GB2095141A

GB2095141A - Protecting machine tool slides and guides

Info

Publication number: GB2095141A
Application number: GB8207668A
Authority: GB
Original assignee: Schweizerische Industrie Gesellschaft
Current assignee: Schweizerische Industrie Gesellschaft
Priority date: 1981-03-20
Filing date: 1982-03-16
Publication date: 1982-09-29
Also published as: CH649244A5; FR2502047A1; DE3203738A1; GB2095141B; IT1155461B; IT8267156A0

Abstract

An arrangement for screening the slide and guide rails in machine tools consists of two outer troughs 20 and 21, having inner walls 33 and 34 respectively which are secured to the slide and guide rails 30, and outer walls 35 and 36 respectively which extend upwardly to the surface of the slide 2. Located between the slide and guide rails 30 is a central trough 23, the walls 38 and 39 of which bear against the inner lateral faces of the rails and are extended upwardly beyond them by screening elements 42 and 43 which, each cover a respective guide rail. The slide 2 is supported on the slide and guide rails 30 by means of support element 24 and by way of bearing elements 26. Since these support elements 24 extend below the drip walls 46 and 47 of the screening elements 42 and 43 respectively a pronounced curve is formed, and this prevents cooling and lubricating fluid from flowing along the support elements to the bearing elements 26. <IMAGE>

Description

SPECIFICATION Improvements in and relating to machine tools The present invention relates to machine tools and in particular concerns an arrangement for screening the slide and guide rails of machine tools.

The problem of screening certain parts of machine tools has existed for some time.

CH-A 531 916, for example, describes a screening arrangement for a machine tool wherein a chip-removing tool is moved relative to the workpiece. In this arrangement, an annular jet is produced around the tool when it enters the chip receiving box, so that the passage opening is sealed off against a spraying, lubricating and cooling medium in which chips are entrained.

For the purpose of screening slide and guide rails in machine tools having reciprocating slides for holding the workpiece, it is also known to use bellows which cover the slide and guide rails at both sides of the slide and in the two directions of movement. A bellows of this kind is described, for example inCH-A 541 387. Apart from the disadvantage of fatigue due to constant stressing of the hinge points and possibly under the effect of harmful substances that attack the material, a further drawback is that no screening is present in the zone of the slide. In the case of grinding machines, it is known to accommodate the workpiece in a trough on the slide so that the cooling and spraying medium has to flow away laterally of the slide, these parts being covered by the top of a compartment.Such an arrangement is shown in Figures 1 and 2 of the accompanying drawings, in which: Figure 1 is a diagrammatic illustration of a grinding machine having a slideway of known construction; Figure 2 shows, in a manner similar to that of Figure 1, a grinding machine requiring the smallest possible amount of space.

Since, as shown in Figure 1, it is necessary for the walls of the trough to be spaced from the workpiece so that the latter can be machined over its entire width, this means that the top of the compartment has to cover the entire length L1, although, as shown in Figure 2, only a length L2 is necessary for the actual machining.

The present invention seeks to provide an arrangement for screening the slide and guide rails wherein the above-mentioned disadvantages are avoided.

According to the invention, there is provided an arrangement for screening the slide and guide rails in machine tools and having a slide which is moved relative to the machine bed during machining of the workpiece, said arrangement comprising cover elements which are arranged one at each side of the slide and guide rails and are shaped to form a respective outer trough; a central trough, having walls which lie within the slide and guide rails; screening elements which each cover a respective guide rail, each screening element comprising an inner wall extending from a respective one of said walls of the central trough and a drip wall spaced from the outer surfaces of the slide and guide rails, the central trough, the two outer troughs and the screening elements being secured, at each end, to an end wall in a fluid-tight manner; and support elements which extend below the screening elements and are secured to the slide, the free end of each support element being supported, by way of a bearing element, on a respective slide and guide rail.

In order that the invention may be better understood, an embodiment thereof will now be described by way of example only and with reference to Figures 3 and 4 of the accompanying drawings in which: Figure 3 is a partially cut-away perspective view of a slide on a machine bed comprising an embodiment of the arrangement in accordance with the invention; and Figure 4 is a sectional view transversely of the slide and machine bed of the Figure 3 construction.

Referring firstly again to Figures 1 and 2, there is illustrated a grinding machine having a machine bed 1 with a slide 2a (Figure 1) and 2b (Figure 2) and with a workpiece 3 clamped on the slide, the machine bed being shown in section in the direction of movement of the slide. In both illustrations, a grinding tool with a guide and drive 4 is located exactly at the edge of the workpiece 3 at the moment when change in direction occurs.

The hitherto normal form of the slide 2a, shown in Figure 1, has two screening walls 5 and 6 for protecting the slide and guide rails on the machine bed against off-flowing cooling and lubricating fluid so as not to interfere with the smooth travel of the slide. Thus a minimal distance B from the screening walls 5 and 6 has to be maintained on each side of the slide 2a, so that hitherto a distance equal to the length L1 has had to be provided for the slide 2a. On the other hand, if the screening walls 5 and 6 were dispensed with, as shown in Figure 2, only a distance equal to the length L2 would have to be provided. As can be clearly seen by comparing Figures 1 and 2, the length L2 is considerably less than the length L1.

