JPH0744462Y2 - Portable power tools - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a portable power tool.

(Prior Art) Generally, a portable electric tool of this type has a main body housing that houses a drive unit such as a motor, and a cylindrical battery housing that is integrally formed with the main body housing and also serves as a handle housing. The structure is such that the battery pack is detachably attached to the battery housing. In such a portable power tool, the body housing side is heavier than the battery housing side. Therefore, for example, when dropped on the floor or carried on an automobile, the body housing first hits the floor surface, and then the battery housing. Since it hits and bounces up and fluctuates, vibration and impact are applied to the battery housing, which causes a connection failure of the battery or a failure of related electric parts.

For this reason, Japanese Utility Model Laid-Open No. 58-113477 proposed by the present applicant proposes a structure in which a separate cushion is attached to the handle portion, that is, the battery housing.

(Problems to be solved by the invention) However, in the structure in which a separate buffer body is attached to the battery housing, the buffer body has to be manufactured purposely, resulting in high cost, and the mounting work needs to be performed separately, and the assembly work is therefore performed. Became complicated, and improvement was desired.

(Means for Solving the Problem) A portable power tool of the present invention is a portable power tool having a cylindrical battery housing and a detachable battery pack with a part thereof protruding to the outside. Is provided with a flange portion that covers a seam with the battery housing when it is attached to the battery housing over substantially the entire circumference, and the flange portion is formed so as to project outside the battery pack and A predetermined gap is formed between the two, and the predetermined gap allows elastic deformation of the flange portion when it collides with the floor surface or the like, so that the impact force on the portable power tool can be mitigated.

(Operation) In the portable power tool of the present invention, the battery pack and the battery housing are provided as a means for mitigating the impact force on the floor surface of the battery pack and the battery housing without providing a shock absorber separate from them. The flange part that covers the seam of almost all the circumference is provided on the outside of the battery pack so that a predetermined gap is formed between the flange part and the battery housing. At the same time, it plays a role as a cover for covering the seam with the battery housing as well as a role of alleviation, and in combination with the provision of a predetermined gap, it is easy for fingers to be caught when the battery pack is gripped by the flange portion and removed.

(Embodiment) Next, one embodiment of the present invention will be described by taking an electric screwdriver as an example with reference to the accompanying drawings.

In the illustrated electric screwdriver, a hollow housing 10 is integrally formed from an upper main body housing 12 and a lower battery housing 14 that also serves as a handle housing.

Electric motor for forward / reverse rotation on the rear side inside the main body housing 12
16 is installed, and the rotation of the output shaft 18 of the electric motor 16 is transmitted to a clutch mechanism 22 arranged at a lower front portion through a drive gear 20 fixed to the output shaft 18, and further, this clutch mechanism 22. It is configured to be transmitted via a driven gear 26 that is arranged at a front upper portion of the spindle 24.

The clutch mechanism 22 has the output shaft 18 with respect to the main body housing 12.
It has a clutch shaft 32 rotatably supported via bearings 28, 30 in parallel with the clutch shaft 32.The clutch shaft 32 has a spline shaft portion 34 on one side and a hollow shaft portion 36 on the other side. Further, a large-diameter shaft portion 38 is provided in the middle of these. Hollow shaft
A first clutch disc 40 having an outer peripheral tooth portion that meshes with the drive gear 20 of the output shaft 18 is loosely fitted to 36, and a clutch ball 42 is provided on one surface of the first clutch disc 40. A pair of recesses 44, 44 in which a part of each of the holes 42, 42 play together are provided in the diametrically opposite direction. The first clutch disc 40 is attached to the large-diameter shaft portion 38.
A dish-shaped second clutch disk 46 for holding the clutch balls 42, 42 between them is loosely fitted to the shaft, and an elongated hole 48 extending along the axial direction is provided so as to penetrate in the direction perpendicular to the axial direction. ing. A clutch pin 50 is loosely fitted in the elongated hole 48, the both ends of which engage with a pair of notch grooves (not shown) formed so as to face the outer peripheral portion of the second clutch disc 46. Spline shaft
34 has a spline 52 that meshes with the driven gear 26 in the front portion, and a spline shaft portion 34 in the rear portion of the spline 52.
A spring receiving member 54 which is slidable in the axial direction is installed. The spring receiving member 54 is composed of a slider 56, a disk 62, and a needle roller type thrust bearing 60 sandwiched between them.
A first coil spring 64 for urging the second clutch disc 46 toward the first clutch disc 40 is interposed between the second clutch disc 46 and the second clutch disc 46. A second coil spring 66 having a smaller diameter and a smaller diameter than the first coil spring 64 is fitted on the large-diameter shaft portion 38 of the clutch shaft 32.

