GB2150615A

GB2150615A - Tunnel driving machine and method

Info

Publication number: GB2150615A
Application number: GB08430197A
Authority: GB
Inventors: Johannes Henneke; Heinz Horst
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1983-11-29
Filing date: 1984-11-29
Publication date: 1985-07-03
Also published as: FR2555655A1; GB2150615B; DE3343120C1; GB8430197D0; FR2555655B1

Abstract

A tunnel driving machine comprises a frame on which a pair of cutters 7,8 are pivoted for movement about a vertical axis. Each cutter is of blade-like form and disposed at an angle of substantially 90 DEG with respect to the other. Rams 10 serve to move each cutter through an angle of substantially 90 DEG . Cutting tools 9 are arranged along a line corresponding to the profile of one half of the tunnel to be driven. <IMAGE>

Description

SPECIFICATION Tunnel driving machine and method It is known to drive a tunnel using a cutting head which rotates about a horizontal axis coinciding with the desired axis of the tunnel.

A full-face machine of this type is capable of producing only tunnels of circular cross-section, generally of a fixed diameter.

An alternative type of machine has a cutting head mounted on an arm which can be rotated about a horizontal axis extending parallel to the desired axis of the tunnel. The cutting head can be moved along the arm to enable various parts of the face to be attacked, and in this way tunnels of various profiles can be produced. However, the accuracy of the operation depends largely upon the skill of the operator unless the operation is pre-programmed. Another disvadvange is that, because only a small part of the face can be worked by the cutting head at any one time, the efficiency of the machine is relatively low.

The machine proposed herein enables a wide variety of tunnel profiles to be driven by making use of a blade-like cutter which can be turned about a vertical axis. The cutter may include a tool carrier, conveniently in the form of a planar structure or frame. Cutting tools are arranged on the carrier along a line corresponding to the profile of one half of the tunnel to be driven. By rotating the carrier about its vertical axis through an angle of up to 90 , one half of the tunnel profile is cut out. If the carrier is turned through a further angle of up to 90 , the remainder of the profile is cut out. Preferably, however, use is made of a pair of such blade-like cutters, each of which turns through an angle of substantially 90 , either about an axis common to both cutters or about respective spaced apart axes.

Compared with the construction which incorporates a single cutter, a machine with a pair of cutters can produce a greater output, provided that the rock is suitable. A simpler form of drive mechanism is also made possible, consising essentially of rams coupled between the frame of the machine and the tool holders, compared with a rack and pinion arrangement, or its equivalent, required for the single cutter machine.

The pivots of the two tool carriers may be mounted eccentrically on a shaft or other holder which is angularly adjustable through 180 , the pivot axes being disposed directly opposite each other. In this way, it is possible for one cutter to be brought into a position in which it performs its cutting operation while the other performs an idle movement. By intermittently rotating the vertical shaft, the two halves of the face are alternately attacked.

In the drawings: Figure 1 consists of cross-sections through three alternative tunnels which can be produced using the proposed machine, Figure 2 is a diagrammatic plan view of a first machine in accordance with the present proposal, Figure 3 is a detail of a modification of the machine shown in Fig. 2, Figure 4 is a diagrammatic section through the cutter carrier, Figures 5a to 5e show the sequence of operations of the machine in Figs. 3 and 4, Figure 6 is a side view of the machine shown in Figs. 3 and 4, Figure 7a is a partly sectioned plan view of a third construction of machine showing a first operating position, Figure 7b is a view similar to Fig. 7a but showing a second operating position, Figure 8a is a partly sectioned plan view showing a fourth construction of machine in a first position, and Figure 8b is a view similar to Fig. 8a showing a second position.

Referring to Fig. 2, a tunnel driving machine illustrated in partly sectioned plan view comprises a frame 1 braced against the side walls of the heading by chocks 2 capable of being urged outwards by rams 3. Mounted on the frame is a guide for a longitudinally extending cylinder 4 receiving a piston 4a, the rod of which is coupled to the frame.

Mounted on a forward extension of the cylinder are bearings for a vertical shaft 5 on which is mounted a cutting unit comprising a pair of essentially planar cutters, each of which is arranged to sweep through a quarter of a circle and remove one half of the face.

