EP0991848B1 - Chisel arrangement for cutting chisels of a tool holder mounted in a rotating manner - Google Patents

Abstract

The invention relates to a chisel arrangement for the cutting chisels of a tool holder mounted in a rotating manner, such as a cutter head or cutting rollers, in which the chisel tips are inclined in a leading manner in the direction of rotation and the direction of circumference of the tool holder and the chisel can be tilted by overcoming a spring force. The tilt axis of the chisel (1) is positioned on the tool holder (7) in the direction of the circumference and rotation of the chisel (1) in front of the projection of the chisel tip towards the axis of rotation (9) of the tool holder (7). In the contact position, the chisel (1) is supported against a spring (3) in a tiltable manner.

Description

The invention relates to a chisel arrangement for cutting chisels a rotating tool holder, e.g. a cutting head or a cutting roller, in which the Chisel tips in the circumferential and rotational direction of the tool holder are arranged at an early incline and the chisel is overcome a spring force is tiltably mounted.

From DE-C-34 41 950 it is known a cutting chisel to be arranged pivotably in a chisel holder, the chisel in Chisel holder can be tilted under the influence of the cutting reaction forces is and in its original position by a return spring is resettable. The chisel shank receptacle is inserted into a ball socket of the chisel holder, which is one through the bore of the chisel holder limited pivotability or tiltability of the chisel results. The ball socket defines the position of the Pivot axis of the chisel, this pivot axis with consideration on the position of the chisel tip relative to the face in Direction of rotation behind the engagement of the chisel in the rock lies.

EP-B1-0 200 037 shows and describes a pivotable holder a cutting chisel in which the chisel is one Swivel axis between stops in a mounting hole of the the pivot axis carrying the chisel holder is pivotable. in the The chisel holder is in operation after an initial swiveling of the component receiving the chisel on such a component Stop on and is thus rigidly supported. The swiveling of the component receiving the chisel serves to to actuate a valve, the actuation of the valve being counter the force of a spring, which receives the chisel Component after exiting the rock again from Lift valve tappet. A support for the reaction forces is not done by such a spring, the pivot axis in the embodiment selected in EP-B1-0 200 037 within the radial projection of the chisel tip onto the tool carrier lies. The chisel is used when active intervention in the Rock swiveled so that it does not move away from the rock contact can solve.

The invention now aims to provide a chisel arrangement at the outset to create the kind with which it is above all succeeds in the chisel engaging in what is to be cut Rock can move out of the rock. To solve this task the object of the invention is that the tilt axis of the chisel in the circumferential or rotational direction of the Chisel before the normal projection of the chisel tip on the axis of rotation of the tool carrier arranged on the tool carrier is and that the chisel in the engaged position against a spring is supported tiltable. The fact that the tilt axis in one Distance is arranged on the tool carrier, which in front of the line connecting the cutter head axis to the chisel tip lies, the possibility is created to get away from the rock contact safely to solve, it is also essential that the Chisel in the rock and thus in the engaged position is supported tiltably against a spring. The chisel is said to be in the engagement position still against the force of a spring be tiltable to improve the balance of power and to absorb occurring force peaks.

The training according to the invention is advantageous so hit that the chisel holder on one arm Swivel lever is fixed, the one facing away from the swivel axis End is pressed against a spring element. The contact pressure of the End of the pivot lever facing away from the pivot axis against Spring element is essential in the operating position for absorbing the forces on the chisel engagement. The swivel lever should hiebei under a defined bias against the spring element be pressed and it therefore corresponds to a preferred one Development of the chisel arrangement according to the invention that the Contact pressure of the swivel lever adjustable against the spring element is. One is just closing a valve after exiting the spring force ensuring the chisel is for the take-up such reaction forces in no way suitable.

Secure support and particularly good power absorption can be achieved in that the longitudinal axis of the pivot lever at an acute angle of less than 35 °, in particular less 25 °, to the tangent to the tool carrier in the area of the swivel axis is articulated, such an arrangement of the pivot lever the appropriate leverage ensures which for a secure springy support of the dynamic passive forces is advantageous.

As already mentioned, the spring element must also be in the engaged position still be resilient and therefore able be able to absorb high reaction forces. It is therefore advantageous the training so that the spring element of a Leaf spring or a leaf spring assembly is formed, the longer Axis approximately parallel to the pivot axis of the pivot lever Tool holder is fixed, which takes up little space also high spring forces and thus high force peaks are absorbed can be.

A particularly good introduction of force to absorb the cutting forces can be achieved in that the distance (a) Swivel axis from the normal projection of the chisel tip onto the Chisel holder at least a third, preferably at least half, the normal distance of the swivel axis from the working face or the cutting track level of the chisel. Such Training allows the desired pivoting counter the force of a spring with effective absorption of the cutting forces, for which the training is advantageously made such that the distance of the contact point or contact center of the Swivel lever on the spring element is larger from the swivel axis than the distance (a) of the swivel axis from the normal projection the chisel tip on the chisel holder. That way the cutting forces over a correspondingly long lever arm in the Spring element initiated, so that small and stiff Feathers that can be found. The introduction of the Reaction forces in the spring occur in a larger way Distance as the distance of the line of action of the passive forces from the Pivot axis.

