JPH02200399A - Driving device of machine press - Google Patents

Abstract

PURPOSE: To obtain a press drive apparatus capable of adjusting various drawing depths of a press tool at each case by connecting a pressure medium container to a pressure medium chamber through a releasable check valve freely flowing thereto. CONSTITUTION: A pressure point of a ram 2 is formed as a double action cylinder having a differential action piston 1. A telescope piston 6 of a telescope cylinder 5 fixed to the ram 2 is forcedly driven by a stopper 7. A pressure medium chamber 37 is connected to an upper side pressure medium chamber 3 through a releasable check valve 35 freely flowing thereto. A lower side pressure medium chamber 4 is connected to a pressure medium container 27 through a throttle valve 10 capable of cutting off corresponding to relative motion of the piston 1. The pressure medium container 27 is connected to the pressure medium chamber 37 through a releasable check valve 20 freely flowing thereto. By this method, the productivity of the press is increased.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a drive for a mechanical press for deforming sheet metal, especially at high stroke numbers.

[Conventional technology]

Driving a mechanical press in such a way that the speed of the ram can be adapted to the technical conditions in a given stroke range by means of a two-stage transmission arranged between the drive and the ram and consisting of a non-load transmission and a loaded transmission. The device is based on DD-WP Patent No. 2
This method is known from Japanese Patent No. 20487. The load transmission is designed as a cam coupling transmission and consists of a crank connected to a drive shaft and a two-piece sliding connecting rod. Both parts of the tN-motion link are supported telescopically relative to each other so as to be movable in the longitudinal direction, and are supported in contact with a cam link consisting of two cam parts that roll against each other during the operating process. .

In the case of this known method, due to the stiff movement course,
The problem is that it cannot be adapted to the particular drawing depth of the product to be manufactured, and that the cam coupling gear requires expensive mechanical parts, so that its production costs are very high.

[Problem to be solved by the invention]

The purpose of the present invention is to improve the quality of the workpiece, reduce the noise during deformation processing, and thereby increase the number of press strokes and increase the production volume.

The problem of the present invention is to reduce the cost as much as possible when the press tool closes at a high number of strokes, and the surface collision speed is small. It is an object of the present invention to provide a press drive device which can be adapted to various drawing depths of the respective press tools.

[Means to solve the problem]

According to the present invention, the problem to be solved by the present invention is to provide a drive device that converts the rotary motion of the NA# wheel into linear interlocking motion of the ram, and its transmission function during a predetermined process of the ram stroke. #j for deforming sheet metal especially at high stroke numbers with a second kinematic system that is 1! In the drives of A-mechanical presses, the pressure point of the ram is designed as a double-acting working cylinder with a differential piston, and the telescopic piston of the telescopic cylinder, which is arranged specifically fixedly on the ram of the press drive, is located at the stopper end. The pressure medium chamber of the telescopic cylinder can be driven forcibly by means of a height-adjustably connected stopper into the upper pressure medium chamber of the ram and freely towards this upper pressure medium chamber! The lower pressure medium chamber of the ram is connected to the pressure medium container via a releasable throttle valve that changes in response to the relative movement of the differential piston, and An advantageous embodiment of the invention is achieved in that the pressure medium container is connected to the pressure medium chamber of the telescopic cylinder via a releasable check valve through which flow can flow freely towards the pressure medium chamber. It is stated in claim 2.

The present invention can also be used in cutting presses.

〔Example〕

The present invention will be described in detail below with reference to the embodiments shown in FIGS. 1 to 4.

The hybrid drive system will be described in terms of its ram stroke operating cycle. In that case, the starting position is the top dead center OT of the crank drive (position 2.1 in FIG. 2).

Actuating piston l hinged to a crank drive
is in its uppermost position, the ram 2 is lowered by the distance of the working stroke 31 of the hydraulic drive, and the working piston 1, which is mechanically in contact with the working piston l in the upper pressure medium chamber 3, is in the differential position. It is designed as a piston and has a small-area upper pressure-medium active surface 32 and a large-area lower pressure-medium active surface 33, which act on the lower pressure-medium chamber 3 and the lower pressure-medium chamber. It is in contact with the ram 2 via 4. Both pressure medium chambers 3.4 are connected to a pressure medium container 27. The pressure medium in the pressure medium container 27 is pressurized by air pressure, and the air pressure is applied to the pressure regulating device 2.
8 can be adjusted in various ways.