The clutch mechanism 22 is the output shaft of the electric motor 16 having the above-mentioned configuration.
The forward and reverse rotations of 18 are transmitted from the drive gear 20, the first clutch disc 40 to the clutch shaft 32 through the engagement of the clutch balls 42, 42 and the clutch pin 50 of the second clutch disc 46, and the clutch shaft 32. The engagement between the spline shaft portion 34 of 32 and the driven gear 26 causes the spindle 24 to rotate forward and backward. If the spindle 24 is overloaded and its rotation is blocked, the clutch shaft
Since the rotation on the 32 side is blocked, the output shaft 18 of the electric motor 16
The clutch balls 42, 42 of the first clutch disc 40, which are being rotated together with the clutch balls 50, ride on the outer periphery of the clutch pin 50 and resist the spring pressure of the first coil spring 64 by the clutch pin 50 and the second clutch disc 46. The first clutch disc 40 to the second clutch disc 46, the drive gear 20 idles with respect to the clutch shaft 32.

An adjusting mechanism 68 for adjusting the spring pressure of the first coil spring 64 is mounted on the integrally formed housing portion 12a on the lower side of the front portion of the main body housing 12. The adjusting mechanism 68 is rotatably supported by the housing portion 12a and has an adjusting shaft 70, one end of which is close to the spline shaft portion 34 of the clutch shaft 32 of the clutch mechanism 22 and the other end of which is protruded from the main body housing 12 to the outside. is doing. An adjusting plate 72 forming a cam surface 72a is integrally formed on the outer periphery of the adjusting shaft 70 on the one end side. The lower surface of the adjusting plate 72 faces the upper surface of the housing portion 12a, and the cam surface 72a is located opposite to the front surface of the slider 56 of the spring receiving member 54. A short piece 74a of an L-shaped contact member 74 integrally fixed to the slider 56 is interposed between the cam surface 72a and the front surface of the slider 56, and a bifurcated long piece 74b of the contact member 74 (see FIG. (Only one is shown) is arranged along the outer peripheral axial direction of the spline shaft portion 34 of the clutch shaft 32, and is slidable in the axial direction of the clutch shaft 32. Therefore, the front surface of the slider 56 is the first
Coil spring 64 keeps cam surface through this member 74
It is pressed against the 72a, and when the adjustment shaft 70 is rotated, the spline shaft portion 3 changes in accordance with the position change of the corresponding cam surface 72a.
Move axially along 4. Here, the shape of the cam surface 72a is set so that the rotation angle of the adjustment shaft 70 and the movement amount of the slider 56, that is, the movement amount of the spring receiving member 54 are substantially linearly proportional. On the other hand, on the other end side of the adjusting shaft 70, a screw portion 78 with which a tightening nut 76 is screwed is provided at a portion protruding to the outside of the main body housing 12. On the other end side of the adjusting shaft 70, a flat washer 80 is further interposed between the tightening nut 76 and the outer surface of the housing portion 12a opposed to the tightening nut 76. At this time, the adjusting knob 82 is fitted to the tightening nut 76 at a position with a slight gap.

With the adjusting mechanism 68 having the above-described structure, when the tightening nut 76 is rotated in one direction and tightened, the lower surface of the adjusting plate 72 is pressed against the upper surface of the housing portion 12a to fix the position of the adjusting shaft 70. 70 is free. Therefore, in the free state, the adjusting shaft 70 is set to an arbitrary rotational position via the adjusting knob 82, and the tightening nut 76 is rotated in the above-described one direction to tighten the tightening nut 76, whereby the axial position of the spring receiving member 54 along the spline shaft portion 34 is set. Can be fixed, and the spring pressure of the first coil spring 66 can be adjusted. By adjusting the spring pressure in this way, the torque for disengaging the clutch mechanism 22 can be set steplessly. When the spring receiving member 54 moves axially rearward along the spline shaft portion 34 to a predetermined position, the front end of the second coil spring 66 comes into contact with the spring receiving member 54, and thereafter the second clutch disk 40 is further moved to the second position. The spring force of the coil spring 66 will be applied.

