RU2341372C2 - Sheet-stamping automatic press - Google Patents

Abstract

FIELD: technological processes.

SUBSTANCE: automatic press contains connecting rod, working table, die plate and die block. Drive of eccentric shaft is installed above the working table. In the working table mechanisms of stamped tape braking are fixed before and after die block. Automatic press is equipped with mechanism of control of die block closed height. Eccentric bushing is mounted on eccentric shaft journal. Concentricity of bushing is equal to concentricity of shaft journal. Bushing has the possibility of rotation depending on pitch of stamped tape supply and fixation by means of end tooth clutch. At that summary eccentricity of shaft journal and bushing changes from 0 to maximum value. Connecting rod head covers eccentric shaft through bearing. Die plate is movably installed in guides of working table and is joined to connecting rod. In the latter top part of die block is fixed.

EFFECT: higher efficiency of stamping process and simplification of press design and device for tape supply.

2 cl, 2 dwg

Description

The proposed press relates to technological equipment for stamping and can be used in the manufacture of presses for cold sheet stamping.

Sheet metal stamping presses with a lower location of the eccentric shaft drive [1] and roll feed of strips for strips of stamped material with a separate and rather complicated drive of feed rolls located before and after the stamp along the feed are widely used in industry.

The disadvantages of these presses include the complexity of the feed mechanism of the strip or tape and the limited space under the bottom plate of the press due to drive mechanisms, which does not allow the use of complex dies with rubber buffers or pillows in the press table for ejectors.

Also known are automatic machines with a floating slider [2], in which the upper part of the stamp (punch) moves along an elliptical trajectory, and the lower part of the stamp (matrix) has a reciprocating motion in the horizontal plane. As a result, the stamping operation is performed not at the moment the tape stops after each feeding step, but in the process of feeding itself when the tape is moved. This is achieved thanks to a horizontally located slider, one end of which is pivotally connected to a vertically swinging rod with adjustable thrust along the length, the other end - with an eccentric shaft with variable eccentricity, and the middle - with a slider for attaching a stamp. Moreover, the slider moves in a vertical plane along four guide columns, which are fixed at the top and bottom in the creepers moving in a horizontal plane along the guide rails of the bed. Thanks to the V-brake, the stamped tape can only be moved forward by the die punch.

These press machines have a complex connecting rod drive with large movable inertial masses, which limit productivity to hundreds of beats per minute. The dimensions of the press are increasing.

Also known rodless press machine [3], working with self-feeding material. This press machine has an upper and lower slide drive, between which a stamp is fixed. The sliders move without connecting rods directly from the eccentric shafts with variable eccentricity, which is provided by eccentric bushings, the rotation of which relative to the shafts is fixed by end cam couplings. In this press, the punch and die make a circular motion.

Despite the fact that this press provides high productivity due to low inertial masses, it has all the drawbacks of presses with a lower drive, in addition, the cantilever design of the sliders and eccentric shafts makes it difficult to obtain large pressing forces, stamping accuracy and tooling resistance. The use of dies without guide columns is difficult, and the presence of columns and bushings complicates the equipment.

Stamps must have a strictly specified and difficult to calculate closed height for each feeding step, which makes it difficult to repair such stamps by grinding the matrix and punches.

Known press machines with top drive [4], adopted as a prototype. These press machines do not differ much from ordinary connecting rod presses of non-automatic machines, with top drive of the eccentric shaft and equipped with mechanisms that automate the feeding of the tape. They differ in more rigid execution and a slight increase in the number of double moves. The tape is fed by a roll mechanism using a connecting rod, connected to a special crank with adjustable eccentricity and mounted on one end of the crankshaft or eccentric shaft. Often presses have two roll feeds before and after the stamp.

The disadvantages of these press machines include the rather complicated design of the tape feed mechanisms and the difficulty of adjusting for a given step (in addition to the variable eccentricity, the crank also has ratchet mechanisms on the rolls), which reduces the reliability of the tape feed process for a given step, there is also a need to coordinate the feed rate both roll mechanisms. In addition to the connecting rod, the presence of a slider in the pressing mechanism also increases the complexity and dimensions of the presses. The connecting rod and slider have a significant mass, which reduces the number of double strokes of the press. Productivity is low due to another important factor: the part is stamped after feeding the tape a step with a fixed strip or tape. Each stamp must have guide columns and bushings, as well as upper and lower plates with a shank (block), which complicates the design of the stamps.

The essence of this technical solution lies in the following set of essential features. A stamping press with a drive and an eccentric shaft above the work table, containing a connecting rod and a sub-stamp plate, with a stamp fixed to them, equipped with a mechanism for adjusting the closed die height by moving the work table vertically, and with stamped tape braking mechanisms on the work table before and after the stamp as well as an eccentric sleeve made with an eccentricity equal to the eccentricity of the shaft neck and mounted on the latter with the possibility of rotation depending on the pitch of the die my ribbon and fixing means of the end gear coupling for changing the total eccentricity of the shaft journal and the sleeve from zero to a maximum value. The connecting rod head covers the eccentric assembly through the bearing, and the sub-die plate is movably mounted in the guides of the working table and connected by means of guide columns to the connecting rod, on which the upper part of the die, made in the form of a package without guide columns, is fixed. In addition, the press machine is equipped with interchangeable gears to change the number of double strokes per minute, that is, the optimum stamping performance for each particular stamp.

