JP5248567B2 - Torque control wrench shut-off valve mechanism - Google Patents

Description

  The present invention detects that the tightening force of the torque control wrench has reached a set value by a relief valve that is released by the hydraulic oil pressure of the hydraulic striking torque generator, and determines the pressure of the hydraulic oil passing through the relief valve. The present invention relates to a shut-off valve mechanism of a torque control wrench that is operated on a pilot valve to operate a pilot valve and actuate a shut-off valve that shuts off the supply of high-pressure air to an air motor.

  Torque control wrench shutoff valve that detects when the torque control wrench tightening force has reached the set value and activates a shutoff valve that shuts off the supply of high-pressure air to the air motor. A mechanism is employed (see, for example, Patent Document 1).

An example of the shut-off valve mechanism will be described based on the torque control wrench 1 shown in FIGS.
The torque control wrench 1 has a main valve 2 for supplying and stopping high-pressure air and a forward / reverse rotation switching valve 3 for selectively generating a forward / reverse rotation impact torque. The air motor 4 that generates rotational torque is driven by the high-pressure air that is discharged.
A hydraulic striking torque generator 5 that converts the rotational torque of the air motor 4 into striking torque is provided in the front case 6.
The hydraulic striking torque generator 5 includes a liner 50 including a liner main body 51, a liner upper lid 52, and a liner lower lid 53. The liner 50 is filled with hydraulic oil and hermetically sealed. One or a plurality (two in this example) of blade insertion grooves are provided on the main shaft 7 that is coaxially inserted therein. Then, the blades 54 are fitted into the blade insertion grooves, and the blades 54 are urged by the springs 55 so as to be in sliding contact with the inner peripheral surface of the liner main body 51, and one or more are provided on the outer peripheral surface of the main shaft 7. Individual sealing surfaces are formed. In addition, a plurality of (four in this example) seal surfaces are formed on the inner peripheral surface of the liner body 51, and an output adjustment mechanism 8 for adjusting the magnitude of the impact torque is provided.
Then, by rotating the liner 50 by the air motor 4, a plurality of seal surfaces formed on the inner peripheral surface of the liner main body 51 of the liner 50 and seal surfaces and blades 54 and 54 formed on the outer peripheral surface of the main shaft 7 are formed. When they match, a striking torque is generated on the main shaft 7.

When the tightening force reaches a set value, the torque control wrench 1 shuts off the supply of high-pressure air to the air motor 4 by the shut-off valve mechanism 9A.
This shut-off valve mechanism 9A uses a relief valve 83 of the output adjustment mechanism 8 that is released by the hydraulic oil pressure of the hydraulic striking torque generator 5 to confirm that the tightening force of the torque control wrench 1 has reached a set value. The pressure of the hydraulic oil that is detected and passes through the relief valve 83 is applied to the piston 91 disposed on the liner upper lid 52, and the pilot valve is passed through the rod 92 disposed through the air motor 4 at the back of the piston 91. 93 is operated to operate a shut-off valve 95 that shuts off the supply of high-pressure air to the air motor.

  As shown in detail in FIG. 7, the shut-off valve mechanism 9A has an air port 11a into which high-pressure air supplied to the air motor 4 is introduced at one end side of the shut-off valve 95 and a communication hole 95a at the other end side. The air ports 11c through which high-pressure air is introduced are formed, and a spring 96 that biases the shut-off valve 95 in the opening direction is disposed, and is formed on the other end side of the shut-off valve 95. The air port 11c and the air port 11d on the front surface side (rod 92 side) of the pilot valve 93 are communicated with each other through the communication hole 12A so that the pressure of the high pressure air is applied to the front surface of the pilot valve 93. The air port 11e on the side (the opposite side of the rod 92) communicates with the outside through the communication hole 13A. Direction of the pilot valve 93 air port 11d in 1e, that is, so as to dispose the spring 94 for urging in a direction to close the pilot valve 93.

As a result, when the tightening force of the torque control wrench 1 reaches a set value, the relief valve 83 of the output adjustment mechanism 8 is opened by the pressure of the hydraulic oil of the hydraulic striking torque generator 5, and the operation passes through the relief valve 83. The oil pressure acts on the piston 91 disposed on the liner upper lid 52, and the pilot valve 93 is operated and opened via the rod 92 disposed through the air motor 4 on the back of the piston 91.
When the pilot valve 93 is opened, the high-pressure air in the air port 11c is released to the outside through the communication hole 12A, the air port 11d, the air port 11e, and the communication hole 13A, and the pressure in the air port 11c decreases. As a result, the shutoff valve 95 moves from the right side position shown in FIGS. 6 to 7 to the left side position, and the air port 11b through which high-pressure air is introduced and the air port 11b communicating with the air motor 4 The supply of high-pressure air to the air motor 4 is stopped, and bolts and the like can be tightened with a predetermined tightening force set in advance.

