JPH0713984Y2 - Striking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a striking device including a working tool such as a chisel for crushing concrete or rock with a piston-type hammer that imparts impact energy by reciprocating motion.

[Conventional technology]

As this type of hitting device, for example, Shoukaisho 63-116284
Or as described in Japanese Utility Model Publication No. 64-1879,
A hammer having an ascending pressure receiving surface and a larger descending pressure receiving surface is fitted in the cylinder in a vertically reciprocating manner,
A high pressure from a high pressure line is applied to the ascending pressure receiving surface, and a high pressure and a low pressure are alternately applied to the descending pressure receiving surface by a switching operation of a switching valve driven in association with the position of the hammer, A striking device that drives the hammer up and down,
Widely used. FIG. 4 shows a specific example of this type of striking device, in which 1 is a cylinder, and a hammer 2 is vertically slidably fitted in the cylinder. 3 is an upper large diameter portion of the hammer, 4 is a lower large diameter portion having the same diameter as this, 5 is an upper small diameter portion, 6 is a lower small diameter portion, and 7 is an annular groove. The upper small-diameter portion 5 is thinner than the lower small-diameter portion 6, and accordingly, the area of the descending pressure receiving surface 8 formed on the upper side of the upper large-diameter portion 3 is equal to that of the ascending pressure receiving surface formed on the lower side of the lower large-diameter portion 4. It is larger than the area of 9. Due to the large diameter portions 3 and 4 of the hammer 2 and the piston holes 10 into which these large diameter portions are fitted in the cylinder 1, the upper chamber 11 and the lower chamber 12 whose volume increases and decreases as the hammer 2 moves, A volume-invariant middle chamber 13 that moves with the hammer 2 is formed. Reference numeral 14 is an annular low-pressure chamber, and 15 is an annular pilot chamber, both of which are formed in a concave groove on the wall surface of the piston hole 10. Further, 16 is the uppermost chamber into which the upper small diameter portion 5 of the hammer comes in and out, and 17 is the lower small diameter portion 6
It is the lowest room in and out of which all communicate with the atmosphere. A tongue 18 is vertically inserted into the lower part of the cylinder 1 and a stopper 19 is provided.

On the other hand, 20 is a switching valve for controlling the reciprocating motion of the hammer 2, and its spool 21 is fitted in a housing 22 slidably in the vertical direction. The spool 21 has a cylindrical shape with a through hole 23 in the center, 24 is an upper large diameter portion, 25 is a lower large diameter portion having the same diameter as this, and 26 is a hammer drive provided between these large diameter portions. An annular concave groove portion for circuit switching, 27 is an upper small diameter portion, and 28 is a lower small diameter portion. The upper small-diameter portion 27 is thinner than the lower small-diameter portion 28, and accordingly, the large annular pressure receiving surface 29 formed above the upper large-diameter portion 24.
Is larger than the area of the annular small pressure receiving surface 30 formed below the lower large diameter portion 25 relative to the large pressure receiving surface 29. 31
Is a first valve chamber provided in the housing 22 for applying hydraulic pressure to the small pressure receiving surface 30, and is provided in the middle of a high pressure pipe 33 connected to the hydraulic pump 32 and reaching the lower chamber 12. Further, 34 is a second valve chamber for applying hydraulic pressure to the large pressure receiving surface 29, which is the pilot chamber 15
Is connected to the pilot line 35 leading to. 36 is a tank
A low-pressure pipe connected to 37 and reaching the low-pressure chamber 14 is an annular low-pressure chamber connected to this low-pressure pipe 36. Further, 39 is an annular switching chamber, which is connected to a switching conduit 40 leading to the upper chamber 11. Reference numerals 41 and 42 denote low pressure chambers into and from which the upper and lower small diameter portions of the spool 21 come in and go out, and are connected to the low pressure pipe 36. Reference numeral 43 is an accumulator provided in the high pressure line 33.

In the conventional striking device 50 having the above-described structure, as shown by the chain line 51 in the figure, when the hammer 2 reaches the lowered position, the low pressure chamber 14
By communicating the pilot chamber 15 with the pilot chamber 15 through the annular groove 7, the inside of the second valve chamber 34 becomes a low pressure, and the spool 21 is switched to the ascending position shown by the high pressure of the first valve chamber 31, and the upper chamber 11 becomes When the pressure becomes low, the hammer 2 reverses and rises. However, during this ascending, as shown in the figure, the lower large diameter portion 4
When the lower edge 4a approaches the pilot chamber 15, the high-pressure oil in the lower chamber 12 flows into the pilot chamber 15 through the clearance between the lower large diameter portion 4 and the piston hole 10, whereby the second valve chamber 34 Due to the high pressure inside, the spool 21 is driven downward before the hammer 2 reaches the normal ascending position, and the upper chamber 11 has the high pressure line 33.
There were many phenomena in which the hammer 2 was turned upside down during the ascending while communicating with the. For this reason, there was a problem that the desired striking force could not be obtained due to a shortage of the descending stroke of the hammer 2. On the contrary, while the hammer 2 is descending, the spool 21 descends toward the first valve chamber 31 due to the high pressure in the second valve chamber 34, but as shown in the drawing, the lower edge 4a of the lower large diameter portion 4 is After closing the pilot chamber 15, the high pressure oil in the second valve chamber 34
The upper large diameter portion 24 and the upper small diameter portion 27 of the spool and the housing 22
Leaks into the low pressure pipe 36 from the clearances of the spool holes 44, 45, etc., the pressure in the second valve chamber 34 drops, and the spool 21 is driven upward before the hammer 2 reaches the normal lowered position,
There were many phenomena in which the upper chamber 11 communicated with the low pressure pipe 36 and the hammer 2 was inverted upward while the hammer 2 was descending. For this reason, there was a problem that the descending stroke of the hammer 2 was insufficient and the desired striking force could not be obtained, and even if the chisel had a small amount of projection, the striking could not be performed and the ball was hit blank.

