JPS6226973B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a strap cutting head, and more particularly to a strap cutting head that automatically and reliably cuts straps tied tightly or loosely to objects with uneven surfaces. Regarding the head.

(Prior art and problems) Conventionally, straps have been cut manually using scissors or wedges. It is necessary to insert it between objects, and in doing so, it is unavoidable to damage the objects to be bound. Moreover, these operations are often carried out on poor footing, which poses safety problems, and the operations themselves are extremely inefficient, and at the same time extremely painful for the workers.

In order to solve these problems, several strap cutting devices have been proposed. For example, as described in the specification of Japanese Patent Publication No. 53-87898, a wedge type cutting edge is inserted between the strap and the object to be bound at an oblique angle by a hydraulic cylinder, and as described in the specification of Japanese Utility Model Publication No. 52-25518, There is a type in which a flat blade is rolled down perpendicular to the strap. There are also some that apply vibration to the wedge-shaped cutting edge when inserting it. However, these types have the disadvantage that the objects to be bound are inevitably damaged and the product yield is unavoidably reduced.

Furthermore, with conventional devices, the strap may not be cut reliably, and there are many cases where the strap is not cut within the travel stroke of the cutting edge. Furthermore, there was a problem in that the cutting end timing was inaccurate and the safety of surrounding workers could not be ensured. In addition, vibration-type cutting devices inevitably generate noise. In addition, the conventional apparatus had to be large in size, and therefore it had to be difficult to arrange the apparatus.

In addition, since it was not possible to self-detect the straps, depending on the size of the objects to be bound, differences in shape, binding position, and number of straps, the operator must visually confirm the position of the straps and place the cutting edge at that position. It was necessary to make it match. Therefore, it is not possible to automatically cut a plurality of binding straps in sequence.

In view of this, the original inventor has made various efforts, studies,
As a result of experiments, it was found that the problem could be solved by employing a device that incorporates a mechanism that uses a rotating blade and senses the presence of the strap itself and cuts only the strap using the rotary blade.

The strap cutting device of the type in which the rotary blade is driven by pressure without being particularly driven is as already proposed by the applicant (Japanese Patent Application No.
54-5809).

However, as further studies were carried out at the practical stage, it was found that the non-driven rotary blade was somewhat insufficient for the purpose of reliably cutting the straps without damaging the objects to be bound. That is,
If a relatively soft strap is tied to a highly rigid object, less pressure is applied to the rotary blade, and the surface of the object will not be damaged after cutting. When a relatively hard strap is tied to an object with relatively low rigidity, the pressure of the rotating blade will inevitably increase, and as a result, there is a tendency to cause some damage to the surface of the object. A problem arose.

As a result of various studies to solve the above-mentioned problems, the inventors of the present invention discovered that by driving the rotary blade itself as a milling cutter or rotary grindstone, the pressure applied to the rotary blade can be significantly reduced. We have already proposed this device.

However, all of the conventional strap automatic cutting devices described so far are intended only for cases where the strap is tightly tied to the object to be tied, and if the strap is loose, the strap and the object to be tied are separated. There was no frictional force between the objects, and the strap was pushed and moved by the nails, making it difficult or impossible to cut.

This state of loose straps may occur due to thermal contraction of the hot-rolled coil, for example, if the hot-rolled coil is tied immediately after being rolled up at a temperature of 600 to 800°C and then allowed to cool naturally. ,
In addition, it may also occur in cold-rolled coils due to vibrations, shocks, etc. during transportation, and the reality is that there are surprisingly many cases of this happening.

On the other hand, when the surface of the object to be bound is smooth, the conventional strap automatic cutting device can sufficiently detect the edge of the binding strap with its claws and automatically cut the strap reliably. In the case of objects to be bound that have severe irregularities, such as the end of a hot-rolled coil with a relatively poor shape, the claws cannot engage with the edge of the strap, and the detection and cutting of the strap often fails.

(Object of the Invention) An object of the present invention is to be able to reliably and automatically cut binding straps that are tightly or loosely tied to objects with uneven and uneven surfaces, without causing any damage to the objects. The object of the present invention is to provide a cutting head that forms a main part of a strap cutting device.

