JP4739910B2 - Battery pack mounting structure for electric tools - Google Patents

Description

  The present invention relates to a mounting structure for mounting a battery pack serving as a power source in an electric power tool such as an impact driver.

In a rechargeable electric tool, for example, a battery pack containing a plurality of storage batteries is attached to a lower end of a handle with a known structure such as a locking claw and used as a power source. That is, at the same time when the battery pack is mounted, the positive and negative terminals on the handle side and the battery pack side come into contact with each other and are electrically connected so that power can be supplied.
In such a rechargeable power tool, such as an impact driver that vibrates during use, if the battery pack rattles due to vibration, chattering occurs between the terminals that come into contact with the battery, reducing the terminal life. I will let you. Therefore, as a measure for preventing such rattling, for example, as shown in Patent Document 1, the battery pack is accommodated in the housing of the electric tool in the same direction as the vibration direction, and the terminal is arranged in a direction orthogonal to the vibration direction. A structure in which the battery packs are brought into contact with each other and the battery pack is urged by a leaf spring in a pressing direction between the terminals can be considered.

Japanese Utility Model Publication No. 62-123064

In this case, when the battery pack is mounted, the leaf spring always comes into contact with the same position of the battery pack, the position of the battery pack is worn out, and the urging force is reduced. In addition, the leaf spring itself may decrease the elastic force with long-term use, and the reliability of preventing rattling has been lacking.
On the other hand, the urging force of the leaf spring acts in a direction orthogonal to the direction in which the battery pack is attached / detached, which causes great resistance when the battery pack is attached / detached, and impairs the feeling of use.

  Therefore, the present invention is capable of preventing rattling with high reliability without causing wear on the battery pack, and mounting the battery pack in an electric tool that does not impair the feeling of use when the battery pack is attached or detached. The purpose is to provide a structure.

In order to achieve the above object, according to the first aspect of the present invention, the mounting portion or the battery pack on the power tool side has elasticity, and the outer surface of the battery pack or the inner surface of the mounting portion is accompanied by the mounting operation of the battery pack. And a rolling element that elastically presses the inner surface of the battery pack or the mounting portion when the battery pack is mounted.
According to a second aspect of the present invention, in addition to the object of the first aspect, the battery pack has a structure in which a part of the battery pack is inserted into the mounting portion to be mounted. And a roller, and in a mounted state of the battery pack, the battery pack is pressed in a direction perpendicular to the insertion direction into the mounting portion.
The battery pack mounting structure of the present invention includes not only a mode in which a part of the battery pack is inserted into the housing of the electric power tool but also a mode in which the entire battery pack is accommodated in a mounting portion provided in the housing.

According to the first aspect of the present invention, by adopting the rolling element having elasticity , the battery pack is not worn, and the rolling element itself also changes its contact location each time the battery pack is mounted, so that the battery pack can be worn for a long time. The elasticity can be maintained throughout. Therefore, it is possible to prevent rattling with high reliability and to expect effective chattering prevention. In addition, since the resistance is reduced by the rolling of the rolling element when the battery pack is mounted, the feeling of use when attaching and detaching is not impaired.
According to invention of Claim 2, in addition to the effect of Claim 1, in the insertion form, a rolling element can be arrange | positioned in a suitable position.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<< Form 1 >>
FIG. 1 is an explanatory view showing a state in which a battery pack 20 is mounted on an impact driver 1 which is an example of an electric tool. First, the impact driver 1 extends a handle 3 downward to divide the left and right halves into two halves. A motor 4 and a striking mechanism 5 including a spindle 6, a hammer 7, a coil spring 8 and the like are provided above the housing 2 assembled with screws, and the hammer 7 is placed in front of the housing 2 (on the right side in FIG. 1). It is a well-known structure that is engaged with the arm 10 of the anvil 9 protruding from the front. That is, when the motor 4 is driven, the hammer 7 is rotated together with the spindle 6 to rotate the anvil 9, and when the load on the anvil 9 is increased, the hammer 7 is retracted and temporarily detached from the arms 10, 10, and the coil spring 8 is attached. By repeating the operation of engaging the arms 10 and 10 while moving forward again due to the force, the anvil 9 is intermittently hit in the rotational direction. Reference numeral 11 denotes a switch provided in the handle 3. Reference numeral 12 denotes a trigger for turning on the switch 11 by a pushing operation. A battery holder 13 having positive and negative terminal fittings 14 and 14 is connected to the switch 11 below. The terminal fittings 14, 14 serving as terminals on the electric tool side protrude into the mounting portion 15 of the battery pack 20 formed so as to open the lower end below the handle 3.

