JP2009083090A - Impact torque adjusting device of hydraulic torque wrench - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an impact torque adjusting device of a hydraulic torque wrench, which enhances accuracy of magnitude of impact torque generated by the impact torque generating device of the hydraulic torque wrench, shortens a generation cycle of the impact torque, and improves durability of the impact torque generating device of the hydraulic torque wrench. <P>SOLUTION: A hydraulic fluid flow passage 11b communicating with inside of a liner 7 to be a high-pressure chamber H and a low-pressure chamber L at the time of generation of the impact torque is formed. The hydraulic fluid flow passage 11b is provided with a valve body 11d energized to a direction of opening the hydraulic fluid flow passage 11b. An oil chamber 11e communicating with the inside of the liner 7 to be the high-pressure chamber H at the time of generation of the impact torque is formed at a rear part of the valve body 11d. The hydraulic fluid flow passage 11b is made to become smaller according to rise of pressure of the hydraulic fluid in the high-pressure chamber H. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an impact torque adjusting device for a hydraulic torque wrench.

Conventionally, a hydraulic torque wrench using a hydraulic hammering torque generator with low noise and vibration has been developed and put to practical use as a hammering torque generator for torque wrenches (for example, Patent Documents 1 and 2). reference).
FIGS. 6 and 7 show an example of this hydraulic torque wrench. The hydraulic torque wrench 1 selectively generates a main valve 2 that supplies and stops high-pressure air and a forward / reverse rotation impact torque. And a forward / reverse rotation switching valve 3 for driving the rotor 4 to generate a rotational torque by the high-pressure air sent through the valves 2 and 3, and hitting the rotational torque of the rotor 4. A hydraulic striking torque generator 5 for converting torque is provided in the case 6 of the hydraulic torque wrench 1.
The hydraulic hitting torque generator 5 is filled with a hydraulic oil in a cavity formed in a liner 7 rotated by a rotor 4, hermetically sealed, and two (1 or 1) on a main shaft 8 that is coaxially inserted into the liner 7. The blade 9 is provided in the blade insertion groove, and the blade 9 is inserted into the blade insertion groove, and the blade 9 is constantly urged by the spring 10 in the outer circumferential direction of the main shaft 8. It is comprised so that it may contact | abut to the internal peripheral surface.
The impact torque generator 5 is provided with an output adjustment mechanism 11 so that the magnitude of the impact torque generated can be adjusted.
When the liner 7 is driven to rotate by the rotor 4, when the plurality of seal surfaces formed on the inner peripheral surface of the liner 7 coincide with the seal surfaces formed on the outer peripheral surface of the main shaft 8 and the blades 9, the main shaft 8. The impact torque is generated on the nut and the nut or the like engaged with the tip of the main shaft 8 is tightened or loosened.

By the way, in the conventional hydraulic torque wrench, the output adjusting mechanism 11 that adjusts the magnitude of the impact torque communicates the inside of the liner 7 that becomes the high pressure chamber and the low pressure chamber when the impact torque is generated by operating the operation shaft. (Specifically, the operating torque is reduced by operating the operating shaft to the open side to increase the operating fluid flow path. The impact torque is increased by reducing the size of the hydraulic oil passage by operating to the closed side.
However, since the size of the hydraulic oil flow path adjusted by operating the operation shaft is constant (fixed) during the operation of the hydraulic torque wrench, the following problems (1) to (4) have occurred. .
(1) There is a large error between the magnitude of the actually generated impact torque and the set impact torque.
(2) An abnormally high impact torque is likely to occur at the start of the tightening operation (when the tightening member is seated).
(3) The resistance after the generation of the impact torque (after the generation of the pulse) is large and the generation period of the impact torque is long.
(4) It is easy to apply load pressure to the seal part and its durability is poor.

Japanese Utility Model Publication No. 3-40076 JP-A-6-297349

  In view of the problems of the conventional hydraulic torque wrench, the present invention increases the accuracy of the magnitude of the impact torque generated by the impact torque generator of the hydraulic torque wrench and shortens the generation period of the impact torque. It is another object of the present invention to provide an impact torque adjusting device for a hydraulic torque wrench that can improve the durability of the impact torque generating device for the hydraulic torque wrench.

  In order to achieve the above object, a striking torque adjusting device for a hydraulic torque wrench according to the present invention is a striking torque of a hydraulic torque wrench comprising a liner rotated by a rotor, a main shaft and a blade disposed inside the liner. In the adjusting device, a hydraulic oil passage that communicates with the inside of the liner that becomes the high-pressure chamber and the low-pressure chamber when an impact torque is generated is formed, and the valve that is biased in a direction to open the hydraulic oil passage to the hydraulic oil passage And an oil chamber that communicates with the interior of the liner that becomes a high pressure chamber at the time of occurrence of impact torque, in response to an increase in the pressure of the hydraulic oil in the high pressure chamber, The hydraulic oil flow path is made small.