Japanese Utility Model Publication No. 3-40076

  By the way, in this shut-off valve mechanism 9A, the pilot valve 93 is operated via the piston 91 to operate the shut-off valve 95. At this time, as shown in FIG. The hydraulic oil pressure was applied from the side.

  In view of the structural problems of the conventional torque control wrench shut-off valve mechanism, the present invention provides a torque control wrench shut-off valve mechanism that allows hydraulic oil to act on the center position of the end face of the piston. The purpose is to provide.

In order to achieve the above object, the shut-off valve mechanism of the torque control wrench of the present invention is released when the tightening force of the torque control wrench reaches a set value by the hydraulic oil pressure of the hydraulic striking torque generator. The pressure of hydraulic oil that is detected by the relief valve and passes through the relief valve is caused to act on the piston from the downstream side of the relief valve via the hydraulic oil passage formed in the liner upper lid, and through the rod arranged on the back of the piston. In the shut-off valve mechanism of the torque control wrench that operates the pilot valve and shuts off the supply of high-pressure air to the air motor, the hydraulic oil passage formed in the liner upper cover is opened. A central position of the end face of the piston, in communication with the opening of the hydraulic oil passage. A passage member having a passage of hydraulic fluid to each opening in the hydraulic impact torque generator side, the passage of the operating oil passage member is disposed so that the end face of the piston to the opening surface of the opening abuts It is characterized by.

The shut-off valve mechanism of the torque control wrench communicates with the opening of the hydraulic oil passage at a position where the hydraulic oil passage formed in the liner upper lid opens, and generates a hydraulic hitting torque and the center position of the end face of the piston. Since the passage member forming the passage of the hydraulic oil that opens to the apparatus side is disposed , the pressure of the hydraulic oil can be applied to the center position of the end face of the piston.

It is a front longitudinal cross-sectional view which shows one Example of the torque control wrench to which the shut-off valve mechanism of the torque control wrench of this invention is applied. It is sectional drawing which shows the hydraulic type impact torque generator. The output adjustment mechanism is shown, (a) is a front longitudinal sectional view of the entire relief valve shaft, (b) is a front longitudinal sectional view of the relief valve shaft, and (c) is a sectional view taken along the line CC of (b). . It is a front longitudinal cross-sectional view which shows the principal part of a shut-off valve mechanism. The shut-off valve mechanism provided with the detection mechanism is shown, (a) is a front longitudinal sectional view, and (b) is an axial orthogonal sectional view. It is a front longitudinal cross-sectional view which shows the conventional torque control wrench. It is a front longitudinal cross-sectional view which shows the principal part of the same shut-off valve mechanism.

  Embodiments of a shut-off valve mechanism for a torque control wrench according to the present invention will be described below with reference to the drawings.

1 to 5 show an embodiment of a torque control wrench to which the shut-off valve mechanism of the present invention is applied.
The torque control wrench 1 has a main valve 2 for supplying and stopping high-pressure air and a forward / reverse rotation switching valve 3 for selectively generating a forward / reverse rotation impact torque. The air motor 4 that generates rotational torque is driven by the high-pressure air that is discharged.
A hydraulic striking torque generator 5 that converts the rotational torque of the air motor 4 into striking torque is provided in the front case 6.

The hydraulic striking torque generator 5 includes a liner 50 including a liner main body 51, a liner upper lid 52, and a liner lower lid 53. The liner 50 is filled with hydraulic oil and hermetically sealed. One or a plurality (two in this example) of blade insertion grooves are provided on the main shaft 7 that is coaxially inserted therein.
Then, the blades 54 are fitted into the blade insertion grooves, and the blades 54 are urged by the springs 55 so as to be in sliding contact with the inner peripheral surface of the liner main body 51, and one or more are provided on the outer peripheral surface of the main shaft 7. Individual (two in this example) seal surfaces 7a, 7a are formed. In addition, a plurality (four in this example) of seal surfaces 5a, 5a, 5b, and 5b are formed on the inner peripheral surface of the liner body 51, and an output adjustment mechanism 8 that adjusts the magnitude of the impact torque is provided. .
Then, by rotating the liner 50 by the air motor 4, a plurality of seal surfaces 5a, 5a, 5b, 5b formed on the inner peripheral surface of the liner 50 and seal surfaces 7a, 7a formed on the outer peripheral surface of the main shaft 7 and When the blades 54 and 54 are matched, an impact torque is generated in the main shaft 7.

