JP2972743B1 - Nut fastening device and fastening method - Google Patents

Abstract

A nut fastening device that can easily discharge residual oil while being attached to a bolt without using a residual oil extracting device or the like, and does not cause loss of hydraulic oil due to outflow of hydraulic oil or contamination of a working environment. I will provide a. SOLUTION: A support cylinder 72 is mounted on a member 56 to be fastened so as to surround a nut 60, and a piston 7 is mounted.
By rotating the inserted cylinder 71, the piston 7
The shaft 59 is screwed to 0. The cylinder 71 is a support cylinder 72
In this state, the hydraulic oil is supplied to the hydraulic chamber 79 to apply tension to the shaft portion 59, and the nut 60 is fastened with the operation rod 121, and the nut is fastened while tension is applied to the shaft portion 59. I do. Thereafter, the switching valve 102 is switched, and air is supplied to the air chamber 90 by the air supply means 74 to displace the cylinder 71 to discharge the residual oil in the hydraulic chamber 79 and return it to the tank 103.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a nut fastening device and a fastening method for firmly fixing a member by applying a predetermined tension to the bolt when fastening a plurality of members with bolts and nuts. .

[0002]

2. Description of the Related Art FIG. 9 is a sectional view showing a configuration of a typical conventional nut fastening device 1. The nut fastening device 1 is disclosed in Japanese Patent Application Laid-Open No. 4-250984. The nut fastening device 1 is a device that is used when fastening a nut 4 that fixes a second fastened member 3 that is a piston to the tip of a first fastened member 2 that is a piston rod. Second
The stud 3 is fastened to the first fastened member 2 with the first fastened member 2 by inserting the stud 11 implanted in the first fastened member 2 and screwing the stud bolt 11 into the nut 4 to fasten. The member 3 is firmly fixed.

The nut fastening device 1 includes a cylinder 5, a stepped piston 6 inserted into the cylinder 5, and a bolt 8 for connecting the stepped piston 6 and the stud 11. A hydraulic chamber 7 is formed between the cylinder 5 and the stepped piston 6, and a bolt 8 inserted into the stepped piston 6 is screwed into a stud bolt 11 to
And the stud 11 are coupled, and the pushing force acting on the piston 6 is transmitted to the stud 11 via the bolt 8. Therefore, when fastening the nut 4, first, hydraulic oil is supplied from the oil supply port 10 to the hydraulic chamber 7, and the piston 6 is pushed up by hydraulic pressure to apply a predetermined tension to the stud 11. Then, the nut 4 separates from the member 3 to be fastened, and a gap is formed between the nut 4 and the member 3 to be fastened.
The nut 4 is rotated until the nut 4 contacts the member 3 to be fastened. As a result, the nut 4 can be fastened with a predetermined tension applied to the studs 11, and the first fastened member 2 and the second fastened member 3 can be firmly fixed.

After fastening the nut, it is necessary to discharge the hydraulic oil in the hydraulic chamber 7 to the outside. In this case, for example, the nut fastening device 1 is mounted on the nut 4, that is, the piston 6 is fixed. Then, the cylinder 5 is pulled up to discharge the oil in the hydraulic chamber 7 to the outside.

Prior art similar to such a nut fastening device 1 is disclosed in Japanese Patent Application Laid-Open Nos.
No. 2,579,322.

[0006]

As described above, the operation of discharging the oil in the hydraulic chamber 7 to the outside has been performed manually, but the bolts and nuts to be fastened are large, and the nut fastening device is large. If so, the task of manually discharging the oil becomes difficult. In this case, for example, the nut fastening device 1 is removed from the nut 4 and attached to a residual oil extracting tool that discharges residual oil using a lever to discharge residual oil.

However, when a large number of nuts are fastened, it is necessary to attach a nut fastening device to the residual oil extracting tool each time the nuts are fastened.
There is a problem that the working time becomes long.

When the residual oil is left without being removed, when the bolt 4 is tightened next, the oil is supplied while the piston 6 is at a high position with respect to the cylinder 5 and a predetermined tension ( In order to add elongation, the piston 6
And the seal (O-ring) attached to the piston 6 is broken, causing a problem that the pressure oil is blown out from the upper end and the seal (O-ring) attached to the piston 6 is broken.

In order to solve such a problem, a nut fastening device for discharging residual oil by using residual oil discharging means such as a disc spring has been proposed.

FIG. 10 is a sectional view showing a nut fastening device 15 using a disc spring. The nut fastening device 15 is a device for fastening a nut 18 screwed to a shaft 17 of a bolt inserted into the member 16 to be fastened, and includes a cylinder 19, a stepped piston 20, and a tension rod 23. The lower end of the pull rod 23 is screwed to the tip of the shaft 17 of the bolt,
The tensile force of the stepped piston 20 is transmitted to the bolt shaft 17 via the top plate 22 provided at the upper end and the ring 21 interposed between the top plate 22 and the stepped piston 20. The top plate 22 is provided on an annular end member 26 fixed to the upper end of the cylinder 19.
A disc spring 27 is interposed between the spring 20 and the stepped piston 20.

When the nut 18 is fastened, a hydraulic chamber 24 formed between the stepped piston 20 and the cylinder 19 is used.
The hydraulic oil is supplied from the oil supply port 25 by a hydraulic pump. Then, the stepped piston 20 is displaced upward by the oil pressure in the hydraulic chamber 24 and applies a predetermined tensile force to the shaft 17 of the bolt. As a result, the nut 18 is connected to the fastened member 1.
6 and the disc spring 27 interposed between the stepped piston 20 and the end member 26 is compressed.

