JPH079355A - Nut runner - Google Patents

Abstract

PURPOSE:To provide a nut runner which can surely maintain the engagement of clutch teeth regardless of either of a high speed low torque mode and a low speed high torque mode, and also can be normally/reversely rotated. CONSTITUTION:The teeth of a top cam 65 and the teeth of a drive shaft which are meshed with each other at the time of a high speed low torque mode, are formed into each rectangular tooth 67 and 68. Both the teeth 67 and the teeth 68 are engaged with each other by the energizing force of a spring 103. The teeth of a bottom clutch 92 and the teeth of an output shaft 36 which are meshed with each other at the time of a low speed high torque mode, are formed into each rectangular tooth 61 and 95. The bottom clutch 92 is held down by air pressure via a piston 76, so that both the teeth 61 and the teeth 95 are thereby engaged with each other.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a nut runner having a front speed reducer and a rear speed reducer.

[0002]

2. Description of the Related Art Conventionally, by controlling the clutch disengagement / connection,
The rotational force of the air motor is reduced / increased by the pre-stage reducer to rotate the drive shaft that tightens the nut with high speed and low torque, while the rotational force of the air motor is reduced by the pre-stage and post-stage reducers.
A nut runner has been proposed in which the drive shaft is rotated to rotate at a low speed and a high torque by increasing the force (Jitsuko Sho 63-
(See Japanese Patent No. 48388).

In the above-mentioned conventional nut runner, the top cam is moved to the rear speed reducer side by the piston operated by air pressure, and the teeth of the top cam and the teeth of the drive shaft are engaged with each other to achieve a high speed and low torque mode. While tightening the nut, release the above air pressure and move the top cam to the pre-stage reduction gear side by the biasing force of the spring, and engage the teeth of the bottom clutch that follows the top cam with the teeth of the output shaft of the pre-stage reduction gear. Then, the nut is tightened in the low speed and high torque mode.

[0004]

However, as shown in FIG.
As shown in (A), since the teeth 1a of the top cam 1 and the teeth 2a of the drive shaft 2 are trapezoidal teeth, unless the top cam 1 is pressed through the piston by air pressure, high speed is achieved. When a load is applied in the low torque mode, a force (thrust) Y in the escape direction acts on the top cam 1 and both teeth 1
There is a risk that a and 2a will come off.

Further, in the low speed and high torque mode, the teeth of the bottom clutch and the teeth of the output shaft are simply engaged only by the biasing force of the spring, so that both teeth are improperly engaged (engaged). May occur. Furthermore, FIG.
As shown in (B), when the teeth 3a of the bottom clutch 3 and the teeth 4a of the output shaft 4 of the front speed reducer are triangular teeth, the nut is loosened because only one direction of forward rotation or reverse rotation functions. I can't.

Therefore, an object of the present invention is to provide a nut runner capable of reliably maintaining engagement of the teeth of the clutch in both high speed and low torque and low speed and high torque modes and capable of forward and reverse rotation.

[0007]

In order to achieve the above object, the present invention provides a nut runner capable of transmitting the output of a motor to a drive shaft via a front speed reducer and a rear speed reducer,
A top cam that is attached to the output shaft of the preceding reduction gear so as to be non-rotatable and axially movable and has rectangular teeth at its end, and a top cam provided at the end of the drive shaft and engaged with the rectangular teeth of the top cam. A first clutch including a rectangular tooth that is detachably engaged and a spring that biases the top cam in a direction in which both rectangular teeth are engaged, and a rectangular tooth that is provided at an end portion of an output shaft of the preceding speed reducer. And a rectangular tooth that is non-rotatably and axially movably attached to the input shaft of the latter-stage reduction gear and has a rectangular tooth that engages with the rectangular tooth in a disengageable manner, and follows the movement of the top cam. And a movable second bottom clutch and air pressure to actuate the top cam in the axial direction by the air pressure to move the first clutch in the disengagement direction, and the top cam causes the bottom clutch to move. The clutch is the second clutch On the other hand, when the air pressure is not applied, the spring allows the top cam to move in the direction to connect the first clutch, and the top cam opens the bottom clutch to the second clutch. It is characterized by having a piston for moving in the cutting direction.