On the other hand, the battery pack 20 has an insertion part 22 with an oval cross section projecting from the upper side of a case 21 containing a plurality of storage batteries, and serves as a terminal on the battery pack 20 side on both sides of the insertion part 22. With a well-known structure in which the positive and negative electrode plates 23 and 23 are exposed, both sides below the case 21 are locked with locking portions 16 and 16 provided at the lower end of the handle 3 in a mounted state on the mounting portion 15. Hook buttons 24, 24 are provided.
Therefore, when the battery pack 20 is inserted into the mounting portion 15 from below the handle 3 with the insertion portion 22 facing upward, and inserted into the mounting portion 15 until the hook button 24 is locked to the locking portion 16, the insertion portion The upper half of the battery pack 20 including 22 is housed in a fitting state in the mounting portion 15, and the left and right electrode plates 23, 23 are held in a manner sandwiched between the terminal fittings 14, 14 of the battery holder 13. Electrically connected.

  In the mounting portion 15 of the impact driver 1, at the rear of the lower end of the handle 3, there are three rollers 17, 17,. Is provided. Each roller 17 is made of urethane, is externally mounted on a pin 18 held in the left-right direction in the handle 3 and protrudes into the mounting portion 15 in a rotatable state, and is attached to the mounting portion 15 of the battery pack 20. The rear surface of the step portion 25 formed so as to close the opening of the mounting portion 15 on the upper side of the battery pack 20 can be contacted. In this contact state, each roller 17 presses the step portion 25 forward by its elasticity, and presses the front end of the step portion 25 against the inner surface of the handle 3.

  Therefore, the roller 17 rolls in contact with the rear surface of the step portion 25 of the battery pack 20 when the battery pack 20 is inserted into the mounting portion 15 from below, and enters the battery pack 20 without applying a large load. On the other hand, when the battery pack 20 is mounted, the battery pack 20 is pressed forward to prevent rattling. Accordingly, when the impact driver 1 is used for screw tightening or the like, the battery pack 20 is held in the mounting portion 15 without rattling even if vibration is generated by the striking operation generated by the striking mechanism 5. Therefore, chattering between the terminal fitting 14 and the electrode plate 23 is also preferably prevented.

As described above, according to the mounting structure of the battery pack 20 of the first aspect, the mounting portion 15 rolls in contact with the outer surface of the battery pack 20 as the battery pack 20 is mounted. Since the roller 17 that elastically presses the outer surface of the battery pack 20 in the state is provided, the battery pack 20 is not worn, and the contact position of the roller 17 itself changes every time the battery pack 20 is mounted. Thus, elasticity can be maintained for a long time. Therefore, it is possible to prevent rattling with high reliability and to expect effective chattering prevention. Specifically, it is confirmed that the durability is three times or more as compared with a conventional battery pack mounting structure in which the roller 17 is not provided.
Further, when the battery pack 20 is mounted, the resistance is reduced by the rolling of the roller 17, so that the feeling of use at the time of attachment / detachment is not impaired.
In particular, in this embodiment, the roller 17 is used as the rolling element, and when the battery pack 20 is mounted, the battery pack 20 is pressed in a direction perpendicular to the insertion direction into the mounting portion 15. The moving body can be arranged at a suitable position.

Hereinafter, other embodiments of the present invention will be described. Since the basic structure of the impact driver and the battery pack is the same as that of the first embodiment, the description will focus on the mounting portion of the battery pack, and duplicate contents will be omitted.
<< Form 2 >>
In the mounting structure of the battery pack 20 shown in FIG. 2, two horizontal pins 30, 30 are provided in parallel up and down, and a wide roller 31 made of urethane is stretched between the pins 30, 30 in an oval shape. A so-called caterpillar (registered trademark) is provided. Also in this case, when the battery pack 20 is mounted, the roller 31 abuts against the step portion 25 and rolls to allow the battery pack 20 to enter the battery pack 20 without applying a load. Pushing forward will prevent rattling. Therefore, the same effects as those of the first aspect such as prevention of wear and chattering of the battery pack 20 and maintenance of feeling of use can be obtained. In particular, here, the roller 31 is stretched in an oval shape, It can be said that the contact area is larger than that of Form 1 and is more effective in preventing rattling.

