RU2116404C1 - Method of advancing direction control in percussion-acting device for driving holes in ground - Google Patents

Abstract

FIELD: construction engineering. SUBSTANCE: this relates to pneumatically-powered devices which can be used for driving holes in ground for laying underground service lines without digging trenches. According to method, hole-driving device is turned in required driving direction due to single-side braking of device body which is asymmetric in longitudinal cross-section. This is achieved by local changing of coefficient of friction along axial and cylindrical surfaces between contacting surfaces of device body and ground. Device for realization of its advance direction control method has following components: axially symmetric cylindrical body, striker with reciprocating motion, mechanism for changing direction of advancing in the form of several elastic balloons located around body circumference with individual supply of working medium such as compressed air. Elastic balloons are arranged in zone of contact between device body and ground. Aforesaid operating procedure and embodiment of device allow for efficient control of advancing direction and for driving hole in required direction. EFFECT: higher efficiency. 11 cl, 11 dwg

Description

 The invention relates to construction equipment and is intended for drilling wells in the ground with the trenchless laying of underground utilities.

 A known method of controlling the direction of movement of the percussion device for driving wells in the soil (US patent N 4632191), the change in direction of movement of which is achieved by applying to the front of its body a radial force from the soil. To implement this method, the front of the device is beveled to the wedge and, in addition, the housing can be rotated using a special impeller interacting with the soil. With the translational movement of the device with rotation, the well is almost straightforward. When driving a curved borehole, the impeller disengages from the casing, the casing does not rotate, the radial force vector acting on the mowed part from the ground does not change direction and deviates the device to the side.

 The disadvantages of the method and device is the large energy consumption for rotation of the body, the violation of the integrity of the walls of the well.

 A known method of controlling the direction of movement of the device for driving wells in the soil (German patent N 2510020), the essence of which is the asymmetric application of a shock pulse relative to the longitudinal axis of the device. This is achieved by performing a striker with a center of gravity displaced relative to the longitudinal axis of the device. When driving a straight hole, the drummer, rotating, inflicts uniform strokes around the longitudinal axis of the device. When driving a curved well, the hammer is fixed in one of the positions and provides asymmetric strikes in this direction only.

 The disadvantage of this method is the low control efficiency due to the small eccentricity of the center of gravity of the drummer.

 A device for driving holes in the soil (as USSR N 236349), including a cylindrical body with a drummer located inside it, is known. On the outer surface of the casing, a shell is pivotally fixed, between the inner surface of which and the casing there are three pneumatic chambers with a separate supply of compressed air. To bend the well, the shell is deployed relative to the body when air is supplied to one or two chambers.

 The disadvantages of the device are the low efficiency of its work due to the increased resistance to penetration into the ground, because the diameter of the hole passed is larger than the diameter of the pneumatic punch.

 A device for drilling holes in the soil, designed to stabilize the direction of movement of the pneumatic punch, containing a cylindrical body with a drummer located inside it. A shell is pivotally attached to the outer surface of the casing, between the outer surface of which and the casing three pneumatic chambers are mounted, the supply of compressed air to which is regulated by a copier attached to the casing of the pneumatic punch. When the well deviates, the copier, fixing the deviation, acts on the spool, providing compressed air to the desired chamber and turning the device in the right direction [1].

 The disadvantages of the device are the inability to penetrate curved wells.

 A device for forming wells in the soil is known, including a pointed cylindrical body with a drummer located in it, a cylindrical shell mounted on the body, and pneumatic cylinders located between the shell and the body and serving to deflect the body during selective air supply to them. The shell is made in the form of two sections located at a certain distance from one another, and the cylinders are grouped in two in each section. The cylinders in one section are perpendicular to the cylinders of the other, while the device is equipped with elastic frames covering the cylinders and the housing [2].

 The disadvantages of the device are the low deviation efficiency due to the large resistances of the sections and the complexity of the device. A common disadvantage of the known devices is the uniformity of the surface of the housing in terms of friction coefficient.

 The technical problem to be solved is improving the efficiency of controlling the direction of movement of the device.

 This is achieved by the fact that on the part of the surface of the casing located on one side of the longitudinal axis of the device, the magnitude of the coefficient of friction of the casing against the soil is changed, which causes the appearance of an asymmetric friction force, which turns the device to the side.

 It is advisable to use a material with a greater or lesser coefficient of friction on the part of the contact surface of the housing with the ground than the friction of the opposite part of the housing surface on the ground. This operation allows you to create a braking force, deploying the device in the desired direction.

