JP2002254338A - Hydraulic impact torque generator for wrench - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic impact torque generator for a wrench that can prevent dislodgment of a roller from a driving blade and improve the durability of the driving blade by supporting the roller smoothly and preventing uneven wear of a recessed groove. SOLUTION: The hydraulic impact torque generator for a wrench has a main spindle 7 fitted in a cavity 81 in a liner 8 turned by a rotor 4, and the driving blades 9 disposed for retractive reciprocation in the main spindle 7, and generates impact torque when sealing surfaces 7b formed on the driving blades 9 mate with sealing surfaces 8b formed on an inner circumference of the cavity 81. The rollers 14 are turnably fitted in the recessed grooves 13 formed in the tips of the driving blades 9. The concave grooves 13 are provided with an opening width shorter than the diameter of the rollers 14, and are formed into a substantially completely round arc whose overall surface is in sliding contact with an outer circumference of the rollers 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic striking torque generator used for a wrench, and more particularly, to preventing a roller from falling off a driving blade, smoothly supporting the roller, and biasing the roller toward a concave groove. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wrench hydraulic impact torque generator capable of preventing wear and improving the durability of a driving blade.

[0002]

2. Description of the Related Art A hydraulic wrench used in a bolting operation or the like has a hydraulic impact torque generating device for generating an impact torque on a main shaft. In this hydraulic impact torque generating device, a main shaft is inserted into a cavity of a liner that rotates via a rotor by high-pressure air, and a driving blade is disposed on the main shaft so as to be freely retractable and formed on the driving blade and the main shaft. When the sealing surface matches the sealing surface formed on the inner peripheral surface of the cavity, a striking torque is generated on the main shaft via the hydraulic oil in the cavity.

In this hydraulic striking torque generator, the tip of a driving blade inserted into a main shaft is spring-loaded to seal the interior of a liner filled with hydraulic oil into a high-pressure portion and a low-pressure portion. During operation, the tip of the driving blade abruptly rubs the inner peripheral surface of the cavity, so that frictional heat is generated. Therefore, in order to reduce the friction between the driving blade and the inner peripheral surface of the cavity, a groove is formed at the tip of the driving blade in the axial direction of the main shaft, and the roller is rotatably supported in the groove. Are known.

[0004]

However, since the conventional hydraulic striking torque generating device for a wrench has a structure in which the rollers are simply supported by the concave grooves, the liner is distorted and the shape of the cavity is changed. However, there is a problem that the roller comes off the groove and falls off the driving blade.

The present invention has been made in consideration of the above-mentioned problems of the conventional hydraulic striking torque generating device for a wrench, to prevent the rollers from falling off from the driving blade, to support the rollers smoothly, and to provide a bias on the concave groove side. An object of the present invention is to provide a wrench hydraulic impact torque generating device capable of preventing wear and improving the durability of a driving blade.

[0006]

In order to achieve the above object, a hydraulic striking torque generating device for a wrench according to the present invention has a main shaft inserted into a cavity of a liner which is rotated by a rotary drive source, and is inserted into the main shaft. In a hydraulic striking torque generating device for a wrench, a driving blade is provided so as to be able to protrude and retract, and a striking torque is generated when a sealing surface formed on the driving blade coincides with a sealing surface formed on an inner peripheral surface of the cavity. While rotatably inserting a roller into a concave groove formed at the tip of the driving blade,
The opening width of the groove is smaller than the diameter of the roller, and the groove is
It is characterized in that it is formed in a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller.

In this hydraulic wrench torque generating device, the roller is rotatably inserted into a groove formed at the tip of the driving blade, and the opening width of the groove is made smaller than the diameter of the roller. It is possible to prevent the roller from falling off the driving blade, and furthermore,
Since the groove is formed in a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller, the roller is uniformly supported, the rotation is smooth, the uneven wear on the groove side is prevented, and the driving blade is driven. Can be improved in durability.

In this case, the diameter of the concave groove can be made larger by 0.05 to 0.2 mm than the diameter of the roller.

Thus, a lubricating oil film can be formed between the concave groove and the roller by the operating oil, and the roller can be extremely smoothly supported by fluid lubrication.

The driving blade can be formed by powder molding.

Thus, the concave groove of the driving blade can be formed with high precision.

[0012]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a hydraulic wrench torque generating device according to an embodiment of the present invention.

1 to 3 show an embodiment of a hydraulic striking torque generating device for a wrench according to the present invention. In FIG. 3, 1
Is a main body of a hydraulic wrench, in which a main valve 2 for supplying / stopping high-pressure air and a forward / reverse rotation switching valve 3 are provided in the main body 1, and a rotational torque is supplied by the high-pressure air supplied from the valve group. It has an air motor structure of a known hydraulic wrench in which a rotor 4 as a generated rotation drive source is provided in the main body 1. In the front case 6 of the main body 1, there is provided a hydraulic impact torque generator 5 for converting the rotational torque of the rotor 4 into an impact torque.