Next, a tool 28 is inserted through an opening 29 formed at the lower end of the cylinder 19, and the nut 18 is rotated until the nut 18 contacts the member 16 to be fastened. Thereafter, when the hydraulic pressure in the hydraulic chamber 24 is released, the cylinder 19 is displaced upward by the spring force of the disc spring 27, and the hydraulic oil in the hydraulic chamber 24 is discharged to the outside. In this way, residual oil can be discharged with the nut fastening device 15 attached to the nut 18.

However, in the case of the nut fastening device 15 using such a disc spring 27, the tensile force applied to the shaft 17 of the bolt must be determined in consideration of the spring force of the disc spring 27. The height of the nut fastening device 15 is increased by the height of the spring 27, which makes it difficult to use in a narrow place. In general, a disc spring is used for a nut fastening device having a small diameter, but it is difficult to apply the disc spring to a nut fastening device having a large diameter.

SUMMARY OF THE INVENTION An object of the present invention is to provide a nut fastening device and a nut fastening device which can easily discharge residual oil without using a residual oil extracting device and which does not cause loss of hydraulic oil due to outflow of hydraulic oil or contamination of a working environment. Is to provide a way.

[0015]

According to a first aspect of the present invention, there is provided a nut fastening device for fastening a nut by applying a predetermined tension to a bolt when a plurality of members are fixed with the bolt and the nut. A piston having a small-diameter portion, a step surface formed between the large-diameter portion and the small-diameter portion, having an axis in the thickness direction, and having a screw hole into which the shaft portion of the bolt is screwed; A cylindrical portion having an inner peripheral surface in which a large diameter portion of the cylindrical portion is in oil-tight sliding contact with one end of the cylindrical portion, and an end member closing one end of the cylindrical portion; And a second end member having an inner peripheral surface on which a small diameter portion of the piston slides in an oil-tight manner, and is interposed between a cylinder into which the piston is inserted, and a member to be fastened and the cylinder to support the cylinder. Formed between the supporting cylinder and the other end of the cylinder and the large diameter part of the piston Hydraulic oil supply means for supplying hydraulic oil to the hydraulic chamber, and air supply means for supplying compressed air to an air chamber formed between the other end member of the cylinder and the piston. It is a nut fastening device.

According to the present invention, since the piston inserted into the cylinder is screwed to the shaft of the bolt, when the operating oil is supplied to the hydraulic chamber by the operating oil supply means, the hydraulic oil in the hydraulic chamber is applied to the shaft. A tensile force is applied, and the nut screwed to the shaft separates from the member to be fastened. Therefore, by rotating and tightening the nut until it comes into contact with the member to be fastened, the nut can be fastened with a predetermined tension applied to the bolt.

The screw hole of the piston is closed by the screw portion of the bolt, the end of the cylinder is closed by one end member, and an air chamber is formed between the one end member and the piston. When compressed air is supplied to the air chamber by the air supply means, the cylinder is displaced in a direction in which one end member of the cylinder is separated from the piston by the air pressure in the air chamber, and the hydraulic oil in the hydraulic chamber is discharged. As described above, the nut fastening device of the present invention does not require removing the residual oil from the nut and attaching the residual oil extracting tool or the like to discharge the residual oil after fastening the nut, and discharges the residual oil with the nut attached. As a result, a large time reduction can be achieved especially when a large number of bolts are tightened. Also, since the residual oil is discharged by displacing the cylinder by air pressure,
A large force can be applied. This eliminates the need to remove the hydraulic hose to reduce the resistance at the time of residual oil discharge unlike a nut fastening device without residual oil discharge means, and allows residual oil to be discharged with the hydraulic hose attached. In addition, loss of hydraulic oil due to residual oil spill and contamination of the working environment can be prevented. In addition, when the nut is used to fasten the nut in a state where the residual oil is not sufficiently discharged, the problem that the piston escapes above the cylinder to eject the pressure oil and that the O-ring is broken, thereby being prevented. . Further, in the conventional nut fastening device using a disc spring, the height of the nut fastening device is increased to equip the disc spring, but in the present invention, only the thickness of one end member forming the air chamber is sufficient, The device can be miniaturized and can be used even in a narrow place.

According to a second aspect of the present invention, the hydraulic oil supply means includes a hydraulic pressure source for supplying hydraulic oil, a flexible hydraulic hose connected to the hydraulic pressure source, and a hydraulic chamber facing one end of the cylinder. A first connection port communicating with the first connection port, and a first pipe joint removably connecting the first connection port and the hydraulic hose, wherein the air supply means has an air pressure source for supplying compressed air, and has flexibility. An air hose connected to the air pressure source, a second connection port facing one end of the cylinder and communicating with the air chamber, and a second pipe joint removably connecting the second connection port and the air hose. It is characterized by the following.

