JP5093767B2 - Enlarged head with fluid pressure and single flow path switching by forward / reverse rotation - Google Patents

Description

  The present invention relates to an expansion head provided at a lower end portion of a drilling work rod such as a drilling screw rod or a drilling agitation rod, and having an expansion blade expanded or contracted by a fluid pressure cylinder.

  As a conventionally known expansion head, the expansion blade is pivotally supported in the expansion / contraction direction on the outer periphery of the drilling blade at the lower end of the screw rod, and the expansion blade is closed and contracted by the surrounding earth pressure during excavation by the positive rotation of the screw rod. However, in the case of expansion excavation, there is one that reversely rotates the screw rod and expands the expansion blade by the surrounding earth pressure. (See Patent Document 1)

  However, the above-mentioned conventional head not only lacks the reliability of the expansion / contraction operation, but also the expansion blade expands to the maximum opening at a time during reverse rotation, so an excessive load is applied to the rotation drive part, especially the expansion of hard ground During drilling, the screw rod often became non-rotatable.

  In order to remedy this, a cylinder that expands with a hydraulic cylinder has been developed. Among them, a double-acting hydraulic cylinder is built in the head rod, and two oil flow paths for supplying and discharging hydraulic pressure to the cylinder are installed in the screw rod. (See Patent Document 1), the structure of the connecting joint of the screw rod is complicated and large in size, and as a result, the passing area of the excavated sediment on the outer periphery of the screw rod connecting section is reduced, and the soil removal function is reduced. There was a difficulty to reduce. (See Patent Document 2)

  As another example of improving the above-mentioned difficulty, a single-acting hydraulic cylinder with a built-in spring is incorporated in the head rod and one oil passage is vertically passed through the screw rod (see Patent Document 2). However, it is the spring force in the cylinder that holds the position of the expansion blade against the earth pressure resistance and excavation resistance when the expansion head moves up and down. In order to prevent this, there has been a problem that the spring needs to be strengthened and enlarged.

For these reasons, the method of Patent Document 4 has been proposed. In this method, a battery is built in the head rod, the pressure of the pressure fluid that operates the cylinder is detected, and the pressure fluid is detected by an electromagnetic switching valve based on the signal. Not only is the maintenance and replacement of the battery troublesome because it switches the flow path and expands and contracts the expansion blades, but it is also used under harsh working conditions such as vibration and wet environments, so troubles such as malfunction of the electric circuit and leakage It sometimes occurred. (See Patent Document 4)
JP2003-239669 JP 2002-322890 A Shoko Sho 62-35745 JP 2006-009540 A

  The first invention of the present application uses a fluid pressure cylinder without a spring as expansion / contraction driving means for the expansion blade, and the cylinder is driven by a single fluid pressure flow path vertically connected to the work rod, thereby connecting the work rod. The objective is to provide an enlarged head that can be simplified and reduced in size, and that is easy to maintain,

  In addition to the problem of the first invention, the second invention of the present application has an object to provide an expansion head capable of expanding and contracting the expansion blade at an arbitrary opening degree even when the expansion head moves up and down.

  The third invention of the present application has an object to provide an enlarged head in which the discharge of fluid does not cause an environmental problem in addition to the problems of the first and second inventions.

Means to solve the problem

The first invention of the present application incorporates a fluid pressure cylinder in the head rod at the lower end portion of the excavation work rod, and vertically passes through one excavation work rod a fluid passage for supplying pressure fluid from the outside to the cylinder. In a configuration in which an enlarged blade that is expanded and contracted by driving the fluid pressure cylinder is provided on the outer periphery of the head rod,
A resistance plate that swings according to the direction of rotation of the head rod is provided, and the switching valve for switching the fluid flow path to the fluid pressure cylinder is operated mechanically by swinging the resistance plate to expand and contract the expansion blade. It is in the magnifying head characterized by that.

Further, the second invention of the present application is connected to a fluid pressure circuit including a fluid pressure pump in which the fluid passage of the one system is arranged outside and a switching valve for fluid passage switching to at least a fluid pressure cylinder,
2. A flow meter for measuring a fluid amount to the fluid pressure cylinder is provided in the fluid passage of the one system, and the flow rate of the expansion blade can be increased or reduced by the flow rate. In the expansion head.

  Further, the third invention of the present application is the expansion head according to claim 1 or 2, wherein water is used as a fluid.

Effect of the invention

  The expansion head that mechanically switches by forward / reverse rotation operation according to the first invention of the present application is supplied through a single-fluid flow path vertically connected to the excavation work rod through a conventional single-acting hydraulic cylinder with a built-in spring. Unlike the expansion head, which is driven in one direction by fluid pressure and driven in the other direction by the spring, the fluid flow line switching valve is connected to the fluid pressure cylinder by swinging the resistance plate. Operates and expands / contracts the expansion wings. Like the conventional head, the connecting portion of the excavation work rod can be reduced in size with a simple structure, and maintenance is performed because the expansion / contraction switching is performed mechanically. It becomes easy.