In the torque control wrench of this embodiment, the straight line connecting the seal surfaces 7a, 7a formed on the outer peripheral surface of the main shaft 7 of the hydraulic striking torque generator 5 and the seal surfaces 7a, 7a is the center of the main shaft 7. It is designed to be eccentric so as not to pass.
As a result, the liner 50 of the hydraulic impact torque generator 5 is rotated by operating the main valve 2 and the switching valve 3 to rotate the air motor 4 by supplying high-pressure air to the air motor 4. The seal surfaces 5a, 5a, 5b, 5b formed on the inner peripheral surface of the liner main body 51 of the liner 50 and the seal surfaces 7a, 7a and the blades 54, 54 formed on the outer peripheral surface of the main shaft 7 are matched once per rotation. At this time, the cavity formed in the liner 50 is divided into two high-pressure chambers H and two low-pressure chambers L, and the blades 54 and 54 are pushed to the low-pressure chamber L side. One intermittent impact torque is generated on the main shaft 7 per rotation.

By the way, the liner main body 51 of the liner 50 is provided with an output adjusting mechanism 8 for adjusting the magnitude of the impact torque.
This output adjustment mechanism 8 includes an output adjustment mechanism inserted between the two chambers divided by the output adjustment mechanism insertion hole 51a formed parallel to the axis of the liner body 51 and the seal surface 7a of the main shaft 7 across the seal surface 5b. Ports P1 and P2 communicating with the hole 51a, and a relief valve shaft 81 inserted into the output adjustment mechanism insertion hole 51a, an adjustment shaft 82, a relief valve 83, and a spring 84 that biases the relief valve 83 in a closing direction. It is made up of.
The relief valve shaft 81 is slid within the output adjustment mechanism insertion hole 51 a by rotating the adjustment shaft 82 screwed with the relief valve shaft 81, and on the outer peripheral surface of the relief valve shaft 81. A passage 81q made of a concave groove that communicates between the port P1 and the port P2 is formed. Further, the relief valve shaft 81 communicates with a passage 81p that passes through the relief valve shaft 81 in a direction perpendicular to the shaft and the middle of the passage 81p. A passage 81r that penetrates in the axial direction and supplies hydraulic oil to the relief valve 83 side of the output adjustment mechanism insertion hole 51a is formed.

When the output adjusting mechanism 8 rotates the liner 50 of the hydraulic striking torque generator 5, a predetermined amount of hydraulic fluid flows from the high pressure chamber H to the low pressure chamber L side through the port P1, the passage 81q, and the port P2. At this time, until the tightening force of the torque control wrench 1 reaches the set value (the pressure of the hydraulic oil in the high pressure chamber H reaches the set pressure), the relief valve 83 is driven by the urging force of the spring 84 to release the relief valve shaft 81. The state where the hydraulic oil passage 81r opened at the end face is closed is maintained.
When the tightening force of the torque control wrench 1 reaches the set value (the pressure of the hydraulic oil in the high pressure chamber H reaches the set pressure), the relief valve 83 is opened, and a part of the hydraulic oil is transferred from the port P1. It flows out through the relief valve 83 through the passage 81q and the passage 81r, passes through the passage formed in the liner upper lid 52, and acts on the piston 91 disposed in the cylinder 52b formed in the liner upper lid 52. It is configured.

In this case, as shown in FIG. 4, the hydraulic oil passage formed in the liner upper lid 52 opens from the downstream side of the relief valve 83 to the cylinder 52b side where the piston 91 is disposed. Communicating, passing through the passage of the passage member 10 that forms the passage of the hydraulic oil that opens to the center position of the end face of the piston 91 and the hydraulic striking torque generator 5 side, into the cylinder 52b formed in the liner upper lid 52 It is configured to act on the disposed piston 91 and is formed so as to communicate with the inside of the liner 50 through a clearance between the hydraulic striking torque generator side, that is, the liner upper lid 52 and the rear portion of the main shaft 7. ing.
A check valve 15 is disposed at the outlet of the hydraulic oil passage on the hydraulic striking torque generator side of the passage member 10 and a spring 16 that biases the check valve 15 in a direction to close the passage member 10. Is arranged in a hole 72 formed in the rear portion 71 of the main shaft 7.

