JPH0121708Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention rotates a socket to the left using a rotary drive device, and uses the socket to rotate a normal right-hand threaded nut screwed onto a horizontally placed bolt. This invention relates to a nut removal device for removing a nut from a bolt.

(Prior Art) Generally, the large end of an engine conrod is divided into two parts, the conrod main body and the conrod cap, for ease of attachment to the crankshaft. joined together. In order to facilitate the screwing operation between the bolt and the nut, a guide part extending in the axial direction is usually formed at the shaft end of the bolt, and the guide part is inserted into the center hole (threaded hole) of the nut. Natsuto is being shown around.

By the way, in the conrod assembly process for machining the conrod, the conrod main body and the conrod cap are connected with bolts and nuts and once assembled into the original shape of the conrod, and in that state, boring of the crankshaft insertion hole, etc. is carried out. After that, the nuts are removed from the bolts, separated into the connecting rod body and the connecting rod cap, and then transported to the next engine assembly process.

In such a case, as a nut removal device for automatically removing the nut from the horizontally placed bolt, a socket capable of engaging with the nut is provided on the rotating shaft of a rotational drive device such as a motor. A device in which the socket is rotated to the left by the operation of the rotary drive device, and a right-handed threaded nut engaged with the socket is rotated to the left to be removed from the bolt is widely adopted.

(Problem to be solved by the invention) However, in the above conventional device, the structure is such that the socket is simply rotated, so after the socket retreats, the nut is left behind in the guide section of the bolt, and this left behind There were problems such as nuts accidentally falling during the process, causing the process conveyance line to stop.

For this reason, in order to solve this problem, conventionally, nuts left behind in the bolt guide section are blown away and recovered by compressed air blow, but the effect is still insufficient.

The present invention has been devised in view of this point, and includes a left-handed screw-shaped guide guide in which a nut can be loosely fitted inside the socket of the above-mentioned rotary drive device, and by counterclockwise rotation of the guide guide, the bolt is tightened. A nut removal device that reliably removes and holds the nut from the bolt by continuously pulling the nut that has come off the threaded part to the outside of the bolt, thereby making it possible to reliably recover the nut. The purpose is to provide the following.

(Means for Solving the Problem) In order to achieve the above object, the solution taken by the present invention is directed to a nut removal device for removing a nut screwed onto a horizontally placed bolt from the bolt. a rotary drive device having a rotary shaft that extends on the same central axis as the shaft of the bolt and rotates to the left; a guide guide formed in a left-hand thread shape with an outer diameter smaller than the inner diameter of the screw hole and abutting the shaft end of the bolt;
It has a cylindrical shape with a longer axial length than the guide, the rear end is fitted and supported on the rotating shaft in an axially slidable and rotatable manner, and the distal end has a
A socket having an engaging portion that can be externally fitted onto a nut with an axial length equal to or longer than the distance that the nut transitions from the bolt to the guide, and a socket with the tip of the engaging portion always protruding beyond the tip of the guide. The nut is provided with a spring that urges the nut to move toward the guide, and a socket retracting cylinder that moves the socket backward against the urging force of the spring when the socket is moved to the nut guide.

(Function) Accordingly, in the present invention, the tip of the engaging portion of the socket, which rotates counterclockwise together with the rotating shaft, is externally engaged with the nut while being buffered by the spring force by the operation of the rotational drive device. As a result of this engagement between the socket and the nut, the nut retreats on the threaded portion of the bolt while rotating counterclockwise, disengages from the threaded portion, and moves to the guide guide that abuts the shaft end of the bolt. When moving to the guide, the socket retracting cylinder is operated and the socket retreats against the biasing force of the spring, and this retreat causes the engagement between the engagement portion of the socket and the nut to be released. Here, when moving to the guide for the nut, the guide is formed so that its outer diameter is smaller than the inner diameter of the threaded hole of the nut so that it can be inserted into the threaded hole with a gap in the radial direction. Because of this, the female thread (right-hand thread) of the threaded hole of the nut is inserted into the tip of the guide and is caught by the nut's own weight. Furthermore, since the guide is formed into a left-handed thread, as the guide rotates to the left,
Due to a kind of screw feeder action, the female threaded portion of the nut comes into contact with the outer periphery of the thread of the guide and moves along this thread. In this way, the nut is pulled in and held in the inner direction (rearward) of the guide.

(Example) Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIGS. 1 and 2 show an embodiment in which the present invention is applied to an engine conrod assembly process. In the figure, reference numeral 1 denotes a fixed stand, and the fixed stand 1 is installed on the side of a support stand (not shown) that supports the workpiece W (con rod), that is, on the side of the large end of the con rod. . and,
On the upper surface of the fixed table 1, there is a horizontal plate-shaped movable table 2 having a bent part 2a bent upward at the front end.
a is mounted and supported so as to be slidable in a direction toward and away from the work W on the support table, and on the movable table 2,
The tip of a piston rod 3a of a cylinder 3 for longitudinal movement installed in the same direction as the moving direction of the movable table 2 is connected to the fixed table 1, and the movable table 2 is moved in the longitudinal direction ( It is configured to move forward and backward in the direction of approaching and separating from the work W.

