JPS61204496A - Reverse impact apparatus for withdrawing rod of impact tool - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an impact device for a rock drill, a chisel, etc. This invention relates to a reverse impact device that applies an impact force in the opposite direction to a drilling rod.

Conventional Technology Recently, with the development of hydraulic rock drills, etc., the efficiency of drilling operations in mines, quarries, etc. has significantly improved.
811, and in the case of work at a depth of 12rrL, the maximum time is about 15 minutes. However, these data are from locations with relatively uniform and good rock quality, and many drilling sites are complex with soft ground, fractured zones, clay layers, etc., so they may not be suitable for actual work. There is also data that says there is one per day. The cause of such inefficiency is the collapse of the excavation wall into the excavation hole, or the occurrence of a cavity during excavation, which makes it impossible to discharge the excavated particles, or what is called jamming, which clogs the excavation hole. It is to wake up. Under such circumstances, conventional extraction methods using hydraulic cylinders connected to tools such as drill bits or rotary motors connected via roller chains cannot easily retrieve the drilling rod. Or sometimes it was impossible to retrieve the rod.

Conventionally, in drilling work in places with poor rock quality, there have been methods for rounding to prevent jamming that makes rod recovery difficult, regulating the feeding force of the working tool, and vertical movement of the working tool for the purpose of discharging drilling powder. It was necessary to drill the hole while performing it frequently. In such a situation, the impact time is long and the time for the impact vibration to propagate to the surrounding area is also long, so the excavated wall surface is likely to collapse, resulting in irregular holes that are far from cylindrical. However, it is important to finish the borehole in an orderly cylindrical shape in order to produce a calculated effect in the blasting operation, and it is undesirable to create an irregular hole in order to prevent jamming.

In addition, in a work environment where jamming can be predicted, operators can adjust the feeding force of working tools and constantly monitor rotational force and flushing pressure to predict signs and thereby avoid jamming. were required to take action. Requiring such work places an excessive mental burden on the operator.

In conventional drilling machines, various devices have been proposed and implemented to prevent jamming as described above, but these devices are only intended to prevent jamming, and do not prevent jamming from occurring. If the rod recovery work could be done easily, they would be almost unnecessary. Therefore, there has been a desire for a device that can easily retrieve rods without being affected by jamming.

Problems to be Solved by the Invention Accordingly, one object of the present invention is to provide an impact device for use in rock drilling, etc., which recovers the drilling rod without being affected by jamming and contributes to improving the work efficiency of drilling operations. It is to be.

Another object of the present invention is to provide an impact device for use in rock drilling, etc., which eliminates or simplifies the jamming prevention mechanism of a drilling machine and reduces the mental burden on the operator.

In order to achieve the above objectives, it is necessary to find a means to automatically apply an impact force in the direction opposite to the driving direction of the working tool to overcome the jamming when it occurs, using a simple mechanism. It is.

Means for Solving the Problems The present invention solves the aforementioned problems by providing a machine housing, a front head cap connected to the front part of the machine housing;
A main piston that reciprocates back and forth within the machine housing, and a different diameter portion that is disposed in front of the main piston and has a forward and reverse position limiting surface, and receives an impact due to the forward movement of the main piston. an impact tool comprising a shank rod; a buffer chamber disposed between the irregularly shaped part of the shank rod and the front end of the front head cap and capable of containing pressurized fluid; and an accumulator connected to the buffer chamber. , an auxiliary piston that is slidably mounted in front of the different diameter portion of the shank rod, constitutes a part of the buffer chamber, and transmits the pressure generated in the buffer chamber to the shank rod, the shank rod The problem was solved by providing a rod pull-out floating impact device that applies an impact in the opposite direction to the impact after the main piston applies the impact.