The cutting unit includes blades or frames 7 and 8 supported for rotation on the shaft by way of collars 7a and 8a respectively, the blades being arranged in respective vertical planes spaced from each other by an angle of 90 , and connected together to form a rigid structure by horizontal webs 6.

The distal end of each blade 7 and 8 is provided with cutting tools. In the illustrated machine, the cutting tools are in the form of conventional disc cutters 9. The shape of the distal end of the blade and the arrangement of the cutting tools thereon depends upon the cross-section of the tunnel to be driven, and conforms to one-half of this cross-section.

Thus, as shown in Fig. 1a, a blade having the shoe 7a shown therein may be used to cut out a tunnel having a semi-circular roof surmounting inwardly inclined walls. By omitting the quandrant-shaped portion of the blade, and using a blade having the shape 7b shown in Fig. 1 b, a tunnel of trapezoidal crosssection may be driven, and by using a blade 7c which is substantially square in crosssection, the rectangular cross-section tunnel shown in Fig. 1c may be driven.

In each case, all of the edges of the blade which make contact with the rock are pro vided with cutting tools throughout their lengths, although only one such tool is depicted herein. With all of the examples, it is possible by an appropriate arrangement of the cutting tools to produce very sharp and cleanly cut corners in the tunnel heading profile. It will aiso be evident that it is possible to drive headings having asymmetrical profiles, for example by combining a blade having the shape shown at 7b with a blade the shape shown at 7c. A profile is then produced, which in one half corresponds to the form shown in Fig. 1 b and in the other half to the form shown in Fig. ic.

Each of the blades has a bracket 1 3 with an articulation point 1 2 for the rod of a piston and cylinder unit 10 articulated at 11 to a bracket fast with the cylinder 4. It will be appreciated from a consideration of Fig. 2, that by retracting the right-hand side ram 10, and extending the left-hand side ram 10, the cutting unit may be made to swing through 90 in the clockwise direction, all as viewed, into a position which appears to be the mirror image of that shown. The piston and cylinder unit 4 applies the tools to the face with the desired pressure.

The rock loosened from the concave face 14 is removed using conveying devices not shown in the drawing. As soon as the piston and cylinder unit 4, 4a has completed its advancing stroke, the blades being in their mirror image position, the chocks 2 are withdrawn from the heading walls, and the frame is moved forwards by admitting fluid to the other chamber of the other cylinder.

When the frame is in its new position, the chocks are again applied to the wall and the machine is ready for a subsequent operation, in which the cutting unit performs a return movement through 90 , but into the position shown in Fig. 2.

In connection with a machine having a single blade-like cutter, the length of the blade may be greater than one-half the width of the machine frame, which will enable different widths of headings to be produced, provided that the frame is capable of being braced in wider headings. The width of the heading then depends only upon the angle through which the blade is pivoted laterally from its central position. A similar effect might be produced in the case of the embodiment with two blade-like cutters, by arranging for the blades to turn through an angle of less than 90 from the central position.

Although Fig. 2 shows the machine to have two blades, spaced from each other through 90 , so that each blade is required to move only through that angle, it is conceivable to omit the blade 8 and to arrange for the blade 7 to turn through 180'. The mechanism for producing this movement may be in the form of a rack made to reciprocate by the piston and cylinder unit, 4, 4a and a pinion on the shaft 5.

The machine shown in Fig. 2 is suitable for performing a cutting operation in relatively soft rock. In relatively hard rock, it is preferred for the face to be attacked by the tools of a single blade at one time. A device is therefore required which will present the tools of one blade to the face, while those of the other balde are withdrawn from the face, while the blades sweep simultaneously across it. This may be achieved, as shown in Fig. 3, by arranging for the blade 7 and 8 to turn about respective axes 1 5 and 1 6 both located in the central longitudinal plane of the machine but spaced apart from each other. Each cutting operation is performed with an alternate one of the blade axes in front of the other.Thus, as illustrated, when the cutting unit is rotated, the cutting tools of the blade 7 will be in work, while those of the blade 8 will sweep substantially ineffectively across the face. In preparation for the next cutting stroke, the axis 1 6 will be moved ahead of the axis 15, and it is the cutting tools of the blade 8 which will perform the cutting stroke, while those of the blade 7 sweep ineffectively across the face, to return to the illustrated position.

