JPH0653350B2 - Rotary tool - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

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 releasing an output shaft.

[Prior art]

For rotating tools such as electric screwdrivers and electric wrenches, enabling rotation lock of the output shaft is
It is very useful because it can be used as a hand-rolled type and can be tightened by the feeling of the hand and auxiliary tightening can be performed by hand tightening when it cannot be tightened by electric power. In order to provide such a lock function, there are an auto-release function that automatically releases the lock when the motor is rotated in the locked state, and an auto-lock function that automatically locks the motor when the motor is stopped. It is preferable in terms of usability to be prepared. Various types of devices having such auto-lock and auto-release functions have been proposed in the past, but as a mechanically constructed device, the switch handle can be turned on and off to the lock part. To automatically lock and release by transmitting
As shown in Japanese Patent Laid-Open No. 62-287979 and the like, the movement of the internal gear of the planetary gear device is utilized to roughly classify the locking by the ratchet pawl and the unlocking.

[Problems to be Solved by the Invention]

However, the former requires a member for mechanically remote-controlling the lock member arranged in the lock portion located at a remote position by operating the switch handle, which tends to complicate the structure and the position where the switch is arranged. Regulations occur,
It has problems such as difficulty in compacting. In the latter case, ratchet pawl operating noise may occur,
There is a problem that the strength of the member that supports the ratchet pawl is difficult and the shape of the member is inevitably complicated, resulting in an increase in cost. What is shown in Japanese Examined Patent Publication No. 47-49360, that is, the inner plate fixed to the rotating tool body, the cylindrical flywheel connected to the motor shaft and the driver shaft to surround the outer periphery of the inner plate, and the outer periphery of the inner plate. It comprises a wedge-shaped notch formed and a roller-shaped lock member arranged between the inner peripheral surface of the flywheel, and the lock member slides freely in a wide free region in the wedge-shaped notch when the motor rotates, and When the driver shaft is rotationally driven from the board via the flywheel and the motor is stopped and the tool body is rotated while holding it, the inner panel integrated with the tool body rotates with respect to the flywheel and the lock member has a wedge-shaped notch. As the lock member comes into pressure contact with the inner peripheral surface of the flywheel and the flywheel rotates integrally in the same direction as the tool body is rotated, that is, with respect to the tool body. Also that so as to perform the hand tightened in a state in which the driver shaft is locked but,
Although this product has both auto-lock and auto-release functions, it can only rotate in one direction when driven by a motor or rotated manually. It can only be used for loosening work, and is extremely inconvenient in actual use. The present invention has been made in view of the above points, and an object of the present invention is to provide a highly reliable electric screwdriver or electric wrench that can perform auto-locking and auto-releasing in both rotation directions with a simple structure. It is to provide such a rotary tool.

[Means for Solving the Problems]