(Structure of the Invention) Therefore, the present inventors developed a cutting head mechanism that is equipped with a lower blade whose tip only slides in contact with the surface of the object to be bound, and when the strap is scooped up, the upper blade descends to cut the strap. Through research, they discovered that by using a movable saw blade or other type of strap stopper, it is possible to reliably automatically cut not only tight binding straps but also loose binding straps, leading to the completion of the present invention. .

According to the present invention, the lower blade has one end pivotally attached to the lower part of the sliding member and the other end pressurized by the surface of the object to be bound, which is biased by its own weight or an elastic body, and is lowered by being pressurized by a fluid pressure cylinder. , comprising an upper blade that engages with the lower blade to cut the binding strap, and includes the sliding member that is movable along the surface of the object to be bound in the width direction of the binding strap by a moving mechanism. A strap cutting head is provided.

The present invention will be explained in detail below using Examples.

FIG. 1 is an overall perspective view showing a strap cutting device including an embodiment of the present invention. In FIG. 1, a coil 2 whose outer periphery is tied with a strap 1 is conveyed to a cutting device 4 by conveyors 3, 3.
The cutting device 4 includes a machine frame 5, a hydraulic cylinder 6 mounted vertically on the machine frame, and two guide rods 8 that are vertically slidable by bearings 7, 7 fixed to the machine frame. , 8, a piston rod 9 of the hydraulic cylinder 6, and a strap cutting head 10 which is attached to the tips of the two guide rods and is movable up and down perpendicular to the coil surface.

FIG. 2 shows that the strap cutting head 10 is connected to the coil 2.
It is a front view showing a state in which the frame 11 is in contact with the surface of the frame 11, and a shock absorber 12 made of wood or a synthetic resin such as hard nylon is attached to both legs of the bottom surface of the frame 11, except for the strap stopper attachment range which will be described later. There is.

Further, a strap stopper 5 having a plurality of swing stopper claws 19 is provided at the center of the bottom surface of the frame 11.
0 is attached.

FIG. 3 is a cross-sectional view of FIG. 2, showing the internal structure of the strap cutting head 10. In FIG. 3, a sliding member 20 is provided inside the frame 11 and is moved in the front-rear direction by means of a ball screw 14 and ball nuts 16, 16. As shown in FIG. The ball screw 14 is rotatably supported at both ends by ball bearings 15, 15, and the shaft end is connected to the air motor 1.
It is connected to 3. The sliding member 20 has running wheels 21, 21, 21, 21, and is movable in the horizontal direction guided by rails 17, 17 attached to the inner wall of the frame 11, but is fixed in the vertical direction. has been done.

FIG. 4 is a cross-sectional view along the line 2 of FIG. 2, showing a cross section of the strap cutting head 10.

Cushioning bodies 12 and 1 are provided on both legs of the bottom of the frame 11.
A strap stopper 50 consisting of two and a plurality of swing stop claws 19 is attached. frame 1
Rails 17, 17 are fixed to both sides of the inner wall of 1. Running wheels 21, 21, 21, 21 are attached to both sides of the casing 22 of the sliding member 20, and the sliding member 20 is attached to the rails 17, 17.
guided by. The buffers 12, 12 serve to soften the shock when the cutting head 10 contacts the surface of the coil 2, and also to determine the heightwise position of the strap cutting head 10 relative to the surface of the coil 2.

A cylinder 26 is attached to the upper part of the casing 22. Further, inside the casing 22 there is an elevator 23 having an inverted U-shaped cross section, and is fixed to the lower end of the piston 27 of the cylinder 26 . The elevator has lifting guide wheels 24, 2.
4, 24, 24 are attached, and the inside of the casing 22 can be moved up and down by the working stroke of the piston 27. Also, elevator 23
A knife mount 25 is attached to the lower part of the blade. An upper blade 30 and a lower blade guide 29 are attached to the blade mount 25 with bolts 31 so as to hold the blade mount 25 from both sides.

FIG. 5 is a sectional view of the sliding member 20. In FIG. 5, a wedge-shaped lower blade 32 is pivotally mounted at its rear end by a pin 33. Further, the lower blade 32 is always pressed downward by a ram 38 biased by a spring 39, so that the tip of the lower blade 32 is always in contact with the coil surface with the pin 33 as the center of rotation. It is pressed downward.