The technical result obtained from this technical solution is as follows. The proposed stamping mechanism allows you to combine the stamping process with the simultaneous supply of stamped tape per step. The punch of the stamp extends the tape at the required step for the period of its contact with the tape. The productivity of the stamping process increases due to the combination of the stamping process during the feed of the tape at a given step, as well as due to the small mass of the connecting rod and the absence of a slider and, therefore, low inertial forces. Interchangeable drive gears, which determine the number of double strokes per minute, contribute significantly to the improvement in punching performance. Interchangeable gears allow you to select the maximum number of double strokes for each feed step, as the larger the feed pitch, the greater the inertial forces and the less the number of double strokes is acceptable for the press. Optimum gear ratios of interchangeable gears allow you to get maximum press performance for each feed step. Without interchangeable gears, the number of double strokes of the press should be selected as minimum in terms of permissible inertial forces with a maximum feed pitch. The combination of the stamping mechanism with the feed mechanism through the guide columns to the movable punch plate and the presence of brake devices greatly simplifies the tape feed device and increases the reliability of the tape feed itself during stamping.

The implementation of stamps in the form of packages (without stamp blocks, which are replaced by a slider and a movable sub-stamp plate with guide columns) greatly simplify the design of the stamps and the design of the press, because in the latter there is no slider with guides on the press frame. The nomenclature of stamps is increasing, as you can use stamp bags without blocks of any height, including with rubber pads, as well as simplify the collection of finished waste parts due to the free space under the table.

The invention is illustrated by drawings, where figure 1 shows a diagram of a stamping press, and figure 2 is a section aa.

The sheet stamping press contains a bed 1 on which the top drive of the eccentric shaft 2 is mounted. The drive consists of an electric motor 3, V-belt drive 4 and interchangeable gears 5. The eccentric shaft is made with variable eccentricity e, with values from 0 to e max, where e max = e ₁ + e ₁ = 2e ₁ .

To fulfill this condition to the eccentric shaft 2 to the eccentricity e ₁ is mounted eccentric bush 6 also with eccentricity e _1, which is rotatable and fixed in position via a gear coupling nuts 7 and 8 to change the total eccentricity. A bearing 9 and a connecting rod 10 are mounted on the eccentric sleeve, made as a whole with the upper die plate, which is movably connected with four guide columns 11 fixed in the movable sub-die plate 12 of the working table 13. The connecting rod 10, the columns 11 and the plate 12 form elements stamp, namely its upper and lower plates with guide columns, which allows to simplify the design of the stamps, using stamping bags 14. The working table 13 is equipped with a mechanism for raising and lowering 15, made in the form of four screw jacks. It is possible to use other mechanisms (gear, hydraulic). The stamped strip or tape 16 passes through two braking devices 17 located before and after the stamp 14.

Eccentric press works as follows. The electric motor 3 rotates the eccentric shaft 2 through the transmission 4 and interchangeable gears 5, while the connecting rod 10 moves in a circle whose radius is equal to the eccentricity e, and through the columns 11 reports a reciprocating movement to the die plate 12 in the guides of the working table 13. This movement, equal to 2e, is the feed pitch for the stamped material 16. Since the punch of the stamp 14 also moves in a circle in a vertical plane like the connecting rod 10, it not only stamps the material, but also moves this material by of another step in the stamping process, since in the process of moving the punch down, in the middle of its stroke, it clamps the material 16, stamps the part and, simultaneously moving in the horizontal direction, together with the stamp, pulls the material through the stationary brake devices 17 until the punch is in motion up will not mesh with the material. After that, the material is stopped by braking devices, and the stamp returns to its original position.

When setting up the press for a given material feeding step, it is necessary to unscrew the nut 8 and disengage the gear clutch 7 from the eccentric sleeve 6, which is rotated through an angle that provides the required total eccentricity, and lock it again with the nut 8. The rollers 9 with parts 6 and 10 form a bearing rolling, perceiving pressing force.

The proposed rodless press machine with top drive is distinguished by the simplicity of the design of both the press itself and its feed mechanism organically linked to the stamping mechanism, the wide possibility of using stamps of various designs, ease of use due to free space under the table, maximum productivity (speed), the ability to work not only with rolled material, but also strip.

The simplicity of the design of the press allows it to be widely used in production. Press productivity over 2000 parts per minute.

Information sources

1. Rovinsky G.N., Zolotnikov S.L. Sheet stamping mechanical presses. M.: Mechanical Engineering, 1968, p. 96.

2. Rovinsky G.N., Zolotnikov S.L. Sheet stamping mechanical presses. M.: Mechanical Engineering, 1968, p. 108.

3. Rovinsky G.N., Zolotnikov S.L. Sheet stamping mechanical presses. M.: Mechanical Engineering, 1968, p. 110.

4. Rovinsky G.N., Zolotnikov S.L. Sheet stamping mechanical presses. M .: Engineering, 1968, p. 106 (prototype).

Claims (2)

1. A stamping press with an eccentric shaft having a top drive and automatic step feed of a stampable tape comprising a connecting rod, a work table, a punch plate and a stamp, the drive of the eccentric shaft being located above the work table, characterized in that it is equipped with a closed adjustment mechanism the height of the stamp fixed on the desktop by the braking mechanisms of the stamped tape before and after the stamp and an eccentric sleeve made with an eccentricity equal to the eccentricity of the eccentric shaft journal, mounted on the latter with the possibility of rotation depending on the pitch of the stamping tape and fixed by means of an end gear coupling to change the total eccentricity of the eccentric shaft neck and eccentric sleeve from 0 to the maximum value, the connecting rod head covers the eccentric shaft through the bearing, the working table is made with guides, and the sub-die plate is movably mounted in the said guides and connected by means of the guide columns to the connecting rod on which the upper part of the stamp is fixed. 2. The press machine according to claim 1, characterized in that the eccentric shaft drive is equipped with interchangeable gears.

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