Therefore, the present invention provides a power transmission connection which is connected to the input shaft side member connected to the rotary drive source and the output shaft side member coaxial with the input shaft side member with a play within a predetermined angle. The lock member is provided so as to be non-rotatable with respect to the tool body, and the lock member is engaged and loosened between the inner peripheral surface of the ring body surrounding the output shaft side member and the outer peripheral surface of the output shaft side member. A formal wedge-shaped space is formed, and a release member for pushing the lock member toward the floating region side of the wedge-shaped space is formed on the input shaft side member, and the connecting portion is a radial direction provided on the output shaft side member. The projection on the output shaft side member and the projection also on the input shaft side member that also serves as a release member protruding in the axial direction. Are placed on both sides of They are provided between the protrusions of the force shaft side member and are located on both sides of the protrusion of the output shaft side member, and the outer peripheral surface of the output shaft side member faces the protrusion toward the center of the output shaft side member. In both wedge-shaped space portions formed by inclining, the inclination directions are opposite to each other, and both of the wedge-shaped space portions are the floating region near the protrusion and the engagement region on the side away from the protrusion. The main feature is that the lock member arranged on one side is for forward rotation lock and the lock member arranged on the other side is for reverse rotation lock. [Operation] According to the present invention, the lock member and the wedge-shaped space portion that allows the lock member to bite and move can be automatically locked, and the release member provided on the input shaft side member can be automatically released. In addition, since the wedge-shaped space is formed by two types with different slopes,
Auto-lock and auto-release can be performed together in both rotation directions, and the formation of these members can be simple. [Embodiment] The sun gear 31 fixed to the output shaft 20 of the motor 2, the internal gear 33 fixed to the inner surface of the gear case 6, and the both will be described in detail below with reference to the illustrated embodiment of the present invention. A planetary mechanism including a plurality of planetary gears 32 that mesh with each other and a carrier 34 having a shaft 35 that supports each planetary gear 32 is provided as a speed reduction means. The carrier 34 in this planetary mechanism and the chuck 8 are provided. The output shaft 7 and the output shaft 7 are arranged coaxially in the axial direction. In the figure, 6 is a gear case, 61 is a sliding bearing for receiving an output shaft, 62 is a thrust plate, 63 is a retaining ring, and 64, 65 and 66 are steel balls and retainers that constitute the thrust bearing. From the outer peripheral surface of the end of the output shaft 7 on the carrier 34 side, as shown in FIG. 2, a plurality of projections 70 are radially provided at equal intervals. Also, on the inner surface of the gear case 6,
A ring body 51 surrounding the outer periphery of the protrusion 70 is fixed. The end surface of the carrier 34 is provided with a plurality of protrusions 36 that project in the axial direction and are located in the space between the inner peripheral surface of the ring body 51 and the outer peripheral surface of the output shaft 7. These protrusions 36 are formed in the same number as the protrusions 70 at equal intervals in the circumferential direction, and are located between the protrusions 70 of the output shaft 7, that is, the protrusions 36 and the protrusions 70 are spaced apart in the circumferential direction. The projections 36, 70 are arranged side by side and form a rotational power transmission connecting portion having a predetermined angle of play in the rotation direction. Here, since the outer peripheral surfaces of the output shaft 7 on both sides of the protrusion 70 are inclined surfaces 71 on the side of the protrusion 70, the outer peripheral surface and the ring body 5 are formed on both sides of the protrusion 70.
A wedge-shaped space portion is formed between the inner peripheral surface of the roller 1 and the protrusion 70 of the carrier 34, and the wedge-shaped space portion is formed between the protrusion 70 and the protrusion 70 of the carrier 34. The locking means 5 is formed by arranging the locking members 50a and 50b respectively. The lock member 5
0a is for one-direction rotation locking, and the locking member 50b is for other-direction rotation locking. The lock members 50a, 50
Since the diameter of b is smaller than the height of the portion of the wedge-shaped space on the side of the protrusion 70 and larger than the height of the portion on the side of the protrusion 36, the lock members 50a and 50b are in a floating state when positioned on the side of the protrusion 70. However, when separated from the projection 70, the output shaft 7 is locked by being caught between the outer peripheral surface of the output shaft 7 and the inner peripheral surface of the ring body 51. FIG. 6 shows the appearance. In the figure, 1 is a main body, 9 is a bit mounted on the chuck 8, 11 is a switch handle, and 1 is a switch handle.
