DE3429125A1 - Thermally loaded cross support, in particular a cross support for flame cutting machines - Google Patents

Abstract

In order to reduce the thermal deformation on tool supports (12), in particular of flame cutting machines, an expansion bar (49) is fastened to the support (12) (Fig. 3). <IMAGE>

Description

Password: expansion rod

Thermally loaded cross members, in particular cross members for flame cutting machines The invention relates to a thermally loaded tool carrier according to the preamble of claim 1.

Tool carriers, in particular cross members of flame cutting machines, are the processing temperatures of Exposed tool and workpiece. This through thermal radiation, heat conduction and heat transfer by flow in the carrier introduced heat flows to deformations of the carrier and of the transverse tracks attached to the carrier as well as Measuring devices.

It is known to prevent the radiation of heat into the cross member a flame cutting machine, in front of the cross member surfaces exposed to the radiation reflective radiation protection plates made of, for example, polished aluminum to be attached Conditional However, due to general mechanical designs, radiation protection plates are Can only be attached to partial areas of the tool carrier. For example, at a flame cutting machine due to the small distance between the torch height adjustment and front side of the carrier and the belts for the cross-feed of the burners, the radiation protection plates at the required minimum distance of 30 millimeters only on the underside of the carrier be attached.

From DE-AS 12 54 224 a device for compensating the Temperature difference became known at which the measured value of the displacement as a reference variable in an electrical follow-up control loop to correct the shift serves.

Such compensation devices, however, require a high level of measurement technology Effort to record the actual temperature values as well as to readjust the deviations.

The invention is based on the problem of thermal deformations to reduce on tool carriers.

This task is carried out with a generic tool carrier the characterizing features of claim 1 solved.

Advantageous further developments are given in the subclaims.

The advantages achieved by the invention are the reduction of default in the simplest possible way. Especially the different ones Heat stress on the front and back of the beam resulting in bending, will inexpensively reduced. A tilting of in particular driven on both sides Machines by the warping of the cross member is prevented.

An embodiment of the invention is shown in the drawing and is described in more detail below.

The figures show: FIG. 1 a simplified perspective illustration of a Flame cutting machine with a tool holder; FIG. 2 shows the detail A of FIG. 1 in an enlarged view; 3 shows a section B-B of the carrier according to the invention.

In Fig. 1, a flame cutting machine 10 is shown schematically, which essentially consists of a carriage 11, a cross member 12 and an undercarriage 13 and 14, consists. The complete drive units are located in the undercarriage 14 for the longitudinal movement (arrow direction y).

The undercarriages 13 and 14 are on rails 15 and 16 in the direction of the arrow y movable. Burner suspensions 17, 18, 19 are also provided on the cross member 12. The burner suspensions 17, 18, 19 are supported by an endlessly rotating steel belt24 for moving the burner suspensions 17, 18, 19 in the direction of arrow x in connection. The Stahlband24 is a, in the transverse drive carriage 26 arranged pinion, the engages in the rack 25, pulled. In Fig. 1 there are only three burner suspensions 17, 18, 19 shown schematically. Of course it is also possible to do more as three or only one torch suspension 17, 18, 19 on the cutting machine 10 to be arranged. On the burner hangers 17, 18, 19 is respectively a cutting torch 20, 21, 22 (for example oxy-fuel welding torch, plasma cutting torch Or the like.) Arranged, via a lifting device not shown in detail in Direction of arrow z are adjustable in height.

The cutting torches 20, 21, 22 are about that on one no closer workpiece table shown lying workpiece 23 numerically according to perforated belt or photoelectrically controlled according to documents.

The permissible deviations from the nominal dimension of the cut workpiece 23 are in DIN 2310, sheet 3 "Thermal cutting Oxygenated flame cutting, process principles, quality, dimensional table 1: Permissible deviations from the nominal dimension (dimensions in mm) according to DIN 2310 Exactly Werttsbäck Nemm area keiupd d thickness 35 to i 315 to I 1000 to 2000 to under 315 under 1000 under 2000 under 4000 3 btx t25 # 1.01 ~ -LS t over 50 to 100 # S0 100 # 1.0 1.0 220 2 0 t 3.0 above softnesses "(Table 1). In order to be able to meet these accuracy requirements, the cutting torches 20, 21, 22 must be exactly in the positions defined by the control in all operating states If the user is required to rationalize through higher cutting speeds and a higher number of cutting torches 20, 21, 22, the positions of the cutting torches 20, 21, 22 must be independent of thermal disturbance variables.