<< Form 3 >>
In the battery pack 20 mounting structure shown in FIG. 3, a cylindrical boss 32 serving as a screw attachment position is provided on the inner surface of the half handle 3, so that a roller 33 is provided on the outer periphery of the boss 32. It has been made. Also in this case, when the battery pack 20 is mounted, the roller 33 rolls to allow the battery pack 20 to enter with a small load, and when the battery pack 20 is mounted, the battery pack 20 is pressed forward to prevent rattling. Will do. Therefore, the same effects as those of the first embodiment such as prevention of wear and chattering of the battery pack 20 and maintenance of the feeling of use can be obtained. However, in this case, since the roller 33 is attached using the existing boss 32, the first and second embodiments are used. This eliminates the need for pins such as the above, and provides a rational structure with a small number of parts, resulting in excellent cost.

<< Form 4 >>
In the mounting structure of the battery pack 20 shown in FIG. 4, the pin 34 and the roller 35 are provided not in the opening of the lower side of the handle 3 but in the upper portion of the mounting portion 15, so It can be pressed. In particular, the roller 35 is not of the same diameter in the axial direction as in the previous embodiment, but is centered in accordance with the circular shape of the rear surface of the insertion portion 22 as shown in the cross-sectional view along line BB shown below. The peripheral surface has a curved shape so that has the smallest diameter. In addition, 36 and 36 are storage batteries accommodated in the insertion part 22.
Also in this form, when the battery pack 20 is mounted, the roller 35 rolls in contact with the peripheral surface of the insertion portion 22 to allow the battery pack 20 to enter with a small load, while in the mounted state of the battery pack 20, The insertion portion 22 is pressed forward and pressed against the inner surface on the front side of the handle 3 to prevent rattling. Therefore, the same effect as the above-described embodiment 1 such as prevention of wear and chattering of the battery pack 20 and maintenance of the feeling of use can be obtained. In particular, the curved shape matched to the shape of the insertion portion 22 is not only used here, Since the movement restriction of the insertion portion 22 works also in the left-right direction, the rattling prevention effect is further improved. Moreover, since the insertion part 22 close | similar to the contact position of the terminal metal fitting 14 and the electrode plate 23 is pressed, there also exists an advantage by which chattering is prevented effectively.

<< Form 5 >>
In the first to fourth embodiments, the battery pack having the insertion portion is inserted from below the handle and attached. However, in the attachment structure of the battery pack 40 shown in FIG. A pair of slide rails (not shown) protruding in the direction is held in a well-known manner between a pair of guide rails 41 and 41 formed in the front-rear direction on the left and right ends of the handle 3. Therefore, if the battery pack 40 is inserted from the front side with the slide rail between the guide rails 41, 41 and is slid until the stopper 42 protruding upward at the front end of the battery pack 40 contacts the front end of the guide rail 41, The installation of the battery pack 40 is completed. On the upper surface of the battery pack 40, a hook 43 that can protrude from the upper surface and is urged to a protruding position upward is provided. When the battery pack 40 is attached to the handle 3, the protruding hook 43 is a recess provided in the handle 3. The battery pack 40 is locked to the front to prevent the battery pack 40 from coming off.

  In this mounting structure, a pin 45 and a roller 46 are provided on the inner surface on the front side in the concave portion 44 of the handle 3, and when the battery pack 40 is mounted, the front surface of the protruding hook 43 is pressed rearward. ing. That is, when the hook 43 protrudes upward at the position of the recess 44, the roller 46 in contact therewith rolls to allow the hook 43 to reliably protrude with a small load, and in the locked state of the hook 43, The battery pack 40 is urged rearward through the hook 43 and the stopper 42 is pressed against the front end of the guide rail 41 to prevent rattling. Therefore, even with such a slide mounting structure, the effect of preventing wear and chattering can be obtained as in the first mode.

<< Form 6 >>
In the first to fifth embodiments, a roller is provided on the handle side to prevent the battery pack from rattling, but it can also be provided on the battery pack side as shown in FIG. Here, in the case 21 of the battery pack 20, a pin 47 with a roller 48 is supported in the left-right direction behind the step portion 25 so that the peripheral surface of the roller 48 protrudes from the rear surface of the step portion 25. ing. In this case, if the handle 3 is provided with a contact portion (for example, a wall portion or a rib) with which the roller 48 contacts when the battery pack 20 is mounted, the contact with the contact portion when the battery pack 20 is inserted. Thus, the roller 48 rolls to allow insertion with a small load, and in the mounted state of the battery pack 20, the roller 48 presses the contact portion to press the battery pack 20 forward. Therefore, as in the above-described embodiments, the contact portion on the handle 3 side is not worn, and the roller 48 itself can maintain elasticity over a long period of time, and it is possible to prevent rattling with high reliability. Moreover, the feeling of use at the time of attachment / detachment by rolling of the roller 48 can also be maintained.

