MXPA96001846A - Machine tool - Google Patents

Abstract

The present invention relates to a machine tool comprising a support that includes one or two vertical posts, two vertically movable heads along at least one vertical post, the means for moving the heads independently one relative to the other substantially as length of the vertical tracks carried by at least one vertical pole, the means for moving the heads independently of each other in a substantially longitudinal direction, horizontally relative to the support, a tool magazine provided in common for both heads, the tank of tool is constructed and accommodated as an elongated circulating reservoir, each of the heads is independently movable towards a tap position to receive a tool from the tool reservoir, when in an exchange position, the circulating tool reservoir is stationary during the transfer of the herr The tool in the tool magazine is arranged in such a way that, with the head positioned in the pick-up position, the tool placed in an exchange position is axially oriented relative to the tool. head, and each head, while in its position of taking to take a tool, is advanced independently in its direction length

Description

MACHINE TOOL This invention relates to a machine tool for the perforation and / or treatment of grinding of workpieces, comprising at least two heads. The machine tools are known, wherein the head removes or respectively returns the tools directly from / to a box for fixed or movable tool. In such machine tools, the head must be advanced to the tool box after the completion of a treatment process. In the tool case, the tools are exchanged, and the head is subsequently guided back to the work piece. The exchange of tools requires a considerable amount of time, which is caused not only by the movement processes to be carried out by the head but also by the losses of time due to deceleration and acceleration of the spindle or spindle job. In all the exchange of tools, the machine tool is not available for the treatment processes. In machine tools that comprise a large number of workpiece spindles in a revolver configuration, the removal of a work spindle from the workpiece and the advancement of another work spindle to the workpiece along with the processes coupling and acceleration consumes considerable time. Although, during the operation of a working spindle, another working spindle can be equipped with new tools, this will require high work spindles. In addition, such a procedure requires the use of a tool box which is advanced to the revolver system located in its operating position. A machine tool forming the basis of the preamble of claim 1 is known from Japanese Patent JP 59-69242 A (Patent Abstracts of Japan M-317, August 15, 1984, Vol. 8, No. 177). This machine tool is provided with a support on it, on which two heads are movable in vertical direction independently of each other. Each head has a box for specialized tool, arranged on it, which is moved along with the head. The transfer of the tools from a tool box to the bearing head is carried out by means of an oscillating arm. The total support of the machine tool is movable in the feed direction (towards the tool). This machine tool offers the advantage that a respective head of the heads can be put in contact with the work piece while an exchange of tools can be carried out on another head. Thus, considerable time is saved because there are no time requirements for the exchange of tools. In addition, a known machine tool of the patent DD 263 725 A1 comprises a single head to be vertically displaced on the support. Additionally, the head can be moved horizontally in its longitudinal direction to allow the exchange of tools with the use of a tool box. The tool box is arranged before the machine stand and carries several tools on a horizontally movable slide, so that each tool can be moved to a transfer position for the head. The guide path for the tool box must be at least twice as long as the slide of the box carrying the tools. It is an object of the invention to provide a machine tool which is very direct in construction and allows a very quick exchange of tools.

- - According to the invention, the above object is solved by the features indicated in claim 1. In the machine tool of the invention, two heads are movable independently of each other on the support along vertical guides. In addition, each head is movable horizontally in its longitudinal direction. While one of the heads carries out a treatment on the work piece by means of a tool, the other head is free to move a box for work piece, deposit the old tool and take a new tool. When the head that carries out the treatment has finished its operation, it will be returned and the head that carries the new tool will be applied to the work piece. In this way, the tool exchange time after completion of a treatment step may be limited to that length of time which is normally necessary for the process from one operating position to the next. Thus, almost no additional time or no time is required for the exchange of tools. The exchange of tools can be carried out in approximately one second. The treatment of the work pieces is carried out by means of the alternative operation of the two heads, where respectively one head is active in the treatment of the work piece while the other carries out an exchange of tools or is maintained in a waiting position. The tool box provided in common for both heads has two exchange positions, this is one for each head. Under the automatic control of the tool box, the individual tools are moved to the exchange position for the respective head for which they are determined. The heads are guided behind the tool box to take the tool positioned in the exchange position, by carrying out a simple forward movement. Accordingly, no transfer devices are required between the tool box and the head. The tool box has a short construction length and a high storage capacity for tools, both heads are serviced by the horizontal lower row of the circulating case, the exchange positions are arranged at the same height. The double arrangement of the heads provides a decoupling between the mobile sequence for the treatment (essential operating time) and the exchange of tools (auxiliary processing time).

By means of the alternative use of the respective head equipped with the new tool and accelerated to the rotational speed of operation, the non-productive auxiliary process times are practically eliminated. Due to the decoupling effect, the mobile processes involved in the exchange of tools can be determined in such a way that the jolts and jerks of the acceleration are largely eliminated, especially during the starting and braking of the working spindle of a head, during the clamping movements of the tool and the box and during axial movement of the head for tool exchange. Thus, the duration of the mechanical and electrical components increases. The heads can be designed for different power specifications, the respective current task is carried out by that head which is suitable for the treatment process in question. Thus, for example, a head can be sized for power machining by means of large grinding tools, and the other can be sized for the use of high speed drilling tools. A further advantage is that the operability of the machine tool is still maintained even in the case of a spindle failure, although more time will be required in this case for the exchange of tools. In addition, it is possible under certain conditions to treat two pieces of work simultaneously and in parallel. Preferably, the support of the machine tool is a gate support comprising two vertical posts and a crosshead. In this arrangement, the guide paths of the heads are located on the mutually confronting inner sides of the posts. Alternatively, use may be made of a support which consists of a single post and where the guide courses of the spindle heads are located on mutually hindered outer sides. The tool box is arranged in an advanced position on the front side of the support. Preferably, the tool box is arranged on the upper end of the support, although it can also be arranged on the lower end, for example on the base portion of the machine. If the tool box is provided on the upper end of the support, the high height will make it difficult for the operator to load the tool box with tools. According to a preferred embodiment of the invention, the tool machine can be made to oscillate about an axis near one of its ends so as to fold the other end into a loading position. The machine tool preferably comprises a carrier for workpiece, which transverse to the longitudinal orientation of the heads is movable in a horizontal direction. A machine tool of this type constitutes a self-contained treatment unit. By integrating the bearer for a work piece to the transfer line, the machine can also be used as a flexible work station in interlaced systems. Preferably, the control of the machine tool is carried out completely numerically, this e3 all the moving process of the heads, the tool box and the carrier for workpiece are controlled according to a predetermined program sequence and they are coordinated with each other, in such a way that all movements are carried out automatically. One embodiment of the invention will be explained in greater detail later herein with reference to the drawings. Fig. 1 is a partially sectioned perspective view of the tool machine, Fig. 2 is a side view of the machine tool, with the upper portion and the tool box seen in cross-section, and Fig. 3 is a partial view of Figure 1 with the tool case turned down to the loading position.