Reference numeral 2 is a rotation direction switching handle, and 13 is a power pack. Next, the operation will be described. Now, when the motor 2 is rotated, this output is decelerated in the planetary mechanism to rotate the carrier 34, and the protrusion 36 of the carrier 34 is rotated to the second position.
As shown in the figure, the protrusion 70 of the output shaft 7 is pressed through the lock member 50b to rotate the output shaft 7. At this time, the pair of lock members 5 located in the wedge-shaped spaces on both sides of the protrusion 70.
0a and 50b, the lock member 50b is located in the floating region in the wedge-shaped space, that is, the portion closer to the protrusion 70 by being pushed by the protrusion 36, and the lock member 50a is located in the floating region in the wedge-shaped space due to its inertia. Therefore, the lock members 50a and 50b do not hinder the rotation of the output shaft 7. In particular, here, the protrusion 70 and the protrusion 36 are substantially fan-shaped, in which the width on the outer peripheral side is wider than the width on the inner peripheral side and the difference is larger than the difference caused by the difference in the radial position. 36 and 70 generate a force that presses the roller-shaped lock members 50a and 50b against the outer peripheral surface of the output shaft 7, and the force generated by the lock members 50a and 50b contacting the inner peripheral surface of the ring body 51. Will not cause a loss. The ring body 51 is made of a non-magnetic material, and a magnetic attraction force acts between the lock members 50a, 50b and the output shaft 7 so that the lock members 50a, 50b and the ring body 51 are attracted by the magnetic attraction force. May be prevented. When the rotation direction of the motor 2 is opposite, as shown in FIG. 3, the protrusion 36 transmits power to the output shaft 7 via the lock member 50a and the protrusion 70 to rotate the output shaft 7. Even at this time, the lock members 50a and 50b are not locked because the lock members 50a and 50b are located on the side of the floating region in the wedge-shaped space. When the main body 1 is rotated in the tightening direction around the output shaft 7 for manual tightening with the motor 2 stopped, the main body 1, that is, the ring body 5 is rotated.
As shown in FIG. 4, the lock member 50b remains in the floating region near the protrusion 70 by the relative rotation generated between the output shaft 1 and the output shaft 7, but the lock member 50a is kept in the relative rotation. In order to move away from the projection 70 and move to the side of the wedged portion in the wedge-shaped space due to the accompanying rolling, the ring body 51
And the output shaft 7 are integrated. That is, the free rotation of the output shaft 7 is locked by the lock member 50a, and the output shaft 7 rotates together with the main body 1, and the screws and nuts can be manually tightened. Then, the shift to the lock state is automatically performed as described above. When the main body 1 is turned in the opposite direction to loosen the screw or nut, the lock member 50b locks the output shaft 7 as shown in FIG. When the motor 2 is rotated again in the locked state as described above, the protrusion 70 comes closer to the lock members 50a and 50b due to the rotation of the output shaft 7 and is in 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 which the protrusions 36 of the carrier 34 are in the engaged position back toward the floating region side of the wedge-shaped space portion. The cancellation is done automatically. The projection 36 is a power transmission member and also a release member, so that the cost can be reduced by reducing the number of parts. 7 to 10 show another embodiment. This has the same structure for auto lock and auto release,
It differs from the one shown in the above embodiment in that a clutch for adjusting the tightening torque is incorporated. That is, here, the internal gear 33 is rotatable about its axis, and an uneven clutch surface 37 is provided on the front end surface of the internal gear 33 in the axial direction. An axial hole 62 is provided in the gear case 6, and a steel ball 74 that engages with the clutch surface 37 is provided in the hole 62. Further, on the outer periphery of the front end surface of the gear case 6, the clutch plate 77, the clutch spring 76,
The thrust plate 75 is provided, and the clutch plate 7
Reference numeral 7 is engaged with a step projection 80 formed on the inner surface of a clutch handle 78 rotatably arranged at the tip of the main body 1. Reference numeral 79 in the drawing denotes a mounting plate for the clutch handle 78. The clutch spring 76 is connected to the steel ball 7 via the thrust plate 75.