The distance between the two axes must be related to the depth of cut of the tools. Of course, although this arrangement has been described as allowing one of the cutters to sweep ineffectively across the face, depending upon the hardness of the rock, it may be acceptable for it to perform a reduced cutting action.

A working cycle employing this procedure is illustrated in Fig. 5. In the first illustration, a, the stage is depicted in which the axis 1 5 is ahead of the axis 1 6 and the cutting unit is half-way through its arc of rotation in the clockwise direction, the tools of the blade 7 being shown attacking the remaining land of rock on the left-hand side of the tunnel. The tools of the blade 8 slide over the surface of the face produced during the previous step.

Fig. 5b shows the cutters in the position they occupy at the end of the first phase of operation, the cutters having been brought to a halt. With the cutters so positioned, the chocks 2 are released and the fame 1 advanced. The axis 1 6 is now brought in front of the axis 15, as shown in Fig. 5c. Resulting from this movement, the tools and centre of rotation of blade 7 do not change their positions. The centre of rotation of the blade 8 is, however, moved forward by the depth of cut.

The tools of the blade 8 may move forward, or may alternatively retain their existing position with the result that the cutting unit adopts a position slightly beyond the quadrant. In any event, when the cutting unit is rotated in the counter-clockwise direction into the position shown in Fig, 5d, the tools of blade 8 remove an arcuate, wedge-like slice of face which increases in thickness towards the centre plane. The tools of blade 7, however, slide over the surface of the face cut during the phase shown in Fig. 5a. With the cutting unit in the position shown in Fig. 5b, the frame is advanced and the axis 1 5 brought in front of the axis 16, into the position shown in Fig. 5e.

It will appreciated from Figs. Sc and 5d, that the side walls of the tunnel are cut finely, the maximum depth of cut being in the centre plane of the tunnel, so that the side walls of the finished tunnel are formed very accurately.

A first embodiment of machine for moperating in accordance with the working cycle depicted in Fig. 5 is shown in Fig. 6, in side view. The view corresponds to that shown in Fig. 5b in which the blade 7 is in its limiting position coinciding with the longitudinal central plane of the tunnel. The eccentric 15 is in its forward position as shownin Fig. 4. The vertical shaft on which the cutters are supported is indicated at 1 7 and is journalled in bearings in the upper, lower and mid-part of the machine frame. The shaft has eccentrics with axes IS and 16, on which the collars 7a and 8a are supported for rotation. The arrangement is shown in a diagrammatic sectional view in Fig. 4, wherein the distance between the two axes is indicated at E, this distance being twice the eccentricity of the shaft.The paths followed by these axes as the shaft is stepped forward following the end of each phase are indicated in broken lines.

To ensure a coordinated oscillating movement of the blades 7 and 8 which are unconnected, the cylinders 10 are connected to a control device.

Of course, one cutter might be arranged to turn about the axis of the shaft itself, and the other about an eccentric axis.

The embodiment shown in Figs. 7a and 7b has characteristics of the machines hereinbefore described which have on the one hand rigidly interconnected cutting blades, and on the other hand independently movable blades.

This embodiment includes a tool carrier 6 pivoted on the advancing ram by a joint 5.

The piston rods of rams 10 are articulated to brackets 1 3 and serve to turn the tool carrier between the positions shpwn in the two Figures. The tool carrier is generally triangular in plan, being pivoted to the advancing ram at its apex, and having its other vertices shaped to conform to the tunnel wall to be produced in the manner indicated in Fig. 6. At intervals along the length of one vertex, the carrier is provided with cylinders 20a which receive pistons 1 9a connected to pistons rods 1 8a which project from the carrier and bear the cutting discs 9a. A long the length of the other vertex, the carrier is provided with cylinders 20b receiving pistons 1 9b with piston rods 1 8b bearing cutting discs 9b.