In Fig. 1, the three types of heat transfer are indicated by the arrows 27, 28, 29 shown symbolically. The arrows 27 represent the heat radiation, the arrows 28 the heat conduction and the arrows 29 the through the flow in the Cross member 12 is introduced heat.

In Fig. 2 a detail A of Fig. 1 from the view C is shown. On the cross member 12 of the cutting machine 10 are transverse tracks 20 and the Rack 25 mounted.

Measurements made in practice showed an expansion of the cross members 12 and the transverse tracks 30 and the racks 25 of about 2 millimeters. To the Improving the heat dissipation and thus reducing the thermal expansion of the The cross member 12 of the cutting machine 10 was preferably a device 31 assigned to air cooling. A radial fan 32 generates an air flow that is guided via an angled injection pipe 33 into the cross member 12 and this flows through. The fan 32 is advantageously connected to a speed control device, with which the volume flow can be regulated according to the cross-section of the carrier.

Fig. 3 shows a cross section (B-B) through the torsion-resistant, welded lightweight construction formed cross member 12. The cross member 12 consists essentially of a rectangular hollow profile 34, which has vertical cross members 36, 37 is connected to the undercarriage 13, 14.

The tool-bearing front side 35 of the hollow profile 34 projects beyond the vertical cross members 36, 37. On the front side 35 and on the underside 38 and the top 39 of the hollow profiles 34 are mounting plates 40, 41, 42 attached, which are used as brackets for the rack 25 and the transverse tracks 30 to serve. Inside the hollow profile 34 are stiffening plates 43 to increase the static and dynamic properties of the cross member 12 are provided. In which the A cooling channel 44 extends through the area of the cross member 12 facing the front 35 the preferably welding in of a partition plate 45 over the entire length of the cross member 12 trained. The recesses provided for connecting the injection pipe 33 or for the air outlet in the end faces are denoted by 46.

The device 31 for cooling the cutting machine 10 works in the case described above as continuous cooling, d. H. the airflow occurs at the one side of the cross member 12 and escapes on the other side into the environment.

Of course, it is also possible that the cross member 12 guided air back to the inlet side of the carrier 12 via a heat exchanger. Further advantages result from the attachment of air baffles inside of the cooling channel 44 and by sucking in cooled air.

With the device for air cooling, the values shown in Table 2 (distortion measurement without cooling device) specified warpage measurements at measuring points I, II, III, IV (Fig. 1) according to the measured values given in Table 3 decreased.

During the measurements, the cutting machine 10 was cold (Room temperature) heated out. The cutting torches 20, 21, 22 were - without to cut - operated with fuel gas and heating oxygen. The flames hit an 8 mm thick sheet and were readjusted by hand.

Every 10 min up to the end of the experiment after 110 min, all measuring points Distortions and temperatures recorded. The duration of the experiment was sufficient to make one stationary To establish the heating state.

Table 2 Distortion measurements on flame cutting machines Trial Verzuq at measuring point (mm) d I II III uer min) 1 II III IV 0 0 0 0 0 10 + 0.23 + 0.2 -0.06 -0.08 20 0.93 0.9 0.10 0.12 30 1.29 1.3 0.10 0.12 40 1.66 1.7 0.10 0.13 50 1.93 2.0 0.10 0.14 60 2.08 2.2 0.10 0.14 70 2.12 2.3 0.10 0.14 80 2.22 2.4 0.11 0.15 90 2.14 2.3 0.11 0.15 100 2.21 2.41 | 0.08 0.13 110 2.12 2.3 0.07 0.11 Table 3 Distortion measurements on flame cutting machines Trial Verzuq at measuring point (mm) duration l II III IV 0 0 0 0 0 10 | +0.29 +0.31 -0.0 -0.10 20 0.41 0.4 0.0 0.12 30 0.43 0.5 0.0 0.13 40 0.41 0.5 0.0 0.13 50 0.34 0.5 0.0 0.14 60 0.26 0.5 0.0 0.13 70 0.17 0.4 0.0 0.13 80 0 0.3 0.0 0.14 90 0 0.3 0.0 0.13 100 0 0.3 0.0 0.07 110 0 0.3 0.0 0.07 It is of course also possible to provide a cooling channel 44 for water cooling instead of air cooling.

