JP3098846B2 - Rotary tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary tool such as an electric screwdriver or an electric wrench, and more particularly to a rotary tool capable of automatically locking and automatically releasing an output shaft.

[0002]

2. Description of the Related Art In a rotary tool such as an electric screwdriver or an electric wrench, it is possible to lock the rotation of an output shaft so that it can be used as a hand-rotated type. In order to be able to perform auxiliary tightening by hand when not tight enough,
It is very useful, and in providing this lock function, an auto release that automatically releases the lock when the motor is rotated while in the locked state, and an auto release that automatically locks when the motor is stopped It is preferable from the viewpoint of convenience that the lock is performed.

Japanese Unexamined Patent Publication No. Hei 3-251374 discloses such an automatic lock and automatic release function which operates in both forward and reverse rotation directions. This is provided with a power transmission connecting portion that is connected to the input shaft side member connected to the motor and the output shaft side member located coaxially with the input shaft side member with a play within a predetermined angle, and a tool. A wedge-shaped space is formed between the inner peripheral surface of the ring body that is non-rotatably fixed to the main body and surrounds the output shaft side member and the outer peripheral surface of the output shaft side member to allow the lock member to bite and play. A lock member is disposed in the wedge-shaped space portion, and a release member that pushes the lock member toward the floating region in the wedge-shaped space portion is formed on the input shaft side member. When the release member pushes the lock member to the floating region side to release the lock, the coupling portion transmits the rotation to the output shaft side, and when the tool body is rotated with the motor stopped, the tool body is rotated. With the relative rotation between the ring body and the output shaft side member that rotate together, the lock member moves toward the biting region side in the wedge-shaped space portion to lock the output shaft to the tool body, and the tool body and the output shaft The side members are rotated integrally. The wedge-shaped space portion is provided with two kinds of inclination angles that are opposite to each other so that this function works in both the forward and reverse rotation directions. And are arranged.

[0004]

However, in the construction in which the lock member is arranged in the wedge-shaped space, as described above, the play within a predetermined angle between the input shaft side member and the output shaft side member. Must be provided, which causes noise. That is, when the motor that was rotating at high speed is suddenly stopped by turning off the switch, the input shaft side member connected to the motor stops at the same time, but the output shaft side member and the lock member will continue to rotate due to inertia. Since the inertia of the lock member is smaller than that of the output shaft side member, the lock member collides with the inclined surface of the output shaft side member that faces the wedge-shaped space, and the impact caused by the biting occurs. Emits a sound.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rotary tool capable of auto-locking and auto-releasing and free from generating an unpleasant impact sound. is there.

[0006]

According to the present invention, there is provided a power transmission connecting portion which is connected to an input shaft side member and an output shaft side member located coaxially with a play within a predetermined angle. A wedge-shaped space is formed between the inner peripheral surface of the non-rotatable ring body surrounding the output shaft side member and the outer peripheral surface of the output shaft side member to allow the lock member to bite and play freely, and the input shaft side member has In a rotary tool forming a release member that pushes the lock member toward a floating region side in a wedge-shaped space portion, an inclined surface formed on an outer peripheral surface of an output shaft member and facing the wedge-shaped space portion and forming the space portion in a wedge shape. However, it is characterized in that it comprises an inclined surface having a large inclination angle on the side of the floating region and an inclined surface having a small inclination angle on the side of the biting region.

[0007]

According to the present invention, when the input shaft side member is suddenly stopped, the force of pushing the lock member back to the idle region by the inclined surface having the large inclination angle causes unnecessary engagement of the lock member. To prevent noise. Locking is performed on the inclined surface on the side of the biting region where the inclination angle is small.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to an embodiment shown in the drawings. As shown in FIG. 2, a rotary tool shown in the figure includes a sun gear 31 fixed to an output shaft 20 of a motor 2 and a gear case. 6, a planetary mechanism comprising an internal gear 33 fixed to the inner surface, a plurality of planetary gears 32 meshing with both of them, and a carrier 34 having a shaft 35 for supporting each planetary gear 32, as a reduction means, In this planetary mechanism, the carrier 34 and the output shaft 7 having the chuck 8 are arranged coaxially in the axial direction. In the figure, reference numeral 60 denotes a motor mount, 61 denotes a sliding bearing for receiving the output shaft 7, 62 denotes a thrust plate, 63 denotes a retaining ring, and 64, 65, and 66 denote steel balls and retainers constituting the thrust bearing.