By applying impact pulses alternately in the compression direction and the tension direction to a working tool such as the above, it is possible to easily perform rond recovery, which has been difficult in the past, in a short period of time. This results in a significant reduction in working time.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The foregoing and other objects of the invention will be understood from the following description of the accompanying drawings, which illustrate one embodiment of the invention. This embodiment is merely for illustrating the invention, and various modifications of the embodiment are possible within the scope of the invention. 1 and 2, a known drilling machine housing 10 is shown including a front head 11, a gear housing 12, a cylinder case 13, and a main piston cylinder 14.' Main piston 1
5 reciprocates within the main piston cylinder 14 by fluid pressure. This main piston 15 has an impact surface 15a and is arranged so as to impact the shank rod (anvil element) 17 in forward motion. Shank rod 17
The piston has a different diameter portion 17d having a collision surface 17a with the main piston, a surface 17b that limits the retracted position relative to the drilling rock, and a surface 17c that similarly limits the forward position. Further, a perforation rod 19a is connected to the shank rod 17 via a sleeve 18.
Bit 20 is connected to b. (FIG. 2) A rotary chuck 21 is connected to rotate together with a chuck driver 22, and this chuck driver 22 has a ring gear 22a and a gear connected to a drive source (not shown). They are engaged. Further, the rotary chuck 21 is arranged so as not to be able to move in the axial direction within the machine housing 10, and is engaged with the shank rod 17 by a spline. Therefore, shank rod 1
7 is forcibly rotated by the action of the drive source and is movable in the axial direction with respect to the rotary chuck 21. The chuck driver 22 is supported by a bearing 23 and a thrust bearing 24 so as to rotate at a fixed position within the machine housing 10, and a thrust bearing member 25 is provided on the cylindrical inner surface to limit the retracted position of the shank rod 17 in the drilling hole. is press-fitted.

Mechanical front housing 3 forming part of buffer chamber 28
0 includes a front head cap 31 and a reverse cylinder 32 (FIG. 1). The buffer chamber 28 is connected to the passage 34
a1 The switching valve 3 is connected via the annular chamber 35, the passage 36, and the conduit 37.
8 is connected.

The switching valve 38 can selectively connect the conduit 37 to a conduit 39 connected to a source of pressurized fluid via a check valve 43 and to a conduit 40 connected to the tank. check valve 4
3 allows flow from the fluid source to the switching valve 38 but not vice versa.

The accumulator 42 is connected to the passage 41 . The annular chamber 35 is constantly connected to the buffer chamber 28 via the passage 34b.

The reverse cylinder 32 has a small-diameter cylindrical inner surface and a large-diameter cylindrical inner surface, and is fixed to the inside of the front head cap 31 in a fluid-tight manner. The inner surface of the front portion of the large-diameter cylindrical inner surface and the rear end surface of the small-diameter cylindrical inner surface are provided with a buffer chamber 28.
constitutes part of. Note that passages 34a and 34b for communicating with the pressurized fluid source and the accumulator 42 are bored at the forefront of the large-diameter cylindrical inner surface.

The sub-piston 33 has a small-diameter cylindrical outer surface and a large-diameter cylindrical inner surface that can slide fluid-tightly on the small-diameter cylindrical inner surface and the large-diameter cylindrical inner surface of the reverse cylinder 32, respectively. It is attached to the front of the portion 17d so as to be able to slide on the shank rod and to come into contact with the forward position limiting surface 17c.

In this embodiment, the front end surface of the large-diameter cylindrical outer surface of the sub-piston 33 is formed in a step shape, and forms a piston surface 33a, and when the sub-piston 33 moves forward, the small-diameter cylindrical inner surface of the reverse cylinder 32 A portion of the stepped portion abuts against the rear end surface, thereby limiting the forward position of the sub-piston 33. The stepped portion including the small-diameter cylindrical outer surface of the sub-piston 33 and the piston surface 33a is the buffer chamber 2.
8. As described above, the reverse cylinder 3 is provided with a stepped portion on the large diameter outer surface of the sub piston 330.
It is clear that the rear end of 2 may be provided with a step.