According to figure 1, the machine tool comprises a support 10 projecting from a base 11. The support 10 is provided as a gate support comprising two mutually spaced vertical posts 12 having their upper ends joined together by a crosshead 13. Arranged on the mutually confronting inner sides of the posts 12 are vertical guides 14 for respectively a vertically movable slide 15. Each slide 15 comprises a horizontal guide for the horizontal movement of a head 16 or respectively 17 along the same. Inside the head 16 or respectively 17, a drive unit for a work spindle 18 is arranged which projects from the front end of the head and comprises a receiving portion for a tool.

Opposite the support 10, a carrier 20 for workpiece is arranged on the base 11 in a manner that allows movement along horizontal guide means 21 transversely to the longitudinal direction of the heads 16 and 17. This direction of movement of the carrier 20 for workpiece is the direction X, the vertical direction is the direction Y and the longitudinal direction of the heads 16 and 17 is the direction Z. In the illustrated embodiment, the carrier 20 for workpiece is movable exclusively in the direction X. The movements in the directions Y and Z are carried out by means of the respective head. The workpiece carrier 20 may be provided with a rotary table, a rotary arrangement, a supportive grasper fastening device, a support spigot exchange device and the like. It is imperative that the carrier 20 of the work piece be able to receive and position the workpiece in an exactly defined manner. The drive units 22, 23 for the vertical movements of the heads 16, 17 are arranged on the crosshead 13. The heads are independently movable independently in the Y and Z directions. While, for example, the head 17 is involved in the treatment of a workpiece, the head 16 can be moved to a tap position for tool exchange. A tool case 24 is arranged in an advanced position (this is opposite the support) at a fixed height on the support 10. The tool case comprises an endless transport medium, this is a chain, arranged for an endless movement in a vertical plane and having tool holding units 25 projecting outwardly joined thereto. The tool box 24 is of an elongated shape and those of the tool holding units 25 which project from the horizontal lower row can be brought into contact with the heads. The tool retention units 25 are provided with clamping arms to respectively retain a tool 2d. As shown in Fig. 2, the head 16 can be moved upward to a pick position UP behind the tool case 24. The tap position is the upper end position of the head 16 in the Y direction and at the same time the position of the rear end in the Z direction. In the tap position, the spindle 18 is in axial alignment behind that tool 26 the which is in the exchange position WP in the lower horizontal row of the tool case 24. When the head 16 is advanced slightly out of the take-up position UP in the direction of the Z-axis, the head 16 grips the rear end of the tool 2d by the receiving portion of the working spindle 18. Simultaneously, the tool 26 is secured to the working spindle 18. Subsequently, the head 16 can be moved downwards and, in doing so, separates the tool 26 from the tool case 24. At the height of its lower row, the box 24 for tool has two exchange positions, notably one for each head. To make it easier for an operator to manually load tools into the toolbox 24 arranged on the upper end of the support 10, the toolbox can be pivoted about a horizontal pivot axis 30 which is schematically indicated - although not shown explicitly - in Figure 1. The pivot axis 30 is arranged in the vicinity of one end of the elongated tool box. When the tool case is pivoted about the pivot axis 30, it will take the articulation position shown in Figure 3, where the end 24a has been hinged downward. Thus, the casing tools 26 of the pivoted end towards ab-jo 24a are easily accessible. To articulate the toolbox, a cylinder 31 is arranged on the crosshead 13. The chain of the toolbox24 is driven by a numerically controlled drive unit, such that the individual tool holding units 25 can be driven. move respectively to the desired position. The tool case 24 is covered by a cover 32 attached to the upper end of the support 10 and opened only in the downward direction.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention is the conventional one for the manufacture of the objects to which it refers.

Having described the invention as above,: property is claimed as contained in the following

Claims (4)

Claims

1. A machine tool comprising a support having two heads arranged on it, to be moved independently of each other along vertical guides, characterized in that each head is additionally movable in its longitudinal direction horizontally on the support, because the support it has arranged on it a box for common tool for both heads which is arranged as a circulating box comprising a means of endless transportation and because each of the heads is movable to a position of taking to receive a tool from the box for tool.

2. The machine tool according to claim 1, characterized in that the tool box is arranged at a fixed height on the upper end of the support.

3. The machine tool according to claim 1 or 2, characterized in that the machine tool is of an elongated shape and can be articulated around a pivot axis near one of its ends to fold the other end to a loading position.

4. The machine tool according to any of claims 1-3, characterized in that a workpiece carrier is arranged in front of the support to be horizontally displaceable transverse to the longitudinal direction of the heads.