JPS5825810A - Control apparatus of carriage type drawing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for controlling carriage-type drawing machines operated at different working speeds, with a clamping device on each carriage, which clamping device serves the carriages.

Since known devices of this type operate with compressed air, they have the disadvantage that the time between switching on and clamping takes place is very long, so that the time delay has to be compensated for by special control devices. (West German Patent No. 1930700). This is particularly important when operating at different working speeds.

This time delay is noticeable in the case of carriage-type drawing machines, which operate at high speeds. For example, in known machines the time delay is 50-100 ms. As long as it is within the so-called overlap range or overlap rotation angle, the time delay itself is permissible up to 10 ms. This rotation angle is approximately 15 degrees at maximum. Known control systems, without special measures, have failed when the speed increases beyond a certain limit value. This is because the infeed from one carriage to the other was outside the overlap rotation angle, resulting in a sudden reduction and re-increase of the working speed. Damage to materials and machinery occurred. However, increasing the overlap rotation angle is not possible for technical reasons. The forward and backward curves were too sharp. Therefore, the aforementioned additional control device must be used to compensate for the switching time constant. This device accepts the feed within an overlap rotation angle. This device complicates the drawing machine. In this case, mainly electrical and electronic control means complicate the drawing machine.

Mechanical control devices (West German Patent No. 2322279, West German Patent No. 23560'46, West German Patent Publication No. 2806380, West German Patent No. 2852)
No. 492) operates with almost no time delay, but has the following drawbacks.

(a) Mechanical equipment is expensive.

(b) Especially at high speeds, parts of the device wear out due to inertial forces when hitting a stationary stop.

(C) Noise is generated due to the collision.

(d) Play occurs at pivot points and bearing points.

The object of the invention is to ensure that the clamping of the drawn material by means of a clamping device takes place within a narrow range of movement, which range lies within the abovementioned overlap range.

To solve this problem, the device according to the invention uses a directional valve and other complicating directional valves to transmit the movement of the spindle to the clamping device. No parts are required and the clamping operation of the clamping device of each carriage is reliably carried out within said narrow range.

Even if the device according to the invention is equipped with a series of valves, these valves are auxiliary valves that do not serve control.

An important advantage of the device according to the invention is that it is suitable for much faster work than the known devices.

Another advantage of the device according to the invention is that it produces low noise even when operating at high speeds.

Preferred embodiments and further embodiments of the device according to the invention are set out in patent claims 2 to 00.

An embodiment of the invention is shown in the figure. The following description relates to this example and the figures. However, this description also includes other general descriptions of the invention. Next, an example of a double carriage type drawing machine will be explained with reference to FIGS. 1 and 6.

The drawing machine 1 comprises two drawing carriages 2, 3. This reciprocating movement of the withdrawal carriage is effected by cams 4,5. This cam rotates together with the main shaft 6 which is driven by a transmission 15. Clamping jaw closing cylinder 7.8.9 on the reciprocating withdrawal carriage 2,3
opens and closes at predetermined points in the travel of the withdrawal carriage. As a result, the drawing material is continuously advanced.

The control device described here is hydraulically operated, and the main shaft 6
A control cam disc 10° 11 rotating together with the piston 13' in the cylinder 12', 12', 12'''
, 13#, 13'''.

This piston itself is connected to the clamp jaw closing cylinder 7.
To operate 8.9, pressurized liquid is forced through a partially flexible conduit.

A particular advantage of this control device is that no switching time constants occur. This switching time constant must be taken into account in the case of known control devices with switching valves and switching valves.

In the case of the control device according to the present invention described here, when increasing the drawing speed from Vmin to Vmax, for example, V
It has been shown that only very short coasting times of less than 10 m5 occur at = 150 m/min, which increases approximately proportionally.

For example, when the withdrawal speed vmax is 150 m/min and the inertia time tmax is 10 m5, the inertia distance of the withdrawal carriage is as follows.

The double stroke t of the drawing carriage is 1 m. Therefore, the angle of rotation required for the forward movement of the extraction carriages to overlap is 1.

In the case of conventional, well-known drawing machines, this oat (-wrap angle of rotation is greater than 9°) ensures that in this machine a perfect opening and closing movement of the clamping jaws is achieved. Discs 10.11 must be configured and adjusted accordingly.

Using hydraulic pressure as a control force transmission member allows operation at a pressure much higher than the limit pressure of compressed air, compared to the conventional case of mainly using compressed air.
This has the advantage that large forces can be transmitted, thereby eliminating inaccurate control due to centrifugal forces.

It has been found that the liquid located between the control cylinders 12', 12', 12'' and the clamping jaw closing cylinders 7.8.9 has sufficient pressure in practical use.

In order to fill the hydraulic system with liquid and to provide a constant supply of liquid, a hydraulic station 19 (6th
(see figure) is provided.

