JPS5915764B2 - Rotary power tool gearbox - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission for a rotary power tool.

A conventional example is shown in FIGS. 1 and 2.

That is, in the one shown in FIG. 1, 10 revolutions of the motor shaft are first transmitted to the gear 3 by the pinion 2, and then to the gear change pinions 4 and 5 provided coaxially therewith.

Shift gears 6 and 7 that mesh with these shift pinions 4 and 5 are integrally spline-fitted to an intermediate shaft 8 and are moved on the shaft by a shift handle 9.

Depending on the position of the shift handle 9, the shift gear 6 meshes with the shift pinion, or the shift gear I meshes with the shift pinion 5, thereby changing the gear ratio and performing a shift.

There is a pinion 9 on the intermediate shaft 8, which transmits force to the next stage speed reduction mechanism 10.

However, in this transmission, since the distance between the speed change pinions 4 and 5 is long, it is difficult to directly connect the speed change pinions 4 and 5 with the motor, and the number of deceleration stages must be increased by one stage (3), resulting in a large transmission.

Also, if the positions of the pinions 4 and 5 and the gears 6 and 7 do not match when changing gears, the tips of the gear teeth will touch each other, making it impossible to shift smoothly and making it difficult to change gears while rotating, resulting in chipping of the tips of the teeth. Sometimes I did.

On the other hand, the one shown in FIG. 2 has the above-mentioned improvement and transmits the rotation of the motor 11 to a pinion 12 provided on the shaft.

This pinion 12 is an integrated pinion 12a and pinion 1.
2b, which are always meshed with the speed change gear 13 and the speed change gear 14, respectively.

Each transmission gear 13, 14 is rotatable on the intermediate shaft 15,
A key 16 movably provided on the intermediate shaft 15 is used to change the speed.
- It is provided so that it can be moved by a handle 17.

Further, each speed change gear 13, 14 is provided with a keyway 13a, 14a that meshes with the key 16, and depending on the movement position of the key 16, the speed change gear with which the protrusion 16a is meshed becomes integral with the intermediate shaft 15. Rotation is transmitted to the shaft 15.

A pinion 1γ is located at the tip of the intermediate shaft 15 and transmits rotation to the next stage reduction mechanism 18.

However, this transmission had the following drawbacks.

That is, if the key 16 does not match the key grooves 13a, 14a of the transmission gears 13, 14 when moving, the key 16 cannot be moved, making it difficult to smoothly change gears, and making it impossible to switch during rotation.

In addition, each transmission gear 13, 14 is stopped by walls 19a, 19b of the outer body 19 so that it does not move when the key 16 is moved, and sliding on these walls 19a, 19b cannot be avoided during operation. Large loss and noise.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a transmission device for a rotary electric power tool that allows smooth and reliable shifting of the gear shift handle and enables switching during rotation.

That is, in the present invention, a pair of springs are held facing each other on a gear shift handle, and one end of an operating member is interposed between the springs.
It is characterized in that the speed change switching means is operated by an operating member.

When the gear shift knob is operated, one end of the operating member is pressed by one of the springs depending on the operating direction, thereby operating the operating member.

Furthermore, even if the switching means is not smoothly engaged, the shift lever elastically deforms the spring, so the shock is absorbed and the operation can be performed smoothly, and the spring action at that time allows for reliable engagement.

As a result, the operation is smooth and switching can be performed during rotation.

A power tool to which an embodiment of the present invention is applied is shown in FIGS. 3 to 10.

That is, this power tool has a pistol-shaped housing 20 that can be split into two parts in the width direction. First, a battery pack 22 containing a storage battery is provided in the handle part 21, and a lower end opening 21a of the handle part 21 is opened. The battery terminal 23 and the contact terminal 24 are brought into electrical contact with each other by being removably loaded.

In addition, there is an important power switch 2 on the front side of the base of the handle 21.
Electrical power is supplied to the motor 28 of the main body 27 via these switches 25 and 26.

A motor 28 is arranged at the lower part of the rear end of the main body 27 which is the trunk, and a speed changer is arranged at the upper part of the rear end of the main body 27 which is above the motor 28.
- A handle device 29 is disposed, a transmission 30 is disposed in the middle of the main body 27, and a transmission 31 is further disposed at the front end, with the chuck 32 protruding from the front end.