According to the present invention, when the nut fastening device is mounted on the nut to be fastened, the piston inserted into the cylinder needs to be screwed into the shaft of the bolt, for which the piston is inserted into the cylinder. In this state, the piston is rotated together with the cylinder and screwed together. In the present invention, the hydraulic oil supply means and the air supply means are respectively the first and second oil supply means.
First and second attached to a cylinder by a fitting
Since it is detachably connected to the connection port, when the piston is screwed into the shaft portion, the hydraulic hose and the air hose respectively connected to the oil and air pressure sources by the first and second pipe joints can be detached. Therefore, when the cylinder is rotated and the piston is screwed together, each hose does not become an obstacle, and the nut fastening device can be quickly mounted.

The piston according to claim 3 is provided with a first connection port, and the first connection port is inserted into one end member of the cylinder to prevent air leakage from the air chamber. An insertion hole allowing relative displacement with the first connection port is formed, and an indication mark indicating the relative position of the first connection port with respect to the one end member when the hydraulic oil in the hydraulic chamber is discharged is described in the first connection port. It is characterized by having been done.

According to the present invention, the first connection port attached to the piston is inserted through one end member, and the first connection port is further provided with an indication mark indicating a relative position with respect to the one end member. The position of the piston when the hydraulic oil in the hydraulic chamber is completely discharged can be grasped from the outside by the instruction mark. Therefore, when the hydraulic oil is discharged by the air supply means, whether or not the hydraulic oil has been completely discharged can be easily grasped from the outside.

According to a fourth aspect of the present invention, when the air hose and the second connection port are in a detachable state, the second pipe joint communicates the air chamber with the atmosphere and is in a state where air can be supplied. In this case, disconnection between the air hose and the second connection port is prevented, and communication between the air chamber and the atmosphere is cut off.

According to the present invention, after the air is supplied and the residual oil is discharged, the pressure in the air chamber is high. Therefore, when the air hose is detached from the second connection pipe, the air hose is vigorously moved by the air pressure in the air chamber. Although there is a risk of detachment, in the present invention, the pipe joint connecting the air hose and the second connection port communicates the air chamber with the atmosphere when it is in a detachable state. When the state is shifted to the detachable state, the air chamber communicates with the atmosphere, and the air chamber becomes equal to the atmospheric pressure. In this state, the air hose is detached from the second connection port. This prevents the air hose from being severely detached by air pressure.
Further, when the second pipe joint is in a state capable of supplying air,
Since the communication with the atmosphere is cut off to prevent the air hose from being disconnected from the second connection port, it is possible to prevent the air hose from being disconnected from the second connection port during air supply.

According to a fifth aspect of the present invention, there is provided a nut fastening method for fastening a nut by applying a predetermined tension to a bolt when fixing a plurality of members with a bolt and a nut, the method comprising a large diameter portion and a small diameter portion. A piston having a stepped surface formed between the large-diameter portion and the small-diameter portion, having an axis in the thickness direction, and having a screw hole into which the shaft portion of the bolt is screwed; A cylindrical portion having an inner peripheral surface that comes into close sliding contact with the cylindrical portion, an end member connected to one end of the cylindrical portion, and closing one end of the cylindrical portion; A cylinder having a small-diameter portion having an inner peripheral surface with which an oil-tight sliding contact is made; a cylinder into which a piston is inserted; a support cylinder interposed between the member to be fastened and the cylinder to support the cylinder; and a cylinder. Hydraulic chamber formed between the other end member of the Hydraulic oil supply means for supplying hydraulic oil, and air supply means for supplying compressed air to the air chamber formed between the other end member of the cylinder and the piston, first, the support cylinder Screw the piston inserted into the cylinder until the cylinder is supported to the shaft of the bolt, then supply hydraulic oil to the hydraulic chamber by hydraulic oil supply means,
Applying a predetermined tension to the shaft of the bolt by hydraulic pressure to separate the nut screwed into the shaft from the member to be fastened, and then rotating and tightening the nut until the nut abuts the member to be fastened, and finally, A nut fastening method characterized in that compressed air is supplied to an air chamber by air supply means, and a cylinder is displaced by air pressure to discharge hydraulic oil in a hydraulic chamber.

According to the present invention, when discharging the residual oil in the hydraulic chamber, the compressed air is supplied to the air chamber to displace the cylinder to discharge the residual oil. Therefore, it is not necessary to attach a residual oil extracting tool as in the related art or to interpose a disc spring between the cover and the piston, and it is possible to easily discharge the residual oil without causing the residual oil to flow out. it can.

[0026]

FIG. 1 is a sectional view showing a nut fastening device 50 according to an embodiment of the present invention. The nut fastening device 50 is used when fastening the nut 60 screwed to the shaft portion 59 of the bolt inserted into the member to be fastened 56.

The nut fastening device 50 includes a piston 70,
A cylinder 71 into which the piston 70 is inserted, and a support cylinder 72 interposed between the cylinder 71 and the member 56 to be fastened.
And hydraulic oil supply means 73 and air supply means 74. The piston 70 has a large-diameter portion 80 and a small-diameter portion 81 in the shape of a right column, and has a bolt shaft 82 formed as a screw hole into which the shaft 59 of the bolt is screwed in the thickness direction. The bolt shaft 82, the large-diameter portion 80, and the small-diameter portion 81 each have a common central axis L1.