Thus, by arranging the check valve 15 at the outlet of the hydraulic striking torque generator side of the passage member 10, a small amount of hydraulic oil leaking from the relief valve 83 at the time of normal striking torque generation is It is possible to prevent the hydraulic oil from flowing out through the gap between the liner upper lid 52 and the rear portion of the main shaft 7, that is, leakage of the hydraulic oil from the relief valve 83, thereby improving the working efficiency of the tightening operation, A stable tightening force can be obtained.
Further, after the shut-off, the check valve 15 is opened against the urging force of the spring 16 together with the return of the piston 91, and the hydraulic oil in the cylinder 52b is allowed to flow between the liner upper lid 52 and the rear portion of the main shaft 7. It is possible to return to the hydraulic striking torque generator through the gap between the two.
For this reason, the biasing force of the spring 16 and the spring 94 is set so that the biasing force of the spring 94 that biases the pilot valve 93 to be described later is larger than the biasing force of the spring 16 that biases the check valve 15. To.
The check valve 15 is opened against the biasing force of the spring 16 even when the relief valve 83 is opened and the hydraulic oil pressure is applied to the piston 91, but the liner upper lid 52 and the rear portion of the main shaft 7 are opened. Since the gap between them is narrow, the movement of the piston 91 is not hindered.

On the other hand, the magnitude of the impact torque is adjusted by rotating the adjusting shaft 82 to slide the relief valve shaft 81 in the output adjusting mechanism insertion hole 51a and being urged by the spring 84. And the opening amount of the passage 81q that connects the port P1 and the port P2 is adjusted.
In this case, when the relief valve shaft 81 rotates, the direction of the opening of the passage 81p changes, and it becomes difficult to accurately adjust the magnitude of the impact torque. Therefore, as shown in FIG. A long hole 81h is formed in the direction, and a knock pin 57 provided on the liner main body 51 of the liner 50 is fitted into the long hole 81h to prevent rotation.

Further, by setting the opening amount of the passage 81p communicating with the port P1 and the port P2 to be small, the detection pressure is reduced, the adjustment of the urging force of the relief valve 83 by the spring 84 is facilitated, and the ports P1 and P2 Although the adjustment of the magnitude of the impact torque by adjusting the opening amount of the passage 81q communicating with each other can be made to function more effectively, if the opening amount of the passage 81p is set too small, The detection pressure for operating the shut-off valve mechanism 9 described later becomes too low, or the amount of hydraulic oil flowing into the passage 81r from the passage 81p is insufficient, so that the impact torque can be adjusted accurately. It may disappear.
In order to improve this, as shown in FIG. 3, the passage 81p is not formed as a through-hole, but is formed in an orifice shape having a large diameter on one side and a small diameter on the other side. The relief valve shaft 81 is arranged so that the port P1 side diameter is larger than the port P2 side diameter on the low pressure chamber L side.
As a result, the amount of oil flowing from the passage 81p into the passage 81r can be ensured while making the adjustment of the magnitude of the impact torque by adjusting the opening amount of the passage 81q communicating with the port P1 and the port P2 more effective. It is possible to accurately adjust the magnitude of the impact torque.

  Further, when adjusting the opening amount of the passage 81q that communicates the port P1 and the port P2, in order to prevent fluctuations in the pressure of the hydraulic fluid applied to the passage 81p that communicates the port P1 and the port P2, the passage 81p and the passage 81q are provided. It is desirable to form a separation wall 81 s on the relief valve shaft 81.

The relief valve shaft 81 can also be provided in the liner upper lid 52 of the hydraulic striking torque generator 5.
By providing the relief valve shaft 81 in the liner upper lid 52, the outer diameter of the hydraulic impact torque generating device 5 can be reduced, and the liner main body 51, the liner upper lid 52, the liner lower lid 53, and the knock pin 57 constituting the liner 50 are provided. The tolerance of the accuracy can be increased, and the sealing performance between the liner main body 51 and the liner upper lid 52 is not affected by the output adjusting mechanism insertion hole 51a.

  As described above, when the tightening force of the torque control wrench 1 reaches the set value (the pressure of the hydraulic oil in the high pressure chamber H reaches the set pressure), the relief valve 83 is opened, and a part of the hydraulic oil is The oil flows out through the relief valve 83, and the pressure of the hydraulic oil acts on the piston 91. The pilot 91 is connected to the back of the piston 91 through a rod 92 that penetrates the air motor 4. Since the valve 93 is disposed, when the piston 91 that has received the pressure of the hydraulic oil moves to the right in FIG. 1, the pilot valve 93 is operated via the rod 92, and the high-pressure air to the air motor 4 is operated. The shut-off valve mechanism 9 is configured so as to operate the shut-off valve 17 that shuts off the supply of the gas.

