent hole 11. The outer peripheral edge of the sealing plate 12 is bent inward and is caulked to the terminal cap 14. The rubber valve body 15 is formed from a rubber material containing EPDM as a main component. The safety valve 10 is attached to the opening 21 of the outer can 20 via an insulating gasket 22 (see FIG. 6).
[0021]
As shown in FIG. 5B, when the pressure inside the outer can 20 increases to a certain value or more, the gas pressure is increased by pushing up the rubber valve body 15 to the terminal cap 14 side through the vent hole 11. Then, the gas vent hole 11 is opened. When the gas vent hole 11 is opened, the gas inside the outer can 20 flows out into a space surrounded by the sealing plate 12 and the terminal cap 14 as shown by a dashed line, and further, the vent hole 13 of the terminal cap 14. Released to the outside. As a result, breakage of the outer can 20 due to an increase in pressure is prevented. When the pressure inside the outer can 20 becomes lower than a certain value due to the gas release, the rubber valve body 15 expands again by its own resilient force, and automatically returns to the state in which the gas vent hole 11 is closed.
[0022]
The safety valve 10 having the above configuration is, for example, 2.94 to 3.92 MPa (30 to 40 kgf / cm). ² ) Designed to operate in the pressure range.
[0023]
In order to confirm the function of the safety valve 10 including the rubber valve body 15, a test for measuring a vent pressure, which is a pressure at which the safety valve 10 operates, and a hold pressure after a lapse of a predetermined time (for example, 5 seconds) after venting. Has been done. This test is performed using a vent pressure tester 30.
[0024]
As shown in FIGS. 1A and 1B, the vent pressure tester 30 according to the present embodiment is, in general, a holding unit 40 (holding unit) that holds the safety valve 10 including the rubber valve body 15 in an airtight state and detachably. ), A closed gas line 50 communicating with the gas vent hole 11 of the held safety valve 10, measuring means 51 for measuring the pressure of the gas line 50, and pressure increasing for increasing the pressure of the gas line 50. A unit 60 (corresponding to the pressure increasing means), a pressure increasing rate adjusting unit 70 (corresponding to the pressure increasing rate adjusting means) for adjusting the pressure increasing rate of the pressure of the gas line 50 by the pressure increasing unit 60, and The supply flow rate adjusting means 52 for adjusting the flow rate of the supplied gas, the vent detecting means 53 for detecting that the safety valve 10 has been operated, and the vent pressure tester 30 are calibrated. And in place of the relief valve 10 is held in the holding unit 40, a relief valve 80 which operates pressure comprising a metal spring 81 is set in advance, including the time. Here, the pressure increasing speed of the gas line 50 by the pressure increasing unit 60 is adjusted by adjusting the pressure increasing speed adjusting unit 70 when the vent pressure tester 30 is calibrated. Specifically, the gas line measured by the measuring unit 51 when the vent detecting unit 53 detects that the gas has been relieved from the exhaust port 82 of the relief valve 80 held by the holding unit 40 instead of the safety valve 10 The pressure of 50 is adjusted to represent the operating pressure of the relief valve 80.
[0025]
As shown in FIG. 2, the holding unit 40 includes a lower holder 41, an upper holder 42 that is provided to be movable toward and away from the lower holder 41, and moves the upper holder 42 forward and backward with respect to the lower holder 41. And a holding cylinder 43. The lower holder 41 has a concave portion 41a, a through hole 41b communicating the concave portion 41a with the outside, and a mounting surface 41c on which the outer peripheral portion of the safety valve 10 is mounted. The upper holder 42 is formed with a concave portion 42a, an internal passage 42b communicating the concave portion 42a with the outside, and a pressing surface 42c for clamping the outer peripheral portion of the safety valve 10 between the mounting surface 41c. . The through hole 41b of the lower holder 41 faces the vent detection means 53 directly or via a pipe (see FIG. 1A). A pipe 50a forming a closed system gas line 50 is connected to an inlet port 42d of the internal passage 42b of the upper holder 42.