4, the spring load is applied to the engaging portion between the steel ball 74 and the clutch surface 37, and the rotation of the internal gear 33 is stopped. When the load torque required to rotate the screw or the nut is small, the rotation of the motor 2 is stopped because the engagement state between the internal gear 33 and the steel ball 74 is maintained and the rotation of the internal gear 33 is stopped. It is decelerated and transmitted to the output shaft 7 side as in the case of the above embodiment. However, if the load torque becomes larger than the set torque due to the spring load, the internal gear 33 starts rotating while pushing back the steel ball 74 against the clutch spring 76 by the clutch surface 37, and the internal gear 33 rotates. Since the power transmission to the output shaft 7 side is interrupted by the idling of the Lugear 33, the tightening torque of the screw or the nut is limited to the set torque. When the clutch handle 78 is rotated, the engagement positions of the stepped projection 80 on the inner surface of the clutch handle 78 and the clutch plate 77 whose rotation around the axis is stopped are changed to move the clutch plate 77 in the axial direction, Since the compression amount of the spring 76 changes, the set torque can be adjusted. Here, when the tightening torque is limited by the idling of the internal gear 33 as described above, the lock is released as in the state shown in FIG. 2 or FIG. That is, when the main body 1 itself is rotated in the screw tightening direction while the motor 2 is still turned on, the rotation of the main body 1, that is, the rotation of the ring body 51, as shown in FIG. Since the lock member 50a in the loose area of the portion moves to the biting position and locks the output shaft 7, the manual tightening operation can be directly performed. Then, when the motor 2 is still turned on and the main body 1 is turned in the opposite direction, the lock by the lock member 50a is released as shown in FIG. At this point, the lock member 50b
Shifts to the lock position, but at this time, the protrusion 36 of the carrier 34 pushes the lock member 50b toward the protrusion 70 side as shown by the arrow in the figure due to the reaction of the idling of the internal gear 33, and thus the lock state does not shift. The auto lock for this reverse rotation does not work. For this reason, manual tightening while operating the switch handle 11 and operating the motor 2 can be performed by ratchet tightening such as a ratchet driver or ratchet wrench. Another embodiment is shown in FIG. 11 to FIG. This is provided with a modified cross section at the rear end of the output shaft 7, and is composed of a plurality of plates, here two plates 80 made of rigid bodies and one elastic body, provided with holes to fit into the modified cross section. The plate 81 is attached, and the projections 7 are formed on the plates 80 and 81.
0 is formed. In particular, the outer diameter of the plate 81 made of an elastic body, excluding the maximum diameter, is made slightly larger than the plate 80 made of two rigid bodies sandwiching the outer diameter. The lock members 50a and 50b are brought into contact with the plate 81 made of an elastic body so that a reliable lock can be obtained. As shown in FIG. 14, a gap c is provided between the deformed cross section of the output shaft 7 and the fitting hole 84 in the plate 83 provided with the protrusion 70, and the rattling due to the gap c is utilized. It may be possible to obtain a secure lock. In this case, the center alignment between the slide bearing 61 and the ring body 51 does not require much precision, and the assemblability is improved. Another embodiment is shown in FIGS. This causes one end of the shaft 35 of the carrier 34 to protrude from the end surface of the carrier 34 toward the output shaft 7 side,
One end of 50b is projected toward the carrier 34 side from the end surface of the output shaft 7, and the pair of locking members 50a,
The shaft 35 located between the two 50b has the lock members 50a, 5
It is configured so that it can freely come into contact with 0b. In this case, the lock member 50 formed in a roller shape
Grease adheres to a and 50b, and lock members 50a and 5b
Even if 0b is stuck to both side surfaces of the protrusion 70 due to the viscosity of grease, when the hand is manually tightened by turning the main body 1, the shaft 35 of the carrier 34 rotating around the output shaft 7 together with the main body 1 is As shown in FIG. 16, since the lock member 50a is brought into contact with and pushed away from the protrusion 70, the lock member 50a is not prevented from moving to the biting position in the wedge-shaped space portion, and thus is reliably retained. When the main body 1 is turned in the opposite direction, as shown in FIG.
Since the shaft 35 pushes the lock member 50b and pulls it away from the protrusion 70, the lock of the output shaft 7 by the lock member 50b is also ensured at this time. The grease that fills the planetary mechanism is locked by the lock member 50a,
Even if it adheres to the lock member 50b, the lock member 50
Therefore, the situation in which the lock function of the output shaft 7 is impaired by the fact that a and 50b remain stuck to the protrusion 70 is not brought about.
It is also possible to reduce the sound by arranging grease in the arrangement portions of a and 50b. Although the shaft 35 supporting the planetary gear 32 is used here, a separate convex portion is provided on the end surface of the carrier 34,
You may make it this convex part contact | abut with the lock members 50a and 50b.