A motor shaft 33 of the motor 28 protrudes toward the front end, and a double pinion 34 is fixed to the motor shaft 33 .

An intermediate shaft 35 of the transmission 30 is arranged parallel to the motor shaft 33 at the center of the main body 27, and both ends thereof are rotatably supported by bearings 36, 37.

A keyway 38 is formed in this intermediate shaft 35.
A sliding key 39 is slidably inserted into the slot.

This sliding key 39 has a pair of protrusions 40 and 41 at both ends thereof, which protrude from the surface of the intermediate shaft 35 at a constant interval L1, and the space between the protrusions 40 and 41 is sunk below the surface of the intermediate shaft 35.

As shown in FIGS. 4 to 6, a ring groove 42 is formed at the rear end of this sliding key 39, and a ring groove 42 is formed at the hole edge of a movable ring 44 having a hole 43 that loosely fits into the intermediate shaft 35. 42
The moving ring 44 is rotatably fitted to the intermediate shaft 35, and as shown in FIG. It fits into the formed arc edge 44a and is fixed integrally.

As shown in FIG. 3, the transmission lever 45 is arranged parallel to the intermediate shaft 35 near the rear end of the main body 27, and is supported so as to be slidable in the axial direction of the intermediate shaft 35. A horizontal portion 47 perpendicular to the intermediate shaft 35 is formed at the lower center of the gear shift handle 46, and a vertical portion 4 is formed at the end of the horizontal portion 447.
8 is formed and inserted into the speed change ladle 46.

The gear shift handle 46 has a knob 46a projecting from the slit 49 of the main body 27 on its upper surface, and an inner surface 27a of the main body 27.
It is frictionally slidably supported by the guide 27b so that it can move parallel to the axial direction of the intermediate shaft 35. Furthermore, a box-shaped leaf storage part 46b with an opening at the lower end is formed on the lower surface of the transmission handle 46, and the storage part 46b is formed on the lower surface of the transmission handle 46. Four ribs 50a to 50d are formed at the center of the portion 46b.

The groove 50a, sob and end wall 46 in this storage section 46b
Coil springs 51 and 52 are interposed in a compressed state between the rib 50c and the end wall 46b', so that the coil springs 51 and 52 face each other, and the rib 50a
~50d forms a gap 53, and the storage portion 46b
A guide recess 54 is cut out in the opening edge of one side wall (FIG. 8).

The horizontal portion 47 of the transmission lever 45 is connected to the guide recess 5.
4, and the vertical portion 48 is located in the gap 53 between the coil springs 51 and 52.

Therefore, when the shift handle 46 is slid in one direction, the guide recess 54 slides smoothly into the horizontal portion 47, and the vertical portion 48 is moved into the rib 50a.

50b or between the ribs 50c and 50d, one end of the coil springs 51 and 52 comes into contact with the side surface of the vertical part 48 of the transmission lever 45 and pushes the transmission lever 45 in the sliding direction, and the transmission lever 45 The moving ring 44 is moved in the axial direction of the intermediate shaft 35, thereby causing the sliding key 39 to move the intermediate shaft 35.

On the other hand, a pair of transmission gears 55 and 56 are rotatably fitted between the protrusions 40 and 41 of the sliding key 39 of the intermediate shaft 35, and have a total axial length L2, )L2.

The sliding direction of the gears 55 and 56 is regulated by a pair of retaining rings 58 fitted in a circumferential groove 57 deeper than the key 39 inserted into the intermediate shaft 35, and the gears 55 and 56 are always meshed with the double pinion 34.

The reduction ratios due to the meshing of these transmission gears 56 and 56 are different from each other, and a washer 59 is interposed between the gears 55 and 56, and a washer 59 is provided on the outer surface of the center of each gear 55 and 56 as shown in FIG. A ring-shaped protrusion 60 protrudes from the inner side of the ring-shaped protrusion 60.
fan-shaped recesses 61a to 61c are formed, and the projection 40 of the sliding key 39 is formed in any of these recesses 61a to 61c.
．． 41 are fitted by sliding, and the recesses 61a to 61c
The rotation of the gear 55.56 is transmitted to the intermediate shaft 35 by the protrusion 40.41 being engaged with the inner surface 661' of the gear 55.56.

The retaining ring 58 is formed of a C-shaped E-ring as shown in FIG.