The cylinder 71 includes a cylinder body 75 on which the piston 70 is mounted, and an end member 83 for closing one end of the cylinder body 75. The cylinder body 75 has a short cylindrical shape, and has a large diameter portion 8 of the piston 70 on the inner peripheral surface 105.
The cylindrical portion 76, whose outer peripheral surface 85 is in oil-tight sliding contact with an O-ring 92, and the cylindrical portion 76 at the other end of the cylinder body 75.
The inner peripheral surface 8 is formed in an annular shape by connecting inwardly to the other end of the inner peripheral surface 8.
The outer peripheral surface 86 of the small-diameter portion 81 of the piston 70 is in contact with the other end member 84 in oil-tight sliding contact with an O-ring 91. One end member 83 includes a ring 78 provided on one end of a cylindrical portion 76 which is one end of a cylinder body 75, and a ring 7.
And a disc-shaped lid 77 provided on the upper surface 8. The lid 77 is fixed by a plurality of holding bolts 88 screwed to the cylinder portion 76 of the cylinder body 75 via a ring 78.

The diameter of the shaft portion 59 of the bolt is, for example, about 10 cm, and the outer diameter of the cylinder 71 is 25 to 3 mm.
It is about 0 cm.

The other end member 84 has a step surface 87 extending from the outer peripheral surface 85 of the large diameter portion of the piston 70 to the outer peripheral surface 86 of the small diameter portion.
Has one surface 106 facing. One surface 106 of the other end member 84, the step surface 87 of the piston 70, and the piston 7
The annular space surrounded by the outer peripheral surface 86 of the small-diameter portion 0 and the inner peripheral surface 105 of the cylindrical portion 76 becomes a hydraulic chamber 79 to which hydraulic oil is supplied from the hydraulic oil supply means 73.

Air is supplied from the air supply means 74 to a space surrounded by one surface 104 of the piston 70, one surface 93 of the lid 77 of the one end member 83, and the inner peripheral surface 94 of the cylindrical portion 76. It becomes the air chamber 90.

The hydraulic oil supply means 73 includes a hydraulic source 98 for supplying hydraulic oil, a hydraulic hose 97 having flexibility and connected to the hydraulic source 98, and a lid 7 of one end member 83 of the cylinder 71.
7, and includes a first connection port 95 communicating with the hydraulic chamber 79, and a first pipe joint 96 for detachably connecting the first connection port 95 and the hydraulic hose 97. First connection port 95
Is inserted through an insertion hole 116 formed in the lid 77 of the one end member 83 and is fixed facing one surface 104 of the piston 70. An oil passage 109 communicating with the first connection port 95 and the hydraulic chamber 79 is formed in the piston 70. The outer peripheral surface 117 of the first connection port 95 inserted into the insertion hole 116 has a straight cylindrical shape, and the insertion hole 116 prevents leakage of air from the insertion hole 116 when air is supplied to the air chamber 90. A small gap between the outer peripheral surface 117 of the inserted first connection port 95 and the insertion hole 116 so as to allow relative displacement of the first connection port 95 to the cylinder 71 due to the vertical displacement of the cylinder 71, In the present embodiment, there is a gap of about 0.05 mm.

A first pipe joint 96 for detachably connecting the hydraulic hose 97 and the first connection port 95 comprises a nipple 99 fixed to the first connection port 95 and a coupling 100 fixed to the hydraulic hose 97. It can be easily attached and detached. The hydraulic source 98 has a hydraulic pump 101, a switching valve 102 and a tank 103 interposed between the hydraulic pump 101 and the hydraulic hose 97.
The switching valve 102 is disposed at a switching position at which the hydraulic oil can be supplied as shown in FIG. 3, and when the residual oil is discharged, the switching valve 102 is switched so that the hydraulic hose 97 and the tank 103 communicate with each other to change the hydraulic oil in the hydraulic chamber 79. Return to tank 103.

The air supply means 74 includes an air pump 108,
An air hose 107 connected to an air pump 108 and having a flexible air hose 107 and a lid 77 of the cylinder 71 facing the air chamber 90.
Connecting port 150 that communicates with the second connecting port 150 and the second pipe fitting 15 that detachably connects the second connecting port 150 and the air hose 107.
1 is included.

An eyebolt 120 is fixed on the center axis L1 of the lid 77. When the nut fastening device 50 is mounted, the wire passed through the eyebolt 120 is hooked by a hook of an overhead crane to suspend the cylinder 71. Since the eye bolt 120 is located on the center axis L1, the eye bolt 120 can be stably suspended, and the cylinder 71 can be stably rotated to smoothly screw the piston 70 into the shaft 59 of the bolt.

FIG. 2 is a sectional view taken along the line II-II in FIG. The nut 60 has a short columnar shape, and a plurality of fitting holes 145, in the present embodiment, eight fitting holes 145 into which the operation rod 121 for rotating the nut 60 is fitted are formed on the outer peripheral portion. The fitting holes 145 are formed at equal intervals in the circumferential direction, face radially, and open outward. The support cylinder 72 is disposed on the fastened portion 56 so as to surround the nut 60 and supports the cylinder 71. The operation rod 12 is provided on the support cylinder 72.
Two openings 122 are formed at intervals in the circumferential direction. The operating rod 121 fitted into the fitting hole 145 of the nut 60 through the opening 122 is
The opening 122 is formed to extend in the circumferential direction so that the nut 60 can be tightened and loosened by rotating the nut 60 around the center.

