JP2009285813A - Driver drill - Google Patents

Abstract

【Task】
To provide a compact power tool that does not reduce the durability of the spring by fully compressing the spring.
[Solution]
According to the present invention, the adjustment of the clutch torque is performed by a ring gear in which a plurality of protrusions having different angles or heights are arranged. The torque adjustment can be performed depending on where on the protrusion the ball gets over. In the drill mode, the clutch can be surely prevented from operating by passing through the outer periphery of the ring gear where the height of the protrusion or the angle of the protrusion, which is appropriately designed so that the ball does not get over, is passed. Moreover, the spring only needs to press a ball | bowl moderately to a ring gear, and can use the short spring with a thin wire diameter extremely. By applying the present invention in this way, the torque adjustment mechanism can be designed easily and without being restricted by the spring.
[Selection] Figure 3

Description

  The present invention provides a mechanism for adjusting torque by using a protrusion having an angle or a height that varies depending on the location, which is provided on a ring gear end surface inside a gear mechanism, and which is provided on a driver drill. About.

  Many conventional power tools use a planetary gear mechanism as shown in FIGS. 1 and 2, and a slip clutch mechanism is formed by pressing a ball 42 against a protrusion formed on the end face of the ring gear 41 at the final stage by a spring 43. is doing. In a screw tightening operation or the like, when a torque greater than the slip-out torque is applied to the output shaft 44, the ball 42 gets over the protrusion of the ring gear 41 against the pressing force of the spring 43, and the clutch operates. On the other hand, when using a tool as a drill for drilling or the like, the torque adjustment cap 45 is rotated, and a stepped plane and a torque adjustment plate provided on the inner periphery of the torque adjustment cap 45 46, the torque adjusting plate 46 is moved in the axial direction and finally the spring 43 is fully compressed, so that the ball 42 does not get over the protrusion of the ring gear 41, that is, the clutch. Set so that does not work.

  The side angles of the protrusions 41a installed on the end face of the ring gear 41 are all constant.

  In the prior art, in order to ensure that the clutch does not operate in the drill mode, the spring is fully compressed so that the ball does not get over the protrusion of the ring gear, or the rotation of the ring gear is stopped when the clutch is in the drill mode. The pin has been inserted into the outer periphery of the ring gear and the ring gear has been forcibly fixed. Further, as a method for adjusting the clutch torque, the pressing force when the ball gets over the ring gear protrusion is compressed by rotating the torque adjusting dial, and the compression force of the spring is used. However, fully compressing the spring also reduces the durability of the spring. In addition, a wide and fine adjustment of the clutch torque requires a relatively long spring compression length and a large spring constant, and there are limits to setting an appropriate spring constant and compression amount. Was contradictory. Also, a method of inserting a pin or the like around the ring gear and stopping the rotation of the ring gear is inconvenient in terms of operability, such as depending on the position of the ring gear, the pin does not enter at once.

  Therefore, in the present invention, the clutch torque is adjusted by a ring gear in which a plurality of protrusions having different angles or heights are arranged, and the torque adjustment can be performed depending on where on the protrusion the ball gets over. In the drill mode, the clutch can be surely prevented from operating by passing through the outer periphery of the ring gear where the height of the protrusion or the angle of the protrusion, which is appropriately designed so that the ball does not get over, is passed. Further, the spring only needs to press the ball moderately against the ring gear, and in short, a short spring with a thin wire diameter can be used. By applying the present invention in this way, the torque adjustment mechanism can be designed easily and without being restricted by the spring.

  By adopting the configuration of the present invention, it is possible to provide a compact electric tool that does not reduce the durability of the spring by fully compressing the spring.

  A specific example of the invention will be described with reference to FIGS.