[0008]

According to the present invention, since the teeth of the top cam and the teeth of the drive shaft are not trapezoidal teeth as in the conventional case but rectangular teeth, even if a load is applied in a high speed low torque mode, Since thrust in the direction of escape to the cam does not work, even if both teeth are engaged only by the biasing force of the spring, there is no risk of both teeth coming off.

Further, in the low speed and high torque mode, since the bottom clutch is pressed by the air pressure through the piston, there is no risk of engagement (meshing) failure between the teeth of the bottom clutch and the teeth of the output shaft. Furthermore, since both teeth are rectangular teeth instead of the conventional triangular teeth, they function in both forward and reverse directions and can both tighten and loosen the nut.

[0010]

The present invention will be described in detail below with reference to the embodiments shown in the drawings. 1 is the front half of the nut runner NR cut along the cutting line AA, and FIG. 2 is the rear half of the nut runner NR cut along the same cutting line AA as in FIG. In FIGS. 1 and 2, 11 is an electric motor, 15 is a front stage reduction gear that increases the rotational force of the electric motor 11, 16 is a rear stage reduction gear, and 17 is a drive shaft that is connected to a nut via a socket (not shown). .

As shown in FIG. 1, the front stage speed reducer 15 is provided.
Is configured to increase and decrease the speed in two stages of the first planetary gear mechanism 21 and the second planetary gear mechanism 22. The first planetary gear mechanism 21 includes a sun gear 25 formed on the outer periphery of the tip end of the output shaft 23 of the electric motor 11, a planetary gear 27, and an internal gear 28 formed on the inner periphery of the case 29. . The second planetary gear mechanism 22 includes a sun gear 32 formed on the outer periphery of the shaft portion of a carrier 31 supporting the planetary gear 27, a planetary gear 33, and an internal gear 34 formed on the inner periphery of the case 29. Has become
The shaft portion of the carrier 35 that supports the planetary gear 33 serves as the output shaft 36 of the pre-stage reduction gear 15.

As shown in FIG. 2, the rear stage speed reducer 16 is provided.
Is a rotation shaft, that is, a sun gear 42 formed on the outer periphery of one end of the input shaft 41, a planetary gear 44 rotatably supported by a carrier 43 formed integrally with the drive shaft 17, and a case 4
6 and the internal gear 45 formed on the inner circumference,
The driving force transmitted from the input shaft 41 to the sun gear 42 is increased / decreased and transmitted to the driving shaft 17.

As shown in detail in FIG. 6, a top clutch 63 having rectangular teeth 61 on the end face and spline teeth 62 on the outer periphery is fitted to the output shaft 36 of the pre-stage reduction gear 15 as shown in FIG. And then fixed. Above top clutch 6
The spline teeth 62 of No. 3 are meshed with the spline teeth 66 on the inner circumference of the top cam 65 shown in detail in FIG. 4 so as to be slidable in the axial direction.

Rectangular teeth 67 are formed on the end surface of the top cam 65 on the rear stage speed reducer 16 side. The rectangular teeth 68 that can be meshed with the rectangular teeth 67 are provided on the carrier 4 of the rear speed reducer 16.
3, that is, the bottom cam 69 (see FIG. 3) fixed to the drive shaft 17. A washer 70 for a retaining ring 70a provided at the end of the top cam 65 on the front speed reducer 15 side.
between the coil spring 103 and the flange 71 provided at the end of the top clutch 63 on the pre-stage reduction gear 15 side.
Disguise.

Then, as shown in FIG. 1, the top cam 65 uses the urging force of the coil spring 103 to drive the rear stage speed reducer 1.
When the rectangular teeth 67 and 68 are engaged with each other by moving to the 6 side, the bottom cam 69 is rotated together with the top cam 65, and the output shaft 36 of the front reduction device 15 is directly connected to the drive shaft 17. Will be connected. Further, when the top cam 65 is moved to the front stage speed reducer 15 side against the biasing force of the coil spring 103, the rectangular teeth 67 and 6
8 is disengaged, and the connection between the output shaft 36 of the pre-stage reduction gear 15 and the drive shaft 17 is broken.

