JPH07269B2 - Nut runner - Google Patents

Description

The present invention relates to a nut runner capable of automatically switching between high speed (low torque) and low speed (high torque) and capable of forward and reverse rotation.

[Conventional technology]

Conventionally used two-speed nut runners include, for example, the one shown in FIG. 5 and the one shown in Japanese Utility Model Publication No. 54-57599. Nut runner 10 shown in FIG.
0 is an output shaft 10 that axially supports the gear 103 via a planetary gear 103 that meshes with a rotary motor shaft gear 102 of the air motor 101.
The planetary gear 106 that is transmitted to the gear 4 and meshes with the drive gear 105 formed at the tip of the output shaft is rotated. The planetary gear 106 is rotatably supported by the tubular transmission frame 107, and therefore the transmission frame 107 is rotated at a slow speed by the rotation of the output shaft 104. An intermediate shaft 109 is rotatably provided coaxially with the output shaft 104, and a clutch 111 is provided between a fixed flange 108 attached to the tip of the output shaft 104 and a sliding shaft 110 fitted into the intermediate shaft 109. The spring 112 presses the sliding shaft 110 toward the fixed flange 108. The clutch 111 has a riding structure by engagement of angled claws, and the sliding shaft 110 allows the intermediate shaft 109 to move in the axial direction but rotates together.

A one-way meshing clutch 113 is provided between the transmission frame 107 and the intermediate shaft 109 to transmit the rotation from the transmission frame 107 to the intermediate shaft 109 and allow the intermediate shaft 109 to rotate at high speed.

The intermediate shaft 109 is connected via a planetary gear 114 to a main shaft 115 that supports the gear 114, and a suitable box (not shown) into which a nut or a bolt is fitted is detachably fitted to the tip of the main shaft. .

When bolts are tightened by the 2-speed nut runner 100, if a load is not applied to the main shaft 115, the main shaft 104 rotates the sliding shaft 110 and the intermediate shaft 109 at the same speed and high speed via the clutch 111. Let At this time, the one-way dog clutch 113 has a higher speed on the intermediate shaft 109 side than the speed change frame 107, and allows the intermediate shaft 109 to freely rotate.

When the bolts are tightened and a constant load is applied to the main shaft 115, the clutch 111 rides up, the sliding shaft 110 is pushed against the intermediate shaft 109 against the spring 112, the clutch 111 is released, and it is constantly rotating at low speed. Power is transmitted from the transmission frame 107 to the main shaft 115 via the one-way meshing clutch 113. As a result, bolt tightening work is performed with high torque, and switching from high-low speed torque to low-speed large torque is automatically performed.

[Problems to be Solved by the Invention]

In the above nut runner, from the transmission frame 107 to the intermediate shaft 1
One-way dog clutch 113 as a means of transmitting power to 09
Therefore, it is impossible to reversely rotate the main shaft 115 due to its configuration. For this reason, the bolts and nuts are used exclusively for tightening or loosening, and the tightening and loosening operations cannot be performed with the same tool. Further, the clutch 111 runs when the intermediate shaft 109 rotates at a low speed and rotates in that state, which causes problems such as noise and abrasion of the clutch teeth. Further, the one disclosed in Japanese Utility Model Laid-Open No. 54-57599 described above has the same problem.

On the other hand, although a two-speed nut runner capable of forward and reverse rotation has also been proposed (see, for example, Japanese Utility Model Publication Nos. 59-191264 and 52-24187), the overall structure is complicated and the operation of the device is complicated. There is a problem that a clutch pawl or a meshing gear having a complicated shape that is difficult to process is required to stabilize the state.

[Problems to be Solved by the Invention]

INDUSTRIAL APPLICABILITY The present invention is capable of automatically switching between high speed (low torque) and low speed (high torque), allowing forward and reverse rotation, maintaining a stable operating state, and having a simple overall structure and a simple structure of each component. The purpose is to provide runners.

[Means for Solving the Problems]

The present invention has been made to achieve the above object, and in a nut runner in which an output shaft connected to a drive source and a main shaft connected to a bolt, a nut and the like are provided so as to face each other on the same axis, A cylindrical transmission frame that is decelerated and rotated by the output shaft is fitted around the shaft and the main shaft, and a clutch unit is fitted between the output shaft and the main shaft in the transmission frame so as to be slidable and rotatable in the axial direction. And a first clutch for high speed rotation and low torque having angled teeth is provided between the clutch unit and the output shaft, and a second clutch for low speed rotation and high torque having rectangular teeth is provided between the clutch unit and the transmission frame. An engaging ball for high speed rotation and low torque for transmitting power from the clutch unit to the main shaft is fitted between the respective parts of the clutch unit and the main shaft into a ball fitting hole formed in the clutch unit. And a lock pin for low-speed rotation and high-torque that engages with a corner portion of the main shaft so as to project from the inner peripheral surface of the clutch unit, and a taper formed on the inner surface of the transmission frame with which the engaging ball abuts and expands in the main shaft direction The gist of the invention is to provide movement restricting means for the clutch unit, which includes a surface and a spring that biases the clutch unit in the output shaft direction.

