JP4716695B2 - Charging method - Google Patents

Description

  The present invention relates to a charging method for rapidly charging a battery in as short a time as possible.

A charger employing the following charging method has already been released in Japan by the applicant. The charging method is a charging method in which the battery temperature is detected and the average charging current is controlled. In this charging method, charging is performed with a large current that increases the battery temperature, and the battery temperature is increased to the holding temperature. Thereafter, the charging method includes a temperature holding charging step of charging while controlling the average charging current so that the battery temperature becomes the holding set temperature and holding the battery temperature at the holding set temperature. (See Patent Document 1 of the present applicant)
Japanese Patent Application No. 2003-349543

Such a charging method is easily affected by the surrounding situation where the charger is placed when charging while maintaining the battery temperature at the holding set temperature. In other words, for example, when the ambient temperature is low (= when the battery temperature is also low), it takes time to reach the holding set temperature, and the heat dissipation from the battery is also large because the ambient temperature is low at the holding set temperature. Accordingly, the current can be increased and charged, and the amount of charge is increased. In addition, for example, when the ambient temperature is high (= when the battery temperature is also high), it takes a short time to reach the holding set temperature, and the heat dissipation from the battery is small because the ambient temperature is high at the holding set temperature. Therefore, the battery is charged with a smaller current. Therefore, when the ambient temperature is high, the amount of charge becomes small.
The present invention has been made to solve such problems, and is capable of rapid charging in a short time without deteriorating battery performance, and charging that can be charged in a short time without being affected by the surrounding conditions. It aims to provide a method.

The charging method of the present invention is a charging method that detects a battery temperature and controls an average charging current so that the battery temperature becomes a holding set temperature, and drives a cooling fan to apply ambient air to the battery. And a temperature holding charging step of charging while holding the battery temperature at the holding set temperature while cooling.

  In addition, prior to the temperature holding charging step, a temperature rising charging step for charging the battery temperature with a large current to raise the battery temperature and raising the battery temperature to the holding set temperature is provided, and the battery is charged in the temperature rising charging step. When the battery temperature reaches the holding set temperature, the process proceeds to the temperature holding charging process, and in the temperature rising charging process, the cooling fan is driven to charge ambient air against the battery while cooling.

  Furthermore, the rotational speed of the cooling fan during the temperature holding charging process is set to be lower than the rotational speed of the cooling fan during the temperature rising charging process.

  The charging method of the present invention has an advantage that it can be rapidly charged in a very short time without deteriorating battery performance. That is, the charging method of the present invention drives the cooling fan to cool the ambient air against the battery and cools it while holding the battery temperature at the holding set temperature. This is because it is possible to rapidly charge with a large current at a holding set temperature near the maximum at a temperature lower than the temperature at which an adverse effect or performance degradation occurs. And since the battery is cooled with the cooling fan, it is possible to suppress the temperature rise of the battery and to charge with a larger current. Furthermore, with respect to the problem that the amount of charge decreases when the ambient temperature is high, which is the conventional problem described above, the battery is cooled by a cooling fan, so that the temperature rise of the battery is suppressed and a larger current is used. Since the battery can be charged, the amount of charge increases.

  Also, in the temperature rising charging process in which the battery temperature is increased to the holding set temperature by charging with a large current that increases the battery temperature before the temperature holding charging process, the battery is cooled by the cooling fan. It is possible to charge with a larger current while suppressing the temperature rise.

Furthermore, since the rotation speed of the cooling fan during the temperature holding charging process is lower than the rotation speed of the cooling fan during the temperature rising charging process, the following effects can be obtained . When the temperature maintaining charging step of this, a predetermined battery temperature (e.g., 62 ° C.) when detecting the full charge at least, from that rotation speed of the cooling fan is low, the temperature is lowered is cooled more than necessary battery Although the battery is in the fully charged state, it is possible to prevent the overcharged state from continuing without reaching the predetermined battery temperature, and it is possible to appropriately detect the full charge above the predetermined battery temperature.

  Embodiments of the present invention will be described below with reference to the drawings. However, the embodiment described below exemplifies a charging method for embodying the technical idea of the present invention, and the present invention does not specify the charging method as the following method.

Charging circuit shown in FIG. 1, the switching element 43 to adjust the power supply circuit 4 2 for charging by supplying a charge current to the battery 41, the connection has been average charging current of the battery 41 between the power supply circuit 42 and the battery 41 And a control circuit 44 that switches the switching element 43 on and off to adjust the charging current, and a temperature sensor 45 that detects the battery temperature and inputs a temperature signal to the control circuit 44.
The battery 41 is arranged so that the temperature sensor 45 is in close contact with the battery 41 when the battery 41 is installed in a charger (not shown) when using standard 1 to 4 type batteries or the like. Further, when the battery 41 is a battery pack, the temperature sensor 45 is disposed in close contact with the unit cell in the battery pack.
In addition, the charger of this embodiment includes a cooling fan 25 that is controlled by the control circuit 44 and that cools the battery 41 by applying ambient air to the battery 41. In the present embodiment, as will be described later, the cooling fan 25 is controlled to stop, low speed, medium speed, and high speed according to the state of charge of the battery 41.

The characteristic of the battery temperature rising when this charging circuit charges the battery 41 and the characteristic of the battery voltage changing are shown in the graph of FIG. In FIG. 2, a curve A indicates a characteristic in which the battery temperature rises, and a curve B indicates a characteristic in which the battery voltage (battery temperature at the start of charging 25 ° C.) changes. As shown in this figure, the charging circuit of FIG. 1 does not reduce the rate at which the battery temperature rises when fully charged, but increases the battery temperature in the first temperature rising charging process that starts charging. After the temperature is raised, in the temperature holding charging step, charging is performed while keeping the battery temperature at the holding set temperature. Therefore, a large current is first supplied to raise the battery temperature. In other words, the battery 41 is charged by passing a current that is large enough to raise the battery temperature. At this time, the battery 41 is charged with a large current. However, since the battery temperature does not increase, the battery performance does not deteriorate, and a large capacity can be charged in this time zone.
In this figure, a curve X indicates the battery temperature when charging is performed by operating the cooling fan 25 in this embodiment, and X (10 ° C.), X (25 ° C.), and X (30 ° C.) are charged. The battery temperatures at the start indicate battery temperature increases of 10 ° C., 25 ° C., and 30 ° C., respectively. A curved line Y indicated by a dotted line shows an increase in battery temperature when the cooling fan 25 does not operate only in the temperature rising charging process. Y (10 ° C.), Y (25 ° C.), and Y (30 ° C.) are charged. The battery temperatures at the start show temperature increases of 10 ° C., 25 ° C., and 30 ° C., respectively. It can be understood that the temperature rise is large when the cooling fan 25 does not operate. When the cooling fan 25 does not operate, the temperature rise is large, and it is necessary to reduce the charging current because the battery temperature reaches a predetermined rising temperature and holding set temperature described later in a short time. Charging time becomes longer.

Power supply circuit 42 has a state of turning on the switching element 4 3, a battery 41, an average current 1.5C～10C, preferably at 2C～8C, more preferably charged with a large current of 2C~5C output. The power supply circuit can be connected to the control circuit via a lead wire as an adapter separate from the control circuit. However, the power supply circuit can be housed in the same case as the control circuit.

The charging circuit can also charge the battery 41 by switching a plurality of power supply circuits 42 as shown in FIG. A plurality of power supply circuit 4 2 is connected to the switching element 43 via the switch 4 6. The changeover switch 46 switches the power supply circuit 42 that charges the battery 41. The plurality of power supply circuits 42 have different peak currents when the battery 41 is pulse-charged. Even if the average charge current of the battery 41 is the same, heat generation increases if the peak current for pulse charging is large. Therefore, when charging the battery 41 with a large current is switched to the power supply circuit 42 that the peak current is reduced, when charging the battery 4 1, can reduce the heat generation of the battery 41. Therefore, the battery 41 can be charged with a larger average charging current, and the rise in battery temperature can be reduced.