Therefore, the top cam 65 and the rectangular teeth 67 and 68 form a first clutch that connects and disconnects the output shaft 36 and the drive shaft 17 of the front speed reducer 15. Even if the rectangular teeth 67 and 68 mesh with each other to transmit the rotational force, the thrust is in the direction of escape to the top cam 65 (direction of arrow Y in FIG. 7) because it is not a trapezoidal tooth as in the past but a rectangular tooth. Does not work.

In the case 75 of the top cam 65,
A stepped pipe-shaped piston 76 is slidably fitted. The seal between the piston 76 and the case 75 is
This is done by an O-ring 77 provided on the piston 76 and an O-ring 78 provided on the case 75, and a control port 79 is provided on the case 75 between the two O-rings 77 and 78. Therefore, when air is supplied to the control port 79, air pressure acts on the stepped portion of the piston 76, and the piston 76 moves to the right in FIG.
The top cam 65 is moved to the right in FIG. 1 via a so that the rectangular teeth 67 and 68 are forcibly removed.

On the other hand, the sun gear 42 of the latter stage reduction gear 16
Spline teeth 85 are formed on the outer circumference of the other end portion 84 of the input shaft 41 formed at one end portion. Spline teeth 8 above
A spline groove 93 formed on the inner circumference of a bottom clutch 92 arranged inside the top cam 65 is slidably fitted to the shaft 5. As shown in detail in FIG. 5, a rectangular tooth 9 that can be meshed with the rectangular tooth 61 on the end surface of the top clutch 63 is provided on the end surface of the bottom clutch 92 on the front speed reducer 15 side.
5 is formed.

When the rectangular teeth 67 and 68 are meshed with each other, the bottom clutch 92 is restricted to a position where the rectangular teeth 61 and 95 do not mesh with each other by the step portion 105 provided on the inner circumference of the top cam 65. On the other hand, when the top cam 65 moves to the right in FIG. 1 so that the rectangular teeth 67 and 68 are disengaged from each other, the bottom clutch 92 is also moved to the right via the auxiliary spring 104. , The rectangular teeth 61 and 95 mesh with each other. That is,
The bottom clutch 92, the rectangular teeth 61 and 95, and the auxiliary spring 104 constitute a second clutch that connects and disconnects the output shaft 36 of the front stage reduction gear 15 and the input shaft 41 of the rear stage reduction gear 16.

The auxiliary spring 104 is for engaging the rectangular teeth 95 of the bottom clutch 92 with the rectangular teeth 61 of the top clutch 63. However, the auxiliary spring 104 is omitted and the inner circumference of the top cam 65 is omitted. The bottom clutch 9 is provided between the retaining ring 82 provided on the
You may comprise so that 2 may be pinched.

When tightening the nut with the nut runner NR having the above structure, air is not supplied to the control port 79, that is, the top cam 65 is moved to the left by the biasing force of the coil spring 103, and the rectangular tooth 67 is formed. And 68
The output shaft 36 of the pre-stage reduction gear 15 and the drive shaft 1
Directly connect with 7 and tighten the nut in high speed and low torque mode.

Next, in this high-speed low-torque mode, a predetermined seating torque is reached and the nut runner NR stalls,
Alternatively, when stopped by an external signal, the control port 79
Supply air to. Then, the piston 76 moves to the right and moves the top cam 65 to the right through the retaining ring 70a, so that the meshing of the rectangular teeth 67 and 68 is forcibly disengaged and the top cam 65 follows. The rectangular teeth 95 of the bottom clutch 92, which moves in the same manner, are meshed with the rectangular teeth 61 of the top clutch 63.

As a result, the output shaft 36 of the pre-stage reduction gear 15 is
And the input shaft 41 of the rear speed reducer 16 is connected to the bottom clutch 92.
The output of the electric motor 11 is increased / decreased by the front / rear reduction gears 15 and 16, and the nut is tightened in the low speed / high torque mode.