In operation, with the carrier in the position shown in Fig. 7a, and moving towards that shown in Fig. 7b, the cylinders 20b are pressurised to urge the pistons outwards and force the cutting discs against the face. The cylinders 20a, on the other hand, are pressurised in the sense of withdrawing the pistons 1 9a and removing the cutting discs 9a from the face, or at least reducing their cutting pressure. The cutting discs 9b thereby remove the wedge-shaped strip of rock indicated by hatching. When the carrier has reached the position shown in Fig. 7b, the fluid supply to the cylinders is reversed, so that the cutting disc 9a is urged against the face, and the cutting discs 9b withdrawn from the face.

This embodiment has the advantage that the pressure fluid actuation permits a very accurate setting and limiting of the cutting pressure. Also, if necessary, both groups of tools can be simultaneously brought into the working position when the nature of the rock permits it.

A machine working on a similar principle is depicted in Figs. 8 and 9, although with this arrangement it is not possible to bring both sets of tools into work simultaneously. In this machine, the tools are carried on opposite ends of a rocker 21, mounted on the carrier 6 by a pivot pin 22. Pairs of oppositely directed cylinders are pivoted on the carrier by pins 26 and have pistons 23a and 23b respectively articulated to the rocker at 25.

In operation, at the start of the working cycle shown in Fig. 8a, the cylinders are pressurised so as to urge the piston 23b outwards and the piston 23a inwards. The rocker is turned relative to the carrier in the counterclockwise direction so as to urge the right-hand side cutting discs against the face and withdraw the left-hand discs from it.

When the rocker reaches the position shown in Fig. 8b, the supply to the cylinders is reversed so as to withdrawn the left-hand cutting discs from the face, and to apply the right-hand cutting discs to it.

It may be possible for the pivot axis or axes to be inclined somewhat from the true vertical and still achieve the desired objective.

Claims

1. A tunnel driving machine comprising a frame to which a blade- like cutter is pivoted about a vertical axis, operating means for moving the blade about a vertical axis, the cutter being provided with cutting tools along a line corresponding to the profile of one half of the tunnel to be driven.

2. A machine according to claim 1, wherein the cutter is movable through an angle of substantially 180 .

3. A tunnel driving machine comprising a frame on which a pair of cutters are pivoted for movement about a vertical axis, each cutter being of blade-like form and disposed at an angle of substantially 90 with respect to the other, means for moving each cutter through an angle of substantially 90", each cutter having cutting tools disposed along a line corresponding to the profile of one half of the tunnel to be driven.

4. A tunnel driving machine comprising a frame on which a pair of cuters are pivoted for movement about respective vertical axes, each cutter being of blade-like form and disposed at an angle of substantially 90 with respect to the other, means for moving each cutter through an angle of substantially 90 , and means for interchanging the axes, cutting tools being disposed on each cutter along a line corresponding to the profile of one half of the tunnel to be driven.

5. A machine according to claim 4, wherein the cutters are mounted to turn about axes, at least one of which is eccentric on a support shaft which is angularly displaceable through 180 about a vertical axis, thereby to present the cutters alternately to the face.

6. A machine according to claim 4, wherein the distance between the pivot axes (E) corresponds to the cutting depth of the tools.

7. A machine according to any preceding claim, wherein the drive for the or each cutter comprises at least one double-acting ram.

8. A machine according to any preceding claim, wherein the or each cutter has tools mounted on a carrier such that the tools can be moved into and out of a working position.

9. A machine according to claim 8, including fluid operated ram means for adjusting the tools relative to the carrier.

10. A machine according to claim 9, wherein the tools are coupled to the pistons of piston and cylinder units.

11. A machine according to claim 8, wherein the tools of the or each carrier are mounted on a rocker pivotal on the carrier, the rocker being adjustable by piston and cylinder units provided between the carrier and the rocker.

12. A tunnel driving machine substantially as hereinbefore described with reference to and as illustrated in Fig. 2 or Fig. 3, Fig. 6, Figs. 7a and 7b or Figs. 8a and 8b of the drawings.

1 3. A method of driving a tunnel comprising angularly adjusting a blade-like cutter about a vertical axis, the carrier being provided with cutting means arranged along a line corresponding to the profile of the tunnel to be driven.

14. A method of driving a tunnel substantially as hereinbefore described with reference to and as illustrated in Fig. 3 or Fig. 5 of the drawings.