As shown in FIG. 1, the hydraulic striking torque generator 5 has a liner 8 having a cavity 81 formed therein, which is rotatably disposed in a liner case 12. The main shaft 7 is rotatably arranged, and a working oil for generating a torque is filled and sealed in the cavity 81 of the liner 8. The main shaft 7 is provided with a blade insertion groove 7c penetrating on a diameter line passing through the center, and in the blade insertion groove 7c, two driving blades 9 each having a roller 14 forming a sealing surface 7b at a tip end are fitted and inserted. Further, the two driving blades 9 are urged by a spring S so as to be able to protrude and retract in a radially outward direction of the main shaft 7. The main shaft 7 between the two driving blades 9 has a fixed sealing surface 7a slightly projecting from the outer peripheral surface of the main shaft.

On the other hand, the liner 8 into which the main shaft 7 is inserted is provided in the opposite constricted portion of the cavity 81 having a cross-sectional shape of the eyebrow.
And a sealing surface 8b corresponding to the sealing surface 7b of the two driving blades 9 is formed on the inner peripheral surface of the opposing expanded portion of the cavity 81. . Thereby, when the liner 8 rotates around the outer periphery of the main shaft 7, as shown in FIG.
The sealing surface 8a of the liner 8 coincides with the sealing surface 7a of the main shaft 7, and the hermetic sealing is performed so as to divide the cavity 81 between the sealing surfaces 7a and 8a. 9 sealing surface 7b
And the cavity 81 is divided into four chambers.

In the vicinity of one sealing surface 8a of the liner 8, an output adjustment valve insertion hole 10 is formed in parallel with the axis of the liner 8, and the output adjustment valve insertion hole 1 is formed.
0, a port communicating with the cavities 81 on both sides of the sealing surface 8a is formed in the back portion of the power adjusting valve insertion hole 10.
The output adjustment valve 11 is adjustably fitted therein.

In this embodiment, in such a hydraulic striking torque generator 5, as shown in FIGS. 1 and 2, a groove 13 is formed at the tip of the driving blade 9, and the groove 13 is formed in the groove 13. Roller 1 so that a part thereof protrudes from the opening of
4 is rotatably fitted, the opening width of the concave groove 13 is made smaller than the diameter of the roller 14, and the concave groove 13 is formed into a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller 14. are doing. In this case, the diameter of the groove 13 is
0.05 to 0.2 mm, preferably about 0.1
mm, so that the grooves 13
Forming a lubricating oil film by hydraulic oil between the roller 14 and
Extremely smooth support by the fluid lubrication of the roller 14 can be performed.

The driving blade 9 having the concave groove 13 is not particularly limited, but can be formed by molding a metal powder such as SKD tool steel as a raw material. Thereby, the concave groove 13 of the driving blade 9 can be formed with high precision.

As described above, in the hydraulic striking torque generator 5 of this embodiment, the roller 14 is rotatably fitted into the groove 13 formed at the tip of the driving blade 9 and the opening width of the groove 13 is adjusted. Is smaller than the diameter of the roller 14, it is possible to prevent the roller 14 from falling off the driving blade 9. Then, FIG.
As shown in (c), since the concave groove 13 is formed in a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller 14, the roller 14 is uniformly supported, its rotation is smoothed, and the concave groove 13 is formed. Uneven wear on the groove 13 side can be prevented, and the durability of the driving blade 9 can be improved. By the way, as shown in FIG. 2D, in the comparative example in which the roller 14 is supported by the opening 15a and the bottom 15b of the groove 15, the opening 15a and the bottom 15b may be biased due to long-term use. The driving blade 9 is worn, the sealing performance of the driving blade 9 is reduced, and the roller 14 is liable to fall off.

Next, the operation of the hydraulic wrench of this embodiment will be described. When the main valve 2 and the switching valve 3 are operated to introduce the pressurized air to the rotor 4 in the main body 1, the rotor 4 rotates at a high speed. The rotational force of the rotor 4 is transmitted to a liner 8 provided integrally with the rotor shaft.