A plurality of protrusions 31a are arranged on the circumference on the end face of the ring gear 31 of the gear box having the speed change mechanism. The angle of the side surface of the protrusion 31a is changed between the inside and the outside of the ring gear 31 (here, the angle of the inner side surface of the protrusion is set to an obtuse angle and the angle of the outer side surface of the protrusion is set to an acute angle with respect to the inner side). A groove 33 is formed in the gear case so that the pin 32 whose both ends are hemispherical can be moved in the outer peripheral direction with a predetermined width of the protrusion 31a of the ring gear 31, and the pin 32 is moved to the shaft side (inside) of the pin 32. A cam 34 is installed so as to be rotatable by a predetermined angle. On the output shaft side of the pin 32, a plate 35 that rotates together with the cam 34, a spring 36 for pressing the pin 32 against the ring gear 31 via the plate 35, and a washer 37 for fixing the spring 36 to the gear case 30 are arranged. Has been. A plurality of protrusions 35a are arranged on the outer peripheral portion of the plate 35. The protrusions 35a are fixed to a groove inside the dial 38. By rotating the dial 38, the cam 34 fixed to the plate 35 rotates, and the cam 34 is pinned. 32 is moved to the outer periphery of the ring gear 31 (in the state on the upper side of the line AA and in the state on the upper side of the BB cross section). As a result, the pin 32 can be moved to a predetermined position of the ring gear 31. The protrusion 31a of the ring gear 31 is designed so that the angle of the side surface changes to an acute angle toward the outer periphery, and the pin 32 cannot get over the protrusion when the pin 32 moves to the outermost periphery. As a result, the maximum torque can be generated without the ring gear 31 rotating in the drill mode. A ring-shaped spring 38, which is partially cut off, is assembled on the outer periphery of the pin 32. The pin 32 is always pressed toward the central axis, and the dial 38 is changed from the drill mode to a setting with a small torque. When rotated, the pin 32 is pushed back to the central axis side (the state on the AA line upper side and the state on the lower side of the BB cross section). As for the spring 36, it is only necessary to install a spring that functions to push the pin 32 back to the bottom surface of the ring gear 31 after the pin 32 has passed over the protrusion 31a of the ring gear 31 and generate a torque at the required minimum tightening torque setting. . With respect to more required torque, the required torque can be generated by adjusting the angle of the side surface of the projection 31a of the ring gear 31 at the position of the pin 32 determined by the rotation angle of the cam 34.
In this description, an example in which six pins are used has been described, but one or more pins may be attached. Steel balls can also be used instead of pins. Furthermore, the same effect can be obtained by reversing the angular relationship of the ring gear protrusions on the inside and outside.
Further, the present invention can be applied as a method for reliably stopping the rotation of the ring gear in the drill mode by combining the pin movement according to the present invention and the conventional torque adjustment by the compression of the spring.

Sectional drawing which shows the clutch of the conventional electric tool (A): Cross-sectional view of a ring gear constituting a clutch of a conventional electric tool (b): Plan view of a ring gear constituting a clutch of a conventional electric tool, and (c): X-ray arrow view of (b) (A): Sectional view showing the clutch of the electric power tool of the present invention, and (b): A view taken along line B-B of a). (A): A view along arrow AA in (d), (b): A view along arrow BB in (d), (c): A view along arrow CC in (d), (d) ): Enlarged view of protrusions of the clutch ring constituting the clutch of the power tool of the present invention, (e): Cross-sectional view of the clutch ring constituting the clutch of the power tool of the present invention, (f): Structure of the clutch of the present invention Plan view of the clutch ring

Claims (3)

At least one protrusion on the circumference of the ring gear in the planetary gear speed reduction mechanism with different slope angles on the inside and outside is arranged on the circumference, and the member pressed against the ring gear end face is rotated by the clutch adjustment dial. Is provided so that the distance can be varied,
A driver drill capable of adjusting the torque by the pressing member getting over any place of the protrusion having the different angle. At least one protrusion having different heights on the inner side and the outer side is arranged on the circumference of the ring gear end face in the planetary gear speed reduction mechanism, and the member pressed against the ring gear end face is moved against the rotating shaft by the clutch adjustment dial. Is provided so that the distance can be varied,
A driver drill capable of adjusting the torque by the pressing member moving over an arbitrary position of the protrusion having the different height.   The driver drill according to claim 1, wherein the driver drill is a means for fixing the ring gear in a drill mode.

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