 It is advisable to simultaneously apply a radial force along with a change in the coefficient of friction on a part of the housing surface in contact with the soil in the same region. This operation allows you to increase the efficiency of rotation of the device.

 It is advisable in the device for punching wells in the soil, which implements the proposed method of controlling the direction of its movement and includes a cylindrical body, a drummer moving reciprocating, a mechanism for changing the direction of movement of the pneumatic punch, made in the form of several elastic cylinders placed around the circumference of the body, with an individual supply of working environment (compressed air, liquid), cylinders should be placed in the contact zone of the pneumatic punch body with soil. This embodiment of the device allows you to locally change the force on the surface of the housing, which contributes to its rotation.

 It is advisable to place flexible cylinders on the surface in the rear of the body of the pneumatic punch or expander attached to the device. This embodiment allows to increase the radial force and the friction force, turning the device.

 It is advisable to provide the device with rods connecting two elastic cylinders placed on both sides of the axis of the device. This embodiment ensures the return of the elastic balloon to its original position.

 It is advisable to arrange the rods in parallel planes. This embodiment of the device design provides a uniform return of the elastic balloon to its original position.

 It is advisable to provide the outer surfaces of the rods in the part where they cover the elastic cylinders with cylindrical plates of material with a coefficient of friction greater than the coefficient of friction of the metal on the ground (for example ferodo, rubber). This design provides a friction force, deploying the housing of the device, and the protection of the cylinders from gust when interacting with soil inclusions.

 It is advisable to front and rear ends of the plate in a longitudinal section to perform inclined to the side surface of the device. This embodiment of the device improves the reliability of penetration.

 In FIG. 1 shows a General view of the proposed device; in FIG. 2 is a section AA in FIG. one; in FIG. 3 - a device with an expander and elastic cylinders located in the rear of the pneumatic punch body; in FIG. 4 - a device in which elastic cylinders are placed on the expander; in FIG. 5 - a device with two sections of elastic cylinders located one after another along the longitudinal axis; in FIG. 6 is a cross section BB in FIG. 5; in FIG. 7 is a cross section BB of FIG. 5; in FIG. 8 is an embodiment of a device with rods attached at its ends to elastic cylinders in section BB in FIG. 5; in FIG. 9 - thrust with cylindrical shells covering the cylinders, placed along the vertical axis of sections BB in FIG. 5; in FIG. 10 - the position of the rods when the device is turned upward in section BB in FIG. 5; in FIG. 11 - the position of the rods when the device is turned to the left in section BB in FIG. 5.

 The essence of the proposed method of controlling a percussion device.

 When driving a well, the axisymmetric body of the device perceives the same resistance from all sides. In homogeneous soils, therefore, it moves rectilinearly. In cases where it is necessary to obtain a curved well, it is necessary to create an asymmetric braking force that will deploy the device for movement along a curved path. To do this, on the one hand relative to the longitudinal axis of the housing change the coefficient of friction on the surface area of the housing interacting with the soil. As a result, an asymmetric force is created, which ensures the rotation of the device when it is necessary to change the direction of penetration.

 To increase the rotation efficiency of the device, it is advisable to apply a radial force at the place of change of the friction coefficient. In this case, a double effect is realized.

 Example. Impact device - pneumatic punch 1 (Fig. 2) is made in the form of a cylindrical body 2 with elastic cylinders 3-6 placed around the circumference (Fig. 2) with individual highways 7 supplying a working medium (air or liquid) to any of the cylinders. The cylinders are placed sequentially one after another (Fig. 2) around the circumference or in two rows along the length of the device (Fig. 5), each of which has two cylinders in pairs that control the movement in horizontal (Fig. 7) or vertical (Fig. 6) ) plane. In the latter case, elastic cylinders placed on both sides of the longitudinal axis of symmetry can be interconnected by rods 9 and 10, as shown in FIG. 8 - 11. It is possible to carry out rods 9 and 10 with cylindrical shells 11 and 12 along the periphery, covering elastic cylinders 3, 6 and 4, 5 (Figs. 9 - 11). In this case, plates 13 and 14 of material having a high coefficient of friction, for example of ferodo, can be fixed on the cylindrical surfaces of these surfaces. Cylinders 3 - 6 can be located on the surface of the casing 2 of the pneumatic punch 1 (Fig. 1 and 2) or on the expander 17 (Fig. 4). When using rods 9 and 10 with peripheral cylindrical plates 13 and 14, it is advisable to form conical surfaces 15 and 16 on their front and rear ends (Fig. 5).