[0026]
The holding cylinder 43 is composed of, for example, an air cylinder. When the holding cylinder 43 is operated to move the upper holder 42 forward (downward in the figure) toward the lower holder 41, the outer peripheral portion of the safety valve 10 is placed on the mounting surface 41c of the lower holder 41 and the pressing surface 42c of the upper holder 42. The safety valve 10 is held in the holding unit 40 in an airtight state. On the other hand, when the holding cylinder 43 is operated to move the upper holder 42 backward from the lower holder 41 (upward movement in the drawing), the outer periphery of the safety valve 10 is released, and the safety valve 10 can be removed from the holding unit 40 freely. In addition, “holding the safety valve 10 in the holding unit 40 in an airtight state” means that the gas pressure acting on the rubber valve body 15 does not leak from the portion holding the safety valve 10 (the mounting surface 41c and the pressing surface 42c). Means that. In order to hold the safety valve 10 in the holding unit 40 in an airtight state, a seal member such as an O-ring may be provided at a position where the safety valve 10 is held.
[0027]
The holding unit 40 can hold the safety valve 10 in which the rubber valve body 15 is temporarily installed, or the safety valve 10 as a product in which the rubber valve body 15 is installed. FIG. 2 shows a state in which the safety valve 10 in which the rubber valve body 15 is temporarily installed is held. The outer peripheral portion of the terminal cap 14 is mounted on the mounting surface 41 c of the lower holder 41, and the rubber valve body 15 is stored in the terminal cap 14. The sealing plate 12 is put on from above, but the outer peripheral edge of the sealing plate 12 is not bent inward and is not swaged to the terminal cap 14. By holding the safety valve 10 in which the rubber valve body 15 is temporarily installed in the holding unit 40, vent pressure performance can be performed by a component manufacturer of the rubber valve body 15. On the other hand, by sealing the sealing plate 12 on the terminal cap 14 and holding the safety valve 10 as a product incorporating the rubber valve body 15 in the holding unit 40, the battery manufacturer can perform vent pressure performance.
[0028]
Referring to FIG. 1, the closed gas line 50 includes a pipe 50 a that communicates the inlet port 42 d of the upper holder 42 with the pressure increasing unit 60, and the gas vent hole 11 of the safety valve 10 held by the holding unit 40. Is in communication with Therefore, as shown in FIG. 2, when the pressure of the gas line 50 rises to a certain value or more, the gas pressure is reduced by pushing the rubber valve body 15 down to the terminal cap 14 side through the gas vent hole 11 and compressing the gas. Open the hole 11. When the gas vent hole 11 is opened, the gas inside the gas line 50 flows out into the space surrounded by the sealing plate 12 and the terminal cap 14 as shown by the dashed line, Is discharged into the concave portion 41a of the lower holder 41 through the lower portion. Then, the gas released into the concave portion 41a is ejected toward the vent detecting means 53 through the through hole 41b.
[0029]
The measuring means 51 is not limited in its detection method as long as it measures the pressure of the gas line 50. For example, a pressure sensor having a piezoelectric element is used. It is preferable that the pressure sensor 51 used conforms to national standards and traceability.
[0030]
The pressure raising unit 60 has a piston 62 slidably disposed on a cylinder 61 and an actuator 63 for driving the piston 62. The actuator 63 includes, for example, an air cylinder 64. When the air cylinder 64 is operated to move the piston 62 forward (leftward in the figure), the gas in the cylinder 61 is compressed, and the pressure in the gas line 50 communicating with the compression chamber 61a is increased. The gas from the gas supply source 75 is filled into the gas line 50 and the compression chamber 61 a via the pipe 77 and the on-off valve 76. After the predetermined amount of gas has been charged, the on-off valve 76 is closed. The gas used is, for example, dry air or nitrogen gas.
[0031]
The step-up speed adjusting unit 70 has a speed control valve, that is, a speed controller 71 connected to an air cylinder 64 forming an actuator 63 of the step-up unit 60, and an electromagnetic valve 72 connected to the speed controller 71. The operating gas is supplied from a gas supply source 75 via a filter or a pressure reducing valve (not shown). By adjusting the throttle of the speed controller 71, the operating speed of the air cylinder 64, and thus the moving speed of the piston 62, is adjusted, and the pressure increasing speed of the gas line 50 is adjusted.