In the above structure, since the teeth of the top cam 65 and the bottom cam 69 are not trapezoidal teeth as in the conventional case but rectangular teeth 67 and 68, even if a load is applied in a high speed low torque mode, the top cam 65 Since the force in the escape direction Y does not work, both rectangular teeth 67 and 68 are not likely to be disengaged even if both teeth are engaged only by the biasing force of the spring 103.

In the low speed and high torque mode, the bottom clutch 92 is pressed by the air pressure through the piston 76, so that the rectangular teeth 95 of the bottom clutch and the rectangular teeth 61 of the top clutch 63 are not engaged (engaged) with each other. There is no danger of it occurring. Furthermore, since both teeth are not the conventional triangular teeth but the rectangular teeth 61 and 95, they function in both forward and reverse directions, and both nuts can be tightened and loosened.

The rectangular teeth 67, 68 and 61, 9
5 is more difficult to mesh than trapezoidal teeth and triangular teeth,
By selecting the number of rectangular teeth, they can be easily meshed and have strength, and can be used for both air motors and electric motors.

[0027]

As is apparent from the above description, in the nut runner of the present invention, since the teeth of the top cam and the teeth of the drive shaft are formed as rectangular teeth instead of trapezoidal teeth as in the prior art, a high speed is achieved. Even if the mode is switched to low torque or low speed high torque mode, the force that escapes to the top cam does not work, so even if both teeth are engaged only by the biasing force of the spring, both teeth will disengage. There is no fear.

In the low speed and high torque mode, since the bottom clutch is pressed by the air pressure through the piston, there is no possibility that the teeth of the bottom clutch and the teeth of the output shaft will be engaged (engaged) with each other. . Furthermore, since both teeth are formed as rectangular teeth instead of the conventional triangular teeth, they function in both forward and reverse rotation directions, enabling both tightening and loosening of nuts. It becomes possible to deal with loosening after seating by smoothing the seat.

[Brief description of drawings]

FIG. 1 is a side sectional view of a rear half of a nut runner of the present invention.

FIG. 2 is a side sectional view of the front half of the nut runner of FIG.

3A is a rear view of the bottom cam, FIG. 3B is a side sectional view of the bottom cam, and FIG.

FIG. 4A is a side sectional view of the top cam, and FIG. 4B is a front view thereof.

5A is a rear view of the bottom clutch, and FIG. 5B is a side sectional view thereof.

FIG. 6 is a side sectional view of (A) of the top clutch,
(B) is a front view.

FIG. 7 is a plan view when meshing rectangular teeth.

8A is a plan view of a conventional trapezoidal tooth when meshing, and FIG. 8B is a plan view of a triangular tooth when meshing.

[Explanation of symbols]

NR nut runner, 11 electric motor, 15 pre-stage reducer, 16
Rear speed reducer, 17 drive shafts,
36 output shafts, 41 input shafts,
61 rectangular teeth, 63 top clutch,
65 top cam, 67 rectangular teeth,
68 rectangular teeth, 69 bottom cam,
76 pistons, 79 control ports,
92 bottom clutch, 95 rectangular teeth, 103 coil spring.

Claims (1)

[Claims] 1. A nut runner capable of transmitting the output of a motor to a drive shaft through a front speed reducer and a rear speed reducer, the end runner being attached to the output shaft of the front speed reducer so as not to rotate and move in the axial direction. A top cam having a rectangular tooth on its part, a rectangular tooth provided on the end of the drive shaft and releasably engaged with the rectangular tooth of the top cam, and a direction in which both rectangular teeth engage the top cam. A first clutch consisting of a spring biased to, a rectangular tooth provided at the end of the output shaft of the preceding reduction gear,
It is attached to the input shaft of the latter stage reduction gear so as not to rotate and movable in the axial direction, and has a rectangular tooth at its end that engages with the rectangular tooth in a disengageable manner, and follows the movement of the top cam. A second clutch consisting of a movable bottom clutch and air pressure actuates the air to press the top cam in the axial direction to move the first clutch in the disengagement direction, and the top cam operates the bottom clutch. While the second clutch is moved in the connecting direction, when the air pressure is not applied, the spring allows the top cam to move in the connecting direction of the first clutch, and the top cam moves the bottom clutch to the second clutch. A nut runner characterized by having a piston that moves in the clutch disengagement direction.