When the pressurized fluid is introduced into the buffer chamber 28, the piston surface 33a moves rearward with respect to the reverse cylinder 32 along the shank rod under the pressure of the pressurized fluid. When the front portion of the stepped portion including the piston surface 33a is in contact with the rear end surface of the small diameter cylindrical inner surface of the reverse cylinder 32, the force applied to the piston surface 33a by the pressure oil from the pressurized fluid source is , is designed to be greater than the maximum value of the reaction force produced by the tensile force applied to the rock breaker 45 (see Figure 3) to move it backwards when jamming occurs.

A cavity 16 in the machine housing 10 of the rock drill is connected with a conduit leading to a lubricator (not shown), which supplies oil mist with compressed air during operation of the rock drill. Therefore, the compressed air is discharged from the gap between the inner surface of the reverse piston 33 and the outer surface of the shank rod 17 after lubricating each sliding member. This means that at the same time,
By keeping the space inside the housing 10 at a constant pressure, dust is prevented from entering from the outside.

Referring to FIG. 3, the drilling Iwatsuki 45 is
is connected by an endless chain via a feed motor 48 so as to move back and forth on a drill guide 46.

The operation of the reverse impact device in Iwatsuki drilling will be explained below with reference to the drawings. After drilling is completed, in the state shown in Figure 2,
In order to move the drilling Iwatsuki backwards, a tensile force is applied to the mechanical housing 10 of the drilling Iwatsuki, and the front head cap 31.
, reverse cylinder 32, and sub-piston 33, it acts on the surface 17c of the different diameter portion of the shank rod. Buffer chamber 28
is connected to the tank port, and both the sub-piston 33 and the shank rod 17 are at the most advanced position relative to the drilling rock. In other words, the collision surface 17a of the shank rod is located further forward than the frontmost portion where the collision surface 15a of the main piston is positioned during its reciprocating cycle. Therefore, the main piston 15 is connected to the shank rod 1
Can't hit 7. This is the same as the conventional Iwatsuki.

Now, with the tension applied to the drilling rod 1
9, when jamming occurs, the switching valve 38 is switched to connect the conduits 37 and 39, and the pressure oil supplied from the pressurized fluid source is transferred to the buffer chamber. 28 and pressurizes the accumulator 42. Next, the fluid pressure acting on a part of the piston surface 33a of the sub-piston constituting the buffer chamber is set to a value such that the tensile force applied to move the drilling rock rearward also becomes larger. When the glaze becomes glazed, the drilling parts excluding the piston 33 and the shank rod 17 start moving forward, that is, toward the drilling rod side, and as shown in FIG. 4a, the bearing member 25 (7) surface 25g is brought into contact with the shank rod surface 17b. At this time, the impact surface 17a of the shank rod is in the normal striking position during the drilling operation of the main piston 15. When the main piston is operated in this state, the main piston 15 hits the shank rod collision surface 17a as shown in FIG. 4b, and then moves backward. The shank rod 17 moves forward accompanied by the sleeve 18, the drilling rod 19, the bit 20 and the secondary piston 33. At this time, the pressure oil in the buffer chamber passes through the passage 41 and enters the accumulator 42 . Accumulator 4
2 effectively absorbs the impact energy transmitted to the shank rod 17 via the sub-piston 33. Therefore, the secondary piston/33 gradually decelerates and then stops.