  The switching element 43 is a transistor or FET, and is switched by the control circuit 44 to charge the battery 41 in a pulse manner. The switching element 43 is not switched and is held in an on state, and the battery 41 is initially charged with a large current to raise the battery temperature to a predetermined rising temperature and a predetermined holding temperature. In this case, constant current charging is performed. Further, the switching element 43 is switched on and off at a predetermined duty ratio, and the battery 41 is initially charged with a large pulse current (a large current having a large average current value) and maintained at a predetermined temperature that is a predetermined temperature. It can also rise to the set temperature.

The switching element 43 adjusts an average charging current for pulse charging the battery 41 with a duty ratio that is switched on and off. The duty ratio (Q) at the time of pulse charging is a ratio of a time (ton) for turning on the switching element 43 and a time (toff) for turning off the switching element 43, and is expressed by the following equation.
Q = ton / (ton + toff)
Therefore, when the duty ratio at which the switching element 43 is switched on / off is reduced, the average charging current is decreased, and conversely, when the duty ratio is increased, the average charging current is increased.

The control circuit 44 detects the battery temperature with a signal input from the temperature sensor 45, and switches the switching element 43 on and off at a predetermined duty ratio. The duty ratio for switching the switching element 43 on and off is small when the battery temperature is high, and is increased when the battery temperature is low, and the battery temperature is held at the holding set temperature. As shown in FIG. 2, since the battery temperature is low at the beginning of charging, charging is performed with a large current until the battery temperature rises to a predetermined temperature, and thereafter, the temperature of the battery 41 is held at the holding set temperature. As described above, the control circuit 44 controls the duty ratio of the switching element 43. The control circuit 4 4, period of switching the switching element 4 3 on and off may, 1Msec～10sec, preferably 10Msec～2sec, further preferably 50Msec～2sec.

When the battery temperature detected by the temperature sensor 45 is lower than the holding temperature, the control circuit 44 increases the duty ratio and increases the average charging current for pulse charging the battery 41 to increase the battery temperature. When the battery temperature rises to holding temperature, battery temperature by decreasing the duty ratio so as not to exceed the holding temperature, and controls the duty ratio of the switching element 4 3 so as not to drop from the holding temperature. Therefore, the control circuit 44 does not charge the battery 41 with a constant current and does not charge with a constant voltage. The control circuit 44 controls the duty ratio of the switching element 43 to control the average charging current for charging the battery 41, and controls the temperature of the battery 41 so as to show the curve of FIG.

The charging circuit in FIG. 1 charges the battery 41 in the following steps. The following illustrates a method for charging a nickel-hydrogen battery, but a nickel-cadmium battery can be charged in the same manner by changing the charging current.
(1) First, before starting charging, the temperature sensor 45 detects the temperature of the battery 41 to be charged in the charging circuit. When the detected battery temperature is within the start set temperature range, the control circuit 44 starts the temperature rising charging process. The starting set temperature range of the battery 41 for starting the temperature rising charging process is 0 to 40 ° C, preferably 10 to 30 ° C. When the battery temperature is lower or higher than the start set temperature range, normal charging is started while detecting the battery voltage. In normal charging, the charging current is limited to 1 C or less, and the battery voltage reaches the peak voltage while detecting the battery voltage, or ΔV is detected and fully charged.
Further, the remaining capacity of the battery 41 is detected from the voltage. This is because a battery that is nearly fully charged is overcharged when it is charged in the next temperature rising charging step, and the battery performance is reduced. The battery whose battery voltage is lower than the set voltage is determined to have a small remaining capacity, and charging is started in the temperature rising charging process. The battery whose battery voltage is higher than the set voltage has a large remaining capacity, and when charging in the temperature rising charging process, it is determined that the battery is overcharged, and normal charging is started.
Here, when measuring the battery voltage for grasping the remaining capacity, the battery 41 is charged for a certain time (for example, 5 to 60 S) (for example, current) in order to more appropriately reflect the remaining capacity. 1.5C to 10C), and after a certain time (for example, 0.5 to 3 minutes), the battery voltage may be measured.

  Further, when charging is started, the internal resistance of the battery 41 is detected. When the internal resistance is higher than a predetermined electric resistance, normal charging is performed without shifting to the temperature rising charging process. After the normal charging, when the internal resistance becomes smaller than a predetermined electric resistance, the temperature rising charging process can be started.

(2) When the temperature of the battery 41 is in the start set temperature range and the battery voltage is lower than the hold set voltage, the temperature rise charging process is started. In the temperature rising charging step, charging is performed with a large current that raises the battery temperature with a predetermined temperature gradient. In this step, the battery is charged with an average charging current at which the rising gradient of the battery temperature is about 3 ° C./min. In the case of an AA type nickel-hydrogen battery having a nominal capacity of 2100 mAh, the average charging current is 2C to 3C, and the temperature rise gradient is about 3 ° C./min. However, in this step, the battery can be charged with an average charging current having a temperature rising gradient of 1 ° C./min to 5 ° C./min. Further, the average charging current of the battery 41 can be set to 1.5C to 10C.
Here, the cooling fan 25 is controlled by the control circuit 44 and is rotated at a high speed. In this temperature rising charging step, the battery temperature is relatively low at the initial stage of charging, and is lower than the high temperature at which the battery deteriorates. The cooling fan 25 is rotated at a high speed to apply a large amount of cooling air to the battery 41, and charging is performed with a large current while suppressing an increase in battery temperature.
Here, when charging at a predetermined average current value (for example, 2.5 C) (normally, the temperature increase gradient is 2 ° C./min to 3 ° C./min), a predetermined temperature increase gradient (for example, When 5 ° C./min) or more is detected, or when −ΔV (for example, 60 mV) is detected, it is determined that the battery is fully charged, and charging is terminated to prevent overcharging. As described above, the battery voltage is measured before the start of charging, and the remaining capacity is detected, and the battery with a large remaining capacity is normally charged to prevent overcharging. However, the remaining capacity is determined based on the battery voltage. In some cases, the battery voltage may not properly reflect the remaining capacity, and this process prevents overcharging of the battery. In other words, if the actual remaining capacity is large, but the battery voltage is determined to be low and the remaining capacity is small and charging is performed with a large current in the temperature rising charging process, as described above, a predetermined temperature rising gradient or more, or When -ΔV is detected, it is determined that the battery is fully charged, and overcharging is prevented.
In this step, the switching element 4 3 is held in the ON state, or by increasing the duty ratio of the switching element 4 3, the average charging current in the range described above. When the battery temperature rises to a predetermined set temperature and approaches the hold set temperature, for example, when the hold set temperature is set to 57 to 60 ° C., when the battery set temperature approaches (for example, about 55 ° C.), the rise predetermined temperature (eg, About 55 ° C.), the average charging current is reduced, and the temperature rise gradient of the battery 41 is reduced.