  The expansion head of the second invention of the present application is provided with a flow meter for measuring the amount of fluid to the fluid pressure cylinder in one system of fluid passage in the first invention, and in addition to the first invention, by this flow rate, Since the expansion blades can be expanded and contracted to an arbitrary opening, it is possible to perform an expansion excavation with a desired opening, and avoid the trouble caused by an excessive load by gradually expanding and contracting the expansion blades.

  As 3rd invention of this application, even if it discharge | releases in an original ground by using water as a fluid, a problem does not generate | occur | produce.

  The present invention will be described below with reference to embodiments shown in the drawings.

FIG. 1 shows an embodiment of an enlargement head having a mechanical switching mechanism by forward / reverse rotation operation used for carrying out the present invention. The enlargement head operated by water pressure is attached to the lower end portion of a general drilling screw rod 1. 2, a hollow head rod 4 is connected to the lower end of the main body rod 3 on the same axis, and a pair of enlarged wings 5 and 5 are provided on the outer periphery of the head rod 4. A hydraulic cylinder 16 for expanding and contracting the expansion blades 5 and 5 is provided.
The expansion blades 5 and 5 are configured to expand when the piston rod 15 moves upward, and close and contract when the piston rod 15 moves downward. The pair of expansion blades 5 and 5 are arranged on the outer peripheral surface of the head rod 4. Brackets 30, 30 projecting at positions opposed to the vertical direction are supported by shafts 31, 31 at the blade base end so as to be swingable on a plane passing through the axis of the head rod 4. An expansion blade expansion / contraction bracket 32 having both ends projecting at positions in the diameter direction on the outer peripheral surface of the lower end portion of the cylinder 16 protrudes through elongated holes 33, 33 formed in the peripheral wall of the head rod 4 in the busbar direction. One end portions of the operating links 34 and 34 are pivotally connected to the projecting portion of the bracket 32 by shafts 35 and 35, respectively, and the other end portions of the operating links 34 and 34 are connected to the base end of the intermediate portion of the expanding blades 5 and 5. Stop It is swingably connected respectively by a shaft 36 and 36 to the position.

Further, as shown in FIG. 2 which is a sectional view taken along the line XX in FIG. 1, a swing bracket 7 having a recess 22 inside on the outer periphery of the head rod 4 is inserted so as to be swingable. A resistance plate 9 is fixed to the head rod 4, and a stopper 8,... For restricting the rotational swing of the resistance plates 9, 9 is fixed to the head rod 4 side.
A flow path switching valve 10 for sending the pressure water from the hydraulic unit 17 to the upper part or the lower part of the piston 14 of the hydraulic cylinder 16 is slidably embedded in the head rod 4 by a spring 23 support. 22, the switching pin 24 of the flow path switching valve 10 protrudes, and the bracket 7 is moved from the left side to the right side stopper 8 by earth pressure applied to the resistance plates 9, 9 by the reverse rotation of the head rod 4.・ It moves to. At this time, the state of the switching pin 24 portion of the flow path switching valve 10 moves from the recess 21 portion of the bracket 7 (FIG. 2-1) to the portion without the recess 21 (FIG. 2-2). It is configured to be pushed into the rod 4 and thereby switch the flow path. In addition, the water in the cylinder 16 sent out by the water supply from the water pressure unit 17 to the hydraulic cylinder 16 is discharged from the check valve 13 through the D flow path from the switching valve 10.

As shown in FIG. 3, the hydraulic unit 17 is provided with a hydraulic pump 18, a relief valve 21 for avoiding abnormally high pressure in the pressurized water discharge line A, a water supply valve 20, and a flow meter 19 for determining the opening degree of the enlarged blade 5. It has been.
Further, pilot check valves 11 and 12 that are operated with both flow path pressures are disposed between the flow path switching valve 10 and the pressure water flow paths B and C of the hydraulic cylinder 16.

  Next, the operation of the above embodiment will be described with reference to FIGS.

  First, vertical excavation is performed in a state in which the expansion blades 5 and 5 are closed (FIG. 3A), and when the expansion blades 5 and 5 are expanded in the middle of excavation or at the end of a predetermined depth, the head is used as it is. While rotating the rod 4, the water supply valve 20 of the water pressure unit 17 is opened to drive the water pressure pump 18, and from the previously created opening (excavation diameter) -pressure water supply amount table, to the desired expansion blade 5 and 5 opening. Corresponding pressurized water is measured and fed by the flow meter 19. At this time, the pressurized water from the hydraulic unit 17 is sent to the lower side of the hydraulic cylinder 16 via the flow path A, the switching valve 10 and the pilot check valve 11 to push up the piston 14 ((b) in FIG. 3). Then, the pilot check valve 12 is opened by applying pressure to the B flow path by the amount removed by pushing up the piston 14 in the water previously filled in the upper part of the hydraulic cylinder 16, and the C flow path, the switching valve 10, the D flow It is discharged into the ground from the check valve 13 via the road. At this time, in this example, since water is used as a fluid, environmental problems do not occur even if it is discharged into the ground. Then, when the pressure water supply amount reaches a predetermined water amount, the water supply valve 20 in the water pressure unit 17 is closed and the water pressure pump 18 is stopped.