  In this case, the valve body can be incorporated in an output adjustment mechanism that adjusts the magnitude of the impact torque.

  Further, the two valve bodies are arranged so as to face each other across the hydraulic oil flow path, and the two hydraulic valve bodies are made smaller in size as the hydraulic oil pressure increases in response to the increase in the pressure of the hydraulic oil in the high pressure chamber. It can be made to move.

  According to the impact torque adjusting device for a hydraulic torque wrench of the present invention, a hydraulic fluid passage is formed that communicates the inside of the liner that becomes the high pressure chamber and the low pressure chamber when the impact torque is generated, and the hydraulic fluid passage is formed in the hydraulic fluid passage. A valve body biased in a direction to open the flow path is disposed, and an oil chamber communicating with the inside of the liner that becomes a high pressure chamber when a striking torque is generated is formed at the back of the valve body, and the high pressure chamber As the hydraulic fluid flow increases, the hydraulic fluid passage becomes smaller, so that the accuracy of the magnitude of the impact torque generated by the impact torque generator of the hydraulic torque wrench is increased and the impact is reduced. The torque generation cycle can be shortened, and the durability of the impact torque generating device of the hydraulic torque wrench can be improved.

  In addition, by incorporating the valve element into an output adjustment mechanism that adjusts the magnitude of the impact torque, the configuration of the impact torque adjusting device can be simplified.

  Further, the two valve bodies are arranged so as to face each other across the hydraulic oil flow path, and the two hydraulic valve bodies are made smaller in size as the hydraulic oil pressure increases in response to the increase in the pressure of the hydraulic oil in the high pressure chamber. The movement stroke of the valve body when moving in order to adjust the size of the hydraulic oil flow path can be reduced, thereby improving the response performance and the impact torque. The accuracy of size can be further improved.

  DESCRIPTION OF EMBODIMENTS Embodiments of an impact torque adjusting device for a hydraulic torque wrench according to the present invention will be described below with reference to the drawings.

1 to 2 show a first embodiment of an impact torque adjusting device for a hydraulic torque wrench according to the present invention.
Similar to the conventional hydraulic torque wrench disclosed in Patent Document 2, the hydraulic torque wrench 1 of this embodiment includes a magnetostrictive torque detection mechanism 12, and the rotor 4 is driven by the output of the magnetostrictive torque detection mechanism 12. A main valve 2 that supplies and stops high-pressure air, and a forward / reverse rotation switching valve 3 for selectively generating a forward / reverse rotation impact torque. The rotor 4 that generates rotational torque is driven by the high-pressure air that is supplied through 3, and the hydraulic impact torque generator 5 that converts the rotational torque of the rotor 4 into impact torque is used as a hydraulic torque wrench. 1 is provided in one case 6.
The hydraulic hitting torque generator 5 is filled with a hydraulic oil in a cavity formed in a liner 7 rotated by a rotor 4, hermetically sealed, and two (1 or 1) on a main shaft 8 that is coaxially inserted into the liner 7. A plurality of three or more blade insertion grooves are provided, and the blades 9 are fitted into the blade insertion grooves, and the blades 9 are constantly urged by the springs 10 toward the outer periphery of the main shaft 8 to form the liner 7. It is comprised so that it may contact | abut to the internal peripheral surface.
The impact torque generator 5 is provided with an output adjustment mechanism 11 so that the magnitude of the impact torque generated can be adjusted.
When the liner 7 is driven to rotate by the rotor 4, when the plurality of seal surfaces formed on the inner peripheral surface of the liner 7 coincide with the seal surfaces formed on the outer peripheral surface of the main shaft 8 and the blades 9, the main shaft 8. The impact torque is generated on the nut and the nut or the like engaged with the tip of the main shaft 8 is tightened or loosened.

  By the way, in the hydraulic torque wrench of the present embodiment, the output adjustment mechanism 11 that adjusts the magnitude of the impact torque operates the operating shaft 11a, and the liner that becomes the high pressure chamber H and the low pressure chamber L when the impact torque is generated. 7 is adjusted (specifically, by operating the operating shaft 11a to the open side to enlarge the hydraulic oil passage 11b (not squeezing), the impact torque is reduced. The size is reduced, and conversely, the magnitude of the striking torque is increased by operating the operating shaft 11a to the closed side to reduce (squeeze) the hydraulic oil passage 11b. Yes.