FIG. 2 shows that when the battery temperature rises to a predetermined temperature of about 55 ° C., this temperature is detected, the average charging current is reduced to loosen the temperature rise gradient, and approach the holding set temperature (the temperature shown in FIG. 2). Ascending charging process). The average charging current is controlled by reducing the duty ratio for turning on / off the switching element 43. As described above, when the temperature of the battery 41 is close to the holding set temperature and reaches a predetermined rising temperature, the method of reducing the average charging current prevents the battery temperature from overshooting the holding set temperature and prevents the battery 41 from overshooting. Can effectively prevent deterioration due to high temperature failure. However, the battery 41 can be charged with an average charging current that increases at a predetermined temperature gradient until the temperature of the battery 41 reaches the holding temperature.
The cooling fan 25 is controlled by the control circuit 44 and rotated at a medium speed while the above-mentioned predetermined temperature rise is detected to reduce the average charging current and reach a holding set temperature described later. The reason why the medium speed rotation is used rather than the high speed rotation in the above temperature rising charging process is that when the battery is cooled at the high speed rotation, the average charging current is reduced and the battery is cooled more than necessary.
Further, in the temperature rising charging process, when a predetermined temperature (for example, a predetermined rising temperature of about 55 ° C. or a holding set temperature described later) is not reached within a predetermined time (for example, 15 minutes), it will be described later. The charge control in the temperature holding charging process can be performed by setting the average charging current in the temperature holding charging process (about 1.5 C, which is about half of the average charging current in the temperature rising charging process). Thereby, in a battery whose battery temperature before the start of charging is low (about 0 to 10 ° C.), it is possible to reduce the temperature from rapidly increasing and adversely affecting the battery.

(3) When the battery temperature rises to the holding set temperature at the end of the temperature rising charging process, the battery 41 is charged in the temperature holding charging process by controlling the average charging current so that the battery temperature is held at the holding set temperature. To do. In this temperature holding charging step, the control circuit 44 controls the duty ratio for switching the switching element 43 on and off, adjusts the average charging current of pulse charging, and holds the battery temperature at the holding set temperature. In this step, the temperature sensor 45 detects the battery temperature and inputs a temperature signal to the control circuit 44. The control circuit 44 controls the duty ratio for switching the switching element 43 on and off with the detected battery temperature. When the battery temperature is increased, the duty ratio is decreased to decrease the average charging current to decrease the battery temperature.When the battery temperature is decreased, the duty ratio is increased to increase the average charging current and increase the battery temperature. Charge the battery while keeping the battery temperature at the set temperature. In the temperature holding charging step, it is desirable to keep the battery temperature at a constant temperature (for example, 58 ° C.).
Here, the holding set temperature is set to a temperature in the vicinity of the maximum below the temperature at which the adverse effect of the battery and the performance degradation occur. Moreover, even if a user touches the battery 41, there is no problem, and the hot battery 41 is set so as not to feel abnormal. The upper limit of such holding set temperature is approximately 70 ° C. at the maximum, preferably 65 ° C. or less, and more preferably 63 ° C. or less. The range of the holding set temperature is preferably 50 to 65 ° C, more preferably 53 to 63 ° C, and even more preferably 56 to 61 ° C and 57 to 60 ° C.

Further, in order to maintain the battery temperature at the holding set temperature, in the present embodiment, the following control is performed. First, at the holding set temperature, the control specified temperature is set to a predetermined temperature (for example, 58 ° C.). Then, every time the detected battery temperature rises by, for example, 1 ° C. from the control specified temperature, the average charging current is decreased stepwise, and the detected battery temperature is 1 ° C. from the control specified temperature. Each time it decreases, the average charging current is increased stepwise. By such control, charging is performed while maintaining the battery temperature at the holding set temperature.
Instead of the control regulation temperature, the control regulation temperature may be set within a predetermined temperature range (for example, 57 to 59 ° C.). Then, every time the detected battery temperature rises by, for example, 1 ° C. from the control specified temperature, the average charging current is decreased stepwise, and the detected battery temperature is 1 ° C. from the control specified temperature. Each time it decreases, the average charging current is increased stepwise. By such control, charging is performed while maintaining the battery temperature at the holding set temperature.

In this temperature holding charging step, when the battery 41 approaches full charge, the tendency for the battery temperature to rise increases even if the average charging current is reduced. Therefore, when the battery 41 approaches full charge, the battery temperature rises or tends to rise, but the average charging current is reduced so as to keep the battery temperature at the hold set temperature. That is, the control circuit 44 controls the duty ratio for switching the switching element 43 on and off very small. For this reason, when the battery 41 is nearly fully charged, the control circuit 44 sharply decreases the average charging current. Therefore, in the temperature holding charging process, even if full charging of the battery 41 is not detected and charging is not stopped, the average charging current is rapidly reduced and overcharging is prevented. About the completion | finish of charge in the temperature holding charge process of a present Example, charge is complete | finished with the timer. The timer is set to a time (for example, about 15 minutes) that can sufficiently charge the battery 41 so that the battery 41 is almost fully charged. In the present embodiment, as described above, the battery temperature rises near full charge and the average charging current decreases. Therefore, when this reduced current is detected, charging is performed even before the set time of the timer. Has ended.
Further, in the temperature holding charging process, when a predetermined temperature rise gradient (for example, 2 ° C./min) or higher, a predetermined battery temperature (for example, 62 ° C.) or higher, or −ΔV (for example, 60 mV) is detected, the battery is fully charged. As well as a function to stop charging.
In this temperature holding charging process, the cooling fan 25 is controlled by the control circuit 44 and rotated at a low speed. The reason why the rotation speed is lower than the medium speed rotation during the period from the detection of the above-mentioned predetermined rising temperature to the holding set temperature is as follows. In the temperature holding charging process, since the average charging current is usually reduced from the time when the rising predetermined temperature is detected until the holding set temperature described later, the battery becomes more than necessary when cooled at a medium or high speed. It is because it is cooled.
In particular, the AA size of nickel-hydrogen batteries has various battery capacities ranging from 1700 mAH to 2500 mAH despite the same size. The user who uses the charger also has a battery with a small capacity (for example, 1700 mAH) sold before, and such a battery may be charged by the charger of this embodiment.
In the charger of the present embodiment, the timer time, the current value, etc. are set so that the battery of 2500 mAH, which is the maximum capacity at the present time, is fully charged.
Thus, for example, if a battery with a small capacity of 1700 mAH is charged, the battery is fully charged before the timer time. Therefore, in the present embodiment, as described above, since there is a function of detecting a full charge at a predetermined battery temperature (for example, 62 ° C.) or higher, such a small capacity battery has a battery temperature before the mimer time. Is detected and full charge is detected. Here, if the cooling fan 25 rotates at a high speed and a medium speed, the measurement is performed by the large cooling by the cooling fan 25 even though the battery with such a small capacity is about to rise in a fully charged state. The battery temperature does not rise, and the battery is overcharged. In order to solve such a problem, in this embodiment, in this temperature holding charging process, the cooling fan 25 is rotated at a low speed rotation that is lower than the high speed and medium speed rotation in the temperature rising charging process. In the temperature holding charging process, it is possible to appropriately detect the temperature rise of the fully charged battery.
Here, the reason why the cooling fan 25 rotates at a low speed without stopping is to suppress a rise in the temperature of the battery and to charge in a short time with a larger average charging current.

Further, when the battery 41 is being charged in the temperature holding charging process, if the internal resistance of the battery 41 is detected and the internal resistance becomes higher than a predetermined electric resistance, normal charging is performed to reduce the charging current of the battery 41. . In the normal charging, the temperature of the battery 4 1 are prevented from becoming higher than the holding temperature.

(4) In the above temperature rising charging process and temperature holding charging process, the battery 41 is almost fully charged.
It is not fully charged. After the temperature maintaining charging step, it is possible to normally charged completely fully charged battery 4 1.

  In the above charging method, the battery 41 is pulse-charged in the temperature rising charging step and the temperature holding charging step. However, the present invention does not necessarily need to adjust the average charging current by controlling the duty ratio for pulse charging. For example, in the temperature rising charging process and the temperature holding charging process, the battery can be charged by controlling the charging current continuously charged and using the average charging current as a predetermined current.