In the state where the impact torque is generated on the main shaft 7,
As shown in FIG. 1A, the sealing surface 7a of the main shaft 7 and the sealing surface 7b of the driving blade are in contact with the sealing surfaces 8a and 8b of the liner 8, respectively. Each driving blade 9 is divided into a pair of high-pressure chambers H and low-pressure chambers L formed on both sides. When the liner 8 is rotated to this state, a high pressure is generated in the high-pressure chamber H, and this hydraulic pressure instantaneously presses the side surface of each driving blade 9 toward the low-pressure chamber L, and the main shaft 7 into which the driving blade 9 is inserted. Then, the striking force is transmitted to the main shaft 7 to generate a desired intermittent striking torque, thereby rotating the main shaft 7 to perform a desired operation.

After the impact torque of the main shaft 7 is generated by the impact of the driving blade 9 and the liner 8 is further rotated by 90 degrees, as shown in FIG. There are two chambers formed with the driving blade 9 interposed therebetween, which are electrically connected to each other. The entire cavity 81 is divided into chambers having the same pressure, and the liner 8 further rotates without generating an impact torque on the main shaft 7. Next, when the liner 8 is further rotated by 90 degrees, the sealing surface 8a of the liner 8 and the sealing surface 7a of the main shaft are slightly displaced from each other and do not match, and a gap is generated between the sealing surfaces 7a and 8a.
The cavity 81 becomes two chambers formed by sandwiching each driving blade 9 between the high-pressure chamber and the low-pressure chamber, and no impact torque is generated on the main shaft 7. Further, the liner 8 is further 90 degrees, that is, 2 degrees from the time when the impact torque is generated.
In the state rotated by 70 degrees, the position of the output adjustment valve insertion hole 10 is merely upside down from the state rotated by 90 degrees, and no impact torque is generated on the main shaft 7. When the liner 8 further rotates from this state, the initial state shown in FIG. 1A is obtained, and the impact torque is generated again as described above.

The hydraulic impact torque generating device for a wrench according to the present invention has been described based on one embodiment. However, the present invention is not limited to the configuration described in the above embodiment. In addition to the blade 9, a similar configuration may be adopted for a fixed sealing surface 7 a formed on the main shaft 7, or an electric motor may be used instead of the rotor 4 as a rotation drive source for rotating the liner 8. (Thus, the function and effect of the present invention can be more effectively exerted.), And the configuration can be appropriately changed without departing from the gist of the invention.

[0024]

According to the wrench hydraulic striking torque generator of the present invention, the roller is rotatably inserted into the groove formed at the tip of the driving blade, and the opening width of the groove is adjusted to the diameter of the roller. Since the roller is narrower, it is possible to prevent the roller from falling off the driving blade.Furthermore, the concave groove is formed in a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller, so that the roller is evenly supported. In addition, the rotation of the driving blade can be smoothly performed, uneven wear on the concave groove side can be prevented, and the durability of the driving blade can be improved.

Further, by making the diameter of the groove 0.05-0.2 mm larger than the diameter of the roller, a lubricating oil film can be formed between the groove and the roller by hydraulic oil.
Extremely smooth support can be provided by fluid lubrication of the rollers.

Further, by forming the driving blade by powder molding, the concave groove of the driving blade can be formed with high precision.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view orthogonal to an axis showing an embodiment of a hydraulic striking torque generating device for a wrench of the present invention.

FIGS. 2A and 2B show a driving blade, wherein FIG. 2A is a cross-sectional front view showing an embodiment of the present invention, FIG.
Is a bottom view, and (d) is a side view of a comparative example.

FIG. 3 is a sectional view showing the hydraulic wrench of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hydraulic wrench main body 2 Main valve 3 Switching valve 4 Rotor 5 Hydraulic impact torque generator 6 Front case 7 Main shaft 7a, 7b Seal surface 7c Blade insertion groove 8 Liner 8a, 8b Seal surface 81 Cavity 9 Driving blade 10 Output adjustment valve Insertion hole 11 Output adjustment valve 12 Liner case 13 Groove 14 Roller

Claims (3)

[Claims] 1. A main shaft is inserted into a cavity of a liner that is rotated by a rotation drive source, and a driving blade is disposed on the main shaft so as to be able to come and go, and a sealing surface formed on the driving blade is formed inside the cavity. In a hydraulic striking torque generating device for a wrench that generates a striking torque when it coincides with a sealing surface formed on a peripheral surface, a roller is rotatably inserted into a groove formed at a tip of the driving blade, and a concave groove is formed. A hydraulic striking torque generating device for a wrench, characterized in that the opening width of the groove is smaller than the diameter of the roller, and the concave groove is formed in a substantially perfect circular arc in which the entire surface is in sliding contact with the outer peripheral surface of the roller. 2. The hydraulic wrenching torque generating device for a wrench according to claim 1, wherein the diameter of the groove is 0.05 to 0.2 mm larger than the diameter of the roller. 3. The hydraulic torque generating device for a wrench according to claim 1, wherein the driving blade is formed by powder molding.