A trigger 84 is rotatably attached to the front portion of the boundary portion between the main body housing 12 and the battery housing 14 via a support pin 85 at its lower end. The trigger 84 is biased counterclockwise by a spring (not shown), and the upper end portion of the trigger 84 is actuated by an actuating member 86 to activate the electric motor 16.
It is linked to 88. Here, in the state where the trigger 84 is illustrated, the starting switch 88 is OFF, and when the trigger 84 is retracted and rotated clockwise, the starting switch 88 is set to ON. An operating rod 90 is linked to the operating member 86. The operating rod 90 is inserted into the hollow shaft portion 36 of the clutch shaft 32 of the clutch mechanism 22 so that the operating rod 90 is in contact with the clutch pin 50, and is always urged by the spring 92 toward the clutch pin 50. With this configuration, the operating rod 90 moves in the axial direction following the clutch pin 50, and the clutch mechanism 22 is disengaged to cause the clutch pin 50 to move.
When the person moves forward in the long hole 48, the person follows the movement and moves forward and turns off the start switch 88 via the operating member 86.

An electric motor is installed on the upper front side inside the main body housing 12.
A changeover switch 94 for switching between 16 normal rotations and reverse rotations is attached so as to be switchable from the outside.

The spindle 24 arranged in the upper front portion of the main body housing 12 is made of a non-magnetic material such as aluminum, some kind of stainless steel, and a body. The spindle 24 is rotatably supported by the main body housing 12 via a bearing 96.98 in parallel with the clutch shaft 32, and one end side of the spindle 24 projects from the main body housing 12 to the outside. A sleeve 100 biased forward by a spring 102 is attached to the tip end portion 24a on the protruding side so as to be slidable in the axial direction. Further, a mounting hole 114 for mounting the driver bit 112 is axially formed in the tip portion 24a, and a diametrical through hole 116 communicating with the mounting hole 114 is formed in the side portion.
Is provided. A ball 118 is placed inside the through hole 116.
The ball 118 is attached to the driver bit 112 by slightly protruding into the mounting hole 114 in the state shown in the drawing.
To prevent the driver bit 112 from coming off the mounting hole 114. Further, a magnet 124 is fixed to the rear end of the mounting hole 114 at the front end 24a of the spindle 24. The magnet 124 is positioned so that the front end of the magnet 124 contacts the rear end of the driver bit 112 when the driver bit 112 is mounted in the mounting hole 114.

Next, in the battery housing 14, batteries BB such as nickel-cadmium batteries for supplying electric power to the electric motor 16 through the opening 14b formed in the lower end 14a thereof.
A synthetic resin battery pack 126 having a built-in battery pack (in the example shown, there are six on the lower side and two on the upper side) is mounted, and FIG. 5 shows the entire structure in a perspective view.

The battery pack 126 has positive and negative electrode terminal plates 128 and 130 on both sides of the upper end as shown in FIG. 2 (only the electrode terminal plate 128 positioned on the front side of the paper surface is shown in FIG. 1), and Thermostat installed inside the upper rear part
It has a thermo terminal plate 134 for preventing overcharging by 132. A support frame 136 is provided at the center of the inside of the battery housing 14, and the support frame 136 has a connector electrically connected to a corresponding terminal of the start switch 88.
138 and 138 (only one is shown in the figure) are attached. These connectors 138,138 are battery pack 1
When the 26 is mounted, it is arranged so as to contact the electrode terminal plates 128 and 130, respectively.

Further, the battery pack 126 is an upper case 140 with an opening at the lower end.
And a lower case 142 having an upper end opening shape. The lower end of the upper case 140 is locked to a step portion 144 formed on the inner surface of the lower case 142, and the outer peripheral surface of the lower end portion corresponds to a corresponding groove formed on the inner surface of the lower case 142 facing each other. Protrusions 148 to 148 that fit into 146 to 146 are formed. Further, on the front part of the lower case 142, there is provided a protrusion 152 which is locked by a stopper 150 made of a rectangular spring plate whose upper end is rotatably attached to the lower end of the battery housing 14 via a pin 149. Has been. Stopper 150
Has a curved portion 150a elastically fitted to the protrusion 152, and when the lower portion of the stopper 150 is pulled from the state shown in FIG. 1, the curved portion 150a expands to engage with the protrusion 152. Out,
The battery pack 126 can be pulled out from the battery housing 14, and conversely, when mounting, the curved portion 150a is projected.
The protrusion 152 can be fitted by pressing it against the outside. Further, as shown in FIG. 3, vertical protrusions 154, 154 are provided on both left and right sides of the protrusion 152 to prevent the stopper 150 from being displaced in the horizontal direction.