FIG. 3 is a front view showing a state in which the nipple 99 of the first pipe joint 96 of the hydraulic oil supply means 73 is separated from the coupling 100, and FIG. 4 is a view in which the nipple 99 and the coupling 100 are connected. It is an expanded sectional view showing a state at the time. The coupling 100 includes an inner cylinder 111 and a plurality of fitting holes 11 formed in the inner cylinder 111 as shown in FIG.
9 and a plurality of steel balls 112 fitted in the inner cylinder 111.
And a lock ring 110 extrapolated to the nipple 9.
9 has an insertion portion 118 inserted into the inner cylinder 111 of the coupling 100, and the insertion portion 118 has a coupling 1
The engagement groove 1 into which each ball 112
15 are formed. A plurality of balls 112 are provided in the circumferential direction, and are provided in the fitting holes 119 formed in the inner cylinder 111 so as to be displaceable in the radial direction. Lock ring 110
Is formed with a reduced diameter portion 113 inside the central portion in the longitudinal direction,
An enlarged diameter portion 114 is formed at the distal end, is displaceably mounted along the inner cylinder 111, and is spring-biased toward the distal end of the coupling 100. In a natural state, the reduced diameter portion 113 faces the ball 112. And the ball 112
Is in a state of protruding inward from the inner peripheral surface 153 of the inner cylinder 111. When the lock ring 110 is pulled toward the base end side against the spring force as shown by the arrow A, the ball 112 faces the enlarged diameter portion 114, and thereby each ball 1
12 can be retracted outside the inner peripheral surface 121 of the inner cylinder 111.

Therefore, when connecting the coupling 100 to the nipple 99, the lock ring 110 is connected to the arrow A.
The inner cylinder 111 of the coupling 100
The insertion portion 118 of the nipple 99 is inserted into the inside, and the hand is released from the lock ring 110. Then, the lock ring 110 is displaced to the distal end side by the spring force, whereby the balls 112 are pushed by the reduced diameter portion 113 of the lock ring 110, and each ball 112 is fitted into the engagement groove 115 of the nipple 99, and easily. The coupling 100 can be prevented from being pulled out of the nipple 99 even when a tensile force acts. When the coupling 100 is to be disengaged from the nipple 99, the lock ring 110 is pulled in the direction of arrow A so that each ball 112 can be displaced in the radial direction, and when the coupling 100 is pulled further, each ball 112 is engaged. The coupling 100 can be pulled out of the groove 115.

FIG. 5 shows the second connection port 150 and the second pipe joint 1.
It is sectional drawing which shows the connection state with 51. The second connection port 150 fixed to the lid 77 of the cylinder 71 is
It has an insertion portion 146 to be inserted into the air chamber 51, and is communicated with the air chamber 90. The second fitting 151 includes a mounting port 126 into which the insertion portion 146 of the second connection port 150 is inserted and mounted, and a mounting port 1.
The rotation unit 154 includes a rotation unit 154 that is provided to be rotatable with respect to 26 and to which the air hose 107 is connected, and a lock ring 125 that is attached to the rotation unit 154. A pair of rotation support pieces 127 that sandwich the mounting port 126 are provided at the distal end of the rotation unit 154.
Is provided. The rotation support piece 127 rotatably holds the mounting port 126 around a rotation axis L2 perpendicular to the paper surface of FIG. A communication passage 128 communicating with the air chamber 90 in a mounted state is formed in the mounting port 126, and the rotating portion 154 is provided.
As shown in FIG. 5A, the air passage 129 communicating with the air hose 107 is provided when the rotating portion 154 of the second pipe joint 151 is in a state where the air can be supplied so as to be linear with respect to the mounting port 126. The air hose 107 and the second connection port 150 communicate with each other, facing the communication passage 128 of the rotating portion 154. Further, in this state, the fork-shaped claw 130 at the pointed end of the rotating portion 154 clamps the neck 131 that protrudes outward at the lower end of the insertion portion 146, and the second connection port 1 of the second pipe joint 151.
The rotation of the rotating part 154 is prevented by the lock ring 125 which is prevented from being detached from the locking member 50 and which is biased by a spring.

When detaching the second pipe joint 151 from the second connection port 150, first, the lock ring 125 is pulled toward the air hose 107 side against the spring force as shown by the arrow B, As shown in FIG.
7 is turned about 70 ° to make it detachable. Then
The communication passage 128 communicates with the hole 132 formed in the rotating portion 127 to open the air chamber 90 to the atmosphere. That is, the second pipe joint 151 is connected to the second connection port 150.
The high-pressure air in the air chamber 90 is discharged to the outside in a state of being connected to the air conditioner.

Thereafter, as shown in FIG.
The pipe joint 151 can be detached by pulling it out of the second connection port 150. Thus, the second pipe joint 1
In the case of releasing the first connection port 51, the rotation section 154 is rotated to open the air chamber 90 to the atmosphere first, and then the second connection port 15 is opened.
Since the second fitting 151 is separated from zero, it is possible to prevent the second pipe joint 151 from being rapidly blown off by high-pressure air or from being hardened by high-pressure air and unable to be separated. Second
When connecting the pipe joint 151 to the second connection port 150,
Connection is made in the reverse order of the above.

FIG. 6 is a diagram showing a fastening procedure of the nut fastening device 50. The fastening method of the nut fastening device 50 will be described in detail with reference to FIG.

First, as shown in FIG. 6A, the support cylinder 72 is placed on the member 56 to be fastened so as to surround the nut 60 to be fastened.