[Action]

In the nut runner configured as described above, when the rotational resistance (torque) applied to the main shaft is small, the clutch unit pressed by the spring of the movement restricting means moves to the output shaft side and the first clutch engages. However, the rotation of the output shaft is the first
It is transmitted to the clutch unit via the clutch and rotates the flat surface of the corner portion of the main shaft via the engaging balls. When the rotational resistance (torque) applied to the main shaft reaches a predetermined value or more, a rotation difference occurs between the main shaft and the clutch unit, and an engaging ball is formed on the inner surface of the shift frame of the movement restricting means by the flat surface of the corner of the main shaft. It is extruded in the outer peripheral direction (radial direction) along the tapered surface that expands in the main axis direction. Since this action and the tooth profile of the first clutch are chevron-shaped, the clutch unit is forcibly moved to the main shaft side against the spring.
As a result, the first clutch is disengaged, the second clutch is engaged, and the rotation of the output shaft is transmitted from the decelerated transmission frame to the clutch unit via the second clutch, and the corner portion of the main shaft is rotated via the lock pin. To do.

Then, unless the rotational resistance (torque) fluctuates between a predetermined value, the movement restricting means of the clutch unit stably maintains the engaged state of either the first clutch or the second clutch, and the rotational resistance ( When the torque is large, the lock pin engages by linearly contacting the corner portion of the main shaft to rotate the main shaft, so that a large rotational force is stably transmitted.

Further, since the second clutch is a meshing clutch having normal rectangular teeth, it can rotate in either forward or reverse directions.

Further, not only the above-described automatic switching from high-speed rotation low torque to low-speed rotation high torque, but also automatic switching from low-speed rotation high torque to high-speed rotation low torque can be performed.

〔Example〕

The present invention will be described below with reference to the embodiments shown in FIGS.

The nut runner A has an air motor 2 inside the casing 1.
And a low speed machine 3 driven by this motor, and an outer cylinder 5 is screwed to the casing 1. Reducer 3
The output shaft 4 of is projected into the outer cylinder 5 and is provided with a drive gear 6 at its tip. The gear 6 can be engraved on the output shaft 4 and integrally provided.

A planetary gear 8 is provided between the drive gear 6 and the inner teeth 51 of the outer cylinder 5.
, The planetary gear 8 is inserted by cutting out a part of the cylindrical transmission frame 10 by notching, and is pivotally supported by the support shaft 9, and the base end and the intermediate portion of the transmission frame 10 are provided with bearings 7 and 14, respectively. The outer cylinder 5 is rotatably supported. A lid 11 is screwed onto the tip of the outer cylinder 5 to rotatably support a main shaft 13 via a bearing 12 on the lid 11, and the main shaft 13 and the output shaft 4 face each other on the same axis. Do like this.

A fixed clutch plate 15 is fixed to the tip of the output shaft 4, and a clutch unit 16 is rotatably and slidably fitted between the main shaft 13 and the transmission frame 10 to fix the fixed clutch plate 15 and the clutch unit 16. The first clutch B is formed between them. This first
As shown in FIG. 2 IV, the clutch B has the chevron teeth 151, 161 protruding from the clutch plate 15 and the clutch unit 16, respectively.
Consists of. The clutch unit 16 is always urged by the spring 17 toward the clutch unit plate 15 side, that is, in the direction of the output shaft 4, and both teeth are meshed with each other to transmit power in both forward and reverse rotations. However, when a rotational resistance (torque) of a predetermined value or more is generated, both teeth 151 and 161 slip on the mountain slopes of the teeth, and the clutch unit 16 moves against the spring 17, as shown in FIG. 4 IV. The tooth 161 is a so-called riding structure clutch that rides on the tooth 151.