A strap detection dog 3 is provided inside the lower blade 32.
4 is installed. The dog 34 has an elongated hole and can slide against the lower blade 32 by means of pins 35 and 36. Further, the dog 34 is always pressed in the direction of the cutting edge with respect to the lower blade 32 by the spring 37, and is positioned in front of the lower blade 32. A limit switch 40 is attached to the rear of the blade mount 25, and the dog 34 is pushed back by the edge of the strap to operate the limit switch lever.

FIG. 6 is a partially sectional front view of the strap stopper 50 described above. A plurality of swing stop claws 19 are swingably supported on the support member 42 by pins 18, respectively. The swing stop pawl 19 is always given a force in the upright direction by a torsion helical spring 41.

That is, the upper end of the swing stop claw 19 is pivotally connected to the support member 42 by a pin 18, and the lower end of the swing stop claw 19 is connected to the surface of the coil 2 by a metal torsion helical spring 41. It is biased so that it comes into pressure contact with the And similar swing stop claw 19
There are one pair on the left and right, and many pairs are arranged.
That is, the strap stopper, which is a part of the device of the present invention, is composed of a plurality of pairs of swing stop claws 19, pins 18, springs 41, and support members 42, and is attached to the lower part of the frame 11 with a mounting bolt 49. It is fixed. Generally, at this stage, the strap 1 has not yet engaged with the lower end of the swing stopper 19. The swing stop claws 19 are inclined at different angles according to the unevenness of the surface of the coil 2, and their lower ends are in pressure contact with the coil surface.

Inside the strap cutting head 10, the tip of the wedge-shaped lower blade 32 provided at the bottom of the elevator 23 of the sliding member 20 that moves in the width direction of the strap slides along the coil surface and comes into contact with the loose strap 1. Then, the strap 1 is pushed by the lower blade 32 and moves to the left in FIG. 5, but when one end of the strap 1 reaches and engages the swing stop claw 19, the swing stop claw 19 moves upward. Since it is not possible to do so, the coil surface is pressed down even more strongly and the movement of the strap 1 is strongly blocked. FIG. 7 is a partial front sectional view of the main part of the sliding member showing this state. Therefore, the lower blade 32
The tip of the strap 1 enters the underside of the strap 1 and lifts the strap 1 onto the upper surface of the wedge. Thereafter, the upper blade 30 descends and the strap is cut.

Further details of these operations are as follows. First, in FIG. 3, when compressed air is supplied to the air motor 13 and the air motor rotates, the ball screw 14 rotates and the ball nuts 16, 16 are rotated.
moves the sliding member 20 forward in the direction of the arrow.

At this time, the tip of the lower blade 32 slides on the coil surface while swinging somewhat depending on the unevenness of the coil surface.

Next, as shown in FIG. 5, when the tip of the lower blade 32 hits the edge of the strap 1 tied to the surface of the coil 2, a horizontal movement resistance force is applied to the tip of the lower blade 32. The tip of the strap can easily slip under the strap 1.

When the lower blade 32 moves further forward, the lower blade 32 is inserted between the surfaces of the strap 1 and the coil 2 and lifts the strap 1, as shown in FIG. 7, which is a sectional view of the main part of the sliding member.

As the lower blade 32 moves further forward, the strap 1 is completely scooped up above the lower blade 32, as shown in FIG. ) to move along. At this time, the edge of the strap 1 comes into contact with the dog 34, and the compression spring 3
7, the dog 34 is moved back as far as the elongated hole of the dog 34 and the pin 35 allow. As a result, the rear end of the dog 34 actuates the lever of the limit switch 40 and issues a "strap detection signal".

The "strap detection signal" of the limit switch 40 activates the control circuit, switches the solenoid valve that operates the air cylinder piston 27 of the sliding member 20, and as shown in FIG. 9, which is a cross-sectional view of the entire sliding member, the piston 27 downwards. The downward movement of the piston 27 lowers the elevator 23 fixed to the piston 27, the cutter mount 25 fixed to the elevator 23, and the upper blade 30 and lower blade guide 29 attached to the cutter mount 25. This downward stroke is regulated by the lower surfaces of the upper blade 30 and lower blade guide 29 reaching the surface of the coil 2 before the piston 27 of the cylinder 26 reaches the stroke end.

