JP3128766B2 - Hydraulic torque wrench - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

2. Description of the Related Art In a device for tightening bolts and nuts using power, instead of a driving method using an impact force generated by a rotary impact of a metal hammer, an impact force generated by confining hydraulic pressure is used. The present invention relates to a hydraulic torque wrench to be used.

[0002]

2. Description of the Related Art Conventionally, a single-blade system has been used as a technique utilizing an impact pressure generated by hydraulic containment. However, in recent years, the two-blade method, which is more energy efficient than this method, has come to be used frequently. However, this method of generating an impact force by hydraulic containment of two blades has a structure in which two blades are simply arranged and seal portions are arranged at four orthogonal positions to each other, resulting in a large energy loss and one rotation and two shocks. Therefore, the energy loss increases, so that the structure of each manufacturer is devised to devise a structure of one hit per revolution.

More specifically, for example, Japanese Utility Model 1-2901
As disclosed in No. 2, the combination of the positions of the sealing surface where the impact force due to the hydraulic containment is generated is intentionally shifted from the directly facing 90 ° position to achieve one hit per revolution. As disclosed in Japanese Examined Patent Publication No. 4-45888, one of the four seal portions that generate the containment pressure is inclined or deformed from the rotation axis, and one impact per rotation. And more, 5-6
As disclosed in U.S. Pat. No. 7,388, the provision of a new containment oil flow path in the cover plate or a part of the anvil allows the
There is a thing with one rotation.

[0004]

All known two-blade hydraulic containment systems are asymmetric in the rotational direction when a containment impact force is generated. This results in a difference in the torque generated between the forward rotation and the reverse rotation, which is not preferable for a user who can not only tighten a right screw but also a left screw. In addition, the rotational balance is deteriorated, which may cause extra vibration and torque unevenness. Further, in some cases, complicated processing is required or new parts are required, so that there is a problem that the manufacturing cost is increased. An object of the present invention is to solve such a problem.

[0005]

An anvil 8 having two blades 11, 12 and two seal portions 21, 21 'in a liner 9 which is rotationally driven by power is coaxially arranged with the liner 9. A hydraulic pressure valve which generates a containment impact pressure once per rotation of the liner 9 in combination with each position of the four seal portions 22, 23, 24, 25 provided on the inner peripheral surface of the liner 9. In the wrench, the two blades 11 and 12 of the anvil 8 are attached to the outer periphery of the anvil 8 by 180 degrees.
° At positions where the phases are different, they are fitted into blade insertion grooves 20 provided in the longitudinal direction of the anvil 8 and mounted by being urged radially outward by springs 13 and 14.
Two seal portions 21 and 21 ′ are provided in parallel with the axis of the anvil 8 at positions shifted by 90 ° from those of the blades 11 and 12.
Seal portions 21 and 21 ′ that are 90 ° away from
One of the seal portions 21 has the same length as the axial length of the liner 9, and the rear half of the length on the non-output side is a linear seal portion 21 a having a small width in the rotational direction. The output-side front half is a wide-width seal portion 21b having a width several times that of the seal portion 21a for the latter half and having a bypass groove 21c for preventing generation of a containment pressure, and is opposed by 180 degrees to one seal portion 21. The other sealing portion 21 ′ in the position has a shape in which the linear sealing portion 21 _′ a and the wide sealing portion 21 _′ b are inverted with respect to the one sealing portion 21. The internal space in which the anvil 8 is built has a cocoon shape as viewed in the axial direction of the liner 9, and the four seal portions 22, 23, 24, 25 in the liner 9 each have a long axis of the cocoon-shaped internal space, The two seal portions 22 are disposed at the position of the short axis orthogonal to the long axis and extend in the long axis direction. , 24 are linear seals with a narrow width in the rotation direction, and short-axis seals 23, 25
One of the seal portions 23 has a linear seal portion 23a having a narrow rotational direction width in the front half on the output side and a wide seal portion 2 having the bypass groove 21c on the anvil 8 side in the rear half.
1b is a combination of a wide sealing portion 23b without the bypass groove 21c and the same width as 1b, and the other sealing portion 25 has a linear sealing portion 25a and a wide sealing portion 25b like the one sealing portion 23. The one seal portion 23 is arranged in a front-rear direction, and is configured to generate one impact pressure on the anvil 8 for one rotation of the liner.

[0006]

[Function] By adopting this structure, the hydraulic containment pressure can be reduced with the same output for both forward and reverse rotations with a simple structure, without adding any special parts and without applying new processing to the lid plate etc. It can be obtained once per revolution.