Particularly easy adjustability of the desired spring preload for the effective support of the forces mentioned can be achieved in that the pivot lever one the swivel lever between swivel axis and contact point penetrating clamping bolt is pressed against the spring element.

The articulation geometry of the chisel arrangement is according to the invention Advantage chosen so that the resilient support of the pivot lever is selected in the operating position of the chisel so that the effective cutting forces are reduced.

The chisel arrangement according to the invention is described below an embodiment shown schematically in the drawing explained in more detail. 1 shows a side view a swiveling chisel holder on the tool carrier and FIG. 2 shows a top view of the arrangement according to FIG. 1.

In Fig. 1, a cutting bit 1 is shown, which in one Chisel holder 2 is added. The pick of the chisel in the Chisel holder 2 can be in a conventional manner and in particular in around the chisel axis 3 rotatable way to wear to minimize.

The cutting reaction force is indicated by the arrow 4, which is the Direction of the resulting cutting forces corresponds, schematically indicated. This resulting cutting reaction force is composed of a passive force, the vector with 5 and a circumferential force, the vector of which is indicated by 6. The Line of action of the passive force, which is to the center of the rotational movement the tool carrier 7 is directed, is designated 8, wherein the axis of rotation of the tool carrier 7 is indicated by 9 is.

The chisel holder 2 is on a one-armed swivel lever 10 the pivot axis 11 is pivotally mounted, the pivot axis 11 is arranged in a bearing component 12, which with the Tool carrier 7 is connected. The pivoting of the swivel lever 10 about the pivot axis 11 takes place against a spring element 13, which is designed as a leaf spring and also on Tool carrier 7 fixed in a corresponding spring holder 14 is. The bias of the pivot lever 10 against that Spring element 13 is correspondingly via a bolt 15 and nuts 16 set.

The distance a of the swivel axis from the line of action of the cutting normal force the cutting reaction forces are chosen so that that in operation the chisel 1 and the chisel holder 2 against that Spring element 13 can dodge and in this way force peaks can be compensated.

The free end of the pivot lever 10 rests on the spring element 13 and is biased against this spring element 13. The forces are here at a greater distance from the Swivel axis 11 initiated in the spring element 13 as the Distance a between the line of action of the normal cutting force and the swivel axis. The lever arm length over which the reaction forces in the Spring element 13 are derived, is indicated here with b.

The pivot axis 11 is also at a distance c from the cutting track, with a suitable choice of this three distances the desired reduction of the force peaks results.

In Fig. 2 it can be seen that the longitudinal axis 17 of the leaf spring 13 substantially parallel to the pivot axis 11 on the schematic is arranged with 7 indicated tool carrier. The tool carrier itself forms part of the circumference of a cutting head or a cutting roller and is naturally in the representations 1 and 2 shown idealized.

The kinematics of the articulation is as shown in FIG. 1 taken so that the longitudinal axis 18 of the pivot lever 10 with the tangent to the tool carrier 7 an acute angle α of about 20 °, one in Fig. 1 to this tangent parallel line is entered.

Claims (8)

1. A cutter arrangement for cutter bits (1) of a rotationally mounted tool carrier (7) such as, e.g., a cutting head or a cutting roll, in which the tips of the cutter bits are inclinedly arranged so as to lead in the peripheral or rotational direction of the tool carrier (7) and each cutter bit (1) is mounted so as to be tiltable while overcoming a spring force, characterized in that the tilting axis of the cutter bit (1) is arranged on the tool carrier (7) in front of the normal projection of the tip of the cutter bit on the axis of rotation (9) of the tool carrier (7), viewed in the peripheral or rotational direction of the cutter bit (1), and that the cutter bit (1) is tiltably supported against a spring (13) in its engagement position.
2. A cutter arrangement according to claim 1, characterized in that the bit holder (2) is fixed to a single-armed pivot lever (10) whose end facing away from the pivot axis (11) is pressed against a spring element.
3. A cutter arrangement according to claim 1 or 2, characterized in that the application force of the pivot lever (10) against the spring element (13) is adjustable.
4. A cutter arrangement according to claim 1, 2 or 3, characterized in that the longitudinal axis (18) of the pivot lever (10) is hinged to the tool carrier (7) in the region of the pivot axis (11) at an acute angle of smaller than 35°, in particular smaller than 25°, relative to the tangent line.
5. A cutter arrangement according to any one of claims 1 to 4, characterized in that the spring element (13) is comprised of a leaf spring or leaf spring assembly whose longer axis (17) is defined on the tool carrier (7) approximately parallel with the pivot axis (11) of the pivot lever (10).
6. A cutter arrangement according to any one of claims 1 to 5, characterized in that the distance (a) of the pivot axis (11) from the normal projection of the tip of the cutter bit on the bit holder (7) amounts to at least one third, preferably at least half, of the normal distance of the pivot axis (11) from the mine face or the cutting trace plane of the cutter bit (1).
7. A cutter arrangement according to any one of claims 1 to 6, characterized in that the distance of the application point or application center of the pivot lever (10) on the spring element (13) from the pivot axis (11) is larger than the distance (a) of the pivot axis from the normal projection of the tip of the cutter bit on the bit holder (2).
8. A cutter arrangement according to any one of claims 1 to 7, characterized in that the pivot lever (10) is pressed against the spring element (13) by a clamping bolt (15) passing through the pivot lever (10) between said pivot axis (11) and the point of application.

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