【The invention's effect】

As described above, in the present invention, the locking of the output shaft by the lock member being engaged with the wedge-shaped space formed between the outer peripheral surface of the output shaft side member and the inner peripheral surface of the non-rotatable ring body, This is automatically performed according to the relative rotation between the output shaft side member and the ring body, and is automatically locked and rotates within the play range of the input shaft side member with respect to the output shaft side member. Also, the automatic release is performed by the release member provided on the input shaft side member, and the wedge-shaped space portion is arranged on the projection on the output shaft side member forming the connecting portion and on both sides of this projection, respectively. The lock member, which is provided between each of the input shaft side members and the projection that also serves as the release member, is disposed in one of both wedge-shaped space portions having mutually opposite inclination directions, for forward rotation lock, and for the other. Locks arranged Since the material is for reverse locking, auto-lock and auto-release work in both directions of rotation, which makes it very easy to use as a rotating tool such as an electric screwdriver or an electric wrench. The shape of the member can be simple and highly reliable.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIGS. 2 to 5 are sectional views taken along the line XX in FIG. 1, and FIG. 2 shows a release state at the time of normal rotation. Sectional view, FIG. 3 is a sectional view showing a released state at the time of reverse rotation, FIG. 4 is a sectional view showing a locked state at the time of hand tightening, FIG. 5 is a sectional view showing a locked state at the time of manual return, and FIG. FIG. 7 is a side view of the above, FIG. 7 is a side view of another embodiment, FIG. 8 is a longitudinal sectional view of the same, FIG. 9 and FIG.
FIG. 11 is a transverse sectional view showing the same operation, FIG. 11 is an exploded perspective view of another example, FIG. 12 is an end view of the same, and FIG. 13 is a sectional view taken along line YY in FIG. Broken side view, FIG. 14
(a) and (b) are exploded perspective views and end views of another example, FIG. 15 is a longitudinal sectional view of another embodiment, and FIGS. 16 and 17 are sectional views taken along line ZZ in FIG. Where 7 is the output shaft, 36 is the protrusion,
50a and 50b are lock members, 51 is a ring body, and 70 is a protrusion.

Claims (4)

[Claims] 1. A connecting portion for power transmission, which is connected to an input shaft side member connected to a rotary drive source and an output shaft side member coaxially with the input shaft side member with a play within a predetermined angle. In addition, the lock member is non-rotatably fixed to the tool body and allows the lock member to be engaged and loose between the inner peripheral surface of the ring body surrounding the output shaft side member and the outer peripheral surface of the output shaft side member. A wedge-shaped space portion is formed, and a release member that pushes the lock member toward the floating region side of the wedge-shaped space portion is formed on the input shaft side member, and the connecting portion is provided in the radial direction provided on the output shaft side member. The wedge-shaped space portion including the protruding protrusion and the protrusion that also functions as a release member that protrudes in the axial direction and that is provided on the input shaft side member, and the wedge-shaped space where the lock member is disposed Inputs located on both sides They are provided between the protrusion of the shaft side member and are located on both sides of the protrusion of the output shaft side member, and the outer peripheral surface of the output shaft side member is inclined toward the center of the output shaft side member toward the protrusion. In both wedge-shaped space portions formed by doing so, the inclination directions are opposite to each other, and both of the wedge-shaped space portions have a floating region near the protrusion and a catching region on the side away from the protrusion. A rotary tool characterized in that the lock member arranged on the other side is for forward rotation lock, and the lock member arranged on the other side is for reverse rotation lock. 2. A planetary speed reduction mechanism is arranged on the input shaft side, and a freely rotatable internal gear in this planetary speed reduction mechanism is elastically fixed by a clutch spring so as to be elastically fixed. Wedge-shaped space portions having different inclination directions are provided between the body and the body, and a lock member for forward rotation lock and a lock member for reverse rotation lock are arranged in each wedge-shaped space portion. The rotary tool described in 1. 3. The rotary tool according to claim 1, wherein the ring body is formed of a non-magnetic body, and the lock member and the output shaft side member are formed of members which mutually exert a magnetic attraction force. . 4. The output shaft side member provided with a protrusion is a plate fixed to the output shaft, and at least one of the plate and the ring body is formed as a laminate of a rigid body and an elastic body, and The rotary tool according to claim 1, wherein the elastic body portion is projected to the outside more than the rigid body portion.