As shown in FIG. 1, a plurality of projections 70 project radially and at regular intervals from the outer peripheral surface of the end of the output shaft 7 on the carrier 34 side. A ring body 51 surrounding the outer periphery of the projection 70 is fixed to the inner surface of the gear case 6. And, on the end face of the carrier 34,
A plurality of projections 36 projecting in the axial direction and located in a space between the inner peripheral surface of the ring body 51 and the outer peripheral surface of the output shaft 7 are provided. The projections 36 are formed so that the same number as the projections 70 are formed at equal intervals in the circumferential direction and are located between the projections 70 of the output shaft 7, that is, the projections 3.
The protrusion 6 and the protrusion 70 are arranged at intervals in the circumferential direction, and the two protrusions 36 and 70 form a rotational power transmission connecting portion having a play at a predetermined angle in the rotational direction.

Here, the projection 70 on the output shaft 7
The outer peripheral surfaces on both sides of the projection 70 are inclined surfaces such that the two inclined surfaces 71 and 72 having different inclination angles are continuous with each other so that the projection 70 side becomes lower. A wedge-shaped space portion having a different inclination direction is formed between the surface and the inner peripheral surface of the ring body 51,
Roller-like lock members 50a and 50b are respectively disposed in these two types of wedge-shaped spaces provided on both sides of the protrusion 70 and between the protrusion 36 and the protrusion 70 of the carrier 34, respectively. 5 are formed.

The lock member 50a disposed in the wedge-shaped space inclined in one direction is used for locking in one direction, and the lock member 50b disposed in the wedge-shaped space inclined in the other direction is used for locking in another direction. It is. The lock members 50a, 50
Since the diameter of b is smaller than the height of the protrusion 70 side of the wedge-shaped space portion and larger than the height of the protrusion 36 side, the lock members 50a and 50b are located on the inclined surface 71 on the protrusion 70 side. When it is in a floating state, the output shaft 7 is locked between the outer peripheral surface of the output shaft 7 and the inner peripheral surface of the ring body 51 when it moves on the inclined surface 72 away from the projection 70.

In addition, the inclined surfaces 71 and 72
The inclination angle of the inclined surface 71 located closer, that is, the inclined surface 71 located on the idle region side is larger than that of the inclined surface 72 located on the biting region side. FIG. 6 shows the appearance of the rotary tool, in which 11 is a switch handle, 12 is a rotation direction switching handle, and 13 is a power pack. Next, the operation will be described. Now, if the motor 2 is rotated in one direction, the projection 3 of the carrier 34 in the planetary reduction mechanism
6 presses the projection 70 of the output shaft 7 via the lock member 50b to rotate the output shaft 7 as shown in FIG. At this time, of the pair of lock members 50a and 50b located in the wedge-shaped space portions on both sides of the protrusion 70, the lock member 50b is the protrusion 3
6, the wedge-shaped space portion is positioned in the floating region, that is, the portion near the projection 70, and the locking member 5
Oa is located in the floating region in the wedge-shaped space due to its inertia, and therefore, the lock members 50a, 5a
0b does not hinder the rotation of the output shaft 7.

When the direction of rotation of the motor 2 is reversed, FIG.
As shown in FIG.
The power is transmitted to the output shaft 7 through the first and second shafts to rotate the output shaft 7. At this time, the two lock members 50a, 50
Since b is located on the floating region side in the wedge-shaped space, no lock is made. When the motor 2 is stopped, the motor 2
When the motor 2 stops suddenly because the power generation braking is applied by short-circuiting both terminals, the carrier 3 which is an input shaft side member is stopped.
Although the projection 36 of 4 stops immediately, the output shaft 7 tends to keep rotating due to its inertia. At this time, if the rotation state shown in FIG.
The lock member 50b, which has a smaller inertia than the output shaft 7 and stops earlier than the output shaft 7, is stopped by the output shaft 7 that is trying to continue to rotate. It hits the inclined surface 71 and tries to move further to the inclined surface 72 side. However, the locking member 50b
Of the locking member 5 caused by the fact that the inclination angle of the inclined surface 71 is larger than the force for shifting to the inclined surface 72.
0b is pushed back to the floating region side in the wedge-shaped space, so that the locking member 50b is
And rotates with the output shaft 7 while sliding on the inner peripheral surface of the ring body 51 while in contact with the output shaft 7. For this reason, the lock member 50b absorbs an impact while sliding without causing a lock state by being engaged in the engagement region of the wedge-shaped space portion, and stops the output shaft 7 without generating an impact sound. FIG.
In the case of a sudden stop from the rotating state shown in FIG.
a plays this role.