Next, as shown in FIG. 6 (2), the cylinder 7 is connected to the hook 141 of the overhead crane via the wire 152.
The cylinder 71 is moved onto the shaft 59 of the bolt by hooking the eyebolt 120 provided on the upper part of the
The cylinder 71 is lowered so that the bottle shaft 82 of the piston 70 is located above. When the cylinder 71 is mounted on the tip of the shaft 59 of the bolt, the cylinder 71 is rotated with the wire rope 142 of the overhead crane slightly slackened. The hook 141 is rotatable with respect to the wire rope 142, and the eye bolt 120 is on the center axis L1, so that the cylinder 71 can be rotated smoothly, and the bottle shaft 82 of the piston 70 is Can be screwed together.

When the cylinder 71 rotates, the hydraulic hose 97 of the hydraulic oil supply means 73 is disconnected from the first connection port 95, and the air hose 107 of the air supply means 74 is also disconnected from the second connection port 150. , Cylinder 71
It does not hinder the rotation of.

When the shaft 71 is screwed into the piston 70 by rotating the cylinder 71, the cylinder 71 gradually descends,
Eventually, the other surface 144 (lower end surface) of the other end member 84 comes into contact with the upper end surface of the support cylinder 72, and the cylinder 71 is supported on the support cylinder 72. The cylinder 71 is rotated until it is supported in this manner. At this time, an annular positioning projection 140 is formed inside the other surface 143 of the other end member 84, and the positioning projection 140 is formed on the inner periphery of the support cylinder 72 while the cylinder 71 is supported by the support cylinder 72. The support cylinder 72 can be accurately positioned by fitting into the surface.

Although the support cylinder 72 and the cylinder 71 are formed separately, the support cylinder 72 and the cylinder 71 may be formed integrally.

Next, as shown in FIG. 6C, the hydraulic hose 97 and the first connection port 95 are connected by the first pipe joint 96. In this state, the hydraulic chamber 79 includes the step surface 87 of the piston 70 and the one surface 14 of the other end member 84 of the cylinder 71.
4 is in a contact state. At this time, on the outer peripheral surface 117 of the first connection port 95, an instruction mark 143 is described by engraving at a position corresponding to the other surface 155 facing the outside of the lid 77. Therefore, the piston 7 with respect to the cylinder 71
The relative displacement along the central axis L1 of 0 can be visually recognized from the outside by the relative displacement between the indication mark 143 and the other surface 155 of the lid 77. That is, the indication mark 143 is placed on the other surface 15 of the lid 77.
When it is at the same height position as 5, the step surface 87 and the one surface 106 of the other end member 84 are in contact with each other, indicating that the hydraulic oil in the hydraulic chamber 79 is discharged to the outside.

The hydraulic hose 97 and the first connection port 95 are connected by the first fitting 96, and before the hydraulic pump 101 is operated, it is confirmed whether the switching valve 102 is at the position where the hydraulic oil can be supplied. When it is not at the position where the hydraulic oil can be supplied, the position is switched to the position where the hydraulic oil can be supplied and the hydraulic oil can be supplied, and then the hydraulic oil is supplied to the hydraulic chamber 79. When hydraulic oil is supplied to the hydraulic chamber 79, the hydraulic pressure in the hydraulic chamber 79 causes the one surface 106 of the other end member 84 of the cylinder 71 and the step surface 87 of the piston 70 to move.
Are moved away from each other in the direction of the center axis L1.
, And a predetermined tension is applied to the shaft portion 59 of the bolt. The hydraulic pressure at this time is, for example, 900 to 150
It is 0 kg / cm ² .

When the piston 70 is displaced upward and tension is applied to the shaft portion 59, the nut 60 screwed to the shaft portion 59 separates from the member 56 to be fastened as shown in FIG.

Thereafter, as shown in FIG. 6 (5), the operating rod 121 is fitted into the fitting hole 145 of the nut 60 from the outside through the opening 122 of the support cylinder 72, and
The nut 60 is rotated until the nut 60 abuts.
In this manner, the nut 6 is applied with a predetermined tension applied to the shaft 59.
0 can be tightened. By forming the opening 122 in the support cylinder 72 in this manner, the nut 60 can be easily tightened from the outside. After the nut 60 abuts, the switching valve 102 of the hydraulic oil supply means 73 is switched so that the hydraulic hose 97 and the tank 103 communicate with each other.
Reduce pressure in hydraulic chamber.

Next, the second pipe joint 151 is connected to the second connection port 15.
0 and the air pump 108 is operated to activate the air chamber 90.
Supply air inside. Then, the air pressure in the air chamber 90 acts in a direction in which the one surface 104 of the piston 70 and the one surface 93 of the lid 77 are separated from each other, and the cylinder 71 is screwed into the shaft portion 59 and fixed. Rises, and the hydraulic oil in the hydraulic chamber 79 is returned to the tank 103 via the first connection port 95, the hydraulic hose 97, and the switching valve 102. When the cylinder 71 is gradually raised and the indication mark 143 of the first connection port 95 becomes the same as the other surface 155 of the lid 77, the hydraulic oil in the hydraulic chamber 79 is regarded as completely discharged and the air supply means 74 The supply of air from. The air supply pressure at this time is, for example, about 6 kg / cm.
²

Thereafter, the rotating portion 154 of the second pipe joint 151
Is rotated to open the air chamber 90 to the atmosphere, and then the second pipe joint 151 is detached from the second connection port 150. The hydraulic hose 97 of the hydraulic oil supply means 73 is also detached from the first connection port 95 by the first pipe joint 96, and the operation of fastening the nut is completed.

