JPS6229186B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a fastener for tightening bolts.

Conventionally, when tightening bolts and nuts using a powered fastener, a bolt with a polygonal shaft at the tip of the bolt is used, the polygonal shaft is fitted into an inner socket, and the nut is then tightened into an outer socket. It is used to firmly tighten the nut while supporting the rotational reaction force with the bolt.

However, if this fastener is tightened without sufficient engagement between the polygonal shaft at the tip of the bolt and the socket, the socket will cross the outer periphery of the bolt at the time of tightening, causing the corners of the bolt to become rounded. There were times when I ended up doing something wrong.

In order to avoid this problem, the applicant has provided the opening surfaces of the inner socket that fits into the bolt tip and the outer socket that fits into the nut at the same forward position, and the inner socket has a structure that ensures that the bolt tip is located deep inside the socket. It is equipped with a fitting detection member that detects whether the nut is completely fitted, and the movement of the detection member allows the inner socket to move to the back, thereby preventing the fitting between the outer socket and the nut. proposed something that would make it possible for the first time.
No. 36640).

In this device, even if power is applied when the inner socket and the bolt tip are not fully fitted, the outer socket will simply spin, the inner socket will not rotate, and the bolt tip will not be damaged. Although this could be prevented, it was not clear from the outside whether the outer socket was idling or whether the nut was rotating while tightening.

〔the purpose〕

The present invention switches the clutch provided between the rotary drive device and the socket using the above-mentioned engagement detection member, so that unless the bolt is securely engaged with the socket,
The purpose of the present invention is to reliably prevent tightening of a bolt and a socket in an incompletely fitted state by preventing the rotation of the rotary drive device from being transmitted to the socket.

〔composition〕

A fitting detection member 7 for detecting that a bolt is fitted into the fitting hole 51 of the tightening socket rotated by a rotary drive device is slidably exposed in the fitting hole 51 at the tip of the tightening socket. In the attachment, there is usually a clutch between the rotary drive device and the socket that connects the rotating shaft and the socket 5 by releasing the connection between the two and causing the detection member 7 to hit the bolt and be pushed backwards. 4 are deployed.

[Action and effect]

When the tip of the bolt is fitted into the socket, the detecting member 7 is pushed back by the tip and the rotating shaft 21 and the socket 5 are linked together, and when the rotary drive device is driven in this state, the socket is rotated and the bolt is tightened.

Insufficient engagement between bolt tip and socket,
Even if the rotary drive device 2 is rotated, the rotation shaft and the socket are disconnected, and the socket will not rotate.

Therefore, it is reliably prevented that the bolt is rotated while the bolt tip and the socket are not sufficiently engaged, and that the socket circumferentially extends around the outer periphery of the tip during closing, thereby rounding the corner of the tip.

The present invention will be specifically described below based on embodiments shown in the drawings.

The fastener of this embodiment is a fastener for a special bolt 9 having a tip 91 for shearing at the tip.

The fastener includes a vane type air motor 2 and an impact generating mechanism 3 driven by the motor in a housing 1, and has a downward grip portion 11 at the base end.
is installed protrudingly.

The rotation shaft 21 of the air motor 2 is opened in a cylindrical shape.

The grip part 11 has a valve switch 12 for regulating compressed air sent to the air motor 2, and a flow path (not shown) that opens the compressed air from the air hose 13 to directly send it to the cylindrical rotating shaft 21 of the motor 2. An ejecting switch 14 is provided for performing a chip ejecting operation, which will be described later.

The impact generating mechanism 3 is of a single hammer rotary type, and as is well known, the cam 3
1. Anvil 36 connected to the hammer 32, hammer pin 33, hammer case 34, and output shaft 35
It consists of

The cam 31 is connected to the rotating shaft 21 of the motor 2 via a clutch 4, which will be described later.

The air motor 2 rotates the hammer 32 via the clutch 4 and the cam 31.
The rotational force of the air motor 2 is increased several hundred times by the impact of the anvil 36, thereby rotating the anvil 36.

A polygonal through hole 38 is formed in the axis of the distal end of the anvil 36, and the air motor side of the through hole is formed as a large diameter hole 36 circumscribing the polygon.

An inner socket 5, which will be described later, is connected to an anvil 36 continuous to the output shaft 35.

As shown in FIG. 1, a cylindrical portion 15 having a threaded surface 16 formed on its outer periphery is projectingly provided at the front end of the housing 1, and an engaging protrusion 17 is formed on the distal end surface of the cylindrical portion.