[0032]
The supply flow rate adjusting means 52 is disposed on the outlet side of the pressure increasing unit 60, and is constituted by, for example, a flow rate control valve such as a needle valve. By restricting the flow control valve 52, the flow rate of the gas supplied from the booster unit 60 to the gas line 50 is adjusted, and the pressure in the gas line 50 is prevented from increasing rapidly.
[0033]
The vent detection means 53 is disposed at a position where gas ejected from the through hole 41b of the lower holder 41 directly or via a pipe collides, and is configured by, for example, a microswitch 53 including a pressure receiving plate 53a with which gas collides. I have. When the gas collides with the pressure receiving plate 53a and the micro switch 53 is switched from off to on, the operation of the safety valve 10 is detected.
[0034]
As shown in FIG. 3, the relief valve 80 includes a metal spring 81, and the metal spring 81 urges the stem 84 with a resilient force for blocking communication between the inlet 83 and the exhaust port 82. I have. As this type of relief valve 80, for example, a model number SS-4R3A manufactured by Swagelok Company can be used. When the pressure acting on the inlet 83 rises and reaches a certain value (operating pressure), the stem 84 is pushed up against the elastic force urged by the metal spring 81, and the gas is relieved from the exhaust port 82. . The operating pressure of the relief valve 80 is adjusted by turning the adjustment cap 85 and the lock nut 86 to change the compression amount of the metal spring 81. In the present embodiment, the operating pressure of the relief valve 80 is previously set to 2.94 MPa (30 kgf / cm). ² ). Further, the operating pressure of the relief valve 80 is calibrated by a pressure standard (det-wet tester), and is confirmed in advance using a standard manometer that is traceable to national standards.
[0035]
A joint 88 is connected to an inlet 83 of the relief valve 80 via a pipe 87. The joint 88 has a center hole 88 a communicating with the internal passage 42 b of the upper holder 42 and a through hole 88 b communicating with the pipe 87. The joint 88 is sandwiched between the concave bottom surface 41d of the lower holder 41 and the concave bottom surface 42e of the upper holder 42, and is detachably held by the holding unit 40 in an airtight state. Note that “holding the joint 88 in an airtight state” means that gas in the gas line 50 does not leak from the portion holding the joint 88 (the concave bottom surfaces 41d and 42e). In order to hold the joint 88 in an airtight state, a seal member such as an O-ring may be provided at a position where the joint 88 is held.
[0036]
When calibrating the vent pressure tester 30, the relief valve 80 is used by being held by the holding unit 40 instead of the safety valve 10. At the time of this calibration, the joint 88 is held by the holding unit 40, and the gas in the gas line 50 flows through the internal passage 42 b of the upper holder 42, the center hole 88 a, the through hole 88 b of the joint 88, and the pipe 87 through the relief valve 80. Is supplied to the inlet 83 of
[0037]
The exhaust port 82 of the relief valve 80 faces the microswitch 53 as the vent detecting means 53 directly or via a pipe (see FIG. 1B). Gas ejected directly from the exhaust port 82 of the relief valve 80 or via a pipe collides with the pressure receiving plate 53a, and the micro switch 53 is switched from off to on, so that the gas is relieved from the exhaust port 82 of the relief valve 80. That is, it is detected that the relief valve 80 has been operated. When the vent pressure tester 30 is calibrated, the through hole 41b of the lower holder 41 is not used.
[0038]
Referring to FIGS. 1A and 1B, a controller 100 is provided to control the operation of the vent pressure tester 30. The controller 100 mainly includes a CPU, and includes a timer, a memory storing a control program, and the like. Detection signals from the pressure sensor 51 and the microswitch 53 are input to the controller 100. A control signal for controlling the operation of is output. The controller 100 displays, on the monitor 101, information on the operation state of the vent pressure tester 30, the pressure of the gas line 50, the measured vent pressure and the hold pressure, the evaluation of the vent pressure performance, and the like. The controller 100 also stores sampling data, prints out, and issues an alarm as needed.