In addition, this downward movement vertically pushes down the pin 33 fixed to the upper blade 30 and the lower blade guide 29, while the tip of the lower blade 32 is pushed down by the surface of the coil 2.
Since the lower blade 32 is relatively pushed up from below, the lower blade 32 eventually rotates clockwise around the pin 33 and performs a scissor-like shearing motion with the upper blade 30.

That is, as shown in FIGS. 10, 11, and 12, which are diagrams showing the operation of the sliding member, the strap 1 is sheared and separated between the upper blade 30 and the lower blade 32.

When the strap cutting operation is completed by the above operation, the piston 27 is raised by the action of a limit switch or a timer (not shown), and returns to the state shown in FIG. 3.

Note that if multiple straps are tied to the same object, these straps can be cut in succession, or two or three straps can be cut by changing the size of the upper and lower blades. It is also possible to cut at the same time.

In addition, the air motor 13 in the above embodiment may be an electric motor or a hydraulic motor, the entire horizontal movement mechanism for the sliding member may be a combination of a hydraulic cylinder mechanism or a chain link mechanism, or a vertical lowering mechanism may be used. It goes without saying that the air cylinder 26 (in this embodiment) can also be replaced with other mechanical mechanisms.

(Effects of the Invention) By carrying out the present invention detailed above, all the objects of the present invention can be achieved and the following effects can be obtained. That is, (1) it is possible to reliably and automatically cut binding straps that are tied tightly or loosely to objects that have an uneven, uneven surface;

(2) Multiple binding straps can be cut sequentially or almost simultaneously.

(3) Hardly scratches the surface of objects to be bound.

[Brief explanation of the drawing]

Fig. 1 is an overall perspective view of a strap cutting device including an embodiment of the present invention, Fig. 2 is a front view of a cutting head which is an embodiment of the present invention, Fig. 3 is a cross-sectional view taken along the line -' of Fig. 2, and Fig. 4 2 is a sectional view along the line 2, FIG. 5 is an overall sectional view of the sliding member, FIG. 6 is a partially sectional front view of the strap stopper, and FIG. 7 is a partial front sectional view of the main part of the sliding member. , FIG. 8 is a sectional view of the main part of the sliding member, FIG. 9 is a sectional view of the entire sliding member, and FIGS. 10, 11, and 12 are front views showing the operation of the main part of the sliding member. . 1... Strap, 2... Coil, 3... Conveyor,
4... Cutting device, 5... Machine frame, 6... Fluid pressure cylinder,
7... Bearing, 8... Guide rod, 9... Piston rod, 1
0... Strap cutting head, 11... Frame, 1
2...Buffer, 13...Air motor, 14...Ball screw, 15...Ball bearing, 16...Ball nut, 17...
Rail, 18...pin, 19...swing stop claw, 20...
sliding member, 21... running wheel, 22... casing,
23...Elevator, 24...Elevating guide wheel, 25...Cutter mount, 26...Air cylinder, 27...Piston, 28...Spacer, 29...Lower blade guide, 30...
Upper blade, 31... Bolt, 32... Lower blade, 33... Pin,
34... Dog, 35... Pin, 36... Pin, 37... Spring, 38... Ram, 39... Spring, 40... Limit switch, 41... Torsion spiral spring, 42... Support member, 49... Bolt, 50... Strap stopper.

Claims (1)

[Claims] 1. A lower blade whose one end is pivotally attached to the lower part of the sliding member and whose other end is pressed against the surface of the object to be bound by being biased by its own weight or an elastic body, and which is pressurized by a fluid pressure cylinder. an upper blade that descends and engages with the lower blade to cut the binding strap, and the sliding member is movable along the surface of the object to be bound in the width direction of the binding strap by a moving mechanism. A strap cutting head characterized by comprising: 2. The strap cutting head according to claim 1, wherein said moving mechanism comprises an air motor, a ball screw, a rail, and wheels.