JPS5833403B2 - fluid circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention generally relates to fluid operated percussion drills or what are commonly referred to as fluid drifters.

More particularly, the present invention relates to a control circuit for use with such a drill that provides maximum fluid force to the impact mechanism when the drill is used in difficult drilling locations.

Hitherto, it is known to use a separate device for rotating the drill bit during drilling in order to achieve uniform drilling and uniform fatigue of the drill bit.

It is also known to use a separate power source to effect the reciprocating motion of the impact mechanism.

An example of a fluid drifter is shown in US Pat. No. 3,701,386, the impact mechanism of which is shown schematically here.

In addition to the above, a separate power source drives the impact mechanism and the feed mechanism that moves the bit toward the formation to be drilled and provides continuous power to it so that the drill drills at even higher speeds. established for the purpose of

This power source is also used to release the impact mechanism from the formation for changing drill bits, adding or removing drill steel, etc.

This feed mechanism powers the impact mechanism during each hole drill operation and when particularly difficult formations are encountered.

A relief valve is provided to prevent the pressure in the fluid delivery circuit from exceeding a predetermined value when the delivery mechanism approaches or reaches installation conditions.

Usually this pressure exceeds the planned value when approaching the installation conditions,
The fluid is then circulated back into the fluid reservoir.

The constant displacement pumps used in such circuits would then operate very inefficiently since a significant amount of fluid would be circulated through the circuit without performing any additional work.

One object of the present invention is to provide an improved fluid circuit for energizing a fluid drifter that utilizes the overpressure created by a pump within the feed mechanism to provide additional force to the impact mechanism. It is.

Another purpose is when a relatively easy to excavate formation is encountered.
An object of the present invention is to provide an improved fluid circuit in which a control circuit automatically prevents fluid bifurcation.

Yet another object is to provide an improved hydraulic circuit for a drifter that automatically closes to prevent fluid bifurcation during movement of the impact mechanism toward or away from the formation, and to provide an improved hydraulic circuit for the feed mechanism. The goal is to provide total fluid flow.

An additional purpose is to provide a method where gold mud is applied to the impact mechanism and gold mud is applied to the feed mechanism when the formation or working conditions require current conditions for both the impact mechanism and the feed mechanism. An object of the present invention is to provide an improved control circuit for a fluid drifter.

What the present invention provides is an improved fluid circuit that controls the feed and impact forces provided by a fluid drifter.

The fluid circuit includes an impact mechanism having a reciprocating piston energized to produce an impact force and a fluid motor energized to direct the fluid toward and away from the formation being excavated. and a feeding mechanism for moving the impact mechanism.

The circuit arrangement of the present invention is further characterized in that the first output means has a conduit that communicates with the impact mechanism and supplies pressurized fluid to the impact mechanism; a second output means having a supply conduit; and valve means having an inlet connected to a conduit in said second output means and an output connected to a conduit in said first output means.

The valve means, which is normally closed, opens the conduit in the second output means to the conduit in the first output means when the pressure in the second output means exceeds a predetermined pressure. Fluid is passed through the impact mechanism such that the impact mechanism receives pressurized fluid from the feed mechanism to increase impact force.

The present invention for achieving the above object will be described in detail below with reference to the drawings.

The drawing shows a fluid drifter 10 and fluid power circuit.

Drifter 10 has an impact mechanism 12 having a housing 14 enclosing a reciprocating piston or striker 16.

Housing 14 is suitably configured with holes and passageways to effect reciprocating movement of piston 16.

A shank par 18 extends from the housing 14.

One end of the shank par 18 is adapted to rest against the piston 16, and the other end is connected to a drill steel 20 which is connected to a drill bit 22 at its lower end.

Of course, multiple drill steels 20 may be used if necessary.

This component is a function of the depth of the hole drilled by the drifter 10.

A fluid rotary motor 24 is mounted to the housing 14''.

The purpose of the motor 24 is to operate the shank par 18 during excavation of the strata.
This is to cause the drill steel 20 and drill pit 1220 rotations.

The impact mechanism 12 is attached to the feed mechanism 26.

The feed mechanism is adapted to move the impact mechanism 12 relative to the formation to be excavated.

A feed motor 28, also fluidically energized, is connected to the feed mechanism 2.
6 to move the impact mechanism 12 in a desired direction.

As previously mentioned, rotation motor 24 is configured to provide rotation of bit 22.

Power for the motor 24 is taken from a rotary pump 30 connected to the motor 24 by a conduit 32.