[0039]
Next, the operation of the present embodiment will be described.
[0040]
First, a case of performing a test for measuring the vent pressure and the hold pressure of the safety valve 10 will be described (see FIG. 1A).
[0041]
In a state in which the holding cylinder 43 is operated to move the upper holder 42 backward from the lower holder 41, the outer peripheral portion of the terminal cap 14 is placed on the mounting surface 41 c of the lower holder 41, and the rubber valve body is placed in the terminal cap 14. 15 is accommodated, and the sealing plate 12 is put thereon. Thereafter, the holding cylinder 43 is operated to move the upper holder 42 forward toward the lower holder 41, and the outer peripheral portion of the safety valve 10 is held between the mounting surface 41c of the lower holder 41 and the pressing surface 42c of the upper holder 42, The safety valve 10 in which the rubber valve body 15 is temporarily installed is held in the holding unit 40 in an airtight state (see FIG. 2).
[0042]
Next, after opening and closing the on-off valve 76 and filling the gas line 50 with a predetermined amount of gas, the on-off valve 76 is closed. At this point, the gas line 50 is closed.
[0043]
Next, the air cylinder 64 of the pressure increasing unit 60 is operated to move the piston 62 forward, compressing the gas in the cylinder 61 and increasing the pressure of the gas line 50 communicating with the compression chamber 61a. The pressure increase rate of the pressure of the gas line 50 is adjusted in advance by a pressure increase rate adjusting unit 70 including a speed controller 71 and the like, and the flow rate of the gas supplied from the pressure increase unit 60 to the gas line 50 is adjusted in advance by a flow rate control valve 52. ing.
[0044]
With the operation of the pressure increasing unit 60, the pressure of the gas line 50 gradually increases (see FIG. 4). The pressure of the gas line 50 acts on the rubber valve body 15 facing the gas vent hole 11 of the safety valve 10 held by the holding unit 40.
[0045]
As shown in FIG. 2, when the pressure of the gas line 50 rises to a certain value or more, the gas pressure is reduced by pushing the rubber valve body 15 down to the terminal cap 14 side through the gas vent hole 11 and compressing the gas. Open 11. Then, the gas inside the gas line 50 flows out into the space surrounded by the sealing plate 12 and the terminal cap 14 as shown by the one-dot chain line, and further passes through the vent hole 13 of the terminal cap 14 and the lower holder 41. Is released into the concave portion 41a. Then, the gas released into the concave portion 41a is ejected toward the microswitch 53 through the through hole 41b.
[0046]
The ejected gas collides with the pressure receiving plate 53a, and the microswitch 53 is switched from off to on. Thereby, the controller 100 detects that the safety valve 10 has been operated, and acquires the peak value measured by the pressure sensor 51 as the vent pressure (see FIG. 4). Further, when detecting that the safety valve 10 has been operated, the controller 100 starts counting by a timer, and when counting a set time (for example, 5 seconds) after venting, the value measured by the pressure sensor 51 is used as a hold pressure. Acquire (see FIG. 4).
[0047]
Then, the quality of the rubber valve body 15 is determined based on the measured vent pressure and hold pressure.
[0048]
Next, a case in which the vent pressure test is calibrated will be described (see FIG. 1B).
[0049]
In a state in which the holding cylinder 43 is operated to move the upper holder 42 backward from the lower holder 41, a joint 88 connected to the relief valve 80 is disposed in the recess 41 a of the lower holder 41 instead of the safety valve 10. Thereafter, the holding cylinder 43 is operated to move the upper holder 42 forward toward the lower holder 41, and the joint 88 is sandwiched between the concave bottom surface 41 d of the lower holder 41 and the concave bottom surface 42 e of the upper holder 42, and the joint 88 is airtight. It is held in the holding unit 40 in the state (see FIG. 3). The operating pressure of the relief valve 80 is, for example, 2.94 MPa (30 kgf / cm ² ) Is set in advance. The operating pressure of the relief valve 80 has been previously confirmed using a standard pressure gauge calibrated by a pressure reference device (dead-wet tester).