If the main body 1 is rotated in the tightening direction around the output shaft 7 in order to perform manual tightening with the motor 2 stopped, the main body 1, that is, the ring body 51 and the output shaft 7 are connected to each other. As shown in FIG. 4, the lock member 50b keeps the state of being located in the play area near the protrusion 70, but the lock member 50a is moved from the protrusion 70 by the rolling caused by the relative rotation. The ring body 51 and the output shaft 7 are integrated with each other in order to move away from the wedge-shaped space on the inclined surface 72 on the side of the biting portion. That is, the free rotation of the output shaft 7 is locked by the lock member 50a, and the output shaft 7 rotates with the main body 1, so that screws and nuts can be manually tightened. The transition to the locked state is automatically performed as described above. When turning the body 1 in the opposite direction to loosen the screws and nuts,
As shown in FIG. 5, the lock member 50b locks the output shaft 7 to enable manual return.

The locking members 50a, 50
If the motor 2 is rotated again in the locked state at 0b, the rotation of the output shaft 7 causes the protrusion 70 to approach the lock members 50a and 50b and to be at the engagement position for locking. In order to return the lock members 50a and 50b to the floating region in the wedge-shaped space portion, or to push the lock members 50a and 50b in the engagement position where the protrusion 36 of the carrier 34 is pushed back to the floating region side of the wedge-shaped space portion. Cancellation is made automatically. The projection 36 is a power transmission member and also serves as a release member.

In the embodiment shown in FIGS. 7 and 8, a rigid ring body 51 is divided in the axial direction, and an elastic ring 52 is sandwiched between the two. The elastic ring 52 having an inner diameter smaller than the inner diameter of the ring body 51 reduces the impact of a collision between the lock members 50a, 50b and the ring body 51 when the motor 2 is stopped suddenly.

[0017]

As described above, according to the present invention, the inclined surface formed on the outer peripheral surface of the output shaft member and facing the wedge-shaped space portion and making the space portion wedge-shaped is located at the idle region side and has an inclination angle of Is large, and the inclined surface that is on the side of the biting region and has a small inclined angle, so that when the input shaft side member is suddenly stopped, the inclined angle becomes The output shaft can be smoothly stopped in order to prevent unnecessary locking of the lock member and generation of noise due to the force of pushing the lock member back to the floating region side due to the large inclined surface. In addition, the lock is reliably performed by the inclined surface having a small inclination angle on the side of the biting region, so that the presence of the inclined surface with a large inclination angle does not make the lock incomplete. .

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of one embodiment, showing a release state during forward rotation.

FIG. 2 is a longitudinal sectional view of the same.

FIG. 3 is a transverse sectional view showing a release state at the time of reverse rotation of the above.

FIG. 4 is a cross-sectional view showing a locked state when the above is manually tightened.

FIG. 5 is a transverse cross-sectional view showing a locked state at the time of hand return according to the embodiment.

FIG. 6 is a side view showing the appearance.

FIG. 7 is a longitudinal sectional view of another embodiment.

FIG. 8 is a cross-sectional view of the same.

[Explanation of symbols]

 7 Output shaft 50a, 50b Lock member 51 Ring body 71 Inclined surface 72 Inclined surface

Claims (1)

(57) [Claims] 1. A non-rotatable ring which is provided with a power transmission connecting portion which is connected to an input shaft side member and an output shaft side member located coaxially with a play within a predetermined angle, and surrounds the output shaft side member. A wedge-shaped space is formed between the inner peripheral surface of the body and the outer peripheral surface of the output shaft side member to allow the lock member to bite and play, and the input shaft side member is provided with the lock member in a floating region in the wedge-shaped space portion. In the rotary tool having a release member pushed out to the side, an inclined surface formed on the outer peripheral surface of the output shaft member and facing the wedge-shaped space portion and making this space a wedge shape is located on the idle region side and has an inclination angle of A rotary tool comprising: an inclined surface having a large inclination angle; and an inclined surface having a small inclination angle on the side of the biting region.