Referring now to Figures 3 and 4, the arrangement for screening the slide and guide rails 30 consists of two cover elements 31 and 32 which, by means of inner walls 33 and 34 respectively, bear against the slide and guide rails 30 and, by means of outer walls 35 and 36 respectively extend to the top surface of the slide 2, so that the two cover elements each form an outer trough 20 and 21 respectively.

Located between the two slide and guide rails 30 is a central trough 23 formed by an element 37, the walls 38 and 39 of which are disposed within the slide and guide rails 30. Figure 4 shows that the bottom walls 40, 54 and 55 each include a portion which slopes downwardly towards the slide and guide rails 30 so as to enable cooling and lubricating fluid to be drained off and collected.

Screening elements 42 and 43 serve to cover the slide and guide rails 30. These screening elements 42 and 43 are of inverted U-section and are secured by their inner walls 44 and 45 respectively to the walls 38 and 39 respectively of the central trough element 37, so that said walls 38 and 39 are extended to points located above the slide and guide rails.

The top walls 48 and 49 of the screening elements 42 and 43 respectively are provided with a ridge 50 and 51 respectively, so that no cooling and lubricating fluid can remain on said top walls; instead it can flow or drip either into the central trough 23 or into an outer trough 20 or 21.

The outer troughs 20 and 21, the central trough 23 and the screening elements 42 and 43 are inter-connected and sealed off at their ends by end-walls 58.

Spaced along the long sides of the slide 2 are a plurality of support elements 24. These support elements 24 are rigidly connected to the slide 2.

Their free ends 25 are supported, by means of bearing elements 26, on the slide and guide rails 30. The usual friction bearings or roller bearings can be used as the bearing elements 26. The method of securing the bearing elements is not illustrated in Figure 2, since this is known to the expert. Furthermore, the bench drive 7 is only shown diagrammatically; as is usual, this can be a spindle drive, a hydraulic drive or a drive using traction means.

The support elements 24 extend below the drip walls 46 and 47 so that a sharp curve is formed below the latter, and the bearing elements 26, if not located above the drip edges of the drip walls 46 and 47, are disposed at least approximately at the same level as these. This arrangement prevents the cooling and lubricating fluid from flowing along the support elements 24 and then finding its way to the bearing elements 26 or on to the slide and guide rails 30.

At their edges, the outer walls 35 and 36 of the two outer troughs 20 and.21 respectively each have an inner screen 52 which is formed by an angle section and has passage openings 53 adjacent the slide 2. On the one hand, these edge screens serve to prevent contact with the interior of the machine, while on the other hand a wall of a covering compartment can be placed in this recess so that a good seal against the exterior is formed but the spray fluid can nevertheless flow away.

The usual grid elements 56 and 57 are located above the bottom walls 54 and 55 of the cover elements 31 and 32 respectively so as to keep larger objects away from the return-flow path for the cooling and lubricating agent.

In contrast with the known arrangements for screening slide and guide rails, this screening system of fixed location obviates the need for providing, on the slide 2 itself, structures that would increase the space requirements, so that the machine tool can be of more compact construction from bottom to top, and the length of the slide is limited to the length over which grinding is to be carried out. Space for additional equipment is created at both sides of the bed.

Uniform moistening of the upper surface of the slide and free circulation of air below the slide results in its acquiring improved thermal stability.

With a closed compartment over the slide and over the entire length of the bed, it is possible to ensure that the cooling and lubricating fluid is able to escape either in the form of droplets or as a cloud.

Instead of the support elements 24 shown in the drawings, use could be made of a continuous support section as known in machine tool technique. Figure 4 shows a spindle 7 for driving the bench 2. Here too, modifications are feasible since the drive could be positioned below the screening elements 42 and 43.

Claims

1. An arrangement for screening the slide and guide rails in machine tools and having a slide which is moved relative to the machine bed during machining of the workpiece, said arrangement comprising cover elements which are arranged one at each side of the slide and guide rails and are shaped to form a respective outer trough; a central trough, having walls which lie within the slide and guide rails; screening elements which each cover a respective guide rail, each screening element comprising an inner wall extending from a respective one of said walls of the central trough and a drip wall spaced from the outer surfaces of the slide and guide rails, the central trough, the two outer troughs and the screening elements being secured, at each end, to an end wall in a fluid-tight manner; and support elements which extend below the screening elements and are secured to the slide, the free end of each support element being supported, by way of a bearing element, on a respective slide and guide rail.

2. An arrangement according to claim 1, wherein the cover elements each have a respective outer wall which extends upwardly at least approximately as far as the plane containing the top surface of the slide.

3. An arrangement according to either one of claims 1 or 2 wherein the free ends of the support elements are disposed at a higher level than are the portions thereof that extend below the drip walls.

4. An arrangement according to any one of claims 1 to 3 wherein the top surface of the slide takes the form of a flat face so that the lubricating and cooling medium can flow off on all sides.

5. An arrangement according to claim 2 further comprising a compartment for receiving spray of lubricating and cooling medium as well as flying pieces of the tool and/or the workpiece, said compartment having front and rear walls, the lower edges of which extend along the slide and guide rails within the cover elements.

6. An arrangement for screening the slide and guide rails in machine tools, substantially as hereinbefore described with reference to the accompanying drawings.