As shown in FIGS. 1 and 5, the shut-off valve mechanism 9 is formed with air ports 18a and 18b into which high-pressure air is introduced on both sides of a T-shaped shut-off valve 17, respectively. The air port 18a is formed so as to communicate with the air motor 4 through the passage 18c.
A communication hole 19 that communicates with the outside is formed in the rod insertion portion that communicates with the air port 18 a via the pilot valve 93.
The pilot valve 93 and the shut-off valve 17 are elastically supported with each other via a spring 94. The spring 94 biases the pilot valve 93 in a closing direction and opens the shut-off valve 17 in a direction. Energized.

In the shut-off valve mechanism 9, when the tightening force of the torque control wrench 1 reaches a set value (the pressure of the hydraulic oil in the high pressure chamber H reaches the set pressure), the pressure of the hydraulic oil in the hydraulic striking torque generator 5 As a result, the relief valve 83 of the output adjusting mechanism 8 is opened, and the pressure of the hydraulic oil passing through the relief valve 83 acts on the piston 91 disposed on the liner upper lid 52, and the air motor 4 is disposed through the back of the piston 91. The pilot valve 93 is operated against the spring 94 through the provided rod 92 and opened.
When the pilot valve 93 is opened, the air port 18a on the side communicating with the air motor 4 communicates with the outside through the communication hole 19, and the pressure is reduced. Therefore, the shutoff valve 17 is connected to the air port 18b on the opposite side. Is moved to the left in FIG. 1 and FIG. 5A, and the passage 18c leading to the air motor 4 is blocked.
Thereby, the supply of high-pressure air to the air motor 4 is stopped, and the bolts and the like can be tightened with a predetermined tightening force.

  The shut-off valve mechanism of the torque control wrench of the present invention has been described based on the embodiment. However, the present invention is not limited to the configuration described in the above embodiment, and for example, as shown in FIG. In addition, a detection mechanism 20 (which detects the number of actuations of the shut-off valve 17 by detecting a change in pressure of the air port 18b in the air port 18b on the rear surface of the shut-off valve 17 and counts the number of tightening of bolts or the like. This detection mechanism 20 is configured such that a pipe line 20c connected to a control device is connected to a detection hole 20a communicating with the air port 18b, and a ball valve 20b urged by a spring 20d is connected to the detection hole 20a. Is arranged to seal high-pressure air.), And the tightening work can be automatically managed, etc. In which it can be changed as appropriate its configuration without departing from the scope of the.

  The shut-off valve mechanism of the torque control wrench of the present invention detects that the tightening force of the torque control wrench has reached a set value by a relief valve that is released by the hydraulic oil pressure of the hydraulic striking torque generator, Can be widely used in torque control wrench that operates the pilot valve by operating the pressure of hydraulic oil that passes through the valve on the piston and operates the shut-off valve that shuts off the supply of high-pressure air to the air motor .

DESCRIPTION OF SYMBOLS 1 Torque control wrench 2 Main valve 3 Forward / reverse rotation switching valve 4 Air motor 5 Hydraulic impact torque generator 50 Liner 54 Blade 6 Front case 7 Spindle 71 Spindle rear part 72 Hole 8 Output adjustment mechanism 81 Relief valve shaft 82 Adjustment shaft 83 Relief Valve 84 Spring 9 Shut-off valve mechanism 91 Piston 92 Rod 93 Pilot valve 94 Spring 10 Passage member 15 Check valve 16 Spring 17 Shut-off valve 18a, 18b Air port 18c Passage 19 Communication hole

Claims (1)

The fact that the tightening force of the torque control wrench has reached the set value is detected by the relief valve released by the hydraulic oil pressure of the hydraulic striking torque generator, and the pressure of the hydraulic oil passing through the relief valve is detected by the relief valve. A shut that shuts off the supply of high-pressure air to the air motor by operating the pilot valve via a rod arranged on the back of the piston, acting on the piston via a hydraulic oil passage formed in the liner upper lid from the downstream side In the shut-off valve mechanism of the torque control wrench configured to operate the off-valve, the hydraulic oil passage formed in the liner top lid is communicated with the opening of the hydraulic oil passage at a position where the hydraulic oil passage is opened. a passage member having a passage of hydraulic fluid to each opening in the center position and the hydraulic impact torque generator side, the Shut-off valve mechanism of a torque control wrench, wherein the passage of the hydraulic oil of the road member is disposed so that the end face of the piston to the opening surface of the opening abuts.

Images