[0050]
Next, after opening and closing the on-off valve 76 and filling the gas line 50 with a predetermined amount of gas, the on-off valve 76 is closed. At this point, the gas line 50 is closed.
[0051]
Next, the air cylinder 64 of the pressure increasing unit 60 is operated to move the piston 62 forward, compressing the gas in the cylinder 61 and increasing the pressure of the gas line 50 communicating with the compression chamber 61a. With the operation of the pressure increasing unit 60, the pressure of the gas line 50 gradually increases. The gas in the gas line 50 is supplied to the inlet 83 of the relief valve 80 through the internal passage 42b of the upper holder 42, the center hole 88a of the joint 88, the through hole 88b, and the pipe 87, and the pressure of the gas line 50 is reduced. Acts on valve 80.
[0052]
When the pressure of the gas line 50 rises and the pressure acting on the inlet 83 exceeds a certain value, the stem 84 is pushed up against the elastic force urged by the metal spring 81 and the gas is released from the exhaust port 82. Is done. Then, the relieved gas is ejected toward the microswitch 53.
[0053]
The ejected gas collides with the pressure receiving plate 53a, and the microswitch 53 is switched from off to on. Thereby, the controller 100 detects that the gas has been relieved from the exhaust port 82 of the relief valve 80, and measures the pressure of the gas line 50 at that time by the pressure sensor 51.
[0054]
Here, when there is a difference between the measured pressure of the gas line 50 and the operating pressure set in the relief valve 80 (2.94 MPa in the present embodiment), the pressure increasing speed of the gas line 50 is increased. Adjust. Specifically, the pressure of the gas line 50 measured by the pressure sensor 51 when the micro switch 53 detects that the gas has been relieved from the exhaust port 82 of the relief valve 80 indicates the operating pressure of the relief valve 80. As described above, the throttle of the speed controller 71 provided in the boosting speed adjusting unit 70 is adjusted to adjust the speed at which the pressure of the gas line 50 is increased by the boosting unit 60.
[0055]
Further, the flow rate of the gas supplied from the booster unit 60 to the gas line 50 is adjusted. Specifically, the pressure of the gas line 50 measured by the pressure sensor 51 when the micro switch 53 detects that the gas has been relieved from the exhaust port 82 of the relief valve 80 indicates the operating pressure of the relief valve 80. As described above, the throttle of the flow control valve 52 is adjusted to adjust the flow rate of the gas supplied from the booster unit 60 to the gas line 50.
[0056]
In order to stabilize the compression force of the metal spring 81 of the relief valve 80, the above-described adjustment of the pressure increasing speed and the adjustment of the gas flow rate are repeated about 3 to 5 times.
[0057]
If the pressure of the gas line 50 measured when the gas is relieved from the exhaust port 82 of the relief valve 80 matches the operating pressure set for the relief valve 80, the control of the pressure increasing speed and the gas flow rate are performed. finish.
[0058]
Further, when the controller 100 detects that the gas has been relieved from the exhaust port 82 of the relief valve 80, the controller 100 starts counting by a timer, and counts a set time (for example, 5 seconds) after the relief. The pressure in the gas line 50 is measured by the pressure sensor 51. The measured pressure is confirmed as a hold pressure. Thus, the calibration of the vent pressure tester 30 is completed.
[0059]
Note that it is preferable to periodically calibrate the vent pressure tester 30 in order to accurately perform a measurement test of the vent pressure and the hold pressure of the safety valve 10.
[0060]
In the present embodiment, when the vent pressure tester 30 is calibrated, the relief valve 80 whose operating pressure is set in advance is used as a standard gauge (reference). Since the relief valve 80 includes the metal spring 81, the operating pressure is less likely to change over time than the master safety valve incorporating the rubber valve body 15, and the operating pressure value can be increased over a long period of time. Can be trusted throughout. Even when the temperature at the time of setting the operating pressure is different from the temperature at the time of calibration, the influence on the operating pressure is small as compared with the degree of change in the hardness of the rubber valve body 15.