On the other hand, the tensile force applied to the drilling machine nozzle is such that the moment the shank rod surface 17b leaves the surface 25a of the bearing member, that is, the rear surface 20a of the rock drilling pit 1-20 moves into the drilling hole. As soon as the object that was clogging is released, the accumulator 42 maintains its balance, does not lose the nine reaction force, and moves the drilling Iwatsuki backwards. Therefore, when the secondary piston 33 stops moving forward, the accumulator 42 moves the secondary piston 33
The stored pressure oil is sent out to the buffer chamber 28 so as to be instantaneously thrown backward. The sub-piston 33 is a shaft 7
17, sleeve L8, and drilling pit 20, and after the drilling bit surface 20a hits the object that was stuck in the drilling hole, the shank rod surface 17b moves instantaneously to the rear, as seen in FIG. 4c. is fixed to the bearing member surface 25a to stop its movement and wait for the next main piston strike.When stopping the operation of the zero reverse impact device, the switching valve 38 is switched so that the conduits 37 and 40 communicate with each other. . Therefore, the oil stored in the accumulator is returned to the tank, and at the same time, the lubricator supply pressure acting on the rear end surface of the sub piston 33 causes the sub piston 33 to move forward, and the oil in the buffer chamber also cools down. returned to the village. A part of the surface 33a of the sub piston is connected to the reverse cylinder 3.
It stops at the position where it touches 2, making it possible to perform the same drilling work as a conventional rock drill.

Effects of the Invention According to the present invention, even in drilling work in poor rock quality, drilling can be performed all at once without worrying about jamming and the rond can be recovered, so the total impact time can be significantly shortened, and at the same time Since the time of impact vibration applied to the surrounding areas is also shortened, it is possible to leave a relatively sturdy excavated wall surface.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a reverse impact device for impact tools according to the present invention, and FIG. 2 is a vertical cross-sectional view of a drilling rock drill incorporating the reverse impact device for impact tools according to the present invention, and a fluid flow to the reverse impact device. Supply circuit diagram, Figure 3 is a schematic diagram showing a conventional rock drilling machine including the operation room. Fig. 4a is a diagram showing the operating state of the reverse shock device according to the present invention when jamming occurs and the hydraulic pressure has sufficiently increased after the pressurized fluid source is connected to the buffer chamber; FIG. 4c shows the operating state of the reverse shock device according to the invention after the shank rod has been impacted by the main piston after the state shown in FIG. 4a; FIG. FIG. 6 is a diagram illustrating the operating state of the reverse impact device according to the present invention after the shank rod is raised by generating a reverse impact using the pressure stored in the accumulator.

Claims (1)

[Claims] 1. A machine housing, a front head cap disposed at the front of the machine housing, a main piston that reciprocates back and forth within the machine housing, and a front head cap disposed at the front of the main piston. and a shank rod having a different diameter portion with a forward and reverse position limiting surface and receiving an impact due to the forward movement of the main piston, the impact tool comprising: a modified portion of the shank rod and a front end of the front head cap; an accumulator connected to the buffer chamber, and an accumulator slidably mounted in front of the different diameter portion of the shank rod, the buffer chamber being able to contain a pressurized fluid; and an auxiliary piston configured to transmit the pressure generated in the buffer chamber to the shank rod, and after the main piston applies an impact to the shank rod, an inverse rod-drawing piston that applies an impact in the opposite direction to the impact. Shock device. 2. The sub-piston has a hollow quasi-cylindrical shape having a rear end surface that can be joined to the forward position limiting surface of the different diameter portion of the shank rod, a front small-diameter outer surface portion, and a rear large-diameter outer surface portion. The reverse impact device according to item 1. 3. The buffer chamber has a hollow quasi-cylindrical shape having a front small-diameter inner surface and a rear large-diameter inner surface that slidably receive the front small-diameter outer surface and the rear large-diameter outer surface of the sub-piston in a fluid-tight manner, respectively. A transition portion between a small-diameter inner surface and a large-diameter inner surface of the reverse cylinder that is liquid-tightly fixed to the inner surface of the front head cap, and a transition portion between the small-diameter outer surface and the large-diameter outer surface of the sub-piston. The reverse impact device according to claim 2, characterized in that it is formed by. 4. The reverse impact device according to any one of claims 1 to 3, wherein the front end surface of the large-diameter outer surface portion of the sub-piston serves as a piston surface of the sub-piston. 5. The reverse impact device according to any one of claims 1 to 4, wherein the buffer chamber can be selectively connected to a pressurized fluid supply source.