JPS5835384Y2 - automatic cutting device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to an automatic cutting device for pipes, etc.

When cutting pipes, etc. with a grindstone, for example, compared to other cutting methods, the diameter decreases significantly due to wear of the grindstone, which is a tool, and it is difficult to maintain a constant circumferential speed. If you press the button on the deflection (unevenness) of the pipe at the beginning, it will give a big shock to the whetstone, making it easy to break.

However, even when cutting with a grindstone, if the circumferential speed and feed of the grindstone are maintained appropriately, it is possible to ensure a beautiful cross section and minimize wear and tear on the grindstone.

Conventionally, a grindstone rotated at a constant rate by a motor installed on a swingable grindstone shaft frame was pressed against an object to be cut using human power, fluid pressure, or screw feed.

In addition, the rotational speed of the grinding wheel was changed in stages according to the diameter of the grinding wheel, and the mechanical feed speed was always constant.

In such a case, the rotational speed may follow the change in the diameter of the grinding wheel, and the appropriate circumferential speed cannot be maintained, resulting in rapid wear of the grinding wheel and poor cutting surface.
It also increases costs.

Furthermore, since mechanical feeding is always at a constant speed, the grinding wheel often cracks due to deflection (unevenness) of the object to be cut, which is dangerous.

Therefore, it was necessary to rely on human power to adjust the feed by bending the object to be cut, and it was also inefficient because delicate feed adjustment was required at the beginning of cutting.

The present invention solves these drawbacks, and provides an automatic cutting device that can automate the soft start of cutting, prevent grindstone cracking due to deflection of the object to be cut, and achieve these with a simple structure. It is something to do.

An embodiment of the present invention will be described below based on the drawings.

In FIG. 1, reference numeral 1 indicates a tube to be cut, and 1a indicates a cut portion thereof.

Reference numerals 3 and 4 denote links constituting the parallel link mechanism 5, which are swung up and down by cylinders 6.6, pick up the tube 1 to be cut from the conveyance table 2, and press it against the rotary face plate 7 while lowering it, and hand it over. It is composed of

Reference numeral 8 denotes a roller supporting the tube to be cut 1 attached to the rotary face plate 7, which is rotated at low speed by a motor 9' and operates so as to sequentially cut the tube to be cut 1 from the outer periphery.

Further, the rotary face plate 7 is configured to be movable left and right in order to set the pipe length based on the position of the cutting grindstone 10.

Further, it may be configured to be able to move up and down for centering according to the diameter of the tube 1 to be cut.

Reference numeral 9 denotes an elevating frame on which a cutting whetstone 10 is installed, which is guided by four guide bars 11 and moved up and down by a cylinder 13 via a piston rod 12 connected to the frame 9.

2 and 3 show the control mechanism of the cutting wheel 10,
The grindstone 10 is attached to one end of a swinging frame 15 which is pivotally connected to the elevating frame 9 via a horizontal shaft 14, and placed on the other end to rotate the grindstone 10 via a belt 16 (FIG. 1). A balance weight 18 is provided at one end to balance the driving variable speed motor 17, so that the cutting load is always constant and acts appropriately.

That is, by setting the horizontal axis 14 as a fulcrum and creating a balanced state in which the blade is tilted toward the grinding wheel 10 rather than the variable speed motor 17 side, cutting is performed by overweighting the grinding wheel 10 side.

Reference numeral 19 denotes a cylinder interposed between the pedestal 20 installed on the elevating frame 9 and the swinging frame 15 on the side to which the grindstone 10 is attached, which operates when not cutting to lift and fix the grindstone 10. .

Reference numeral 21 denotes an elongated hole in the axial direction of the piston rod, which is provided in the connection portion between the piston rod 22 of the cylinder 19 and the swing frame 15, and is used to prevent deflection (unevenness) of the pipe 1 to be cut during cutting.
Flexibility is provided so that the grindstone 10 can escape even if there is a problem.

Reference numeral 23 denotes a movable plate attached to the lower end of a guide rod 26 that is guided in the vertical direction by a guide 25 fixed to a cover 24 of the grindstone 10, and is pivotably supported around a pin 27 within a certain range. It has a swinging arm 28.

The swinging arm 28 is formed in a rectangular shape in plan view,
A contact roller 29 is provided at the tip of one arm 28a.
is attached so that its lower end is at the same height as the lower end of the grindstone 10.

In addition, when the tip of the other arm 28b comes into contact with a stopper 30 fixed to the movable plate 23, the swinging arm 28b
is prevented from upward swinging above a certain level.

The fixed amount of rocking is set by adjusting the amount of movement of the stopper 30 depending on the pipe thickness.

Reference numeral 31 denotes a detector such as a proximity switch attached to the swing arm 28, which is adapted to detect when the grindstone 10, that is, the contact roller 29, comes into contact with the pipe to be cut 1. is configured such that the lift frame 9 stops and the lowering of the lifting frame 9 stops.

The thickness of the pipe 1 to be cut is now δ1, the distance from the position detected by the detector 31 to the pipe 1 to be cut is δ2, and the elongated hole 21
If the flexible distance is δ3, it is appropriate to set δ1+δ2<δ3.

Reference numeral 32 denotes a ratchet provided on the cover 24 so as to engage with a screw thread carved on the upper part of the guide rod 26, and the movable plate 23 moves against the contact roller 2 as the grinding wheel 10 wears.
When pushed up through the stopper 30 by 9,
It is configured to hold its position and forms a wear memory.