The weight of the ram 2 including the upper die 26 is balanced by a balance cylinder 30 in a known manner. A force consisting of the product of the area difference between the upper pressure medium working surface 32 and the lower pressure medium working surface 33 and the pressure inside the pressure medium container 27 is applied to the ram 2.
It acts on This places ram 2 in its mechanically limited lower position in the event of a limited range of loss of balance.
In the connecting pipe between the lower pressure medium chamber 4 and the pressure medium container 27,
Check valve 9, shutoff restrictor lO and pressure limiting valve 1
1 are arranged in parallel. Throttle valve 10 in shutoff position
, a check valve 9 which blocks the flow from the lower pressure medium chamber 4 and a pressure limiting valve 11 which acts as a safety valve when the lower pressure medium chamber 4 is in an overpressure state, reduce the pressure in the lower pressure medium chamber 4. Since the medium is confined, the working piston l and ram 2
cannot move relative to each other, the ram 2 moves downward at the speed of the working piston 1.

Fixedly connected to the ram 2 is a telescopic cylinder 5 with a telescopic piston 6 that can be moved in the direction of the kinematic force of the ram 2. The stopper rod 8 with the stopper 7 is
A ram 2 is placed in a restraining cylinder 12 connected to a press frame.
A telescopic piston 6 is connected to the gap in which the piston moves forward so as to be driven by the stone puff. The stopper rod 8 is supported in a restraining cylinder 12 so as to be able to reciprocate and is pulled by a restraining piston 17 connected to the stopper rod 8 . The tension is directed against a stop 18 whose position is adjustable by means of the pressure in the pressure medium chamber 34. The pressure medium chamber 34 is connected to the pressure medium container 14, and the pressure medium in this pressure medium chamber 14 is pressurized with air pressure. The air pressure can be changed by a pressure regulator 29. Pressure medium chamber 34 and pressure medium container 14
A check valve 13 for controlling the flow from the pressure medium chamber 34, a direction control valve 15, and a restraining cylinder 1 are connected to the piping connected to the pressure medium chamber 34.
Pressure limiting valve 16 used as overpressure protection device for 2
are arranged in parallel. The pressure medium chamber 37 of the telescopic cylinder 5 is connected on the one hand to the upper pressure medium chamber 3 of the ram 2 and on the other hand to the pressure medium container 27 . Releasable check valves 20.35 in the lines between the upper pressure medium chamber 3 and the telescopic cylinder 5 and between the telescopic cylinder 5 and the pressure medium container 27 are in each case closed in the direction of the pressure medium container 27. placed and selectively acts as a release device.

The height of the stopper 7 is located in relation to the adjustment of the ram 2 and the drawing depth! It is adjusted as follows by the adjustable Stonno Moon 8. That is, when the ram 2 moves forward and the telescopic cylinder 5 including the telescopic piston 6 moves forward, the stopper 7 and the telescopic pink piston 6 come into mechanical contact immediately before the upper mold 26 collides with the workpiece 21. (Position 2, 2 in Figure 2).

Immediately before the mechanical contact between the stop 7 and the telescopic piston 6 occurs, the control cam of the press drive switches the shutoff throttle valve lO into the throttle position. The throttle characteristic of this throttle valve lO is the operating stroke 31 of the hydraulic drive device.
The drawing characteristics with respect to the zero working stroke 31, which are forcibly controlled and variably adjusted in relation to the deformation force of the press tool in each case, the number of pressing strokes and the drawing depth, are determined by the flow resistance of the pressure medium in the first half of the stroke. , and then increases gradually until the working piston l and the stopper piston I9 come into contact with each other.

Stop piston 19 is operatively connected to a hydraulic overload protection device 36 . When the stator cylinder and the telescopic piston 6 start contacting each other, the ram 2 advances further by -I, and when the releasable check valve 20 is closed, pressure medium flows from the telescopic cylinder 5 into the upper pressure medium chamber 3. The ram 2 is pushed out, thereby lifting the ram 2 relative to the working piston 1. In that case, the difference between the forward speed of the working piston l and the backward speed of the ram 2 becomes the effective collision speed between the upper die 26 and the workpiece 21.

The telescopic pink piston 6, depending on its number of stages, increases the volumetric flow sufficiently continuously and thereby changes the speed of the ram 2 accordingly. This telescopic piston 6 ensures a position- and time-related volumetric flow.

This volumetric flow is independent of the number of press strokes and drawing depth.
It has a constant ratio to the respective ram speed. With the advancing ram 2 itself acting as the drive for its return stroke, the determination of the impact velocity is limited only by the position of the stonpuff.

After the upper mold 26 collides with the workpiece 21 ((Q72 in Fig. 2)
．． 3) Cushion force is applied to the press rod 23 and die plate 22
, act against the ram 2 moving forward via the workpiece 21 and the upper die 26. From this point on, the ram 2 is braked. The ram 2 has previously been accelerated in the return stroke direction by the telescopic piston 6 towards the working piston 1 .

The cushioning force is used as a driving force for the continued stroke movement of the working piston 1 and the ram 2. The pressure in the lower pressure medium chamber 4 determines the volumetric flow of pressure medium from the throttle valve lO to the pressure medium container 27 as a function of the instantaneous opening degree of the shutoff throttle valve 1o, thereby determining the approaching actuation. Determine the speed of the piston l and the stopper piston 19.

