JP4097376B2 - Battery powered portable power tool - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a contact configuration of a terminal that can contact a terminal provided in a storage battery that supplies electric power to a motor that is a drive source.
[0002]
[Prior art]
A conventional portable electric tool will be described using an impact driver, for example. As shown in FIG. 5, the impact driver transmits a rotational force and a striking force to a motor 10 as a drive source in the housing 5, a gear mechanism for reducing the rotational power of the motor 10, and a tip tool (not shown). And a handle portion for operating the impact driver main body is formed in the housing 5. In the handle portion, a switch 9 that mainly controls power supply to the motor 10 and a terminal 3 that can be electrically contacted with the terminal 2 of the storage battery 1 that is detachably disposed at the lower end portion of the handle are accommodated. Has been. In the impact driver having such a configuration, in order to transmit power to the tip tool, the power of the storage battery 1 is supplied to the switch 9 via the terminal 3 that contacts the terminal 2 of the storage battery 1 and further via the lead wire. It is necessary to supply power to the motor 10.
[0003]
Here, the contact part of the terminal 2 and the terminal 3 of the storage battery 1 is demonstrated using FIGS. 6 is an arrow view seen from the direction A of FIG. 5, FIG. 7 is an external view showing the copper terminal 3 and the stainless steel back spring 4, and FIG. 8 is an arrow view seen from the direction B of FIG. is there. In addition, in FIG. 6, the left side from the center line shows a state where the storage battery 1 is not mounted, and the right side shows a state where the storage battery 1 is inserted. The terminal 3 is caulked to the terminal support 6 together with the back spring 4, and the terminal support 6 is fixed to the housing 5. The terminal 3 and the switch 9 are directly connected by caulking. Further, the R portion of the terminal 3 formed by being bent into a U-shape is in press contact with the terminal 2 of the storage battery 1 and a load applied to the terminal 3 from the contact surface is arranged on the outer periphery of the terminal 3. 4 to cover.
[0004]
In addition to the contact configuration described above, for example, there are contact configurations shown in FIGS. FIG. 9 is a vertical side view of the handle portion showing another contact example, FIG. 10 is an external view showing the copper terminal 3, and FIG. 11 is an arrow view seen from the direction B of FIG. In FIG. 9, the left side from the center line shows a state where the storage battery 1 is not mounted, and the right side shows a state where the storage battery 1 is inserted. The terminal support 6 restrains the terminal 3 by being incorporated between the left and right terminals 3. Further, the top of the bent portion bent into a chevron is in pressure contact with the terminal 2 of the storage battery 1 and the load applied to the terminal 3 from the contact surface is covered with the terminal 3 itself having a leg portion that always contacts the housing. It is configured to
[0005]
[Problems to be solved by the invention]
Each problem of the contact configuration described above will be described in detail below.
[0006]
In the contact configuration shown in FIGS. 6 to 8, the contact surface of the terminal is R-shaped, so the contact area is small, and a large current easily flows at a local location. Further, when using an impact driver or impact wrench, etc. The problem is that chattering is likely to be induced in the contact portion due to the generated vibration, thereby generating an oxide and causing poor conduction, and heat generated by the resistance of this oxide makes the terminal and the terminal of the storage battery unusable. was there.
[0007]
Moreover, in the contact structure shown in FIGS. 9-11, since the terminal is contacting the housing, there existed a problem that the heat which generate | occur | produced in the contact part was directly transmitted to a housing from a terminal, and the housing was thermally deformed. .
[0008]
An object of the present invention is to solve the above problems, stabilize the contact between the terminal of the storage battery and the terminal, and prevent the housing from being thermally deformed, thereby improving the life of the contact surface and its peripheral members.
[0009]
[Means for Solving the Problems]
The object is to provide a housing for housing the motor, a handle portion formed on the housing, a storage battery detachably attached to the handle portion, a terminal provided on the storage battery, a copper terminal that is in electrical contact with the terminal, and a terminal and a terminal. A battery comprising a back spring arranged on the outer periphery of the terminal so as to cover a load received from the contact surface, a terminal support to which the back spring and one end of the terminal are fixed, and a housing part for arranging the terminal support in the handle part In the portable power tool, a flat portion that comes into contact with the terminal is provided on the other end of the terminal, and an extension that contacts the inner periphery of the handle portion is provided on the other end of the back spring. This is achieved by pressing the flat portion with a deformed back spring.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
A portable electric tool according to the present embodiment will be described using an impact driver shown in FIGS. 1 is a partially longitudinal side view showing an impact driver according to the present embodiment, FIG. 2 is an arrow view seen from the direction A in FIG. 1, and FIG. 3 is an external view showing a terminal 3 and a back spring 4 according to the present embodiment. It is a figure, (a) is an external view which shows the copper terminal 3 and the stainless steel back spring 4, (b) is the stainless steel back with the slit formed like the copper terminal 3 with the slit formed. FIG. 4 is an external view showing the spring 4, and FIG. 4 is an arrow view seen from the direction B of FIG.
[0011]
As shown in FIG. 1, the impact driver transmits a rotational force and a striking force to a motor 10 as a drive source, a gear mechanism for reducing the rotational power of the motor 10, and a tip tool (not shown). And a handle portion as a grip portion for operating the impact driver main body. In the handle portion, a switch 9 that mainly controls power supply to the motor 10 and a terminal that makes electrical contact with a terminal 2 (hereinafter referred to as a battery terminal) of the storage battery 1 that is detachably disposed at the lower end of the handle portion. 3 etc. are accommodated. In the impact driver configured as described above, in order to transmit power to the tip tool, the power of the storage battery 1 is supplied to the switch 9 via the terminal 3 that is in electrical contact with the battery terminal 2, and further the lead wire. It is necessary to supply power to the motor 10 via