A nut-engaging outer socket 6 is attached to the cylindrical portion 15.

The outer socket 6 is non-rotatably fixed to the housing 1 by a socket cap 18 which is screwed onto the cylindrical portion 15, with a groove 62 at the proximal end engaged with the protrusion 17 of the cylindrical portion 15.

An engagement hole 61 for engaging a nut is formed on the front end surface of the outer socket 6, and at the bottom of the hole there is a hole 61 at a position corresponding to the height of the nut to regulate the amount of penetration of the nut, and to control the amount of penetration of the nut into the inner socket 5, which will be described later. A stopper 63 is formed which also serves as a retainer.

There is an inner socket 5 inside the outer socket 6.
is arranged so that it can slide.

A fitting detection member 7 is connected to the inner socket 5 for detecting whether the tip 91 at the tip of the bolt 9 and the inner socket 5 are fully engaged. As will be described later, the fitting detection member 7 also serves as a switching member for the clutch 4 and a protruding member for protruding the sheared tip 91.

The fitting detection member 7 includes a detection pin 71 and a ball 7.
2, a pin spring 73, an inner socket spring 75, and an ejector pin 76.

An engagement hole 51 that engages with the polygonal shape of the bolt tip 91 is formed at the tip of the inner socket 15 with a necessary and sufficient depth, and a projecting pin 71 projects from the center of the bottom surface. The position of the tip of the protruding pin 71 is at the minimum engagement depth at which the outer polygonal shape of the tip 91 will not be destroyed even if the necessary torque is applied to the bolt tip 91, and if it goes deeper than that, it will be sufficiently safe.

The protruding pin 71 passes through the inner socket 5 from the tip toward the rear end, has a large diameter portion 71a in the middle, and is then set by being biased by a spring 73 that is prevented from coming out by a bushing 77. Axial movement is possible.

The rear end 71b of the protruding pin 71 is on the same plane as the rear end of the inner socket 5 when the bolt tip is not inserted into the inner socket 5 as shown in FIG. It is configured to protrude rearward by the amount of movement of the protruding pin 71.

The base end side of the inner socket 5 is connected to the hexagonal through hole 38 of the anvil 36 of the impact generating mechanism 3.
It is a polygonal column 52 that engages with the polygonal column 52, and is configured to be able to transmit rotation and move in the axial direction.

The inner socket 5 is biased by the inner socket spring 75 so that its end surface is always at a position slightly recessed from the outer end surface of the polygonal engagement hole 61 for nut engagement of the outer socket 6. In this state, the ball 7 is positioned at the side of the polygonal column 52 at the entrance of the anvil 36.
The hole is machined so that about 1/3 of its diameter can protrude outside.

A large diameter portion 71a of a protruding pin 71 is provided inside the inner socket 5 to prevent the ball 72 from falling into the inside. That is, the protruding pin 71
When the large diameter portion 71a of the anvil 36 is in the protruding/retracting position of the ball 72, the ball 72 always protrudes to the outside, so that the polygonal column 52 of the inner socket 5 is prevented from moving in the axial direction inside the anvil 36. There is.
That is, unless the bolt tip 91 is securely fitted into the engagement hole 51 of the inner socket 5, the inner socket 5 will not move back, and therefore the nut 92 will not fit into the outer socket 6.

Ejector pin 76 is axially movable within anvil 36.

The clutch 4 is connected to the rotating shaft 21 of the air motor 2.
Through holes 22 are formed at regular intervals, and balls 41 having a diameter larger than the wall thickness of the rotating shaft 21 are fitted into the holes 22 so as to be able to roll.

A cylindrical body 42 is slidably fitted into the rotating shaft 21. The ejector pin 76 is slidably fitted into the cylindrical body 42, and the pin 76 has a piston portion 76a at its rear end, and its tip abuts the inner socket 5.

The cylinder 42 is connected to the piston portion 76a by the spring 43.
is energized by

A groove 44 into which the ball 41 is fitted is formed in the axial direction on the outer periphery of the cylinder 42, and the length of the groove 44 is such that the tip 91 is inserted into the inner socket 5 and the nut 92 is inserted into the outer socket 6. When the inner socket 5 is retracted until it is securely engaged, the ball 41
The length is determined so that the groove 44 goes beyond the end and rides on the outer periphery of the cylindrical body 42 as shown in the lower half of FIG.