The ram 2 remains temporarily stationary until the ram force as the product of the pressure in the lower pressure medium chamber 4 and the lower pressure medium working surface 33 exceeds the cushion force. After that, the workpiece 21 provided between the upper die 26 and the Goui plate 22 is spaced from the IE ejection start point and the deformation start point! Move further by 25 (second
Figure position 2.4).

In addition to the cushioning forces, deformation forces now act on the ram 2 as driving forces. The ram 2 remains temporarily stationary until the forces acting theoretically on the ram 2 and the lower die 24 are balanced, as in the case of the onset of the cushioning force. Thereafter, the actuating piston l and the stop piston 19 approach each other with deceleration due to the reduction in the throttle area of the shut-off throttle valve 10 until they come into mechanical contact (position 2.5 in FIG. 2). From this point on, the return stroke of the hydraulically driven ram for shock damping ends, and further ram movements are determined by the mechanical drive of the working piston 1.

When the rated pressure in the telescopic cylinder 5 is exceeded when the mechanical upper position of the telescopic pink piston 6 is reached, the directional control valve 5 is switched to the open position and the restraining piston 17 transfers the pressure medium to the pressure medium chamber 34. The position 2.6 in Fig. 2 is the bottom dead center U.
Ram 2 at T is shown.

During the ram return stroke after the bottom dead center, the pressure medium is sealed in the lower pressure medium chamber 3 by closing the check valve 35, so that relative movement between the working piston and the ram 2 occurs. However, the telescopic pink piston 6 and the arresting piston 17 are each pushed back into their starting position by the pressure in the pressure medium chamber 27.14.

During the upper stroke of the ram 2 (position 2.7 in Figure 2), the check valve 35.20 is released, so that the pressure acting on the ram 2 on the lower pressure medium acting surface 33 is reduced by the pressure medium. flows from the pressure medium container 27 via the non-return valve 9 into the lower pressure medium chamber 4, causing a loss of balance and moving the ram 2 to its lowest mechanically restricted operating position (
2.8), the ram 2 is now in the starting position for the next working stroke.

[Brief explanation of the drawing]

Figure 1 is a schematic configuration diagram of a two-point ram hybrid drive with a crank drive, and Figure 2 shows the movement stroke of the hydraulic drive depending on the crank position of the press drive in relation to the press tool. Figure 3 is a diagram showing the progress of the stroke distance and speed of the ram according to the crank position of the press drive device, and Figure 4 is an enlarged detailed view of parts A and 8 in Figure 3. be. l Differential piston 2 Ram 3 Upper pressure medium chamber 4 Lower pressure medium chamber 5 Telescopic cylinder 6 Telescopic pink piston 7 Stopper 8 Stone barondo 0 Throttle valve 7 Restraint piston O check valve 7 Pressure medium container 5 Check valve 7 Pressure medium chamber Appearing agent Mr. Sato - Continued from page 1 @ Inventors 0 0 0 0 0 0 0 Bieland, Peter Rolf, Zeidler Raimund, Albert Neugebauer, Waurziniakmanfred, Karla Ezi Kutreet, Kraben, German Democratic Republic of Erfurt, SE, 9/14 German Democratic Republic - German Democratic Republic - European Union, 26 German Democratic Republic - German Democratic Republic of Erfurt, SE, 50/3 German Democratic Republic - German Democratic Republic of Erfurt, Pirniusser, Stra- Brager, Strasse,

Claims (1)

[Claims] 1. A particularly high-speed motor system comprising a drive device that converts the rotational motion of the drive wheels into linear motion of the ram, and a second motion system whose transmission function is superimposed during a predetermined course of the ram stroke. In the drive of a mechanical press for deforming sheet metal in a number of strokes, - the pressure point of the ram (2) is configured as a double-acting working cylinder with a differential piston (1), and the ram (2) of the press drive ), the telescopic piston (6) of the telescopic cylinder (5), which is arranged in particular fixedly on the stopper (
7), - the pressure medium chamber (37) of the telescopic cylinder (5);
is connected to the upper pressure medium chamber (3) of the ram (2) via a releasable check valve (35) through which flow can flow freely towards this upper pressure medium chamber (3), - the ram (2) The lower pressure medium chamber (4) of the isolating throttle valve (
10) to a pressure medium container (27), said pressure medium container (27) being free to flow through the pressure medium chamber (37) of the telescopic cylinder (5) towards the pressure medium chamber (37); Releasable check valve (20)
A drive device for a mechanical press, characterized in that: 2. Stopper rod of telescopic piston (6) (
8) is supported in a reciprocating manner by a restraining piston (17) on a restraining cylinder (12) arranged on the press frame and is operatively connected to a position adjustable stop (18). Item 1. A drive device for a mechanical press according to item 1.