The motor 24 is also connected to a fluid reservoir 36 by a pipe 34.

Operaably disposed on pipes 32 and 34 is a three-position valve 38, which in one position blocks flow from pump 30 to motor 24 and in a second position blocks flow from pump 30 to motor 24.
to the motor 24.

In the third position, fluid flows from pump 30 through pipe 34 to motor 24 and through pipe 32 to sump 36.

When in the first and third positions, the valve 38 causes the motor 24 to rotate in opposite directions.

Power for driving the piston 16 is extracted from the impact pump 40 via a pipe 42 that connects to a pipe 44.

Pipe 44 extends from pump 40 to reservoir 36 through a two-position impact valve 46.

When valve 46 is in the position shown, fluid from pump 40 flows through valve 46 to sump 36 and thus not through pipe 42 to piston 16.

A pipe 44 extending to the sump 36 when the valve 46 is in the other position.
is prevented so that fluid is transferred from pipe 44 to pipe 42.
It passes through to the impact mechanism 12 and causes the piston 16 to reciprocate.

a conduit or pipe 42 connected to the impact mechanism;
44, valve 46 and pump 40 will be referred to as the first output means.

Power for driving the feed motor 28 is provided by a feed pump 748.

Pump 48 is connected by pipe 52 to a three-way valve 50 .

Valve 50 is connected to one side of motor 28 by pipe 54 and to the other side by pipe 56.

As shown, pipe 54 extends directly from valve 50 to motor 28.

A pressure reducing device 58 is provided in the pipe 56. The combination of conduits or pipes 52, 56, valve 50 and pump 48 leading to the feed mechanism is designated as the second output means.

Device 58 has an adjustable pressure reducer 60 and a bypass 62 that includes a check valve 64.

Valve 64 is configured to allow fluid to flow freely through bypass 62 as it passes from motor 28 through pipe 56, but to prevent that flow as it enters motor 28 through pipe 56.

Thus, the pressure reducer 60 is only effective when flow is directed through the pipe 56 to the motor 28.

Flow through pipe 56 to motor 28 causes motor 28 to rotate in a direction that drives feed mechanism 26 and impact mechanism 12 toward the formation to be drilled.

Valve 50 is configured in one position to flow fluid through pipe 52 from feed pump 48 through valve 50 directly to pipe 54 and to motor 28.

When fluid enters pipe 54, motor 28 rotates in a direction that releases impact mechanism 12 from the formation.

As fluid flows from pipe 54 to motor 28, it passes through via 56 and through valve 50 where it is directed from pipe 66 to sump 36.

The vibro 8 is a pipe 56 between the pressure reducing valve 58 and the feed valve 50.
, to the middle of the via 42 that enters the impact mechanism 12 .

Operatively disposed within the vibro 8 is an adjustable pressure sensitive bypass valve 70 which is normally closed but which shuts down the vibro when the pressure within the motor 28 and pipe 56 exceeds a predetermined preset value. 8 to allow flow toward the pipe 42.

Valve 70 is preferably set to open at a pressure slightly above the maximum expected or desired delivery pressure in pipes 52 and 56.

From the foregoing it can be seen that motor 28 drives impact mechanism 12 and bit 22 into engagement with the formation.

The motor 28 continues to apply a force thereon until the resistance of the formation builds up pressure thereon, exceeding a preset expected value.

At this point, bypass valve 70 opens to allow excess fluid pressure flowing through pipe 56 to flow through vibro 8 and through 42 to impact mechanism 12.

This additional fluid flow and pressure increases the power applied to the impact mechanism 12, thereby providing even greater efficiency in drilling the formation.

For purposes of explaining the operation of the fluid drifter 10, it will be assumed that it is placed adjacent to the formation to be excavated.

When the pumps 30, 40, 48 are operating, the rotary valve 38
The fluid flows from the pump 30 through the pipe 32 to the motor 24.
It is moved to a position where it flows out, passes through the pipe 34, and returns to the reservoir 36.

If it is desired to rotate bit 22 in the opposite direction, valve 38 can be positioned so that flow flows through pipe 34 in the opposite direction.

Reciprocation of the piston 16 can, if desired, begin before the bit 22 engages the formation to be excavated.

As the piston 16 reciprocates, fluid flows from the pump 40 to the pipe 44.
, 42 and into the impact mechanism 12 by closing the impact valve 46.

Details of the operation of one type of drifter 10 that may be utilized can be found in US Pat. No. 3,701,386.