[0061]
Therefore, the calibration of the vent pressure tester 30 can be accurately performed with good reproducibility. As a result, a test for measuring the vent pressure and the hold pressure of the safety valve 10 can be performed with high accuracy, and the reliability of the vent pressure test for the rubber valve body 15 increases. Since the reliability of the vent pressure test is increased, the time required for the test can be reduced, and the quality and function of the rubber valve body 15 can be improved.
[0062]
Further, even in the case of performing a trial production in which the material and the shape of the rubber valve body 15 are changed, it is not necessary to provide a master safety valve from a battery manufacturer, so that the performance evaluation of the prototype can be efficiently performed in a short time. Can be done. Therefore, the development schedule of the rubber valve body 15 as a product can be shortened.
[0063]
As described above, according to the calibration method of the vent pressure tester 30 of the present embodiment, it is possible to easily achieve the consistency of the vent pressure tester 30 owned by each of the battery manufacturer and the component manufacturer of the rubber valve body 15. Thus, the vent pressure performance of the rubber valve body 15 can be checked accurately and quickly.
[0064]
(Modification example)
In the illustrated boosting unit 60, an air cylinder 64 is used as an actuator 63 for driving a piston 62, and in the boosting speed adjusting unit 70, a speed controller 71 is used. However, the present invention is limited to these configurations. is not. For example, by connecting a pulse motor as the actuator 63 to the piston 62 and changing the number of pulses supplied per unit time to the pulse motor, the pressure increasing speed of the gas line 50 can be adjusted.
[0065]
【The invention's effect】
According to the method for calibrating the vent pressure tester of the safety valve for a sealed secondary battery according to claim 1 or 2, the vent pressure of a rubber valve body incorporated in the safety valve for a sealed secondary battery is accurately measured. And a calibration technique for the vent pressure tester.
[0066]
According to the method for calibrating the vent pressure tester of the safety valve for a sealed secondary battery according to the third aspect, by holding the safety valve in which the rubber valve body is temporarily installed in the holding unit, the component manufacturer of the rubber valve body can be used. The vent pressure performance can be accurately tested, and the vent pressure performance can be accurately tested by a battery manufacturer by holding the safety valve as a product incorporating the rubber valve body in the holding unit.
[0067]
According to the vent pressure tester of the fourth aspect, the vent pressure tester can be accurately calibrated, so that the vent pressure of the rubber valve element incorporated in the safety valve for the sealed secondary battery can be accurately measured. It becomes possible.
[Brief description of the drawings]
1 (A) and 1 (B) are schematic configuration diagrams showing a vent pressure tester of a safety valve for a sealed secondary battery according to an embodiment of the present invention, and FIG. FIG. 1B is a schematic configuration diagram illustrating a state in which a test for measuring a pressure and a hold pressure is being performed, and FIG. 1B is a schematic configuration diagram illustrating a state in which a vent pressure tester is being calibrated.
FIG. 2 is a cross-sectional view illustrating a holding unit that detachably holds a safety valve including a rubber valve body in an airtight state.
FIG. 3 is a cross-sectional view showing a relief valve having a metal spring used when calibrating a vent pressure tester.
FIG. 4 is a diagram showing a measurement example of a vent pressure and a hold pressure of a safety valve having a rubber valve body.
FIGS. 5A and 5B are cross-sectional views showing a safety valve for a sealed secondary battery having a rubber valve body.
6 is a cross-sectional view showing a state where the safety valve shown in FIG. 5 is assembled to an outer can of a sealed secondary battery.