The clutch unit 16 is slidable with respect to the main shaft 13, but rotates together with the main shaft 13, and is provided with a connecting means F. The connecting means F includes an engaging ball 18 and a lock pin 19.
The engaging ball 18 is provided by being fitted into a plurality of ball fitting holes 162 formed in the clutch unit 16, and the lock pin 19 is rotatably provided so as to slightly project from the inner peripheral surface of the clutch unit 16. The tip of the main shaft 13 fitted in the clutch unit 16 has a square shape.
The engaging balls 18 are always positioned on the flat surface portion of the 131, and the power is transmitted from the engaging ball 18 to the flat surface portions of the respective parts 131 of the main shaft 13. The number of lock pins 19 is preferably the same as the number of engaging balls 18, and as shown in FIG.
Lock only at the corners 131a of the 131, and from the lock pin 19 to the spindle 1
Power is transmitted to the corners 131a of the three corners 131.

A second clutch C is provided between the other end of the clutch unit 16 and the transmission frame 10. The clutch C is provided with an annular sliding clutch plate 20 provided on the inner surface of the transmission frame 10 so as to face the clutch unit 16, and has rectangular teeth 163, 20 for engagement, respectively.
1 is provided. The noisy clutch plate 20 is slidable in the axial direction by a pin 21 implanted in the speed change frame 10, but is fitted and inserted integrally in the circumferential direction, and the speed change frame 10
A spring 23 is interposed between the stopper 22 locked to the clutch plate 20 and the clutch plate 20, and the spring pressure presses the clutch plate 20 toward the clutch unit side. The teeth 163 and 201 are kept in contact with the portion 101 and are separated from each other.

When the rotation resistance (torque) applied to the main shaft 13 reaches a predetermined value or more, the clutch unit 16 resists the spring 17 when the movement restricting means D of the clutch unit 16 provided between the speed change frame 10 and the clutch unit 16 is reached. The main shaft formed on the inner surface of the transmission frame 10 with which the engaging balls 18 come into contact is designed to maintain the state when it moves and meshes with the second clutch C.
It consists of a taper surface 16t that widens in 13 directions and a spring 17.

At the meshing position of the first clutch B of the clutch unit 16, the taper surface 16t causes the engagement ball 18 to move to the main shaft.
When the rotation resistance (torque) applied to the main shaft 13 reaches or exceeds a predetermined value by contacting and supporting the flat surface of the corner portion 131 of the main shaft 13, the engaging ball 18 is moved by the flat surface of the corner portion 131 of the main shaft 13 into a daper surface. The clutch unit 16 moves toward the main shaft 13 side against the spring 17 as the clutch unit 16 is pushed out in the outer peripheral direction (radial direction) along 16t.

Next, the operation at the time of high speed rotation and low torque will be described based on FIG. 1 and FIG. The output shaft 4 rotates the transmission frame 10 at a slow speed via the planetary gear 8 that meshes with the drive gear 6, but the second clutch C is separated, so the transmission frame 10 is in the idling state. On the other hand, the first clutch B provided at the tip of the output shaft 4
Are in mesh. In this state, the engaging balls
The shift 18 is prevented from moving outward by the base portion (small diameter portion) of the tapered surface 16t of the transmission frame 10, and is locked to the flat surface portion of the corner portion 131 of the main shaft 13. Therefore, the rotation of the output shaft 4 is transmitted to the flat surface portion of the corner portion 131 of the main shaft 13 via the first clutch B, the clutch unit 16, and the engaging balls 18, and the main shaft 13 has the same high speed as the output shaft 4. Is rotated.

Next, the tightening procedure by the low speed rotation and high torque when the rotation resistance (torque) of the spindle 13 or more is generated due to the tightening of the bolts and nuts will be described with reference to FIGS. 3 and 4.

When the rotation resistance (torque) of the spindle 13 exceeds the setting,
A rotation difference is generated between the main shaft 13 and the clutch unit 16, and the engaging balls 18 move to the corners 131 of the main shaft 13 as shown in FIG.
By the flat surface portion of the movement restricting means D, it is extruded in the outer peripheral direction (radial direction) along the tapered surface 16t formed on the inner surface of the speed change frame 10 and expanding in the main axis direction. And the engaging balls 18
Since there is the speed change frame 10 outside and the engaging ball 18 is in contact with the taper surface 16t that expands in the main axis direction of the speed change frame 10, the engagement ball 18 moves toward the outer circumference (radial direction). The pushing moves the engaging balls 18 along the tapered surface 16t. Since the engaging ball 18 is fitted in the clutch unit 16, the engaging ball 18
Due to the movement of 18 and the tooth shape of the first clutch, the clutch unit 16 is forcibly moved against the spring 17 toward the main shaft 13 side. As a result, the first clutch B is separated and the second clutch C is engaged. Therefore, the rotation of the output shaft 4 is transmitted from the decelerated transmission frame 10 to the second clutch C,
It is transmitted to the corner portion 131a of the corner portion 131 of the main shaft 13 via the clutch unit 16 and the lock pin 19, and the main shaft 13 is rotated at a low speed.