This has the advantage that water has a higher heat capacity and has a higher heat transfer coefficient. It can be with a lower When the cooling medium is heated, a greater flow of heat can be dissipated.

In order to achieve a further reduction in the distortion of the cross member 12, an expansion rod 49 is attached to the rear side 47 of the support wall 48 by means of a screw connection 50 attached.

The expansion rod 49 preferably extends over the entire length of the carrier and thus compensates for the temperature gradient of the carrier 12 Thermal bending caused in the x-direction. In doing so, a material forces, preferably an aluminum plate, with a large thermal expansion coefficients the (cooler) support back wall 47 to an expansion.

This expansion compensates for the thermal expansion on the heated front of the carrier.

The difference in the coefficient of thermal expansion is given by structural steel = 11.5 x 10-6 1 / K AlMgSi = 23.1 x 10-6 1 / K with the expansion rod 49 on the back 47 and the air cooling 31 on the front 35 of the carrier 12 are those in table 4 values are determined.

Table 4 Trial warpage at measuring point (mm) duration 1 II III IV 0 0 0 0 0 10 +0.30 +0.26 0 -0.06 20 0.39 0.33 0 0.09 30 0.1? +0.04 0 0.10 40 0.13 -0.07 0 0.11 50 Q, 31 0.28 0 0, 12 60 0.35 0.34 0 0.12 70 0.25 0.31 0 0.13 80 +0.06 -0.13 0 0.13 90 - 0.11 +0.05 0 0.13 100 0.16 0.08 0 0.13 110 - 0.11 +0.01 0 0.13 Table 5 lists the warpage measurements that can be achieved when using an expansion rod 49 without additional air cooling 31.

Table 5 Trial Verzuq at measuring point (mm) duration I II III IV 0 min 0 10 +0.28 +0.28 0 -0.11 20 0.77 0.82 0 30 1.08 1.1B 0 0.16 40 1.30 1.46 0 0.18 50 1.32 1.52 0 0.19 60 1.35 1.60 0 0.19 70 1.31 1.60 0 O, 20 80 1.25 1.54 0 O, 21 90 1.19 1.52 0 0.21 100 1.17 1.50 0 0.22 110 1.17 1.50 0 0.22 As the evaluations of the measured values show, an almost steady state is established after approx. 90 minutes (except for Table 5). At the end of the test, the distortions at beam height (measuring point II): without measures: 2.36 mm only with expansion rod: 1.50 mm only with air cooling: 0.34 mm with expansion rod and air cooling 0.01 mm Aluminum plate as an expansion rod 49 leads to a reduction in warpage of 0.9 mm.

Claims (9)

Claims 1. Thermally loaded tool carriers, in particular cross members for flame cutting machines, characterized in that an expansion rod is attached to the carrier (12) (49) is attached. 2. Carrier according to claim 1, characterized in that the expansion rod (49) a preferably plate-shaped material with a coefficient of thermal expansion compared to the coefficient of thermal expansion of the carrier material has a higher coefficient of expansion. 3. Carrier according to one of claims 1 or 2, characterized in that that the material of the carrier (12) structural steel and the material of the expansion rod (49) Aluminum is. 4. Carrier according to one of claims 1 to 3, characterized in that that the carrier (12) is designed as a hollow profile (34) and the expansion rod (49) inside of the carrier (12) is attached. 5. Carrier according to one of claims 1 to 4, characterized in that that the expansion rod (49) is attached to the back of the carrier (47). 6. Carrier according to one of claims 1 to 5, characterized in that that preferably the front (35) of the carrier (12) has a device (31) for Cooling is assigned. 7. Carrier according to claim 6, characterized in that the cooling device (31) is an air blower (32, preferably a radial fan, with which the wearer (12) a preferably cooled air stream can be supplied. 8. A carrier according to claim 6 or 7, characterized in that the The carrier (12) is designed as a hollow profile (34) and the air blower is attached to the hollow profile (34) (32) is connected. 9. Carrier according to one of claims 6 to 8, characterized in that that within the hollow profile (34) at least one cooling channel (44) for guiding air is trained.