Thereafter, the cylinder 7 is moved by an overhead crane.
1 and the nut 60 to be fastened to the support cylinder 72 next.
Is mounted on the member 56 to be fastened so as to surround the same, and the cylinder 71 is mounted in the same manner as described above, and the next fastening operation of the nut 60 is performed.

As described above, since the residual oil is discharged by the air supply means 74, the cylinder 71 can be displaced with a large force, and it is necessary to disconnect the hydraulic hose in order to reduce the resistance of the hydraulic oil when discharging the residual oil. And the discharged residual oil can be returned to the tank 103 via the hydraulic hose 97, so that the work environment is prevented from being polluted due to the residual oil flowing out, and the residual oil can be reused.

Instead of performing the residual oil discharging operation after the nut is fastened, a nut fastening device may be mounted on the nut and performed before the supply of the hydraulic oil.

The nut fastening device 50 of the present invention can also be used to loosen the fastened nut 60.

FIG. 7 is a sectional view showing a marine diesel engine 52 which is an example in which the above-described nut fastening device 50 is used, and FIG. 8 is a plan view thereof. The marine diesel engine 52 has a large base plate 53 as shown in FIG.
Frame 54, jacket 55 and cylinder cover 4
9, a bolt 57 called a tie rod over the base plate 53, the frame 54, and the jacket 55.
Are inserted and fastened by a nut 58 on the jacket 55 and a nut 58a below the base plate 53, whereby the base plate 53, the frame 54 and the jacket 55 are fixed to each other.
Further, the nut 47 is fastened to the stud bolt 48 inserted from the jacket 55 from above from above, and the cylinder cover 49 is fixed to the jacket 55.

The jacket 55 is provided on the cylinder cover 49 by a sudden increase in pressure due to explosive combustion in the combustion chamber 61.
A large force acts in the direction away from the object. Therefore,
The stud 48 for fixing the cylinder cover 49 to the jacket 55 needs to be tightened by applying a predetermined tension capable of withstanding such a force. Similarly, the base plate 53,
Bolt 5 for fixing frame 54 and jacket 55
Since a large tension acts on the piston 7 due to the pressure applied to the piston 62, the bolt 57 also needs to be fastened by applying a predetermined tension against the large tension.

The nut fastening device 50 is configured such that the nuts 58, 6
0, and the member 56 to be fastened becomes the cylinder cover 49 or the jacket 55. FIG.
Reference numeral 63 is a crankshaft, reference numeral 64 is a connecting rod, reference numeral 65 is a crosshead, and reference numeral 66 is a piston rod.

[0061]

According to the first aspect of the present invention, the hydraulic oil in the hydraulic chamber can be discharged by displacing the piston by the air supply means, so that the nut fastening device can be easily mounted on the nut. Since the residual oil can be discharged and the residual oil is prevented from flowing out, loss of hydraulic oil and contamination of the working environment can be reduced.

According to the second aspect of the present invention, the hydraulic hose for supplying hydraulic oil and the air hose for supplying air are detachably connected to the first connection port and the second connection port, respectively. When the nut fastening device is mounted, the cylinder can be rotated while the hoses are detached, and the piston can be screwed into the bolt shaft, thereby improving the working efficiency.

According to the third aspect of the present invention, since the indication mark is described in the first connection port, the position of the piston when the residual oil is discharged can be grasped from the outside, and the piston can be moved from the cylinder. Pressurized oil spills out or O
The problem that the ring is broken can be prevented.

According to the present invention, when the air hose is detached from the second connection port, the air pipe is first opened to the atmosphere and then the second pipe joint is detached from the second connection port. It is possible to prevent the air hose from being rapidly blown by the high-pressure air at the time of departure.

According to the fifth aspect of the present invention, since the compressed air is supplied by the air supply means to displace the piston to discharge the residual oil, the residual oil can be easily discharged with the nut fastening device mounted on the nut. The residual oil can be drained with a large force by air pressure, eliminating the need to disconnect the hydraulic hose to drain the residual oil. Fouling is reduced.

[Brief description of the drawings]

FIG. 1 shows a nut fastening device 5 according to an embodiment of the present invention.
FIG.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

FIG. 3 is a front view showing a state where the nipple 99 of the first pipe joint 90 and the coupling 100 are detached.

FIG. 4 is an enlarged sectional view showing a state in which a nipple 99 of the first pipe joint 96 and a coupling 100 are connected.

FIG. 5 is a cross-sectional view showing a connection state between a second pipe joint 151 and a second connection port 150.

FIG. 6 is a view showing a fastening procedure of the nut fastening device 50.

FIG. 7 is a sectional view showing a marine diesel engine 52.

8 is a plan view of the marine diesel engine 52. FIG.

FIG. 9 is a sectional view showing a conventional nut fastening device 1.

FIG. 10 is a sectional view showing a conventional nut fastening device 15.