  Further, the output adjusting mechanism 11 is provided with a valve body 11d biased in a direction to open the hydraulic oil passage 11b via the operation shaft 11a and the spring 11c in the hydraulic oil passage 11b. An oil chamber 11e that communicates with the inside of the liner 7 that becomes the high-pressure chamber H when the impact torque is generated is formed on the back of the body 11d, and the pressure of the hydraulic oil in the high-pressure chamber H increases as the tightening operation proceeds. As shown in FIGS. 2 (a) to 2 (b), the hydraulic oil passage 11b is made smaller (squeezed) as the pressure of the hydraulic oil in the chamber H increases.

  As a result, the accuracy of the magnitude of the impact torque generated by the impact torque generator of the hydraulic torque wrench is increased, the impact torque generation cycle is shortened, and the durability of the impact torque generator of the hydraulic torque wrench is further improved. Can be improved.

Regarding the above-described effects, the output characteristic diagram shown in FIG. 3 (FIG. 3A shows a conventional example (the size of the hydraulic fluid passage is constant (fixed) during operation of the hydraulic torque wrench), FIG. b) shows the case of this example, respectively, and is explained as follows.
(1) Since the pressure of the hydraulic oil inside the liner 7 serving as the high-pressure chamber H can be accurately controlled according to the tightening state, the magnitude of the actually generated impact torque and the set impact torque The error becomes conventional example: Δt1> this example: Δt2, and the accuracy of the magnitude of the hitting torque can be increased.
(2) At the start of the tightening operation (when the tightening member is seated), the hydraulic oil flow passage 11b becomes large (not throttled), so that an abnormally high impact torque tx as in the conventional example is not generated. .
(3) After the impact torque is generated (after the pulse is generated), the hydraulic oil passage 11b becomes large (not throttled), so that the resistance after the impact torque is generated (after the pulse is generated) is small, and the generation period of the impact torque However, the conventional example: T1> This example: T2, and the working time required for tightening can be shortened.
(4) Since the pressure of the hydraulic oil inside the liner 7 serving as the high pressure chamber H can be accurately controlled according to the tightening state, it is difficult to apply load pressure to the seal portion as in the conventional example, and the impact torque The durability of the generator 5 can be improved.

FIG. 4 shows a second embodiment of the impact torque adjusting device for a hydraulic torque wrench according to the present invention.
The hydraulic torque wrench 1 according to the present embodiment is replaced with a control for driving the rotor 4 by the output of a torque detection mechanism such as the magnetostrictive torque detection mechanism 12 according to the first embodiment. Similar to the conventional hydraulic torque wrench disclosed in Document 1 and FIG. 7, the relief valve B is disposed in the output adjustment mechanism 11, and the tightening operation proceeds and the pressure of the hydraulic oil in the high-pressure chamber H (blow torque). When the pressure reaches the set size, the relief valve B is opened, and the pressure of hydraulic oil is transmitted to the shut-off valve mechanism 13.
In the case of this type of hydraulic torque wrench 1, the valve body 11 d cannot be incorporated into the output adjustment mechanism 11. Therefore, the valve body 14 d is disposed on the liner 7 separately from the output adjustment mechanism 11.

  The valve body 14d is urged in a direction to open the hydraulic oil flow path 14b via the spring 14c, and communicates with the inside of the liner 7 that becomes the high-pressure chamber H when a striking torque is generated at the back of the valve body 14d. When the pressure of the hydraulic oil in the high-pressure chamber H rises as the tightening operation proceeds, the hydraulic oil flow path 14b becomes smaller as the pressure of the hydraulic oil in the high-pressure chamber H increases (throttling). Is).

  The operation of the impact torque adjusting device of the hydraulic torque wrench of the present embodiment is the same as that of the impact torque adjusting device of the hydraulic torque wrench of the first embodiment.

FIG. 5 shows a third embodiment of the impact torque adjusting device for a hydraulic torque wrench according to the present invention.
As in the second embodiment, the hydraulic torque wrench 1 of this embodiment is provided with a relief valve in the output adjustment mechanism 11 (see FIG. 4 for details), and the tightening operation proceeds to activate the high pressure chamber H. When the oil pressure (blow torque) reaches a set level, the relief valve is opened, and the hydraulic oil pressure is transmitted to the shut-off valve mechanism 13 (see FIG. 7).
In the case of this type of hydraulic torque wrench 1, since a valve body cannot be incorporated in the output adjustment mechanism 11, a valve body 15 d is provided on the liner 7 separately from the output adjustment mechanism 11.

The valve body 15d is composed of two valve bodies 15d disposed so as to face each other with the hydraulic oil passage 15b interposed therebetween, and is biased in a direction to open the hydraulic oil passage 15b via a spring 15c.
An oil chamber 15e that communicates with the inside of the liner 7 that becomes the high-pressure chamber H when the impact torque is generated is formed on the rear portion of each valve body 15d. When the pressure rises, the valve bodies 15d move in the approaching direction, and the hydraulic fluid passage 15b becomes smaller (squeezed) as the hydraulic fluid pressure in the high pressure chamber H increases.