[0007]

An embodiment of the present invention will be described below.
In the following description, the impact pressure caused by the hydraulic containment is simply referred to as "pulse", and the positional relationship of the entire tool is set such that the rotation axis of the posture in which the tool is normally used is horizontal and the grip portion is vertically downward. In the case of holding, the output side is referred to as “front side” and the side opposite to the output side is referred to as “rear side”.

The tool shown in FIG. 1 has a motor (not shown) as a power source in a main body 1, a driving force transmitting section 3, a pulse generating unit 2 of the present invention, and a tip end of an output shaft 6. This is a hand-held power wrench of the type that drives the square drive 7. The pulse generating unit 2 of the present invention is rotatably fitted by a driving force transmitting unit 3 and a bearing 5 held by a cover-4.

FIG. 2 is a diagram showing a cross section taken out of the pulse generating unit 2 of the present invention from FIG. 1 and cut along the center of the rotation axis. The relative rotation angle between the liner 9 and the anvil 8 indicates a 90-degree position in FIG. 7 described later. The structure of the anvil 8 is such that the two blades 11 and 12 are arranged at positions 180 ° out of phase with each other on the rear side opposite to the output shaft 6.
The springs 13 and 14 press the springs 13 and 14 in the inner circumferential direction of the liner 9 and press the same, and are coaxially supported by the bearings 17 and 18 of the front lid 15 and the rear lid 16 coaxially with the liner 9. The anvil 8 is held rotatably separately from the liner 9. The liner 9 has a cocoon shape in which the outer periphery is circular with the rotation axis concentric and the inner periphery has the same center. 10 is a liner case, and 19 is an output torque adjusting unit.

FIGS. 3 and 4 are single views of the anvil 8.
4 is a perspective view, and FIG. 4 is a side view as viewed in the direction of the arrow A in FIG. 20 is 1
The pair of blade insertion grooves, 21 and 21 ′, are seal portions provided at positions orthogonal to the blade insertion grooves 20. The blade insertion groove 20 and the seal portions 21 and 21 'form a pair. The seal portion 21 is a linear seal having a width in the rotation direction which is half the length thereof.
Seal portion 21a having a linear width in the other half of the seal portion 21a.
And a wide seal portion 21b having a bypass groove 21c for preventing a containment pressure from being generated. The pair of seal portions 21 and 21 'have a shape which is opposite to the front and rear. That is, one has a wide seal portion 21b at the front and the other has a wide seal portion at the back. A blade support shaft insertion hole 20a is provided at the center of the blade insertion groove 20, and a spring insertion hole 20b is provided on both sides of the insertion hole 20a.

FIGS. 5 and 6 show a single view of the liner 9.
FIG. 5A is a perspective view seen from the lower right rear side of FIG. 1, and FIG.
FIG. 6 is a perspective view of the cocoon-shaped inner peripheral surface developed in the rotation direction, similarly viewed from the upper left side of the rear side. The liner 9 is provided with four seal portions 22, 23, 24 and 25.
The seal portions 22 and 24 form a linear shape with a narrow width in the rotational direction,
The seal portions 23 and 25 have the same shape as the seal portion 21 of the anvil 8, but have no bypass groove.

FIGS. 7 and 8 show the operating state of the pulse generating unit 2 in a cross section at each rotation angle of the liner 9. FIG. 7 is a sectional view taken along the arrow A in FIG. 2 and FIG. 8 is a sectional view taken along the arrow B in FIG. 2 for each rotation angle of the liner 9 (0 °, 90 °, 180 °).
(°, 270 °) corresponding to the same phase. The manner in which one pulse per rotation is generated in FIG. 7 will be described below. First, at the 0-degree position, the two blades 11, 12 installed on the anvil 8 and the two seal portions 21 correspond to the four seal portions 22, 23, 24, 25 on the inner surface of the liner 9. , 21 'coincide with both the A and B cross sections, and the enclosed oil flow paths are all sealed. If the anvil 8 is fixed and the liner 9 is rotating, a pulse is generated, and the action can be taken out to the output shaft 6 as torque.
In the drawing, the liner 9 is moved in the direction indicated by the arrow indicating the rotation direction.
Will be described. Even if the rotation direction is reversed, the same operation as described below is performed, so that the same torque can be output in both the forward and reverse directions.