  Next, by using the charging circuit shown in FIG. 1, a temperature sensor 45 and a switching element 43 are provided corresponding to each battery 41, whereby a charger that charges a plurality of batteries 41 can be obtained. An example of the structure of such a charger will be described in detail below.

  The battery charger shown in FIGS. 3 to 10 has a box shape having a substantially rectangular parallelepiped shape and is provided with a battery pocket 3 on the upper surface of the case 1 so that the battery 2 to be charged can be attached and detached. The case 1 shown in the plan view of FIG. 4 is provided with a battery pocket 3 at the bottom in this figure. The battery pocket 3 is provided with a temperature detection unit 12 that detects the temperature of the battery 2 mounted here. Further, in the charger, a charging circuit (not shown) that controls the average charging current of the battery 2 by detecting the battery temperature by the temperature detection unit 12 is mounted on the circuit board 5 in the case 1. Note that this charger basically has a bilaterally symmetrical structure on the paper surface of FIG. 4 except for the power supply line 32, the socket 33, and the like.

  The case 1 is made of a resin material, and includes a lower case 1B and an upper case 1A. The upper case 1A is connected to the lower case 1B, and a circuit board 5 is built therein. The circuit board 5 is fixed to the lower case 1B. Output terminals 6 and 7 connected to the positive and negative electrodes of the battery 2 set in the battery pocket 3 are fixed to the circuit board 5. The output terminals 6 and 7 are metal plates that are elastically deformed. As shown in FIG. 4, the charger shown in FIG. 4 has four AA batteries 2 </ b> A set in the battery pocket 3 for charging. Therefore, four pairs of output terminals 6 and 7 are provided.

  Furthermore, the charger in the figure can charge both the AA batteries 2A and the AAA batteries 2B having different dimensions. The rechargeable AA batteries 2A and AAA batteries 2B, which are single cells, are cylindrical batteries extending in an elongated manner. Specifically, positive and negative electrodes are provided at both ends, and the surface of a metal can other than the electrodes Is covered with a resin tube.

  First, the state in which the AA battery 2A is charged is shown in FIGS. The AA battery 2A is set in the battery pocket 3 in a state where the switching output terminal 8 is tilted. The AA battery 2 </ b> A is charged by contacting the positive electrode on the output terminal 6 and the negative electrode on the other end on the output terminal 7. In FIG. 4, the AA battery 2 </ b> A located in the leftmost holding part 11 is indicated by a solid line, and the AA batteries 2 </ b> A located in the other holding part 11 are indicated by a chain line. . Moreover, the state which charges the AAA battery 2B smaller than AA is shown in FIG. 9 and FIG. As shown in these drawings, the AAA battery 2B is charged by setting two batteries on the left and right sides of the sheet of FIG. 4 in the battery pocket 3 with the switching output terminal 8 raised vertically (see FIG. 4). In FIG. 9, only one AAA battery 2B is disclosed. As shown in FIG. 10, the switching output terminal 8 in this posture connects the output terminal 6 to the electrode of the AAA battery 2 </ b> B via a metal auxiliary terminal 10. The auxiliary terminal 10 is located between the electrode of the AAA battery 2B and the output terminal 6, and connects the output terminal 6 to the electrode of the AAA battery 2B. With this structure, the AAA battery 2B shorter than the AA battery 2A is connected to the output terminal 6. The output terminal 7 is connected to the electrode on the negative electrode side of the AAA battery 2B.

  The switching output terminal 8 has an auxiliary terminal 10 fixed to a plastic support member 9. As shown in FIG. 10, the auxiliary terminal 10 is in a position to raise the switching output terminal 8, is between the electrode of the AAA battery 2 </ b> B and the output terminal 6, and connects the output terminal 6 to the electrode of the AAA battery 2 </ b> B. As shown in FIG. 11, the support member 9 includes a substantially plate-like insulating base portion 9A that fixes the auxiliary terminals 10 and a connecting portion 9B that connects these insulating base portions 9A. As shown in FIG. 8, the switching output terminal 8 is provided with a concave portion 9a into which a positive electrode, which is the convex electrode 2a of the AAA battery 2B, can be inserted into each insulating base portion 9A, and penetrates the bottom of the concave portion 9a. Then, the auxiliary terminal 10 is arranged so that the auxiliary terminal 10 can come into contact with the positive electrode, which is the convex electrode 2a of the AAA battery 2B. The support member 9 connects the shaft portion 9C protruding from both ends to the case 1 and the circuit board 5 so that the plate-like surface of the insulating base portion 9A can rotate from a horizontal posture to a vertical posture. Further, in the state where the plate-like surface is raised in the vertical posture, the support member 9 has an inverted C-shaped support protrusion to hold the lower part of the AAA battery 2B as shown in FIG. Part 9D.

  FIG. 10 shows a state in which the AAA battery 2B is charged. In this state, the switching output terminal 8 is disposed in front of the output terminal 6 of the AA battery 2A with the insulating base portion 9A raised in a vertical posture. When the insulating base portion 9A is raised vertically, the auxiliary terminal 10 is connected to a charging circuit (not shown) of the AAA battery 2B. When charging the AAA battery 2B, the switch pressing portion 9E formed integrally with the shaft portion 9C of the switching output terminal 8 releases the pressing of the position switch 15 installed on the circuit board 5, and this The position switch 15 is turned off to connect to the charging circuit of the AAA battery 2B. Also, as shown in FIG. 7, when the insulating base portion 9A is tilted horizontally to charge the AA battery 2A, the switch pressing portion 9E rotates to press the position switch 15 and turn it on. It is connected to the charging circuit of the AA battery 2A. The switch pressing portion 9E is a cam protruding from the shaft portion 9C of the support member 9, as shown in FIGS. The switch pressing portion 9E presses the position switch 15 installed on the circuit board 5 with the tip of the cam in a state where the insulating base portion 9A is tilted horizontally, and in a state where the insulating base portion 9A is raised vertically, The structure is configured to rotate and release the pressure of the position switch 15.

When charging the AA battery 2A, as shown in FIGS. 3 and 7, the insulating base portion 9A of the switching output terminal 8 is horizontally tilted and moved downward from the front of the output terminal 6 of the AA battery 2A. Is done. The insulating base portion 9 </ b> A moved to this position does not interfere with setting the AA battery 2 </ b> A in the battery pocket 3. In other words, the insulating base portion 9A is moved to a position that does not interfere with the setting of the AA battery 2A in the battery pocket 3. In this state, when the AA battery 2 </ b> A is attached to the battery pocket 3, the AA battery 2 </ b> A is connected to the output terminal 6 fixed to the circuit board 5. The output terminal 6 is connected to a charging circuit (not shown) and charges the AA battery 2A.
As will be described later, such a charging circuit controls the average charging current so that the battery temperature becomes the holding set temperature, and charges in a short time.

  In the case 1 shown in the drawing, a pair of holding portions 11 including a first holding portion 11A and a second holding portion 11B that hold both end portions of the cylindrical battery 2 in the battery pocket 3 so as not to be displaced are provided. Provided. As shown in FIGS. 5 and 9, the first holding portion 11A includes a circular opening 13 that is a holding portion of the AA battery 2A and an elastic arch 14 that is a holding portion of the AA battery 2B. The circular opening 13 is provided through the surface of the case 1 so as to insert and hold the negative electrode side end of the AA battery 2A. The circular opening 13 is inserted into the end of the AA battery 2A, which is a cylindrical battery, so that its inner shape is slightly larger than the outer shape of the AA battery 2A. To make the inner shape of the circular opening 13 slightly larger than the outer shape of the AA battery 2A, the AA battery 2A can be smoothly inserted into and removed from the circular opening 13, but the shape can be held so as not to be displaced in the inserted state. means.