The clamping jaw closing force itself is not applied by this pump, but rather from a main drive motor (not shown) to the main shaft 6, cam disc 10.11 and cylinder 12', 1.
2', 12"' to the hydraulic system. Pressure reducing valve 20 regulates the filling pressure on the closing side of the system and pressure reducing valve 21 regulates the pressure on the open side of the system. Cylinder 7.8 .9 shows the position when the clamp jaw is open.

The pressure liquid reaches the cylinder 7.8.9 via the check valve 22 and holds this cylinder in a position for opening the clamping jaws. The accumulator 23 remains empty. This is because the pressure of the gas inside it overcomes it. Throttle valve 24 is substantially closed. This throttle valve serves for fluid exchange and drainage.

On the closed side of the hydraulic system, the pressure liquid passes through check valves 25°26',
26', 26#, the control cylinder 12', 121°12''' is reached, and depending on the position of the piston of this control cylinder, the preload valve 27', 27', 27 is reached from the cylinder outlet 14', 14#, 14'''. Return to the tank via #'.

Accumulator 2 B', 2 Bl, 2 B"
' is initially empty because the gas pressure overcomes it, but the accumulator 29 is filled with liquid. Furthermore,
When the closed side is in the rest position, the directional valve 30'
, 30#, 30'' are closed, so that no pressure liquid reaches the cylinders 7, J, 9. As a result, the control cylinders 12', 12# are closed during machine operation.

The clamping jaws remain open during forward and backward strokes of the 12'' piston. The pressure limiting valves 31', 31#, 31'# make the hydraulic system safe, i.e. , normally no pressure fluid flows through this pressure limiting valve to the tank of the hydraulic station.

Next, an example of the retraction process will be described with reference to FIG.

When the drawing machine is started, the drawing carriages 2 and 3 reciprocate in opposite directions. The control cam discs 1[], 11 are the cam discs 4, 5 that drive the extraction carriage 2.3.
and control cylinders 12', 12
', 12'' piston 15', 13#, 13
"" is moved forward and backward. First of all, during a forward stroke, the liquid displaced by a piston, for example piston 13, reaches the associated accumulator 28'. The curved trajectory of the cam disk 10 is controlled. As soon as liquid is allowed to enter the cylinder 12', the liquid that has entered the accumulator 28' is transferred to the control cylinder IJ.
Push the piston 13' of the x cylinder 12' again.

``The switching signal 1 retraction ON l issued by the operator only acts on the return stroke of the first withdrawal carriage 2. This is because the switch 17 (see FIG. 4) operated by the switching ring 16 rotating together with the main shaft 6 is closed only at that time. This signal switches the directional valve 30' so that system pressure is initially generated only on the piston side of the cylinder 7. This pressure still does not move the piston. Control cylinder 12 operated by control cam disc 10
Only by movement of the piston 13' in the cylinder is the cylinder outlet 14' isolated from the tank and the control cylinder 12
The liquid pushed out from the cylinder 7 flows through the directional valves 30' and 32 to the cylinder 7. This cylinder closes the retraction clamping jaws at the front dead center of the first retraction carriage 2. Thereby, the drawing material can be retracted without sudden movement during the next feeding of the drawing carriage 2. Since the amount of liquid pushed out by the piston 13' is greater than the amount of liquid that entered the cylinder 7 by the time the retraction clamp jaws closed, this remaining I overcomes the gas pressure in the accumulator 28' and flows into the accumulator 28'. flow inside. The liquid on the piston rod side of the cylinder 7 is stored in an accumulator 23.

At the end of the retraction stroke of the withdrawal carriage 2, the cam disc 10 allows a return stroke of the control piston 13';
Pressure liquid enters the control cylinder 12' from the accumulator 28' and the hydraulic station 19 via the pressure reducing valve 20.

At the latest during the return stroke of the withdrawal carriage 2, the retraction jaw releases the retracted rod. The liquid flowing back from the accumulator 23 to the cylinder 7 overcomes the pressure on the piston side and causes the piston rod to enter. The liquid on the piston side of the cylinder 7 flows into the tank via the directional valves 32, 30', the control cylinder 12' and the preload valve 27'. After the first retraction stroke has been carried out by the cylinder 7 which operates the retraction jaw, the directional valve 32 is switched over.

The above retraction process is repeated, but the liquid pushed out by the piston 13' of the control cylinder 12' flows through the directional valve 30' and the redirected directional valve 52 to the cylinder 8, which is then clamped. The only difference is that two or three retraction strokes are performed by alternately closing and opening the jaws.

After the drawing process, a continuous drawing process takes place. During retraction, the control cam disk 10 is in an adjusted position on the main shaft 6 such that the retraction stroke begins from the front dead center of the extraction carriage 2 . The control cam disc 11 must now be adjusted taking into account the overlap section. The cam disc 11, which controls the successive withdrawal process, is adjusted to rotate in the opposite direction, so that the clamping jaw closing cylinders 8, 9, which are controlled by this cam disc and are located on the withdrawal carriages 2, 6, can move in the overlapping section. The clamp jaws can be closed with the beginning.