At 90 degrees, the pulse generation starts from the liner.
The encapsulated oil follows the movement of the liner 9 side with only the 9 side rotated 90 degrees. At the 180 degree position, the positions of the four seal portions on the inner surface of the liner 9 and the two blades 11 and 12 installed on the anvil 8 again coincide with the positions of the two seal portions. At this time, the combination of the cocoon-shaped short-diameter direction seal is
A combination of a liner-side seal 23 with respect to the seal portion 21 and a liner-side seal 25 with respect to the anvil-side seal portion 21 '. In this state, a sealed state is formed by the combination of the seal portion 21 'and the seal 25 on the left side of the section A in FIG.
On the left side of section B in FIG.
Since the seal width of the seal 25 is smaller than that of the bypass groove 1 ', no sealing action against the sealed oil occurs, and a sealed oil flow path indicated by an arrow in the figure is formed. Therefore, a pulse cannot be generated in the left sealed oil chamber. Similarly, in the right sealed oil chamber, the section B in FIG. 8 is sealed, but the section A in FIG. 7 is not sealed, so that no pulse is generated. Next, the liner returns to the process of generating the 0-degree pulse again through the process of 270-degree.

[0014]

According to the above-mentioned structure, one rotation is possible without complicating the structure or adding new parts.
A pulse generating unit can be obtained, and a device with less noise and vibration and less burden on the operator can be provided.

[Brief description of the drawings]

FIG. 1 is a partially cutaway side view of a hydraulic torque wrench.

FIG. 2 is a sectional view of a pulse generation unit.

FIG. 3 is a perspective view of a single item of the anvil.

FIG. 4 is a side view as viewed in the direction of arrow A in FIG. 3;

FIG. 5 is a perspective view of a liner.

FIG. 6 is a development view of a liner.

7 is an explanatory diagram of a pulse generation mode of the torque wrench, and is a change diagram of a section A in FIG. 2;

FIG. 8 is an explanatory diagram of a pulse generation mode of the torque wrench, and a change diagram of a B section in FIG. 2;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Main body 2 Pulse generating unit 3 Driving force transmission part 4 Cover 5 Bearing 6 Output shaft 7 Square drive 8 Anvil 9 Liner 10 Liner case 11,12 Blade 13,14 Spring 15 Front lid 16 Rear lid 17,18 Bearing 19 Output torque adjustment part 20 Blade insertion groove 20a Insert hole 20b Insert hole 21, 21 '(anvil side) Seal part 21a Linear seal part 21b Wide seal part 21c Bypass groove 22,23, 24, 25 (Liner side) Seal

Claims (1)

(57) [Claims] A liner (9) rotatably driven by power.
Inside, two blades (11, 12) and two seals (2
An anvil (8) having a base (1, 21 ') is provided coaxially with the liner (9), and each position of four seal portions (22, 23, 24, 25) provided on the inner peripheral surface of the liner (9). By combining with
In the hydraulic torque wrench configured to generate one containment impact pressure per one rotation of the liner (9), the two blades (11, 12) of the anvil (8) may be an anvil.
(8) The anvil is located at the 180 ° phase difference on the outer circumference.
The blades (11, 12) are fitted by being inserted into blade insertion grooves (20) provided in the longitudinal direction of (8) and urged radially outward by springs (13, 14). ) And two seals (2) parallel to the axis of the anvil (8)
1, 21 '), and one of the two seal portions (21, 21') at a position shifted by 90 degrees from the blade (11, 12) is provided with a liner (21, 21 '). The rear half of the length on the opposite side to the output side is the same as the axial length of 9), and the linear seal portion (2
1a). Similarly, the output-side front half is a wide seal portion (21b) having a width several times that of the seal portion (21a) for the latter half and having a bypass groove (21c) for preventing generation of a containment pressure. There, one of the sealing portion (21) relative to the other of the seal portion in the 180-degree opposite positions (21 ') is a linear seal portion _{(21' a)}
And a shape reversed back and forth with respect to the wide of the seal portion (21 _'b) is the one sealing portion (21), the liner (9) the internal space liner that incorporates the anvil (8) (9 ) Is formed in a cocoon shape when viewed in the axial direction, and the four seal portions (22, 23, 24, 25) in the liner (9) are each formed with a long axis of the cocoon-shaped internal space and a direction orthogonal to the long axis. The two seals (22, 2
4) is a linear seal portion having a narrow width in the rotation direction, and one of the short-axis-direction seal portions (23, 25) has a narrow rotation direction width in the front half of its output side. Straight seal
(23a) and a wide seal portion (23b) having the same width as the wide seal portion (21b) having the bypass groove (21c) on the anvil (8) side and having no bypass groove (21c) in the rear half. The other seal part (25) is combined with the one seal part (2).
As in 3), the linear seal (25a) and the wide seal (25
b), wherein said one seal portion (23) is arranged in a front-rear direction, and is configured to generate one impact pressure on the anvil (8) for one rotation of the liner. Features a hydraulic torque wrench.