  The elastic arch 14 that is the holding portion of the AAA battery 2B is inserted and held at the end of the AAA battery 2B, and therefore the inner shape thereof is slightly larger than the outer shape of the AAA battery 2B. To make the inner shape of the elastic arch 14 slightly larger than the outer shape of the AAA battery 2B, the AAA battery 2B can be smoothly inserted into and removed from the elastic arch 14, but the shape can be held so as not to be displaced in the inserted state. means. However, the inner shape of the elastic arch 14 is smaller than the outer shape of the AA battery 2A, and cannot be inserted through the AA battery 2A.

  The AAA battery 2 </ b> B is inserted into the elastic arch 14 and set at a fixed position of the battery pocket 3. The AAA battery 2B arranged at a fixed position normally contacts the temperature detection unit 12 and the battery temperature is detected. The AAA battery 2 </ b> B that is not arranged at a fixed position cannot be accurately detected by the temperature detector 12. In order for the temperature detector 12 to normally detect and charge the temperature of the AAA battery 2B, the elastic arch 14 includes a mechanism for detecting whether the AAA battery 2B is set at a normal position.

  As shown in the enlarged perspective views of FIGS. 12 and 13, the elastic arch 14 is formed by bending a conductive elastic metal wire in a U shape and fixing both ends to the circuit board 5. The illustrated elastic arch 14 is provided with a coil spring portion 14A at the lower end so that it can tilt smoothly. When not pressed by the battery 2, the elastic arch 14 is at a position away from the output terminal 7 as shown in FIG. 12, and the AAA battery 2B is inserted and held at a fixed position as shown in FIG. In position. When pushed by the AA battery 2A, it is elastically deformed and contacts the output terminal 7 as shown in FIG. Further, even if the battery is pushed by the AAA battery 2B that is not set at a normal position, it contacts the output terminal 7. That is, the elastic arch 14 contacts the output terminal 7 when the AA battery 2A is set at a normal position, and does not contact the output terminal 7 when the AA battery 2B is set at a normal position. Therefore, it is possible to detect whether or not the AAA battery 2B is set at a normal position by detecting whether or not the elastic arch 14 contacts the output terminal 7.

  FIG. 16 shows a circuit diagram of a detection circuit 16 that detects whether or not the elastic arch 14 is in contact with the output terminal 7. The elastic arch 14 is turned on when it is in contact with the output terminal 7, and is turned off when it is not in contact with the output terminal 7, thereby configuring the wire forming SW 17. The wire forming SW 17 uses the elastic arch 14 and the output terminal 7 as contacts, and the output terminal 7 serving as one contact is connected to the ground side because it is connected to the negative electrode of the battery 2. The detection circuit 16 shown in the figure includes a voltage dividing resistor 18 in which two resistors are connected in series, and a voltage detection circuit 20 such as a microcomputer for detecting the voltage at an intermediate connection point 19 of the voltage dividing resistor 18. The voltage dividing resistor 18 is connected to the power source 21 by connecting the wire forming SW 17 in series. In the illustrated detection circuit 16, one end of the voltage dividing resistor 18 is connected to the positive side of the power source 21, and the other end is connected to the elastic arch 14 constituting the wire forming SW 17, and the output terminal 7 of the wire forming SW 17 is connected to the negative side of the power source 21. It is connected to the earth 22 which is the side. The detection circuit 16 further includes a position switch 15 that detects the rotational position of the switching output terminal 8 that switches between the AA battery 2A and the AAA battery 2B. The position switch 15 is connected between the intermediate connection point 19 of the voltage dividing resistor 18 and the ground 22. The position switch 15 is switched on at the charging position of the AA battery 2A and turned off at the charging position of the AAA battery 2B.

The above detection circuit 16 performs the following operations to determine whether or not the AA batteries 2A and the AAA batteries 2B are set at normal positions.
(1) When the AA battery 2A is normally set In this state, the position switch 15 and the wire forming SW 17 are turned on. As shown in FIG. 7, the position switch 15 is turned on at the charging position of the AA battery 2A, and the wire forming SW 17 is turned on so that the elastic arch 14 is brought into contact with the output terminal 7 in the AA battery 2A. . Since the position switch 15 is turned on, the voltage at the intermediate connection point 19 becomes 0V. Accordingly, it is confirmed that the voltage at the intermediate connection point 19 is 0 V, and charging of the AA battery 2A is started. When the position switch 15 is turned on, the voltage at the intermediate connection point 19 becomes 0 V regardless of whether the wire forming SW 17 is turned on or off. Accordingly, in this state, it is not possible to determine whether the wire forming SW 17 is on or off. However, in the state where the AA battery 2A is set, the wire forming SW 17 is always turned on, so it is not necessary to detect the on / off state of the wire forming SW 17. The reason why the wire forming SW 17 is always turned on is that the inner shape of the elastic arch 14 is made smaller than the outer shape of the AA battery 2A.

(2) When the AAA battery 2B is normally set In this state, the position switch 15 and the wire forming SW 17 are turned off. As shown in FIG. 10, the position switch 15 is turned off when the switching output terminal 8 is switched to the charging position of the AAA battery 2B, and the wire forming SW 17 is inserted into the elastic arch 14 through the AAA battery 2B to be elastic. This is because the arch 14 is not in contact with the output terminal 7 and is turned off. Since the position switch 15 and the wire forming SW 17 are turned off, the voltage at the intermediate connection point 19 of the voltage dividing resistor 18 becomes the power supply voltage. Therefore, in a state where the voltage at the intermediate connection point 19 is the power supply voltage, it is determined that the AAA battery 2B is normally set, and charging of the AAA battery 2B is started.

(3) When the AAA battery 2B is not set normally When the AAA battery 2B is not set normally and the elastic arch 14 is pressed against the output terminal 7 as shown in FIG. 17, the wire forming SW 17 is turned on. . In this state, since the position switch 15 is turned off and the wire forming SW 17 is turned on, the voltage at the intermediate connection point 19 of the voltage dividing resistor 18 is the voltage obtained by dividing the power supply voltage by the ratio of the electric resistance of the voltage dividing resistor 18. Become. When a resistor having the same electric resistance is connected in series to the voltage dividing resistor 18, the voltage at the intermediate connection point 19 is ½ of the power supply voltage.
Therefore, when the voltage at the intermediate connection point 19 is a voltage that divides the power supply voltage by the voltage dividing resistor 18, for example, ½ of the power supply voltage, it is determined that the AAA battery 2B is not normally set, Charging of the AAA battery 2B is not started.
When the AAA battery 2B is set in this state, the temperature detector 12 cannot accurately detect the battery temperature. This is because the temperature detection unit 12 does not contact the surface of the AAA battery 2B in a normal state. If the temperature detector 12 is charged in a state where the temperature of the AAA battery 2B cannot be accurately detected, the battery temperature may become abnormally high and the battery may be deteriorated. In this state, the AAA battery 2B is charged. Do not start.

  In the above detection circuit 16, one end of the voltage dividing resistor 18 is connected to the positive side of the power source 21, and the wire forming SW 17 and the position switch 15 are connected to the ground 22 that is the negative side of the power source 21. On the other hand, one end of the voltage dividing resistor is connected to the ground which is the negative side of the power supply, the wire forming SW and the position switch are connected to the positive side of the power supply, and the AA batteries and the AAA batteries are in a normal position. It is also possible to detect whether it is set to.

