JPH02139182A - Rotating impact tool - Google Patents

Abstract

PURPOSE:To constrain the generation of a rotating impact caused by a hammer performing the movement in the axial direction by providing a hammer regulating means fixing a rotating power transmission part located between the hammer and anvil by regulating the axial directional movement of the hammer. CONSTITUTION:An engaging pin 66 is moved along a cam groove 63 by rotating an operation handle 65 and after abutting the engaging pin 66 to the side wall of the front side of a recessed groove 22, the retreat of a hammer 2 is checked and the stroke part 21 of the hammer 2 is held in the state of its engaging with an anvil 3 at all times. As a result, the hammer 2 gives no rotation impact to the anvil 3.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a rotary impact tool called an impact wrench or an impact driver.

[Conventional technology]

Rotary impact tools generally have a structure in which a rotational impact is generated by striking an anvil with the rotational inertia of a hammer. The rotating impact tool disclosed in Japanese Patent Application Laid-open No. 59-88264 is shown in Fig. 12↓. Grip portion 7 to which a storage battery pack 5 as a power source is attached
In the casing 6 equipped with a motor M as a drive mechanism,
A spindle 1, a hammer 2, and an anvil 3 are arranged. A sun gear 41 is fixed to the output shaft of the motor M, which is fixed to the casing 6 via a mounting base 60.
Mounting base 60 via bearing 61? A plurality of planetary gears 42 that mesh with the sun gear 4 are attached to the spindle 1 on which the grain end is supported. Since these planetary gears 42 also mesh with the mounting base 60 and an internal gear 43 fixed to the gear case 62 which is a part of the casing 6, the spindle 1 is connected to these sun gears 42.
1, a planetary gear 42, and an internal gear 43. The hammer 2 is a ring-shaped member surrounding the spindle 1, is slidable in the axial direction with respect to the spindle 1, and is urged forward in the axial direction by a spring 25. Moreover, a plurality of axial arms 20 are provided on the inner peripheral surface of the hammer 2, and the distal end surface engages with the anvil 3 supported by the casing 6 via a bearing 64 to apply rotational force. A striking portion 21 that transmits rotational impact to the anvil 3 and applies rotational impact to the anvil 3 is provided in a protruding manner. On the other hand, a cam groove 10 inclined with respect to the axial direction is cut on the outer peripheral surface of the spindle 1, and the spindle 1 and the
In the figure, 30 is a holder to which a tool such as a screwdriver bit is attached, and 8 is a switch handle. If the tool attached to the holder 30 is applied to an object to be tightened and the motor M is rotated, the ball 4 is attached to the spindle 1 as the spindle 1 rotates due to the deceleration output of the motor M. The hammer 2 connected thereto also rotates. At this time, if the rotational torque of the hammer 2 is smaller than the load torque for rotating the object, the hammer 2 moves back along the cam groove 10 while compressing the spring 25, and the striking part 21 At the time when the hammer 2 is disengaged from the anvil 3, it is urged by the spring 25 and guided by the cam groove 10, moves forward while rotating, and applies a rotational impact to the anvil 3 with its striking portion 21. The tightening caused by this rotational impact is the force used to tighten screws and bolts.

[Problem to be solved by the invention]

Here, in such a mechanism, the load torque at which a rotational impact is applied is normally set to a very small value of around 10 kg/cm, whereas the torque when a rotational impact is applied is approximately 1000 kg/cm. The value is . In this case, when tightening bolts and nuts into steel frames, high impact torque is applied only at the final stage of the tightening process, and there is no problem with this setting, but when tightening wood screws into wood, Or, when tightening a screw into a thick steel plate, a high impact torque is applied from the beginning of the tightening process, resulting in so-called screw looseness. For this reason, a rotary impact tool is used to tighten bolts and nuts and large diameter iron screws, and a regular electric screwdriver or power drill that does not generate rotational impact is used to tighten wood screws and drill holes. Currently, they are used differently. The present invention has been made in view of these points, and its object is to provide a rotary impact tool that can also be used as a regular screwdriver or drill.

[Means to solve the problem]