Reference numeral 33 denotes a probe provided at the upper end of the guide rod 26, and a position detector 34 provided on the cover 24, such as a magnetic type, a rechargeable type, a potentiometer type, or a differential transformer.
, and is configured to detect the amount of rise of the guide rod 26, that is, the amount of relative movement of the movable plate 23 with respect to the cover 24.

The variable speed motor 17 changes the rotation speed according to the output from the position detector 34, and changes the rotation speed of the grindstone 10 according to the degree of wear, so that the circumferential speed of the grindstone 10 is kept constant.

35 is a detector such as a proximity switch that detects when to replace the grindstone 10, and is operated by an arm 36 attached to the movable plate 23 when the grindstone 10 is worn down to an unusable diameter.

Next, its operation will be explained.

The rotating whetstone 10 is placed in the cylinder 1 while the pipe 1 to be cut is set on the rotating surface 7 whose position is determined according to the diameter and length, and is placed on the rollers 8 and rotates at a low speed.
3, the grinding wheel 10, ie, the contact roller 29, is lowered at a rapid forwarding speed, and the detector 31 detects this just before the grinding wheel 10, that is, the contact roller 29 comes into contact with the tube 1 to be cut, and the grinding wheel 10 stops at an interval of δ2 from the tube 1.

Next, the pressure in the cylinder 19 is released by the output of the detector 31, and in this no-load state, the swing frame 15 swings toward the grindstone 10 due to the overweight on the grindstone 10 side, and the grindstone 10 By pulling down the piston rod 22 of the cylinder 19, the tube 1 to be cut is hit while the hitting speed is controlled, and cutting is started with a constant cutting load.

At this time, the connecting part at the tip of the piston rod 22 is in contact with the upper surface of the elongated hole 21, and there is no deflection (unevenness) in the pipe during cutting.
However, due to the flexible distance δ3 of the elongated hole 21, only the grinding wheel 10 can be freely pushed upward to escape through the elongated hole 21 while leaving the connecting portion at the tip of the piston rod 22 in that position. It will be done.

Therefore, the grindstone 10 is not subjected to shock, and cracks and wear can be kept to a minimum.

Further, as the cutting progresses, the contact roller 29
When the cutting is finished, the swinging arm 28
comes to a position where the other arm 28b just hits the stopper 30.

When the diameter of the grindstone 10 becomes smaller due to wear during cutting, the other arm 28b of the swing arm 28 pushes up the stopper 30 before the cutting is finished, the movable plate 23 rises along the guide 25, and the cutting is finished. Ratchet 32 at the moment
fixes the movable plate 23 in that position via the guide rod 26, automatically corrects the lower end of the grinding wheel 10 and the lower end of the contact roller 29 when hanging down to be at the same height, and connects the grinding wheel 10 and the tube. The distance δ2 from the wall 1b before cutting is always constant.

On the other hand, the amount of rise of the guide rod 26 is limited in accordance with the amount of wear of the grinding wheel 10, and as described above, this amount of rise is determined by the amount of rise of the position detector 3.
4 and the rotational speed of the motor 17 is controlled accordingly, so that the circumferential speed of the grindstone 10 is always kept constant within the roughness of the thread pitch of the guide rod 26.

When the cutting of the tube 1 to be cut is completed, a change in the current of the motor 17 due to the no-load state is detected, and pressure is applied to the cylinder 19 to pull up the swinging frame 15 and at the same time cause the cylinder 13 to return quickly.

When the cylinder 13 stops rising, the parallel link mechanism 5 swings and moves upward upon detection, and the tube 1 to be cut is carried out from the rollers 8.

As described above, according to the present invention, cutting work that conventionally requires manual operation, monitoring, and adjustment, lacks reliability and safety, and is low in efficiency, can be cut using a constant cutting load method.
This has made it possible to automate the soft start of cutting and improve efficiency.

Furthermore, cracking of the grindstone due to deflection (unevenness) of the object to be cut can be prevented, and this can be achieved with a very simple structure using a long hole provided in the connecting portion between the cylinder and the swing frame.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, with FIG. 1 being a side view of the whole, FIG. 2 being a partially cutaway side view of the main part, and FIG. 3 being a partially sectional front view thereof. 1... Pipe to be cut, 9... Lifting frame, 10...
Rotating grindstone (cutting tool), 13... Cylinder, 14... Horizontal shaft, 15... Swinging frame, 17... Variable speed motor, 19... Cylinder, 21... Long hole, 22... ...Cylinder Rondo, 23...Movable plate, 25...Guide,
26... Guide rod, 28... Swing arm, 29
...Contact roller, 30...Stopper, 31
...Detector, 32...Ratchet, 34...Position detector.

Claims (1)

[Scope of utility model registration request] A rotary cutter is provided at one end of a swinging frame that is pivotally connected to the lifting frame via a horizontal shaft, and further a variable speed motor is placed on the other end of the swinging frame to rotationally drive the cutter, and the cutter is mounted on the swinging frame. A balance weight is provided to maintain a balance with the blade and apply an appropriate cutting load to the cutter, and a cylinder is installed to lift the swinging frame on the side where the cutter is attached to the lifting frame, and a piston of the cylinder is installed. An automatic cutting device characterized in that the rod and the swing frame are movably connected to each other via an elongated hole in the axial direction of the bistone rod.