 The principle of operation of the proposed device for punching wells in the ground.

 Straight hole drilling.

 Compressed air entering the pneumatic punch 1 leads to a reciprocating motion (not shown), which strikes the housing 2. The shock pulses created by the pneumatic punch 1 propel the device forward and it forms a well in the ground with its front surface. Due to the axial symmetry of the casing 2 of the device, a straight borehole is formed in a homogeneous soil.

 Drilling a curved well.

 Compressed air through line 7 enters an elastic container, for example 3, inflating the latter. In contact with the wall of the well, the cylinder creates a radial friction force, which tend to deflect the device from the original direction.

 When using a device with rods 9 and 10, an inflated balloon pulls up a cylinder located on the other side of the longitudinal axis. The execution of rods 9 and 10 with cylindrical shells 11 and 12 on the periphery, which cover the cylinders located on both sides of the longitudinal axis of the device, protect the cylinders when they meet with the inclusion in the ground. Ferodo plates 13 and 14 can be attached to shells 11 and 12 (FIGS. 9 and 10). In this embodiment, the cylindrical shells 11 and 12 of the rods 9 and 10, equipped with conical surfaces 15 and 16 when the device moves (forward, backward), will not destroy the soil surface of the well. The presence of rods 9 and 10, located at a distance greater than the diameter of the housing 2, allows, without applying much effort, to move them behind an inflated elastic balloon. If it is necessary, after turning, to pass a straight borehole into the container 6, located on the other side of the deformed cylinder 3, compressed air is supplied and thereby the inflatable balloon 6 is installed due to the rods outside the contact surface of the housing 2 (expanders 17) with soil. Compressed air from cylinder 3 is removed through line 7.

 If, during a straight hole, a device is encountered turning on or falling into repeated soil, an asymmetric force from the soil acts on it, turning the device off the track. To stabilize the direction of movement, it is necessary to supply compressed air (liquid) to an elastic cylinder located on the other side from the action of the resulting shear force.

 By the pressure of compressed air (liquid) supplied to the elastic cylinder, the direction of movement of the pneumatic punch can be regulated during the drilling of the wells.

 The application of the proposed device allows you to control the direction of movement of the pneumatic punch in the vertical and horizontal planes, which will ensure the penetration of rectilinear wells in heterogeneous soils, if necessary - curvilinear wells.

Claims (11)

 1. The method of controlling the direction of movement of the percussion device for drilling holes in the soil (pneumatic punch), including turning the latter in the direction of the desired direction of movement due to the application of a force asymmetric in the cross section of the device casing, characterized in that the coefficient is changed on one side relative to the longitudinal axis of the casing friction of a part of the surface of the body interacting with the soil.  2. The method according to claim 1, characterized in that the coefficient of friction is changed due to the fact that a material with a greater or lesser coefficient of friction is introduced onto a part of the contact surface of the device’s casing with soil than the friction of another part of the casing’s surface against the ground.  3. The method according to claim 1 or 2, characterized in that at the same time as changing the coefficient of friction on the part of the surface of the housing contacting with the soil, a radial force is applied in the same region.  4. A device for punching wells in the ground (pneumatic punch), including a symmetrical cylindrical body, a striker moving reciprocating, a mechanism for changing the direction of movement of the pneumatic punch in the form of several elastic cylinders with an individual supply of a working medium (compressed air, liquid), characterized in that elastic cylinders are placed in the contact zone of the device casing with the ground.  5. The device according to claim 4, characterized in that the elastic cylinders are located in the rear of the pneumatic piercer body.  6. The device according to claim 4, characterized in that it is made with an expander attached to the housing, and elastic cylinders are placed in the rear of the expander.  7. The device according to any one of paragraphs.4 to 6, characterized in that it is made with rods connecting two elastic cylinders located on both sides of the longitudinal axis of the device, while the rods are located on both sides of the device.  8. The device according to claim 7, characterized in that the rods are located in parallel planes.  9. The device according to claim 7, characterized in that the peripheral traction encompasses elastic cylinders placed on both sides of the longitudinal axis of the pneumatic punch, and plates of material with a coefficient of friction exceeding the coefficient of friction of the body against the ground are fixed on their outer surface.  10. The device according to p. 9, characterized in that the front and rear ends of the plate in longitudinal section are made inclined to the side surface of the device.  11. The device according to any one of paragraphs.7 to 10, characterized in that the rods are made of material with a coefficient of friction greater (less) than the coefficient of friction of the metal on the ground, for example, from rubber or "ferodo".

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