  By repeating this operation, the expansion blades 5 and 5 can be gradually expanded without sudden expansion, and expansion excavation at a desired opening degree can be performed at an arbitrary place. FIG. 3 (C) shows a state in which the piston 14 is pushed up to the uppermost position by water supply, that is, the enlarged blades 5 and 5 are in the maximum opening.

  In the actual widening excavation, the water supply valve 20 in the hydraulic unit 17 is opened at a desired position where the vertical excavation is performed, and then the expansion blades 5 and 5 are expanded to a fixed opening degree in the middle by the above method. 20 is closed, the first stage widening excavation is performed, and then the water supply valve 20 is opened again to further increase the opening of the expansion blades 5 and 5 by the above-described method. Widening excavation can be performed gradually by repeating the operation of widening excavation a predetermined number of times, so that the expansion blades 5 and 5 are expanded to the maximum opening at a stretch, adding excessive addition to the rotation drive unit, and the screw rod cannot rotate There is no such thing as reaching.

  In this way, when the desired widening excavation or intermediate widening excavation is completed, the rotation of the main body rod 3 is reversed. By doing so, the bracket 7 is moved from the left side to the right stopper 8 by the earth pressure applied to the resistance plates 9, 9, so that the depression 22 of the bracket 7 also moves to the right side. The protruding pin 24 of the flow path switching valve 10 is pushed into the head rod 4 and the flow path of the switching valve 10 is switched ((2-2) in FIG. 2, (D) in FIG. 3). In this state, the water supply valve 20 in the water pressure unit 17 is opened and pressure water is sent from the flow path A to the upper part of the cylinder 16 via the flow path C, whereby the piston 14 is pushed down and the enlarged blades 5 and 5 are closed. Shrink. At this time, the pilot check valve 11 is opened by the pressure applied to the C flow path by the amount that is removed by pushing down the piston 14 in the water filled in the lower part of the hydraulic cylinder 16, and the B flow path, the switching valve 10, the D flow It is discharged into the ground from the check valve 13 via the road.

  Further, when performing widening excavation on the way, closing the expansion blades 5 and 5 and continuing the closed excavation, and performing widening excavation again, the rotation of the main body rod 3 is reversed when the desired widening position is reached. . In this way, the resistance plate 9, the earth pressure applied to the bracket 7 moves from the right side to the left side stopper 8..., So that the pin 24 of the switching valve 10 pushed into the head rod 4 is It will protrude in the hollow 22 of the bracket 7 which appeared ((2-1) of FIG. 2, (A) of FIG. 3), and the flow path of the switching valve 10 switches. At that time, the water supply valve 20 of the water pressure unit 17 is opened and the water pressure pump 18 is driven, and the pressure corresponding to the desired expansion blade 5 and 5 opening is determined from the previously created opening (excavation diameter) -pressure supply amount table. By measuring and feeding water with the flow meter 19, widening excavation can be performed again.

  And finally, by the same method, the expansion wings 5 and 5 are closed and contracted, the main body rod 3 is lifted to the ground, and widening excavation is completed.

  In this way, the desired expanded excavation can be performed without the various problems listed as challenges.

  The longitudinal section front view showing one embodiment of the expansion head in the present invention.   It is XX arrow sectional drawing of FIG.   FIG. 3 is a hydraulic circuit for driving an enlarged blade for explaining the present invention and a state diagram thereof. (A) is an enlarged blade closed / contracted state (b) is a partially expanded state, (c) is a fully opened state, and (d) is a closed / closed switch. It is a hydraulic-pressure circuit diagram at the time.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw rod 2 Expansion head 3 Main body rod 4 Head rod 5 Expansion blade 6 Flow path 7 Oscillation bracket 8 Stopper 9 Resistance plate 10 Switching valve 11, 12 Pilot check valve 13 Check valve 14 Piston 15 Piston rod 16 Cylinder 17 Hydraulic unit 18 Water pressure pump 19 Water meter 20 Water supply valve 21 Relief valve 22 Recess 23 Spring 24 Pin 30 Bracket 31 Shaft 32 Expansion / contraction bracket 33 Long hole 34 Actuation link 35 Shaft 36 Shafts A, B, C, D

Claims (3)

A fluid pressure cylinder is built in the head rod at the lower end of the excavation work rod, and a fluid passage for supplying pressure fluid from the outside to the cylinder is vertically passed through the excavation work rod, and the outer periphery of the head rod In the configuration in which the expansion wing that is expanded and contracted by driving the fluid pressure cylinder is provided in the part,
A resistance plate that swings according to the rotation direction of the head rod is provided, and the switching valve for switching the fluid flow path to the fluid pressure cylinder is operated by swinging the resistance plate to expand and contract the expansion blade. And an enlarged head. The one-system fluid flow path is connected to a fluid pressure circuit including a fluid pressure pump arranged outside and at least a fluid flow path switching valve to a fluid pressure cylinder,
2. A flow meter for measuring a fluid amount to the fluid pressure cylinder is provided in the fluid passage of the one system, and the flow rate of the expansion blade can be increased or reduced by the flow rate. Enlargement head. Enlarged head of claim 1 or claim 2, characterized in that water is used as the pressure fluid.

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