During the above-mentioned drawing process, the drawing material is drawn in with intermittent drawing strokes by the first drawing gear ridge 2 until its starting end reaches the rear of the second drawing carriage 3 .

During the retraction of the extraction carriage 3, the above-mentioned state is maintained by the control, so that the directional valves 30', 52
is switched to its starting position and the valve 301 associated with the extraction carriage 2 and the valve 30'' associated with the extraction carriage 3 are switched on.

During the transfer of the drawn material from the first drawing carriage 2 carrying out the last drawing stroke to the second drawing carriage 3 carrying out the first drawing stroke, a shock-free feeding of the drawing material is achieved. This is because the liquid pushed out by the piston 13"' first reaches the cylinder 9 of the withdrawal carriage 3 via the directional valve 30"', and then the liquid pushed out by the piston 13# reaches the directional valve 3'OF, 32 to reach the cylinder 8 of the drawing carriage 2.

The individual functions of continuous withdrawal, which are performed alternately and repeatedly, are carried out by two control cylinders 12# and 1, which are 180 degrees opposed to each other.
2"' differs from the individual functions of the retraction process in that it is controlled by one control cam disc 11.

Cylinder 8, which controls the clamping jaws of the withdrawal carriages 2, 3 which move forward in opposite directions in an overlapping manner.
By alternately advancing and retracting 9, a continuous extraction process is achieved.

Even if the drawing machine continues to operate, interruption of the drawing process is
This is achieved by switching the directional valves 30# and 30'' to their original positions.

FIG. 5 shows an example in which a plurality of control cylinders are arranged radially around a control cam disk. For functional or space reasons, the control cam discs can also be provided next to individually adjustable control cam discs.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of a double-carriage drawing machine equipped with a first drawing carriage, a second drawing carriage and a part of the control device according to the invention, with the front side wall removed; , FIG. 2 shows the individual control cylinders with control cam discs for the retraction function or of a discontinuously operating single-carriage drawing machine, which is not described here. 6 is a cross-sectional view taken along the line -■ of FIG. 4 shows a switching cam with a switch; sectional view along the TV--TV line of FIG. 1; FIG. , a modification of FIGS. 2 and 3, in which three control cylinders are connected with a control cam disk offset by 120 degrees, and FIG. 6 shows a double-carriage drawing machine for the control device according to the invention. FIG. Symbol 6 in the figure...Main shaft 7.8, 9...Conflict...Operation cylinder 10 N
−−−−−−φ control cam disc 12@・・・・・・・・・
・Pressure cylinder 12', 12#, 12#'...Pressure cylinder 13・
...■...O・Piston 13', 13', 13#...Piston 14...O■
...Outlet 16.0...Switching ring 17...Switch 19...Hydraulic pressure station 20.21
・・・・・・■・Pressure reducing valve 22.25.26-・・・Check valve 23, 28, 29--L・Storage container 27...
... Outflow prevention means 30', 301, 30'"・
... Directional switching valve 31 ...... Pressure limiting valve FIG, I FIG, 2 FI13

Claims (1)

[Claims] (1) In a device for controlling a carriage-type drawing machine in which each carriage is provided with a clamping device, and the clamping device is operated at different working speeds to achieve a predetermined narrowing of the carriage. , a device characterized by low compressibility and low flow resistance for transmitting the movement of the main shaft (6) to the clamping device. (2) The device according to claim 1, characterized in that elastic means are provided for opening the clamping device. (3) A device according to claim (2), characterized in that the elastic means are formed as gas cushions. (4) The device according to claim 1, further comprising a column of liquid for closing the clamping device and a column of liquid for opening the clamping device. (5) adjustable pistons (13', 13#, 13'') of the pressure cylinders (12', 12., 12'') rotating together with the main shaft (6); A control cam disk (10.11>) is provided, the pressure cylinders (12', 12l, 12''') being connected via a liquid column with the actuating cylinders (7, 8, 9) of the clamping device. The device according to any one of the preceding claims (1) to (4), characterized in that: (6) a pressure cylinder (12', 12', 1);
At least one directional valve (30', 30...
3O-) for supplying pressure liquid to the entire device. Device according to any one of the patents, characterized in that a hydraulic station (19) equipped with a pump is provided for normal filling and starting. (8) Storage container (23.28.29) and check valve (2.
2, 25, 26), a pressure reducing valve (20, 21), and a pressure limiting valve (31). (9) Liquid outflow An outlet (14) is attached to each of the pressure cylinders (12) in order to limit the
2. The device according to claim 1 or claim 5, characterized in that the liquid level is kept constant every time the double action is performed. (10) The device according to claim (9), characterized in that means (27) for preventing free outflow are provided at the outlet (14). αυ Said patent characterized in that an adjustable switching ring (16) is provided which rotates with the main shaft (6) and is equipped with a switch (17) in order to enable switching only at predetermined points. Claims (1) to (10)
Apparatus according to any one of the preceding paragraphs.