RU2135333C1 - Sheet material cutting shears - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: sheet material is fed into shears between moving and immovable blades when carriage is in upper initial position. In this case hydraulic cylinder piston is in extreme left-hand position. When pressure is supplied into head end of hydraulic cylinder 20 system consisting of two main and two auxiliary levers turns. Moving blade is lowered relative to lower immovable blade, thereby cutting the sheet material. When pressure is supplied into rod end of hydraulic cylinder 20 system of levers turns in opposite direction, and carriage with blade is returned to upper initial position. Eccentric shaft 21 is used for changing the clearance between blades. In this case, hydraulic cylinder is shifted to the left or to the right and carriage is lifted or lowered through system of levers. After required clearance between blades is set eccentric shaft 21 is fixed by tightening of nut to prevent it from turning. EFFECT: increased process capabilities. 5 dwg

Description

 The invention relates to the cutting of sheet material, including metal, and can be used in procurement workshops of engineering enterprises.

 Known scissors for cutting sheet material containing a bed with a lower fixed knife, in the bores of which an eccentric shaft is mounted, which is connected by connecting rods to a support carrying a movable knife (see copyright certificate N 1393552, MKI B 23 D 15/04, 1988 )

 However, to rotate the eccentric shaft, in order to carry out the cutting process, it is necessary to use two hydraulic cylinders, the sequential operation of which is provided by an additional synchronizing device.

 In addition, to balance the mass of the caliper, two additional hydraulic cylinders are required.

 Also known are guillotine shears for cutting sheet material, comprising a bed, a knife rigidly mounted on it with a straight cutting edge, a movable support with a knife fixed to it with a straight cutting edge, located at an angle to the cutting edge of the fixed knife, and a drive mechanism of the movable support two main and two additional levers (see USSR author's certificate N 745605, B 23 D 15/14, 07/10/80) - prototype.

 However, this design of scissors does not provide for a change in the vertical clearance between the knives, which must be changed due to regrinding of the knives or changes in the thickness of the material being cut.

 The technical effect of the invention is the ability to change the vertical clearance between the knives.

 To achieve this effect, in shears for cutting sheet material containing a bed with a knife rigidly mounted on it with a straight cutting edge, a movable support with a knife fixed to it with a straight cutting edge, located at an angle to the cutting edge of the fixed knife, and the drive mechanism of the movable support in the form of a hydraulic cylinder, two main and two additional levers, according to the invention, the scissors are equipped with a synchronizing rod and an eccentric shaft with a mechanism for fixing it against rotation, a bed made with supports, the hydraulic cylinder is pivotally mounted on an eccentric shaft, the latter is placed on the indicated supports, while the main levers are installed parallel to one another, and the additional levers are connected by a synchronizing rod and form an articulated parallelogram.

 The parallel arrangement of the main levers of the drive mechanism to each other leads to the fact that the caliper carrying the movable knife performs a rectilinear movement. The use of an eccentric shaft, on which the hydraulic cylinder is mounted, allows you to adjust the vertical clearance between the movable and fixed knives, which must be changed when cutting sheet material of different thicknesses and when grinding knives on the front surfaces.

 The invention is illustrated by drawings. In FIG. 1 shows a general view of shears for cutting sheet material; in FIG. 2 - section along aa; in FIG. 3 - section along BB; in FIG. 4 is a section along BB; in FIG. 5 - section along G-G.

 Scissors for cutting sheet material contain a frame 1 with a knife 2 having a straight cutting edge 3, a caliper 4 with a knife 5 having also a straight cutting edge 6, levers 7, 8, 9, 10, which are interconnected by a synchronizing rod 11, hinges 12 and 13 in such a way that the main levers 8 and 9 are parallel to each other (Fig. 1). The hinges 14 and 15 of the additional levers 7 and 10 are fixed in the frame 1 (Fig. 2 and 5). The hinges 16 and 17 connect the additional levers 7 and 10 with the main levers 8 and 9, and the hinge 18 - the rod 19 of the hydraulic cylinder 20 with the additional lever 10 (Fig. 5). The eye of the hydraulic cylinder 20 is pivotally mounted on an eccentric shaft 21, which is mounted to rotate in supports on the frame 1 (Fig. 4). The lever 22 with one end is rigidly connected to the eccentric shaft 21, and the other with a screw 23, which can be moved in the arcuate recess 24 of the frame 1. The nut 25 serves to fix the lever 22 in a certain position. The main levers 8 and 9 with hinges 26 and 27 are connected to the caliper 4. The hinged connection of the main lever 8 with the caliper 4 and the additional lever 7 is similar to the hinged connection of the main lever 9 with the caliper 4 and the additional lever 10 (Fig. 3). The support 4 has the ability to make a rectilinear vertical movement relative to the lower knife 2 from the hydraulic cylinder 20. In this case, the additional levers 7 and 10, the rod 11 and part of the frame 1 with hinges 12-15 form a parallelogram, and therefore the rod 11 during the rotation of the levers 7, 8, 9, 10 always remains in a horizontal position. To move the caliper 4 in the frame 1 of the scissors installed guides 28, 29.

 The device operates as follows. The sheet material is fed into the scissors between the knives 2 and 5 when the caliper 4 is in the upper initial position, while the piston of the hydraulic cylinder 20 is in the extreme left position. When applying pressure to the piston cavity of the hydraulic cylinder 20, the lever system 7, 8, 9, 10 rotates, while the knife 5 is lowered relative to the lower knife 2 and cuts the sheet material. When applying pressure to the rod cavity of the hydraulic cylinder 20, the lever system 7, 8, 9, 10 rotates in the opposite direction and the caliper 4 with the knife 5 returns to its original upper position.

 The gap between the knives 2 and 3 is changed by turning the eccentric shaft 21, while the hydraulic cylinder 20 is shifted left or right and the caliper 4 is raised or lowered through the lever system 7, 8, 9, 10. After setting the required gap between the knives 2 and 3, the eccentric shaft 21 fixed from twisting by tightening nut 25.

 Tests of the proposed design of scissors showed that with a minimum stroke of the movable knife, the productivity of the cutting process can be increased by 10 percent by maintaining the necessary minimum clearance between the movable and fixed knives at different thicknesses of the processed material.

 Also significantly increases the allowance for regrinding knives. The resource of using knives increases by 2 times.

Claims (1)

 Shears for cutting sheet material, containing a bed, a rigidly mounted knife on it with a straight cutting edge, a movable support with a knife fixed to it with a straight cutting edge, located at an angle to the cutting edge of the fixed knife, and the drive mechanism of the moving support in the form of a hydraulic cylinder, two main and two additional levers, characterized in that they are equipped with a synchronizing rod and an eccentric shaft with a mechanism for fixing it against rotation, the bed is made with supports, the hydraulic cylinder hinges It is mounted on an eccentric shaft, the latter is placed on the indicated supports, while the main levers are mounted parallel to one another, and the additional levers are connected by a synchronizing rod and form an articulated parallelogram.

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