  As shown in FIGS. 3 and 8, the second holding portion 11B includes a support portion 23 that is a holding portion of the AA battery 2A and a support convex portion 9D that is a holding portion of the AA battery 2B. The support portion 23 is a groove shape having an inclined surface or a curved surface with an inverted C-shaped cross section perpendicular to the extending direction of the AA battery 2A to be mounted, and holds the lower part on the positive electrode side of the AA battery 2A. The AA battery 2A inserted in the groove is held so as not to be laterally displaced. The supporting protrusions 9D, which are the holding parts of the AAA battery 2B, are a pair of inverted C-shaped protrusions provided in the lower part inside the insulating base part 9A raised in a vertical posture, and are positive electrodes of the AAA battery 2B. The lower part on the side is held, and the AAA battery 2B mounted here is held so as not to be laterally displaced. In the illustrated battery pocket 3, one holding portion 11 has a shape into which the end of the battery 2 can be inserted, but both holding portions can also have a hole shape into which the end of the battery can be inserted and held. . In addition, both the holding portions can be shaped so as not to be laterally displaced.

  When the AAA battery 2B is mounted, the battery 2 is held in the state shown in FIGS. The negative output terminal 7 is made of a metal contact piece. As shown in FIGS. 12 to 15, the output terminal 7 is bent in a mountain shape that protrudes toward the negative electrodes of the AA batteries 2 </ b> A and the AAA batteries 2 </ b> B. The illustrated output terminal 7 is provided with two rows of contact pieces 7A that elastically deform independently (see FIG. 15).

  In the illustrated battery pocket 3, a cooling opening 24 is provided between the first holding portion 11A and the second holding portion 11B. The cooling opening 24 forcibly cools the battery 2 by allowing the air blown from the cooling fan 25 built in the case 1 to pass therethrough. The charger that incorporates the cooling fan 25 in the case 1 and forcibly blows air to the battery 2 from the cooling opening 24 has a feature that it can be fully charged in a short time while lowering the battery temperature. In the case 1 shown in the figure, the bottom plate of the lower case 1B is curved in a central recess, and the ventilation hole 26 is opened so that the cooling fan 25 can efficiently suck the outside air. The cooling fan 25 accommodated in the case 1 sucks outside air through the vent hole 26 of the bottom plate, and cools the sucked air by forcibly blowing the sucked air from the cooling opening 24 toward the battery 2.

  Further, the battery pocket 3 of the charger shown in the figure is provided with a first holding portion 11A and a second holding portion 11B so that a gap 27 (see FIG. 4) is formed between the adjacent batteries 2. This charger passes air forcedly blown from the cooling opening 24 toward the battery 2 through the gap 27 between the batteries 2. For this reason, there is a feature that the battery 2 mounted in the battery pocket 3 can be efficiently cooled with air forcibly blown to reduce the rise in battery temperature and be charged. In FIG. 4, the AA battery 2 </ b> A located in the leftmost holding part 11 is indicated by a solid line, and the AA battery 2 </ b> A located in the other holding part 11 is indicated by a chain line.

  The charger includes four sets of temperature detectors 12 that are pressed against the cylindrical surface of each battery 2 mounted in the battery pocket 3. The temperature detector 12 independently detects the temperature of each battery 2 mounted in the battery pocket 3 independently. Since the charger shown in the figure charges four batteries 2, four sets of temperature detection units 12 are provided to detect the temperature of each battery.

  Next, the heat conductive plate that is a feature of the present invention will be described in detail. 12, 13, 18 to 22 includes a heat conduction plate 28 and a temperature sensor 4 that is fixed to the heat conduction plate 28 and is a temperature detection element that detects a battery temperature. . The heat conduction plate 28 includes a pair of sandwiching plates 28A and 28B for sandwiching the temperature sensor 4 at the top and bottom, an elastic connection arm 28C for connecting the top and bottom sandwiching plates 28A and 28B at a first end, At the second end located on the opposite end to the first end, there is provided an engaging portion 28D for connecting the upper and lower sandwiching plates 28A and 28B for sandwiching the temperature sensor 4. The heat conduction plate 28 has a first end that is one end of the upper and lower sandwiching plates 28A and 28B connected by an elastic connecting arm 28C, and a second end connected by a locking portion 28D. The temperature sensor 4 is clamped and fixed.

  The temperature sensor 4 has a temperature detection element unit 4 </ b> A fixed to a flexible substrate 39. The temperature sensor 4 is generally sold. As shown in the cross-sectional views of FIGS. 18 to 21, a plate-shaped temperature detecting element portion 4 </ b> A having a substantially rectangular shape and thickness is provided on the surface of the flexible substrate 39. It is protruding. The flexible substrate 39 has a width that can be guided between the ridges 28E provided on both sides of the lower sandwiching plate 28B. As shown in the figure, the temperature sensor 4 is sandwiched between the upper and lower sandwich plates 28A and 28B, and the temperature detection element portion 4A is in close contact with or close to the inner surfaces of the sandwich plates 28A and 28B. 13 is fixed. The flexible substrate 39 of the temperature sensor 4 is drawn out of the heat conducting plate 13 and connected to the circuit board 5. The temperature sensor 4 uses a thermistor, but a temperature sensor other than the thermistor can also be used.

18 to 22 show a state in which the heat conduction plate 28 clamps and fixes the temperature sensor 4 to the upper and lower sandwich plates 28A and 28B. The sandwiching plates 28A and 28B sandwich and fix the temperature sensor 4 as follows.
(1) The temperature sensor 4 is disposed on the lower sandwiching plate 28B in the state indicated by the chain line in FIG. 22, that is, the upper and lower sandwiching plates 28A and 28B are opened and not connected by the locking portion 28D. .
(2) The upper sandwiching plate 28A is tilted in the direction indicated by the arrow, and the temperature sensor 4 is sandwiched between the upper and lower sandwiching plates 28A and 28B. When the upper sandwiching plate 28A is tilted in this direction, the elastic connecting arm 28C is elastically deformed. The upper sandwiching plate 28A is tilted in the direction indicated by the arrow, the upper sandwiching plate 28A is moved in a direction approaching the lower sandwiching plate 28B, and the temperature sensor 4 is moved by the upper and lower sandwiching plates 28A and 28B. Pinch.
(3) When the upper and lower clamping plates 28A and 28B approach until the temperature sensor 4 is clamped and fixed, the locking portion 28D is locked by the convex 28E, and the upper and lower clamping plates 28A and 28B are opened. There is no concatenation. This completes the assembly.

  The temperature detector 12 is configured so that the portion of the heat conduction plate 28 pressed against the battery 2 has a shape along the cylindrical shape of the battery 2, and the heat conduction plate 28 in the figure is a groove shape, so that the heat of the battery 2 can be effectively used. Conducted to 28. Although it is desirable for heat conduction to contact the battery surface, the heat conduction plate 28 may have a slight gap. In the illustrated temperature detection unit 12, the heat conducting plate 28 is elastically pressed against the battery surface by the elastic legs 29. The elastic legs 29 are integrally formed with a heat conduction plate 28 made of a metal plate that can be elastically deformed.

  In the illustrated charger, the temperature detection unit 12 is disposed at a position approaching the first holding unit 11 </ b> A from the center of the battery 2. The charger shown in the figure is provided with the temperature detection unit 12 close to the hole-shaped holding unit into which the end of the battery 2 is inserted. Therefore, even if the heat conduction plate 28 of the temperature detection unit 12 pushes up the battery 2, It is possible to effectively prevent the upward displacement of the battery 2. This is because the hole-shaped holding portion can prevent the battery 2 from shifting vertically and horizontally. For this reason, the charger of this structure can press the heat conduction plate 28 of the temperature detection part 12 firmly on the surface of the battery 2, and can detect a battery temperature more correctly.