  The operation of the impact torque adjusting device of the hydraulic torque wrench of the present embodiment is the same as that of the impact torque adjusting device of the hydraulic torque wrench of the first and second embodiments, but the two valve bodies 15d are supplied with hydraulic fluid. It arrange | positions so that it may oppose on both sides of the path | route 15b, and it moves so that the two valve bodies 15b may become small (throttle) the hydraulic oil flow path 15b according to the raise of the hydraulic oil pressure of the high pressure chamber H. Thus, the moving stroke of the valve body 15d when moving to adjust the size of the hydraulic oil passage 15 can be reduced, thereby improving the response performance and the accuracy of the magnitude of the impact torque. Can be further improved.

  As mentioned above, although the impact torque adjusting device of the hydraulic torque wrench of the present invention has been described based on a plurality of embodiments, the present invention is not limited to the configuration described in the above embodiments, for example, an output adjusting mechanism. 11. The arrangement of the valve bodies 11d, 14d, and 15d can be changed as appropriate within a range that does not depart from the gist, such as a lid portion instead of the cylindrical portion of the liner 7.

  The impact torque adjusting device for a hydraulic torque wrench of the present invention has high accuracy of the magnitude of the impact torque generated by the impact torque generating device of the hydraulic torque wrench, shortens the generation period of the impact torque, Since it is possible to improve the durability of the impact torque generator of the hydraulic torque wrench, it can be suitably used for a hydraulic torque wrench using a hydraulic impact torque generator.

1 is an overall front sectional view showing a first embodiment of a striking torque adjusting device for a hydraulic torque wrench according to the present invention. (A) is a principal front sectional view at the start of the tightening operation, (b) is a principal front sectional view at the time of the tightening operation, and (c) is AA of (a). Sectional drawing and (d) are BB sectional drawings of (a). An output characteristic diagram is shown, (a) shows the case of the conventional example (the size of the hydraulic fluid passage is constant (fixed) during operation of the hydraulic torque wrench), (b) shows the case of the first embodiment, Each is shown. It is principal part front sectional drawing which shows 2nd Example of the impact torque adjusting device of the hydraulic torque wrench of this invention. FIG. 3 shows a third embodiment of the impact torque adjusting device for a hydraulic torque wrench according to the present invention, in which (a) is a front sectional view of the main part at the start of the tightening operation, and (b) is the main part at the time of the tightening operation. Front sectional drawing, (c) is AA sectional drawing of (a). It is a whole front sectional view showing an impact torque adjusting device of a conventional hydraulic torque wrench. It is a whole front sectional view showing an impact torque adjusting device of a conventional hydraulic torque wrench.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic torque wrench 2 Main valve 3 Forward / reverse rotation switching valve 4 Rotor 5 Impact torque generator 6 Case 7 Liner 8 Main shaft 9 Blade 10 Spring 11 Output adjustment mechanism 11a Operation shaft 11b Hydraulic oil flow path 11c Spring 11d Valve body 11e Oil Chamber 12 Magnetostrictive torque detection mechanism 13 Shutoff valve mechanism 14b Hydraulic oil passage 14c Spring 14d Valve body 14e Oil chamber 15b Hydraulic oil passage 15c Spring 15d Valve body 15e Oil chamber B Relief valve H High pressure chamber L Low pressure chamber

Claims (3)

  In a striking torque adjusting device for a hydraulic torque wrench comprising a liner rotated by a rotor, and a main shaft and blades disposed inside the liner, the inside of the liner that becomes a high pressure chamber and a low pressure chamber is communicated when a striking torque is generated. A hydraulic fluid passage is formed, a valve body biased in a direction to open the hydraulic fluid passage is disposed in the hydraulic fluid passage, and a high-pressure chamber is formed at the rear portion of the valve body when an impact torque is generated The hydraulic torque wrench is characterized in that an oil chamber communicating with the inside of the liner is formed, and the hydraulic oil passage becomes smaller as the pressure of the hydraulic oil in the high pressure chamber increases. Torque adjustment device.   2. The impact torque adjusting device for a hydraulic torque wrench according to claim 1, wherein the valve body is incorporated in an output adjusting mechanism for adjusting the magnitude of the impact torque.   Two valve bodies are disposed so as to face each other across the hydraulic oil flow path, and the two hydraulic valve bodies become smaller in size as the hydraulic oil flow path increases as the pressure of the hydraulic oil in the high pressure chamber increases. 3. The impact torque adjusting device for a hydraulic torque wrench according to claim 1 or 2, wherein the impact torque adjusting device for the hydraulic torque wrench is provided.

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