This ball 41 rides on the outer periphery of the cylinder 42, causing the groove 3 of the cam 31 of the impact generating mechanism 3 to
The ball 41 engages with the ball 1a, the rotation of the rotating shaft 21 is transmitted to the impact generating mechanism 3, and the anvil 36
rotates, thus causing the inner socket connected to the anvil to rotate.

The through hole 20 of the rotating shaft 21 of the motor 2 is filled with pressurized air that urges the piston portion 76a of the ejector pin 76 forward with a force slightly stronger than that of the ejector pin spring 43.

Next, how to use the fastener will be explained.

[Before bolt engagement]

When the bolt tip 91 is not engaged with the inner socket 5, the fitting detection member 7 is in the forward position as shown in FIG.
1 and the impact mechanism 3, thus the socket 6
The connection between them has been severed.

Even if you accidentally rotate the air motor in this state, the socket will not rotate.

The ball 41 in the lower half of the clutch 4 tries to fit into the groove 31a of the cam 31 due to its own weight, but since the ball 41 is allowed to move in the axial direction of the cylindrical body 42, the rotating shaft 21 Due to the high-speed rotation of the ball 41, the ball 41 moves inward and outward in the radial direction while
2 and does not rotate the cam 31.

[Engagement between socket and bolt]

As shown in Fig. 3, when the bolt tip 91 is engaged with the engagement hole 51 of the inner socket 5 and inserted beyond the required minimum depth, the protruding pin 71 is pushed in the axial direction against the spring 73, and its large Diameter portion 71
a moves to a position where it does not obstruct the movement of the ball 72 inside. At this time, the polygonal column 52 of the inner socket 5 becomes movable in the axial direction into the anvil 36.

As the entire fastener is continued to be pressed against the bolt, the inner socket 5 moves axially into the outer socket 6 while compressing the inner socket spring 75, and is released from the locking hole 61 for nut engagement. Back up and nut and outer socket 6
This makes it possible to engage.

During the above operation, the ejector pin 76 is pushed rearward as the detection pin 71 retreats. As a result, the cylindrical body 42 of the clutch 4 is moved rearward by the spring 43, pushing the ball 41 into the groove 31a of the cam 31 and connecting the rotating shaft 21 and the cam 31.

Next, the switch 12 is turned on to rotate the motor 2, and the bolt can be tightened via the impact generating mechanism 3 and the socket 5. During this tightening work,
The nut 92 is fitted into the outer socket 6 and is completely prevented from rotating.

[Chip shearing]

The moment the tightening torque exceeds the shearing torque of the tip 91 set by the circumferential groove 93 of the bolt 9,
The chip 91 is sheared at the circumferential groove 93 portion.

[Discharge of chips]

The fastener is removed from the bolt, and the ejection switch 14 is pressed to send compressed air from the hose directly into the through hole 20 of the rotating shaft 21.

The piston 76a is pushed forward and the ejector pin 76 and therefore the detection pin 71 are pushed forward and the chip 9 remaining in the engagement hole 51 of the inner socket 5 is pushed forward.
Hit 1.

In addition, when implementing the present invention, if the outer socket 6 is shortened by the length of the polygonal hole 61 for engaging the nut and the inner socket 5 is exposed to the outside, it can be used in a location where there is no need to prevent tail rotation. It can be used as a normal bolt tightener, and can tighten special bolts 9a as shown in FIG.

The bolt 9a has a shearing tip 91a for torque regulation protruding from the head of the bolt 9a.The tip 91a is engaged with the inner socket 5 and tightened, and the tip is tightened with a tightening torque exceeding a certain value. Shear 91a.

The bolt head is round, so once the bolt is tightened, it cannot be removed.

[Brief explanation of the drawing]

Figure 1 is a sectional view of the fastener, Figure 2 is Figure 1-
3 is a cross-sectional view of the main part with nuts and bolts properly fitted into the outer socket and inner socket, and Figure 4 is a cross-sectional view taken along the line.
FIG. 5 is a front view of another embodiment of the bolt. 2...Air motor, 4...Clutch, 5...
Inner socket, 7... Fitting detection member.

Claims (1)

[Claims] 1. A fitting detection member 7 for detecting that a bolt is fitted into the fitting hole 51 is slidably exposed in the fitting hole 51 at the tip of the tightening socket rotated by the rotational drive device. In a fastener, there is usually a connection between the rotary drive device and the socket, and the connection between the two is released, and the fitting detection member 7 hits the bolt and is pushed backward to connect the rotating shaft and the socket. A bolt tightening tool equipped with a clutch 4.