Two rotary drive devices 4, 4 each consisting of a motor or the like are fixed to the upper surface of the movable table 2. The rotation shafts 4a of each rotary drive device 4 are formed, for example, in a hexagonal cross section, and project in parallel to each other in front of the movable table 2 (work W side) through the bent portion 2a, and each bolt W ₃ of the work W. The two rotating shafts 4a, 4a extend on the same central axis, and the distance between the two rotating shafts 4a, _4a is the same as the distance between the nuts _W5 , _W5 (bolts) that fasten the connecting rod body W1 of the workpiece W and the connecting rod cap _W2 .
The dimensions are set to be the same as the interval between W ₃ and W ₃ ).

Further, the rotating shaft 4a of each rotational drive device 4 is provided with a socket ₅ which is externally engaged with a nut W5 of the workpiece W.
is supported. The socket 5 has a cylindrical shape having a longer axial length than a guide 6, which will be described later.
On the tip side, the inner periphery has a hexagonal cross section with an axial length equal to or longer than the _{distance that the nut W 5 moves} from the bolt W ₃ to the guide 6 when the nut W ₅ is removed, and can be externally fitted onto the nut W 5. A cylindrical engaging portion 5a is formed, and the rear end of the engaging portion 5a has a hexagonal insertion hole (not shown) through which the rotating shaft 4a is slidably but non-rotatably inserted. The circular support portions 5b are integrally arranged, and the rotation shaft 4a of the rotation drive device 4 is inserted into the engagement portion 5a through the insertion hole of the support portion 5b.
It is fitted and supported in a slidable and rotatable manner with respect to a.

Furthermore, a left-handed screw (nut W ₅ A guide guide 6 is provided, which is formed in a threaded state in the opposite direction to the formed thread, and can come into contact with the guide portion W ₄ of the bolt W ₃ . As shown in FIG. 3, the guide 6 has an outer diameter _D1 smaller than an inner diameter _D2 of the screw hole of the nut _W5 , and has no play with respect to the screw hole of the nut _W5 . It is provided so that it can be inserted with a gap (that is, it can be inserted with a gap in the radial direction). In other words, the outer diameter D ₁ of the thread on the outer periphery of the guide 6
is the inner diameter of the right-hand thread of the threaded hole of the nut _W5
Since it is smaller than D ₂ , the guide 6 can be inserted into the nut W ₅ with a gap in the radial direction without being screwed into the nut W 5 .

On the other hand, a rotary drive device 4 is provided between the circular support portion 5b of each socket 5 and the bent portion 2a of the movable base 2.
A coil spring 7 is compressed around the rotating shaft 4a, and the spring 7 is used to move the socket 5 in the forward direction of the rotating shaft 4a (the second The force is applied upward (in the figure).

Further, a socket retracting cylinder 8 extending in the front-rear direction is fixed to the upper surface of the bent portion 2a of the movable base 2, and the tip of the piston rod 8a of the socket retracting cylinder 8 is connected to the engaging portion 5a of both the sockets 5, 5. , 5a, and when the nut W ₅ moves to the guide guide 6, the sockets 5, 5 are connected to the springs 7, 7 by the contraction of the socket retracting cylinder 8. It is configured to retreat against the urging force of.

Next, to explain its operation, when it is not in operation, the cylinder 3 for forward and backward movement contracts and the movable base 2
And the rotary drive devices 4, 4 are retracted. Also,
The socket retraction cylinder 8 is in an expanded state, and therefore each socket 5 is positioned at the frontmost position with respect to the rotating shaft 4a of the rotary drive device 4 due to the biasing force of the spring 7, and the leading end of the rotating shaft 4a is guided. The guide 6 is recessed into the engaging portion 5a of the socket 5.

In this state, the bolt W ₃ of the workpiece W, which is correctly positioned and supported on the support stand, is placed horizontally.
When the rotation drive devices 4, ₄ are operated to remove the nuts W ₅ , W 5 from W ₃ , the sockets 5, 5 fitted to the rotation shafts 4a, 4a of the rotation drive devices 4, 4 so as to be relatively non-rotatable. rotates counterclockwise (in the direction of rotation shown by the arrow in FIG. 1), and the cylinder 3 for forward and backward movement is extended to move the movable base 2 and the rotary drive device 4 integrally fixed to the movable base 2.
4 moves forward, and as the rotary drive devices 4, 4 move forward, the sockets 5, 5 also move forward.