The invention thus provides a rotationally driven spindle, a hammer that is axially slidable relative to the spindle and spring-biased axially forward and rotationally connected to the spindle, and a tool. In a rotary impact tool in which the holding anvil is hollow and a rotational force transmission part is formed between the hammer and the anvil by concave-convex engagement, the rotational force is transmitted between the hammer and the anvil by restricting the axial movement of the hammer. It is characterized by being equipped with a hammer regulating means for fixing the parts. [Function] According to the present invention, since the axial movement of the hammer can be restricted by the hammer regulating means and the rotational force transmitting portion between the hammer and the anvil can be fixed, the hammer cannot move in the axial direction. It is possible to suppress the occurrence of rotational impact caused by. [Example] The present invention will be described below based on an illustrated embodiment. FIGS. 1 and 2 show one embodiment. The basic structure is the same as that of the conventional example, and the action of the hammer 2 applying rotational impact to the anvil 3 is also the same as that of the conventional example. An annular groove 22 is provided, and a gear case 62 is provided.
has a cam groove 6 that is inclined with respect to the axial direction of the spindle 1.
3 is provided, and the tip of an engagement pin 66 protruding inward from a ring-shaped operating handle 65 arranged on the outer peripheral surface of the gear case 62 is positioned in the concave groove 22 through the cam groove 63. There is. Here, the axial force width of the spindle 1 in the groove 22 is:
It is set to be equal to or larger than the sum of the diameter of the locking pin 66 and the stroke of axial movement that occurs when the hammer 2 applies a rotational impact to the anvil 3. In this rotary impact tool, the operating handle 65 is rotated to move the engagement pin 66 along the cam groove 63, and as shown in FIG. When brought into contact with the side wall, the hammer 2 is prevented from retreating, and the striking part 21 of the hammer 2 is kept in constant engagement with the anvil 3. For this reason, the hammer 2 is rotated by the anvil 3. No more shocks. However, as shown in FIG. 2, if the engagement pin 66 is moved backward, the hammer 2 can be moved back freely.
The anvil 3 is now in a state where it is subjected to a rotational impact. As shown in FIGS. 3 and 4, the engagement pin 66 is disposed behind the hammer 2, and when the engagement pin 66 abuts against the rear end surface of the hammer 2, the rotational impact movement is suppressed, and the engagement pin 66 is placed behind the hammer 2. 6
When the engagement pin 66 is away from the rear end surface of the hammer 2, the rotational impact action may be performed.
As shown in the figure, a rotatable backup ring 67 is disposed on the inner circumferential side of the gear case 62, and the engagement pin 66 is engaged with a groove 68 on the outer circumferential surface of the backup ring 67. Backup ring 67 moving in the direction
The movement of the hammer 2 in the axial direction may be restricted by. FIGS. 7 and 8 show still other embodiments. Here, a movable body 71 that is movable in the axial direction but not rotated is disposed within the gear case 62, and the movable body 71 and ring 72 form a spring 25 whose one end is in contact with the hammer 2. supports the other end. Further, the gear case 62 is provided with a long hole 64 in the circumferential direction.
An engagement pin 66 protruding from an operating handle 65 disposed on the outer circumferential surface of the movable body 71 is engaged with a cam groove 73 formed on the outer circumferential surface of the movable body 71 through the elongated hole 64. In this case, when the operation handle 65 is rotated, the moving body 71 moves back and forth, and the moving body 71 moves back and forth.
When the hammer 1 moves forward, the spring 25 is completely compressed, preventing the hammer 2 from retreating and suppressing the rotational impact application operation. In the embodiment shown in FIGS. 9 to 11, the pin 76 is slidably arranged in a diametrical hole provided in the hammer 2, and one end of the pin 76 is engaged with the outer peripheral surface of the spindle 1. A hole 16 is provided. Furthermore, a movable body 71 that can freely move in the axial direction is arranged on the inner peripheral side of the gear case 62, and
A cam portion 74 whose inner diameter changes in the axial direction is provided on the inner peripheral surface of the movable body 71. An engagement pin 66 protruding from the operating handle 65 is connected to the movable body 71 through an axially elongated hole 64 provided in the gear case 62. Now, as shown in FIG. 9, when the movable body 71 is positioned forward, the bin 76 moves toward the outer circumference of the hammer 1 as the hammer 1 rotates, and the engagement hole of the spindle 1
Since the bottle 76 is pulled out from the anvil 6, the hammer 2 can be moved in the axial direction, and therefore the hammer 2 can apply a rotational impact to the anvil 3, but as shown in FIG. When the body 71 is moved backward, the moving body 7
1 presses the pin 76 and the pin 76 is engaged with the retaining hole 16 of the spindle 1, that is, in order to restrict the axial movement of the hammer 2, a rotational impact is applied. Movement is suppressed.

【Effect of the invention】

As described above, in the present invention, since the axial movement of the hammer can be restricted by the hammer regulating means and the rotational force transmission section between the hammer and the anvil can be fixed, the hammer cannot move in the axial direction. It is able to suppress the rotational impact generated by the machine, and it can also be used as a regular electric screwdriver or electric drill, so there is no need to use multiple types of tools depending on the work. It is.

[Brief explanation of the drawing]

FIG. 1 is a cutaway side view of one embodiment of the present invention, FIG. 2 is a cross-sectional view of the same as above, FIGS. 3 and 4 are force cross-sectional views of other embodiments, and FIG.
6 and 6 are sectional views of still another embodiment, FIGS. 7 and 8 are sectional views of another embodiment, FIGS. 9 and 10 are sectional views of still another embodiment, and FIG. The figure is an exploded perspective view of the same as the above, and FIG. 12 is a cutaway side view of the conventional example, in which 1 is a spindle, 2 is a hammer, 3 is an anvil, and 66 is an engaging pin. Agent Patent Attorney Ishi 1) Chief Seven copies Figure 2 Figure 3 Figure 4 Figure 7 Figure 8 Figure 5 Figure 6 Figure 9 $10 Figure 11 76 Procedural amendment (voluntary) 1920 @ 4゛ January 7th

Claims (1)

[Claims] (1) A rotationally driven spindle, a hammer that is slidable in the axial direction with respect to the spindle, is spring-biased axially forward, and is rotationally connected to the spindle, and an anvil that holds the tool. It consists of
In a rotary impact tool in which a rotational force transmission part is formed between the hammer and anvil by concave-convex engagement, hammer regulation that restricts the axial movement of the hammer and fixes the rotational force transmission part between the hammer and anvil. A rotary impact tool characterized in that it is provided with means.