[0012]
Here, the contact between the battery terminal 2 and the terminal 3 will be described in detail with reference to FIGS. In FIG. 2, the left side of the center line shows a state where the storage battery 1 is not attached to the handle part, and the right side shows a state where the storage battery 1 is inserted into the handle part.
[0013]
The case where the terminal 3 and the back spring 4 shown in FIG. 3A are used as the contact members of the impact driver shown in FIGS. 1 and 2 will be described. A back spring 4 is arranged on the outer periphery of the terminal 3 having a plane portion having a larger contact area than the conventional R portion for electrical contact with the battery terminal 2, and the back spring 4 is disposed on the opposite side of the switch. Since the back spring 4 presses the center of the flat surface portion to contact the battery terminal 2 by the elastic force generated when the extending end portion is always in contact with the inner periphery of the housing 5, the contact pressure is made uniform. In addition, the load from the contact surface applied to the terminal 3 can be reliably covered by the back spring 4. With such a configuration, stable conductivity and contact pressure can be obtained, and the battery terminal 2 can be obtained by arranging the back spring 4 made of stainless steel having high heat resistance and low thermal conductivity on the terminal 3. Since heat generated at the contact surface between the terminal 3 and the terminal 3 is transmitted through the back spring 4, thermal deformation of the housing 5 can be prevented.
[0014]
The terminal 3 is caulked to the terminal support 6 together with the back spring 4, and the terminal support 6 is movably disposed in a terminal support accommodating portion formed in the housing 5. That is, as shown in FIG. 4, a predetermined gap is provided between the housing part and the terminal support 6, which is larger than the movable range of the storage battery 1 housed in the handle part. In addition, by connecting the terminal 3 and the switch 9 together with a flexible conductor 8 ′, the terminal 3 can easily move together with the storage battery 1 due to the vibration of the impact driver main body, and contact failure is unlikely to occur. By adopting such a configuration, more stable conductivity and contact pressure can be obtained.
[0015]
Further, as shown in FIG. 3B, when the terminal 3 ′ having a slit in the longitudinal direction and the back spring 4 ′ are used, the contact parts divided into two parts move independently, so that vibration is generated in the impact driver main body. However, even if one of the contact pieces is separated from the contact surface, the other contact piece is kept in contact with each other, so that more stable conductivity can be obtained. In the present embodiment, the terminal 3 ′ and the back spring 4 ′ divided into two parts have been described.
[0016]
In the present embodiment, a flat portion (flat portion) is provided in the terminal 3 that contacts the terminal 2. However, even if vibration occurs in the flat portion, the terminal 2 and the terminals 3 and 3 ′ are in sufficient electrical contact. What is necessary is just to have an area.
[0017]
Further, in the present embodiment, the impact driver has been described as an example, but in addition to this, the same effect as described above can be obtained even when the battery powered electric tool is used in an impact wrench, a driver drill, a grinder, or the like. Can do.
[0018]
【The invention's effect】
According to the present invention, the flat surface portion that contacts the terminal is provided on the other end side of the terminal, the extending portion that contacts the inner periphery of the handle portion is provided on the other end side of the back spring, and further, elastic deformation by the extending portion is provided. By configuring the flat portion to be pressed by the back spring formed, the contact between the terminal and the terminal can be stabilized and the housing can be prevented from being thermally deformed. As a result, the life of the contact surface and its peripheral members is improved. Can be achieved.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing a battery-powered portable power tool according to the present invention.
FIG. 2 is an arrow view seen from the direction A in FIG.
FIG. 3 is an external view showing a terminal and a back spring according to the present invention, (a) is an external view showing a copper terminal and a stainless back spring, and (b) is a copper terminal with a slit formed therein. It is an external view which similarly shows the stainless steel back spring in which the slit was formed.
4 is an arrow view seen from the direction B in FIG. 2;
FIG. 5 is a vertical sectional side view showing a conventional battery-powered portable power tool.
6 is an arrow view seen from the direction A in FIG. 5;
FIG. 7 is an external view showing a conventional copper terminal and a stainless back spring.
FIG. 8 is a view seen from the direction B in FIG. 6;
FIG. 9 is a longitudinal side view of a handle portion showing another contact example.
FIG. 10 is an external view showing another copper terminal.
11 is an arrow view seen from the direction B in FIG. 9;
[Explanation of symbols]
1 is a storage battery, 2 is a terminal, 3 is a terminal, 3 'is a terminal, 4 is a back spring, 4' is a back spring, 5 is a housing, 6 is a terminal support, 7 is a terminal crimping portion, 8 is a switch crimping portion, 8 'Is a conducting wire, 9 is a switch, 10 motors, and 11 is an output mechanism.

Claims (1)

A housing for housing the motor;
A handle portion formed in the housing;
A storage battery detachably attached to the handle part;
A terminal provided on the storage battery;
A copper terminal in electrical contact with the terminal;
A back spring disposed around the terminal so as to cover a load received from a contact surface between the terminal and the terminal;
A terminal support to which one end side of the back spring and the terminal is fixed;
A battery-powered portable power tool comprising: a housing portion for disposing the terminal support in the handle portion;
A flat portion that contacts the terminal is provided on the other end side of the terminal, and an extending portion that contacts the inner periphery of the handle portion is provided on the other end side of the back spring made of a material having a lower thermal conductivity than the terminal. And the back spring that is elastically deformed by the extending portion is configured to press the center of the flat surface portion, and further, a clearance is provided between the housing portion and the terminal support so that the terminal is connected to the storage battery. A battery-powered portable power tool characterized in that the terminal and a switch for supplying power to the motor are connected by a flexible conductive wire.

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