When the movable base 2 reaches the forward end position, the engaging portions 5a of the rotating sockets 5,
The tips of 5a are externally engaged with the nuts W ₅ , W ₅ of the workpiece W while being buffered by the spring force of the springs 7 , 7 , and the rotation shafts 4 a , 4 of the rotary drive devices 4 , 4 .
a The tip part, that is, the guide guides 6, 6 is the workpiece W
The bolts W ₃ and W ₃ come into contact with the guide portions W ₄ and W ₄ of the shaft portion. Then, due to the engagement between each socket 5 and the nut W ₅ , the nut W ₅ moves backward on the threaded part of the bolt W ₃ while rotating counterclockwise, and the nut W ₅ comes off from the threaded part and moves to the guide part W. Move to the guide 6 which is in contact with the _{guide 4} . When the nut W ₅ moves to the guide 6, the socket retraction cylinder 8 is activated and each socket 5 retreats against the biasing force of the spring 7, and this retreat causes the engaging portion 5 of the socket 5 to move backward.
The engagement between a and nut _W5 is released. When this nut W ₅ moves to the guide guide 6, the guide guide 6 is formed so that its outer diameter D ₁ is smaller than the inner diameter D ₂ of the screw hole of the nut W ₅ to create a radial gap in the screw hole. Since the guide 6 is provided so that it can be inserted into the guide 6, a nut _W5 is attached to the tip of the guide 6.
The female threaded part (right-hand thread) of the center hole is inserted and caught by the weight of the nut _W5 . Further, since the guide guide 6 is formed into a left-handed screw shape, as the guide guide 6 rotates to the left, the internal thread of the nut W ₅ is rotated into the guide portion of the bolt W ₃ by a kind of screw feeder action. The nut W ₅ comes into contact with the threaded outer periphery of the guide 6 via W ₄ and moves rearward along this thread. In this way, the nut W ₅ is pulled in toward the back (backward) of the guide 6 and held.

Thereafter, the cylinder 3 for forward and backward movement is contracted, and the movable base 2 and each member installed on the movable base 2 are moved backward. At this time, the nut W ₅ is pulled in and held in the inner direction of the guide 6, so the nut may be damaged due to vibration during or at the end of the retreat.
There is no risk of W ₅ falling. When the movable base 2 reaches the backward end, the socket retracting cylinder 8 stops operating, and each socket 5 moves forward relative to the rotation shaft 4a of the rotary drive device 4 by the biasing force of the spring 7, and this socket As the nut W 5 moves forward, the nut W ₅ held by the guide 6 is pushed forward and falls, and is collected in a predetermined receiving tray (not shown). As described above, the operation for removing the nuts W ₅ and W ₅ is completed, and the same operation as above is repeated for the replaced workpiece W.

Therefore, the bolt W ₃ of the work W 3 ,
Since the nuts W ₅ and W ₅ can be reliably removed and held from W ₃ , it is possible to prevent the accident of nuts falling during transportation as in the conventional case, and it is possible to improve the operating rate of the line.

In addition, in the above embodiment, the present invention was applied to the engine conrod assembly processing process, but the present invention can be applied to various other processes in which it is necessary to remove nuts from bolts. In that case, the number of rotary drive devices, sockets, etc. may be increased or decreased as required.

(Effects of the Invention) As described above, according to the nut removal device of the present invention, a horizontally placed bolt can be removed by a socket that is slidably and rotatably supported on the rotating shaft of a rotary drive device. The nuts removed from the
Since the left-hand threaded guide at the tip of the rotating shaft is pulled in and held in the inner direction, the nut can be securely removed from the bolt and held, thereby preventing the nut from falling. This prevents the conveyance line from stopping, etc., and improves the operating rate of the line.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a perspective view, FIG. 2 is a plan view, and FIG. 3 is an enlarged cross-sectional view of the main part. 4... Rotation drive device, 4a... Rotating shaft, 5...
Socket, 5a...engaging portion, 6...guiding guide,
7...Spring, 8...Socket retracting cylinder, W...Work (con rod), _W3 ...Bolt, _W5 ...Nut.

Claims (1)

[Claims for Utility Model Registration] A nut removal device for removing a nut screwed onto a horizontal bolt from the bolt, which extends on the same central axis as the shaft of the bolt and rotates to the left. A rotary drive device having a rotary shaft; and a rotary drive device provided at the tip of the rotary shaft of the rotary drive device, concentrically with the rotary shaft and formed in a left-hand thread shape with an outer diameter smaller than the inner diameter of the threaded hole of the nut, and a bolt. a guide guide that comes into contact with the shaft end of the guide; and a cylindrical shape having a longer axial length than the guide guide, the rear end of which is fitted to the rotating shaft so that it can slide in the axial direction and be rotatably driven. a socket that is supported and has an engaging portion at its tip that can be externally fitted onto the nut with an axial length equal to or longer than the distance that the nut transitions from the bolt to the guide; and a socket retracting cylinder that forces the socket to move back against the urging force of the spring when the socket is transferred to the nut guide. nut removal device.