After the tightening of the bolts and nuts is completed, the clutch motor 16 is stopped by the action of the spring 17, so that the clutch unit 16 slides, the second clutch C separates, and the first clutch B meshes. Therefore, at the time of restart, the spindle 13 is driven at high speed and low chill.

Then, during operation, the movement restricting means D of the clutch unit 16 unless the rotational resistance (torque) fluctuates across a predetermined value.
Maintains a state in which either the first clutch B or the second clutch C is engaged in a stable manner.

The second clutch C is a meshing clutch having normal rectangular teeth 163 and 201, so that it can rotate in either forward or reverse directions.

In addition to the automatic switching from high-speed rotation low torque to low-speed rotation high torque described above, it is possible to perform automatic switching from low-speed rotation high torque to high-speed rotation low torque as well, so that bolts and nuts can be loosened efficiently. You can do it.

As described above, according to the present invention, the high speed / low speed rotation of the main shaft can be automatically switched by the rotational resistance (torque) applied to the main shaft, and the second clutch is a meshing member having normal rectangular teeth. Since it is a clutch, it does not have the direction of rotation as in the past, so it can be used for both tightening and loosening bolts and nuts with one tool by the forward and reverse rotation of the drive source such as the air motor. You can

Further, since the clutch used for switching between the high speed and the low speed has the movement restricting means, the clutch teeth are formed according to the rotational resistance (torque) of the main shaft together with the angled teeth of the first clutch that assists the movement of the clutch unit. Since the unit is moved to separate the first clutch on the high speed side and the second clutch on the low speed side is engaged, either the first clutch or the second clutch is engaged unless the rotational resistance (torque) fluctuates between a predetermined value. When the rotation resistance (torque) is large, the lock pin can engage with the corner of the main shaft by linear contact to rotate the main shaft and rotate the main shaft. Can be transmitted stably. Therefore, when the power is not transmitted in the conventional device, the clutch claws come into contact with each other, noise is generated, and the problem of poor durability is solved, and a sound at the time of driving is small, and a durable device is provided. Can be provided.

Further, not only automatic switching from high-speed rotation low torque to low-speed rotation high torque, but also automatic switching from low-speed rotation high torque to high-speed rotation low torque can be performed.

Further, the entire structure of the device and the structure of each component are simple, and the device can be manufactured with high accuracy and at low cost, and other advantageous effects that are not available in the conventional techniques are exhibited.

[Brief description of drawings]

1 to 4 relate to a nut runner of the present invention,
Fig. 1 is a longitudinal sectional view at high speed rotation, and Fig. 2 I, II, III, IV are I-I, II-II, III-III, IV-IV in Fig. 1, respectively.
Explanatory drawing along the line, FIG. 3 is a longitudinal sectional view at low speed rotation,
Figures I, II, III and IV are I-I, II-II and III-II in FIG.
FIG. 5 is an explanatory view taken along lines I and IV-IV, and FIG. 5 is a sectional view of a known nut runner. A is a nut runner, B is a first clutch, C is a second clutch, D is a movement restricting means, 4 is an output shaft, 10 speed change frames, 13 is a main shaft, and 16 is a clutch unit.

Claims (1)

[Claims] 1. An output shaft (4) connected to a drive source (2).
And a main shaft (13) connected to a bolt, a nut, etc. are provided on the same shaft center so as to face each other, the output shaft (4) is provided on the outer periphery of the output shaft (4) and the main shaft (13). A tubular transmission frame (10) that is rotated at a reduced speed is fitted, and a clutch unit (sliding in the axial direction between the output shaft (4) and the main shaft (13) is rotatably and freely rotatable. 16) is inserted and has angle teeth (151, 161) between the clutch unit (16) and the output shaft (4).
The clutch (B) is installed and the clutch unit (1
A second clutch (C) having rectangular teeth (163, 201) for low speed rotation and high torque is provided between the gear unit (6) and the speed change frame (10), and the corner unit (131) of the clutch unit (16) and the main shaft (13). An engaging ball (18) for high speed rotation and low torque for transmitting power from the clutch unit (16) to the main shaft (13) is formed in the ball fitting hole (16) formed in the clutch unit (16).
2) It is fitted into the main shaft (13) and the corner (131) of the main shaft (13)
A low-speed rotation high-torque lock pin (19) that engages with the main unit formed on the inner surface of the clutch unit (16) and formed on the inner surface of the transmission frame (10) with which the engagement ball (18) abuts. Is provided with a movement restricting means (D) for the clutch unit (16) including a tapered surface (16t) that expands in the direction and a spring (17) that biases the clutch unit (16) in the output shaft direction. A nut runner.