[Explanation of symbols]

 Reference Signs List 50 Nut fastening device 56 Member to be fastened 59 Shaft portion 60 Nut 70 Piston 71 Cylinder 72 Support cylinder 73 Hydraulic oil supply means 74 Air supply means 75 Cylinder body 76 Cylinder part 77 Cover 78 Ring 79 Hydraulic chamber 80 Large diameter part 81 Small diameter part 82 Bolt shaft 83 One end member 84 End member 85 Outer peripheral surface of large diameter part 86 Outer peripheral surface of small diameter part 87 Step surface 88 Holding bolt 89 Inner peripheral surface 90 Air chamber 91,92 O-ring 93 One surface 94 Inner peripheral surface 95 First Connection port 96 First fitting 97 Hydraulic hose 98 Hydraulic source 99 Nipple 100 Coupling 101 Hydraulic pump 102 Switching valve 103 Tank 104 One surface of piston 105 Inner peripheral surface 106 One surface 107 Air hose 108 Air pump 109 Oil passage 110 Lock ring 111 Inside Tube 112 Steel ball 113 Diameter part 114 Large diameter part 115 Engagement groove 116 Insertion hole 117 Outer peripheral surface 118 Insertion part 119 Fitting hole 120 Eyebolt 121 Operating rod 122 Opening 125 Lock ring 126 Mounting port 127 Rotation support piece 128 Communication path 129 Air path 130 Fork type Claw 131 neck 132 hole 140 positioning projection 141 hook 142 wire rope 143 indication mark 144 other surface 145 fitting port 146 insertion section 150 second connection port 151 second pipe joint 152 wire 153 inner peripheral surface 154 rotating section 155 other surface 158 nut

Claims (5)

(57) [Claims] 1. A nut fastening device for fastening a nut by applying a predetermined tension to a bolt when fixing a plurality of members with a bolt and a nut, the nut fastening device having a large diameter portion and a small diameter portion, and a large diameter portion and a small diameter portion. A piston having a step surface formed therebetween, an axis in a thickness direction, and a screw hole into which a shaft portion of the bolt is screwed, and an inner peripheral surface on which a large-diameter portion of the piston is in oil-tight sliding contact A cylindrical portion having an end member connected to one end side of the cylindrical portion and closing one end of the cylindrical portion, and formed in an annular shape inwardly connected to the other end portion of the cylindrical portion;
A small-diameter portion of the piston having an inner peripheral surface having an inner peripheral surface with which the piston is inserted in an oil-tight manner; a cylinder into which the piston is inserted; and a support cylinder interposed between the member to be fastened and the cylinder to support the cylinder. A hydraulic oil supply means for supplying hydraulic oil to a hydraulic chamber formed between the other end member of the cylinder and the large diameter portion of the piston, and air formed between the other end member of the cylinder and the piston An air supply means for supplying compressed air to the chamber. 2. The hydraulic oil supply means includes: a hydraulic source for supplying hydraulic oil, a flexible hydraulic hose connected to the hydraulic source, and one end of a cylinder communicating with a hydraulic chamber. A first connection port, a first pipe joint for detachably connecting the first connection port and the hydraulic hose, wherein the air supply means has an air pressure source for supplying compressed air; and has flexibility. An air hose connected to an air pressure source, a second connection port facing one end member of the cylinder and communicating with the air chamber, and a second pipe joint detachably connecting the second connection port and the air hose. The nut fastening device according to claim 1, wherein 3. A first connection port is attached to the piston, and a first connection port is inserted into one end member of the cylinder to prevent air from leaking from the air chamber to the first connection port. An insertion mark is formed in the first connection port so as to allow relative displacement of the first connection port with respect to the one end member when the hydraulic oil in the hydraulic chamber is discharged. The nut fastening device according to claim 2, characterized in that: 4. The second pipe joint communicates with the air chamber and the atmosphere when the air hose and the second connection port are in a detachable state, and connects with the air hose when the air hose and the second connection port are in an air supplyable state. The nut fastening device according to claim 2 or 3, wherein a pipe joint is used to prevent disconnection from the second connection port and cut off communication between the air chamber and the atmosphere. 5. A nut fastening method for fastening a nut by applying a predetermined tension to a bolt when fixing a plurality of members with a bolt and a nut, comprising: a large diameter portion and a small diameter portion; A piston having a step surface formed therebetween, an axis in a thickness direction, and a screw hole into which a shaft portion of the bolt is screwed, and an inner peripheral surface on which a large-diameter portion of the piston is in oil-tight sliding contact A cylindrical member having a cylindrical portion, an end member connected to one end of the cylindrical portion, and closing one end of the cylindrical portion, and an annular member formed inwardly connected to the other end of the cylindrical portion so that the small-diameter portion of the piston slides in an oil-tight manner. A cylinder into which a piston is inserted, the other end member having an inner peripheral surface in contact with the cylinder, a support cylinder interposed between the member to be fastened and the cylinder to support the cylinder, and the other end member of the cylinder and the piston To supply hydraulic oil to the hydraulic chamber formed between the large diameter part Hydraulic oil supply means, and air supply means for supplying compressed air to an air chamber formed between the other end member of the cylinder and the piston. First, the cylinder is supported until the cylinder is supported by the support cylinder. The piston inserted into the bolt is screwed to the shaft of the bolt, and then hydraulic oil is supplied to the hydraulic chamber by hydraulic oil supply means, and a predetermined tension is applied to the shaft of the bolt by hydraulic pressure to screw the shaft to the shaft. The nut is separated from the member to be fastened, and then the nut is rotated and fastened until the nut contacts the member to be fastened. Finally, compressed air is supplied to the air chamber by air supply means, and the cylinder is displaced by air pressure. Discharging the hydraulic oil from the hydraulic chamber.