58b is inclined at an angle θ toward the opening side with respect to the radial direction P, and as the retaining ring 58 rotates in the circumferential groove 57, the end 58a of the retaining ring 58 and the inner edge 58' of the retaining ring 58 and the inner edge 58' of the retaining ring 58 slide around the circumference of the key 39. When it comes into contact with the part protruding from the groove 57, the end 5
8a and sab are not positioned on the sliding key 39 so as not to obstruct the sliding of the sliding key 39.

The reduction gear 31 transmits rotation to a planetary gear 63 by a pinion 62 formed at the tip of an intermediate shaft 35 , and supports an internal gear 67 via a ball 66 by a coil spring 65 supported by a torque adjustment knob 64 . When the planetary gear 63 rotates the internal gear 67, the pin 68 of the planetary gear 63 is connected to the eccentric position of the chuck 32, so that the chuck 32 rotates at a reduced speed.

Next, the speed change operation of this power tool will be explained.

When the switch 25, 26 is operated, the motor shaft 33 of the motor 28 rotates in a predetermined direction, and the pinion 34 rotates each transmission gear 55, 56.

The state shown in FIGS. 3 and 10a is a state in which the shift handle 46 is slid in the direction 35 rotates at low speed by the speed change gear 560 rotations,
It is transmitted to the chuck 32 via the speed reduction device 31.

FIG. 10 shows a state in which the gearshift handle 46 is being slid in the direction of the arrow Y, and the vertical portion 48 of the transmission lever 45 is pushed by the coil spring 51, and the protrusion 40 of the sliding key 39 is moved via the moving ring 44. Recessed portion 61a of transmission gear 56
, and the rotation of the speed change gear 56 reaches the intermediate shaft 3.
5 will no longer be transmitted.

At this time, the protrusion 41 of the sliding key 39 is not engaged with the recesses 61a to 61c of the speed change gear 55 according to the relationship L1)L2 in FIG. 4, so the intermediate shaft 35 stops rotating.

FIG. 10C shows a state in which the shift handle 46 is pushed further in the direction Y. At this time, if the protrusions 41 of the sliding key 39 do not properly fit into the recesses 61a to 61c of the shift gear 55, the protrusions 61 between them Therefore, the coil spring 51 is compressed and the gear shift handle 46 advances to the switching position, and the compression of the coil spring 51 moves the sliding key 39 through the transmission lever 45 and the moving ring 44 to the gear gear 5.
It is in a state of elastic contact with 5.

FIG.
1a to 61c and are engaged by the restoring action of the coil spring 51, whereby the speed change gear 550 rotations are transmitted to the intermediate shaft 35 via the key 39, and the chuck 32 rotates at high speed. That will happen.

By further operating the speed change handle 46 in the direction X, the speed change gear 5
The operations that may occur when switching to 6 are also similar to those described above.

As described above, in the transmission device for a rotary power tool of the present invention, a pair of opposing springs are provided in the transmission handle, and a switching operation member is interposed between the opposing springs to perform a switching operation.

This makes the steering wheel operation smoother.
The effect is that switching can be performed reliably without feeling any impact, and switching can be performed while rotating.

[Brief explanation of the drawing]

Figures 1 and 2 are sectional views of a conventional example, Figure 3 is a sectional view of a power tool to which an embodiment of the present invention is applied, Figure 4 is a partially sectional tooth of a transmission, and Figure 5 is its left side. 6 is a perspective view thereof, FIG. 1 is a sectional view showing the retaining ring, FIG. 8 is an exploded perspective view of the gear shift handle, Figure 9 is a bottom view of the gear shift handle, and Figure 10 is a bottom view of the gear shift handle. The figure is a sectional view of the gear shifting operation state. 39...Sliding key (shift change), 45...
・・Transmission lever (operating member), 46... Speed change-
・Handle, 51゜52... Coil spring, 54・
...Guide recess, 55°56...Transmission gear (transmission member).

Claims (1)

[Claims] 1. A pair of transmission members having different rotational speeds relative to the output of a motor, a sliding key having a protrusion that can be freely engaged and detached from the transmission member, a transmission bundle for moving the sliding key, and a transmission bundle held by the transmission bundle. A pair of opposing springs, one end of which is disposed between these springs and operates via one of the springs depending on the operating direction of the shift handle, and the other end is connected to the sliding key. A transmission device for a rotary power tool, which is equipped with an operating member.