Further, on the inner peripheral surface of the upper portion of the lower case 142, a step portion 15 that locks the lower end of the lower case 142 when the battery housing 14 is attached.
6 is formed, and a thin-walled flange portion 158 which is connected to the step portion 156 and is formed in a slightly outwardly protruding shape is provided at the upper end. As shown in FIG. 4, the flange portion 158 has the left and right projecting pieces 154, 154 as the end and the start, and the lower case 1
It is formed over almost the entire circumference of 42, and the lower end portion 1 of the battery housing 14 is formed between the opposite surface of the upper case 140 and the opposite surface.
A groove for accommodating 4a is formed. Where the flange part 15
The overhanging dimension of 8 is set so that a slight gap S is formed between the flange portion 158 and the lower end portion 14a of the battery housing 14 in the mounted state shown in FIG. The gap S also includes a very small amount such that the flange portion 158 and the lower end portion 14a of the battery housing 14 do not come into close contact with each other.

Next, the operation of the above-described embodiment will be described particularly in connection with the case where the electric screwdriver falls on the floor surface or the like.

In the above electric screwdriver, main body housing 12
The heavy components such as the motor 16 and the clutch mechanism 22 are housed inside, while the battery housing 14 is compared with the motor 16 such as the battery pack 126 and the batteries BB contained therein. In case that the main body housing 12 hits the floor surface etc. first, then one side of the battery housing 14 hits the floor surface etc., and the collision speed is high because the parts with small dynamic weight are stored. Then, the battery housing 14 rolls around the main body housing 12, then the other side hits the floor surface or the like, and the other side rolls again, causing one side surface to hit the floor surface again. However, when such rolling occurs, the flange portion 158, which is the floor surface, is formed of a thin synthetic resin material and has flexibility,
Moreover, since there is a gap S between the battery housing 14 and the battery housing 14, the flange portion 158 elastically bends in the range of the gap S when it collides with the floor surface or the like. Therefore, the impact when the vehicle collides with the floor or the like is absorbed by the flange portion 158, and the battery pack 126
Side battery BB, electrode terminal board 128, 130, thermo terminal board
The impact on the connector 138 or the like on the side of the battery housing 14 or the battery housing 14 is mitigated, and failure of these parts or defective electrical connection is prevented. Further, since the flange portion 158 is located so as to cover the joint between the battery pack 126 and the battery housing 14, it serves as a protective cover. Further, since there is a gap S between the flange portion 158 and the side surface of the battery housing 14, the fingers are easily caught when the battery pack 126 is removed from the battery housing 14 by grasping the flange portion 158, and the battery pack 126 can be removed easily. It will be easy.

(Effect) In the portable power tool of the present invention, the impact at the time of a collision with the floor surface or the like is absorbed by the flange portion formed in a protruding shape on the outside of the battery pack without separately mounting a shock absorber. Therefore, a portable electric tool having impact resistance can be manufactured at low cost and the assembling work becomes simple. Further, the flange portion has an advantage that fingers are easily attached when the battery pack is removed, and the battery pack can be easily removed.

[Brief description of drawings]

FIG. 1 shows an embodiment of the present invention. FIG. 1 is a vertical sectional view of an electric screwdriver, FIG. 2 is a plan view of the battery pack shown in FIG. 1, and FIG. 3 is a similar battery pack. FIG. 4 is a sectional view taken along line VI-VI of FIG. 1, and FIG. 5 is a perspective view of the battery pack. 14 ... Battery housing 126 ... Battery pack 158 ... Flange

Claims (1)

[Scope of utility model registration request] 1. A portable power tool having a cylindrical battery housing and a detachable battery pack with a part thereof protruding to the outside, wherein the battery pack is mounted on the battery housing. A flange portion is provided so as to cover the joint with the housing over substantially the entire circumference, and the flange portion is formed in a protruding shape on the outside of the battery pack and forms a predetermined gap with the battery housing. The gap is configured to allow elastic deformation of the flange portion when it collides with a floor surface or the like, and to relieve impact force on the portable power tool.