When the impact mechanism 12 is in the upper position of the feed mechanism 26, the piston 16 is connected to the shank par 18, the drill steel 2
0. The bit 22 does not hit the shank par 18 because it has enough weight to hold the bar 18 of the housing 14 and the piston 16 in a position where they do not engage.

Movement of impact mechanism 12 toward the formation is accomplished by moving valve 50 to a position where flow from pump 48 to motor 28 occurs through pipes 52,56.

Fluid from motor 28 flows through pipe 54, valve 50, and pipe 6.
6 and return to reservoir 56.

In this flow direction, the motor 2B has the proper direction of rotation such that the impact mechanism 12 is moved downwards, ie, towards the formation.

After bit 22 engages the formation, fluid pressure in pipe 56 is applied to motor 28 to maintain a downward force to hold the impact mechanism against the formation.

During this time, the piston 16 reciprocates and engages the bar 18;
Then, impact force is applied to bit 22.

If drilling is relatively easy, ie, the bit 22 penetrates without great difficulty, the entire system continues to operate as described above.

On the other hand, if this is difficult, motor 28 continues to apply a downward force to impact mechanism 12, but little or no impact action occurs, thus motor 28 approaches installation conditions.

When this condition is approached, a pressure will develop in motor 28 and pipe 56 that exceeds the preset pressure of bypass valve 70.

When this occurs, bypass valve 70 opens, allowing flow from pipe 52 to pipe flow 8, which connects with pipe 42 as described above.

At this time, the pump 48 is supplying pressurized fluid to the impact mechanism 12 through the pipe 42 in order to increase the fluid being supplied to the impact mechanism 12 by the pump 40.

Thus, in cases where drilling is extremely difficult, this system provides a means for providing additional power to the impact mechanism 12 to increase the rate of formation penetration.

When a stratum that is easy to excavate is encountered again, the bypass valve 70 is closed and the branched flow toward the vibro 8 is stopped.

When it is necessary to remove bit 22 from the formation, valve 50
is returned to a position where pump 48 supplies fluid to motor 28 via pipe 54.

When this flow occurs, the direction of rotation of the motor 28 is reversed, the bypass valve 70 is closed, and the fluid from the motor 28 passes through the pipe 56 and the vibro 2 of the valve 58 via the sump 3.
6. Let it flow.

Rotation of motor 2B in this direction moves impact mechanism 12 upwardly, ie, away from the formation.

At this time, the drifter 10 is returned to its starting position.

If desired, the rotary valve, impact valve, and feed valve may be in the closed position.

From the foregoing, it can be seen that this system provides the maximum pressure and maximum amount of fluid to the impact mechanism piston 16 when the impact mechanism 12 requires maximum force.

This system also provides sufficient fluid to the feed motor to maintain feed force on the drifter 10 when digging is most difficult.

The volume and pressure of this fluid from the pump 48 is automatically redirected as needed and is then redirected to the feed motor when the impact mechanism 12 needs to be moved at high speed along the feed mechanism 26 in either direction. Apply maximum fluid volume to 28.

[Brief explanation of the drawing]

The drawing is a schematic diagram of a fluid circuit for controlling a fluid drifter according to the invention. 10... Drifter, 12... Impact mechanism, 16... Piston, 24...
Fluid motor, 26... Feeding mechanism, 28...
...Feed motor, 30...Pump, 40...
... Impact pump, 46... Impact valve, 48... Feed pump, 50... Feed valve, 58... Pressure reducing device, 64... ...Check valve.

Claims (1)

[Scope of Claims] 1. An impact mechanism that has a reciprocating piston energized by fluid pressure to generate an impact force in a fluid circuit that controls the feed force and impact force applied by a fluid drifter. , a feed mechanism energized by a fluid motor to move said impact mechanism toward and away from the formation being excavated, the fluid circuit having a feed mechanism energized by a fluid motor to move said impact mechanism toward and away from the formation being excavated; a first output means having a conduit for supplying pressurized fluid to the impact mechanism; and a second output means having a conduit leading to the delivery mechanism and supplying pressurized fluid to the delivery mechanism.
an output means having an inlet connected to a conduit 56 in said second output means;
Valve means 70 having an outlet connected to the conduit 42 in said first output means, which is normally closed, but when the pressure in the second output means exceeds a predetermined pressure; ,
valve means adapted to pass fluid from said conduit 56 to said conduit 42, thereby causing the impact mechanism to receive pressurized fluid from the delivery mechanism to increase impact force.