[Explanation of symbols]
10. Safety valve for sealed secondary battery
11 ... vent hole
12 ... Sealing plate
13 ... vent
14 ... Terminal cap
15… Rubber valve
30 ... Vent pressure tester
40 ... holding unit (holding means)
50 ... closed gas line
51 ... pressure sensor (measuring means)
52 ... Flow control valve (supply flow rate adjusting means)
53 ... Micro switch (vent detection means)
60 ... Boost unit (boost means)
64 ... Air cylinder
70: step-up speed adjusting unit (step-up speed adjusting means)
71 ... Speed controller
80 ... Relief valve
81 ... Metal spring
82 ... Exhaust port

Claims (4)

In a state compressed between the sealing plate (12) with the vent hole (11) opened and the terminal cap (14) with the vent hole (13) opened so as to cover the gas vent hole (11). A vent pressure tester (30) for measuring a vent pressure at which a safety valve (10) for a sealed secondary battery in which a rubber valve body (15) is arranged is operated,
Holding means (40) for detachably holding the safety valve (10) including the rubber valve body (15) in an airtight state;
A closed gas line (50) communicating with the vent hole (11) of the held safety valve (10);
Measuring means (51) for measuring the pressure of the gas line (50);
Pressure increasing means (60) for increasing the pressure of the gas line (50);
Pressure increasing speed adjusting means (70) for adjusting the pressure increasing speed of the gas line (50) by the pressure increasing means (60);
A vent detection means (53) for detecting that the safety valve (10) has been actuated.
A relief valve (80) provided with a metal spring (81) and having a preset operating pressure is retained by the retaining means (40), and gas is relieved from an exhaust port (82) of the relief valve (80). The pressure of the gas line (50) measured by the measuring means (51) when the pressure is detected by the vent detecting means (53) so as to exhibit the operating pressure of the relief valve (80). A method of calibrating a vent pressure tester for a safety valve for a sealed secondary battery, comprising: adjusting a speed adjusting means (70) to increase a pressure increasing speed of the gas line (50) by the pressure increasing means (60). . The vent pressure tester (30) further includes a supply flow rate adjusting means (52) for adjusting a flow rate of gas supplied from the pressure increasing means (60) to the gas line (50),
When the vent detection means (53) detects that gas has been relieved from the exhaust port (82) of the relief valve (80), the gas line (50) measured by the measurement means (51) is detected. The flow rate of the gas supplied to the gas line (50) by the supply flow rate adjusting means (52) is adjusted by adjusting the supply flow rate adjusting means (52) so that the pressure exhibits the operating pressure of the relief valve (80). 2. The method for calibrating a vent pressure tester of a safety valve for a sealed secondary battery according to claim 1, wherein the pressure is adjusted. The holding means (40) is capable of holding a safety valve (10) in which the rubber valve body (15) is temporarily installed or a safety valve (10) in which the rubber valve body (15) is installed. The method for calibrating a vent pressure tester of a safety valve for a sealed type secondary battery according to claim 1, wherein: In a state compressed between the sealing plate (12) with the vent hole (11) opened and the terminal cap (14) with the vent hole (13) opened so as to cover the gas vent hole (11). A vent pressure tester (30) for measuring a vent pressure at which a safety valve (10) for a sealed secondary battery in which a rubber valve body (15) is arranged is operated,
Holding means (40) for detachably holding the safety valve (10) including the rubber valve body (15) in an airtight state;
A closed gas line (50) communicating with the vent hole (11) of the held safety valve (10);
Measuring means (51) for measuring the pressure of the gas line (50);
Pressure increasing means (60) for increasing the pressure of the gas line (50);
Pressure increasing speed adjusting means (70) for adjusting the pressure increasing speed of the gas line (50) by the pressure increasing means (60);
Vent detection means (53) for detecting that the safety valve (10) has been activated;
When calibrating the vent pressure tester (30), the relief valve (80) which is held by the holding means (40) instead of the safety valve (10) and has a metal spring (81) and has a preset operating pressure is provided. , Including
When the vent detection means (53) detects that gas has been relieved from the exhaust port (82) of the relief valve (80) held by the holding means (40) instead of the safety valve (10), The pressure increasing speed adjusting means (70) is adjusted so that the pressure of the gas line (50) measured by the measuring means (51) indicates the operating pressure of the relief valve (80). 60. A vent pressure tester for a safety valve for a sealed secondary battery, wherein a rate of pressure increase of the gas line (50) according to (60) is adjusted.

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