  The four heat conductive plates 28 have substantially the same shape. The heat conducting plate 28 is made of a metal plate that can be elastically deformed. The heat conduction plate 28 sandwiches the temperature sensor 4 with upper and lower sandwiching plates 28A and 28B. The sandwiching plates 28A and 28B sandwiching the temperature sensor 4 are elastically pressed against the battery surface by the elastic legs 29, and the battery temperature is detected. The illustrated heat conducting plate 28 has protrusions 28E on both sides of the lower sandwiching plate 28B. The protrusions 28E are located on both sides of the upper sandwiching plate 28A, more precisely on the outer side of the upper sandwiching plate 28A. Such ridges 28E are formed by bending a metal plate into a groove shape. The upper sandwiching plate 28A is laminated between the ridges 28E of the lower sandwiching plate 28B. The protrusion 28E protrudes upward from the upper sandwiching plate 28A, and is formed into a groove shape by the upper sandwiching plate 28A and the protrusion 28E of the lower sandwiching plate 28B. As shown in the cross-sectional views of FIGS. 18 to 21, the heat conducting plate 28 detects the battery temperature by bringing the ridges 28E and the upper surface of the upper sandwiching plate 28A into contact with or approaching the battery surface.

  The heat conduction plate 28 having this shape is manufactured by punching and bending a single metal plate. The heat conducting plate 28 manufactured from one metal plate is processed into a shape in which upper and lower sandwiching plates 28A and 28B, an elastic connecting arm 28C, a locking portion 28D, and an elastic leg 29 are connected. . In the illustrated heat conduction plate 28, the metal plate has a shape in which the upper and lower sandwiching plates 28A and 28B are coupled by the elastic coupling arm 28C, and the ridge 28E and the elastic leg 29 are coupled to both sides of the lower sandwiching plate 28B. It is manufactured by punching into the shape to be made.

  As shown in FIG. 15, the elastic connecting arm 28 </ b> C has a shape that is easily elastically deformed as two narrow rows of elastic connecting arms 28 </ b> C and 28 </ b> C. Further, as shown in FIGS. 13 and 20, the elastic connecting arm 28 </ b> C has a shape that is curved with a predetermined radius of curvature, and is further easily deformed. As shown in FIG. 13, the heat conducting plate 28 is provided with slits 28 </ b> F between two narrow rows of elastic connection arms 28 </ b> C. The heat conduction plate 28 shown in the figure has a first end portion at the center side in the extending direction of the battery 2 of the sandwich plate 28A, and an elastic connection arm 28C is provided at this end portion. However, the first end may be the opposite end. Further, in the illustrated heat conduction plate 28, the end portions in the vertical direction (= extending direction) of the battery 2 are used as the first and second end portions of the sandwiching plate. The ends in the horizontal direction perpendicular to the current direction may be the first and second ends.

  The illustrated heat conduction plate 28 is provided with locking portions 28D on both sides of the upper sandwiching plate 28A. The upper sandwiching plate 28A is bent at the tip end in an L shape, provided with notches 28G on both sides of the bent portion, and the outside of the notch 28G is used as a locking portion 28D. The locking portion 28D is bent so that the tip thereof is inclined toward the elastic connecting arm 28C. That is, the locking portion 28D is inclined in the direction of the elastic connecting arm 28C from the vertical direction in the state when the assembly is completed. The locking portion 28D is locked to the inner surface of the ridge 28E provided on both sides of the lower sandwiching plate 28B. Therefore, the locking portion 28D has a shape guided by the inner surface of the protrusion 28E of the lower sandwiching plate 28B. In other words, the locking portion 28D has an outer shape smaller than the inner shape of the protrusion 28E. As shown in FIG. 22, when the upper and lower sandwiching plates 28A and 28B are brought close to each other, the locking portion 28D bent in an inclined posture is locked to the inner surface of the ridge 28E. When the upper sandwiching plate 28A is tilted in the direction indicated by the arrow and moved so as to approach the lower sandwiching plate 28B, the locking portion 28D is elastically deformed and exceeds the end of the ridge 28E. , Is guided and locked to the inner surface of the ridge 28E. The protrusion 28E protrudes to a position where the end of the locking portion 28D can be locked to the end.

  As described above, the structure in which the locking portions 28D are provided on both sides of the upper sandwiching plate 28A can reliably and stably connect the upper and lower sandwiching plates 28A and 28B. However, the charger of the present invention does not specify the structure of the locking portion 28D that locks the upper and lower sandwiching plates 28A and 28B as the above mechanism. Although the upper and lower clamping plates are not shown, they can be connected so as not to open with one locking part provided in the middle of the bent part, and the lower clamping plate is provided with a locking part, It can also be connected so that it does not open. Furthermore, it is also possible to provide a structure in which a through hole is provided in one of the sandwiching plates, and a latching portion is inserted into this through hole so that the upper and lower sandwiching plates are not opened.

  The heat conducting plate 28 is formed by cutting one metal plate that can be elastically deformed and connecting elastic legs 29 to the sandwiching plate 28B. The elastic legs 29 are provided on both sides of the sandwiching plate 28B. The heat conducting plate 28 can press the sandwiching plate 28B against the battery surface with a good left / right balance. This is because the elastic legs 29 on both sides press the sandwich plate 28B against the battery surface. A heat conducting plate 28 with elastic legs 29 is shown in FIGS. 12, 13, 18, 19, and 22. FIG. The heat conducting plate 28 shown in these figures is connected to both sides of the lower sandwiching plate 28B and provided with elastic legs 29. A pair of elastic legs 29 provided on both sides of the sandwiching plate 28 </ b> B have lower ends connected to the fixed plate 30. The fixing plate 30 is the circuit board 5. However, the fixed plate does not necessarily need to be a circuit board. For example, although not shown, it may be a base plate formed by molding plastic or the like.

  The fixed plate 30 opens a through hole 31 that connects the lower ends of the pair of elastic legs 29. The elastic leg 29 is inserted into the through hole 31 and connected to the fixed plate 30. As shown in FIGS. 13, 18, and 19, the elastic leg 29 is inserted into the through hole 31 so as to move up and down with respect to the fixed plate 30. The elastic leg 29 has its lower end bent outward so as not to come out of the through hole 31 of the fixed plate 30. The elastic leg can be connected to the fixed plate so that the lower end is bent inward and does not come off.

  The heat conducting plate 28 moves the elastic legs 29 up and down into the through holes 31 of the fixed plate 30 and elastically presses the sandwich plates 28A and 28B against the battery surface. In order to realize this, the pair of elastic legs 29 shown in the figure has a shape that inclines in a direction gradually separating upward from the through hole 31. The pair of elastic legs 29 shown in FIGS. 18 and 19 are formed by bending the left elastic leg 29 into a square shape and the right elastic leg 29 into a reverse letter shape so that the intermediate gap is wide. Yes. Contrary to this figure, the elastic leg 29 is bent upward on the right elastic leg and bent upward on the left elastic leg upward from the through hole of the fixed plate. Therefore, it can also incline in the direction which approaches mutually.

  The illustrated elastic leg 29 is biased in a direction in which the interval between the lower ends is elastically widened, and elastically pushes the sandwich plate 28B upward. The elastic legs 29 that are expanded in the direction in which the interval is elastically widened are urged in the direction in which they are removed from the fixed plate 30 to elastically push up the sandwiching plate 28B upward. When the sandwiching plate 28B is pushed against the battery surface, the elastic legs 29 that are elastically expanded are pushed into the through holes 31 with the interval narrowed. Since the pair of elastic legs 29 is elastically biased in a direction in which the interval is increased, the elastic legs 29 pushed into the through holes 31 of the fixed plate 30 are elastically expanded from the fixed plate 30. Extruded.

  The elastic leg 29 having the above structure is moved up and down in the through hole 31 of the fixed plate 30 to press the clamping plate 28B against the battery surface, so that the vertical stroke of the clamping plate 28B is increased to increase the clamping plate 28B. 28B can be elastically pressed against the battery surface. Therefore, there is a feature that the battery temperature can be accurately detected by reliably pressing the sandwiching plates 28A and 28B against the battery surface.