Hereinafter, a modification example common to each embodiment will be described.
One roller may be provided on one pin, or a plurality of rollers may be provided. In the case of a plurality, it is also possible to arrange them at predetermined intervals in the axial direction.
In addition, such a set of pins and rollers is not limited to being provided at one place. For example, if it is possible to prevent the battery pack from rattling, it may be provided before and after the mounting portion or vertically on the same side of the mounting portion. Or may be provided at a plurality of locations in parallel. Of course, it is not limited to urethane, but may be made of other synthetic resin or rubber.
Further, the rolling element is not limited to a roller, and the same effect can be expected even if a ball that is accommodated so as to partially protrude into an accommodating portion that is recessed in a handle (a case in a battery pack) is used. In the case of a plurality of locations, it may be possible to use both rollers and balls.

  In addition, it is also possible to provide protrusions, protrusions, grooves, etc. on the peripheral surface of the rolling elements such as rollers and balls so as to make them contact with the battery pack or the handle side. In this way, a reliable rolling of the rolling element can be expected. However, this unevenness is not limited to the rolling element side, and may be provided on the contact surface with the rolling element on the battery pack side (the rear surface of the stepped portion in the above embodiment), or may be provided on both the rolling element and the battery pack. good.

And each said form is not restricted to what is applied independently, respectively, For example, either form 1-3 which provides a roller in a handle lower end, and form 4 which provides a roller above a mounting part, or this form 4, It is also possible to prevent rattling by combining a plurality of forms, such as combining with a form 6 in which a roller is provided on the step of the battery pack.
In addition, the oval roller stretched between the two pins described in the form 2 is applied to the roller of the form 5 or form 6, the form 3 using the boss is applied to the form 5, etc. The design can be changed between each form.

On the other hand, in the above embodiment, a part of the battery pack is attached to the housing. However, the present invention can be adopted even in a structure in which the entire battery pack is accommodated and attached to the attachment part provided in the housing. is there. In addition, the specific mounting structure between the mounting portion and the battery pack is not limited to the locking between the locking portion and the hook button as described above in the insertion mode, but an elastic spring provided in the mounting portion is attached to the battery pack. Even other systems such as a structure to be engaged do not hinder the adoption of the present invention.
Further, the rechargeable power tool is not limited to the impact driver of the above-described form, and the present invention is naturally applicable to other types such as a soft impact driver and a driver drill using an oil pulse generator.

It is explanatory drawing of the mounting structure of the battery pack of the form 1 (AA line cross section is shown on the lower side). 12 is an explanatory diagram of a mounting structure for a battery pack according to mode 2. FIG. 12 is an explanatory diagram of a mounting structure for a battery pack according to form 3. FIG. It is explanatory drawing of the mounting structure of the battery pack of the form 4 (a BB line cross section is shown on the lower side). FIG. 11 is an explanatory diagram of a battery pack mounting structure according to a fifth embodiment. It is explanatory drawing of the mounting structure of the battery pack of the form 6.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Impact driver, 2 ... Housing, 3 ... Handle, 5 ... Stroke mechanism, 13 ... Battery holder, 14 ... Terminal fitting, 15 .... Mounting part, 17, 31, 33, 35, 46, 48..Roller 18, 30, 34, 45, 47..Pin, 20, 40..Battery pack, 21..Case, 22..Plug part, 23..Electrode plate, 25..Step part.

Claims (2)

A battery pack mounting structure in a power tool in which a battery pack is detachably mounted on a mounting portion formed in a housing of the power tool and the terminals provided on the mounting portion and the battery pack are electrically connected to each other. ,
The mounting portion or the battery pack has elasticity and rolls in contact with the outer surface of the battery pack or the inner surface of the mounting portion in accordance with the mounting operation of the battery pack. A mounting structure for a battery pack in an electric tool, comprising a rolling element that elastically presses the outer surface of the battery pack or the inner surface of the mounting portion. The battery pack has a structure in which a part of the battery pack is inserted into the mounting portion, and the rolling element is a roller. When the battery pack is mounted, the battery pack is in a direction orthogonal to the insertion direction of the mounting portion. The battery pack mounting structure in the electric tool according to claim 1, wherein the battery pack is pressed.

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