  In addition, since the lower end of the elastic leg 29 can be inserted into the through hole 31 of the fixed plate 30 and connected to the fixed plate 30, the elastic leg 29 can be easily and easily connected to the fixed plate 30. Further, since the lower end of the elastic leg 29 can be pulled out from the through hole 31 of the fixed plate 30 and removed, the heat conducting plate 28 can be easily replaced.

  The temperature detection unit 12 described above conducts the heat of the battery 2 to the temperature sensor 4 through the sandwiching plates 28A and 28B, as indicated by arrows in FIG. In particular, the sandwiching plates 28A and 28B that are elastically in contact with the surface of the battery 2 effectively conduct the heat of the battery 2. The temperature sensor 4 is sandwiched between the sandwiching plates 28A and 28B, and the heat of the sandwiching plates 28A and 28B is effectively conducted. In the illustrated heat conduction plate 28, protrusions 28E are provided on both sides of the lower sandwiching plate 28B, and the surface of the protrusions 28E is brought into contact with the battery surface. The lower sandwiching plate 28 </ b> B that contacts the protrusion 28 </ b> E with the battery surface efficiently conducts heat from the battery 2 and conducts it to the temperature sensor 4. Further, the central portion of the upper sandwiching plate 28A can also be brought into contact with the battery surface. The upper sandwiching plate 28A efficiently conducts heat of the battery 2 and efficiently conducts heat to the temperature sensor 4 sandwiched on the lower surface.

  The charger that efficiently conducts the heat of the AA battery 2A and the AAA battery 2B to the temperature sensor 4 through the above path efficiently conducts the heat of the battery 2 from the sandwiching plates 28A and 28B to the temperature sensor 4. Further, the temperature sensor 4 is not cooled due to contact with air. Further, air flows between the sandwiching plates 28A and 28B of the heat conducting plate 28 and the battery 2, and the sandwiching plates 28A and 28B are not cooled by air, so that the heat of the battery 2 is sandwiched. Conductive from 28A, 28B to temperature sensor 4 effectively. Therefore, the heat of the battery 2 is effectively conducted from the sandwiching plates 28A and 28B to the temperature sensor 4, and cooling of the sandwiching plates 28A and 28B and the temperature sensor 4 by air is reduced, so that the AA batteries 2A and AAA The temperature of the battery 2B can be accurately detected by the temperature sensor 4 with little time delay and with high accuracy.

  When the AAA battery 2B thinner than the AA battery 2A is mounted, the battery surface comes into contact with the central portion of the upper sandwiching plate 28A. In the AA battery 2 </ b> A, the protrusion 28 </ b> E of the lower sandwiching plate 28 </ b> B contacts the surface, but in the AAA battery 2 </ b> B having a small radius, the central portion of the upper sandwiching plate 28 </ b> A contacts the surface of the battery 2.

  The charger of this embodiment has a socket 33 (see FIG. 11) for connecting an external power line 32 and four LED elements 34 corresponding to each battery that emits light during charging and displays the state of charge. ing.

The charging circuit detects the battery temperature with the temperature sensor 4, controls the average charging current so that the battery temperature becomes the holding set temperature, and performs charging while holding the battery temperature at the holding set temperature. This charger has the feature that the battery 2 can be charged in an extremely short time. In particular, both the AA battery 2A and the AAA battery 2B can be charged in a short time by charging both the AA battery 2A and the AAA battery 2B while maintaining the battery temperature at the holding set temperature.

It is a circuit diagram which shows an example of the charging circuit of the charger concerning one Example of this invention. It is a graph which shows a temperature characteristic and voltage characteristic when charging a battery with the charger concerning one Example of this invention. It is a perspective view of the charger of one Example of this invention. It is a top view which shows the state which attached the AA battery to the charger shown in FIG. FIG. 5 is a rear perspective view of the charger shown in FIG. 4. It is a side view of the charger shown in FIG. It is an AA line sectional view of the charger shown in FIG. It is a perspective view which shows the state which raised the switching output terminal of the charger shown in FIG. It is a back perspective view which shows the state which mounted | wore the charger shown in FIG. 8 with the AAA battery. It is sectional drawing of the charger shown in FIG. 8, Comprising: It is a figure corresponded in the AA sectional view of FIG. It is a perspective view which shows the state which removed the upper case of the charger shown in FIG. It is an expansion perspective view which shows the vicinity of the temperature detection part of the charger shown in FIG. It is the perspective view which looked at the temperature detection part shown in FIG. 12 from the other side. FIG. 9 is a perspective view showing a state where the AAA battery is mounted on the charger shown in FIG. 8 and the upper case is removed. FIG. 4 is a perspective view showing a state in which an AA battery is attached to the charger shown in FIG. 3 and an upper case is removed. It is a circuit diagram which shows an example of a detection circuit. It is sectional drawing which shows the state in which an AAA battery is not normally set to the charger shown in FIG. It is sectional drawing which shows the state which detects the battery temperature of an AA battery in a temperature detection part. It is sectional drawing which shows the state which detects the battery temperature of a AAA battery in a temperature detection part. It is a longitudinal cross-sectional view of the temperature detection part shown in FIG. It is an expanded sectional view which shows the state which detects battery temperature with a temperature sensor. It is an expansion perspective view of a temperature detection part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Case 1A ... Upper case 1B ... Lower case 2 ... Battery 2A ... AA battery 2B ... AAA battery
2a ... convex electrode 3 ... battery pocket 4 ... temperature sensor 4A ... temperature detection element part 5 ... circuit board 6 ... output terminal 7 ... output terminal 7A ... contact piece 8 ... switching output terminal 9 ... support member 9A ... insulating base part 9B ... Connecting part
9C ... Shaft part 9D ... Supporting convex part
9E: Switch pressing part
DESCRIPTION OF SYMBOLS 9a ... Recessed part 10 ... Auxiliary terminal 11 ... Holding part 11A ... 1st holding part 11B ... 2nd holding part 12 ... Temperature detection part 13 ... Circular opening 14 ... Elastic arch 14A ... Coil spring part 15 ... Position switch 16 ... Detection Circuit 17 ... Wire forming SW
DESCRIPTION OF SYMBOLS 18 ... Voltage dividing resistor 19 ... Intermediate connection point 20 ... Voltage detection circuit 21 ... Power supply 22 ... Ground 23 ... Support part 24 ... Cooling opening 25 ... Cooling fan 26 ... Ventilation hole 27 ... Gap 28 ... Heat conduction plate 28A ... Clamping plate 28B ... sandwiching plate
28C ... Elastic connecting arm 28D ... Locking part 28E ... Projection 28F ... Slit 29 ... Elastic leg 30 ... Fixing plate 31 ... Through hole 32 ... Power line 33 ... Socket 34 ... LED element 41 ... Battery 42 ... Power supply circuit 43 ... Switching Element 44 ... Control circuit 45 ... Temperature sensor 46 ... Changeover switch

Claims (1)

It is a charging method for detecting the battery temperature of the battery and controlling the average charging current so that the battery temperature becomes the holding set temperature, while driving the cooling fan to cool the ambient air against the battery, A temperature holding charging step of charging while holding the battery temperature at the holding set temperature ;
Prior to the temperature holding charging step, a temperature rising charging step of charging the battery temperature with a large current to increase the battery temperature and raising the battery temperature to the holding set temperature,
When charged in the temperature rising charging step and the battery temperature reaches the holding set temperature, the process proceeds to the temperature holding charging step,
In the temperature rising charging step, the cooling fan is driven to charge the ambient air against the battery while cooling,
The charging method according to claim 1, wherein a rotation speed of the cooling fan at the temperature holding charging step is set lower than a rotation speed of the cooling fan at the temperature rising charging step.

Images