[Problems to be solved by the device]

This invention solves the above-mentioned conventional problems, and an object of the invention is to provide a striking device in which the hammer is prevented from reversing during the ascending / descending stroke and the desired striking force can be obtained.

[Means for Solving the Problems]

The striking device of the first invention of this application hits a hammer having a rising pressure receiving surface and a descending pressure receiving surface larger than the area of the pressure receiving surface with a working tool such as a chisel during the descending motion. As described above, the lower chamber for applying hydraulic pressure to the ascending pressure receiving surface is connected to the high pressure pipeline while the upper chamber for applying hydraulic pressure to the descending pressure receiving surface is connected to the hammer as described above. Of the striking device which is alternately connected to the high pressure line and the low pressure line by the switching operation of the spool of the switching valve which is hydraulically driven in relation to the position of (1) to drive the hammer up and down. A small pressure receiving surface and a large pressure receiving surface for driving the spool are provided on the spool of the valve so as to face each other, and a first valve chamber for applying hydraulic pressure to the small pressure receiving surface is connected to a high pressure pipe line,
In the striking device, in which the pilot valve line that alternately communicates with the high pressure line and the low pressure line by the reciprocating motion of the hammer is connected to the second valve chamber that applies hydraulic pressure to the large pressure receiving surface, the spool has the second valve chamber. A high resistance oil discharge passage that communicates the second valve chamber with the low pressure pipe passage in a state of being moved to the side is provided on the outer peripheral portion of the spool.

Further, in the striking device of the second invention of this application, a hammer having a rising pressure receiving surface and a descending pressure receiving surface larger than the area of the pressure receiving surface is used to strike a working tool such as a chisel during the descending motion. Is vertically reciprocally fitted in the cylinder, the lower chamber for applying hydraulic pressure to the ascending pressure receiving surface is connected to the high-pressure pipe line, and the upper chamber for applying hydraulic pressure to the descending pressure receiving surface is provided in the hammer. A percussion device which is alternately connected to a high pressure line and a low pressure line by a switching operation of a spool of a switching valve hydraulically driven in relation to a position to drive the hammer up and down. The spool is provided with a small pressure receiving surface and a large pressure receiving surface for driving the spool in opposition to each other, a first valve chamber for applying oil pressure to the small pressure receiving surface is connected to a high pressure pipe line, and oil pressure is applied to the large pressure receiving surface. In the second valve chamber, a high pressure line is created by the reciprocating motion of the hammer. In a striking device in which a pilot line communicating with the low pressure line in an alternating manner is connected, a high resistance oil supply line for supplying high pressure oil to the second valve chamber in a state where the spool has moved to the first valve chamber side, It is characterized in that it is provided in the housing of the switching valve.

The hammering device of the third invention of this application is designed to strike a hammer having a pressure receiving surface for raising and a pressure receiving surface for lowering, which is larger than the area of the pressure receiving surface, with a working tool such as a chisel during the lowering motion. Is vertically reciprocally fitted in the cylinder, the lower chamber for applying hydraulic pressure to the ascending pressure receiving surface is connected to the high-pressure pipe line, and the upper chamber for applying hydraulic pressure to the descending pressure receiving surface is provided in the hammer. A percussion device which is alternately connected to a high pressure line and a low pressure line by a switching operation of a spool of a switching valve hydraulically driven in relation to a position to drive the hammer up and down. The spool is provided with a small pressure receiving surface and a large pressure receiving surface for driving the spool in opposition to each other, a first valve chamber for applying oil pressure to the small pressure receiving surface is connected to a high pressure pipe line, and oil pressure is applied to the large pressure receiving surface. In the second valve chamber, a high pressure line is created by the reciprocating motion of the hammer. In percussion device connected to pilot conduit communicating with the alternating the low pressure pipe, which is characterized in that between the second valve chamber and the upper chamber is connected by a high-resistance supply and discharge oil passage.

[Action]

In the striking device of the first invention, when the spool moves to the second valve chamber side due to the low pressure in the second valve chamber due to the operation of the hammer, the second valve chamber is connected to the low pressure pipe line through the high resistance drainage passage. The second valve chamber is reliably maintained at a low pressure regardless of the inflow of high-pressure oil from the clearances of each part, and the hammer is reversed until the high-pressure oil is supplied to the second valve chamber by the operation of the hammer. Never.

In the striking device of the second invention, when the spool moves to the first valve chamber side due to the high pressure in the second valve chamber due to the operation of the hammer, the second valve chamber is connected to the high pressure line via the high resistance oil supply line. Since they communicate with each other, the second valve chamber is reliably maintained at a high pressure regardless of leakage of high-pressure oil from the clearances in each part, and the hammer must be reversed until the second valve chamber communicates with the low-pressure pipe line by the operation of the hammer. There is no.

Further, in the striking device of the third invention, when the pressure of the second valve chamber becomes low due to the operation of the hammer and the spool moves to the second valve chamber side, this movement causes the upper chamber of the cylinder to be switched to the low pressure, Since the second valve chamber communicates with this low pressure upper chamber through the high resistance oil supply / discharge passage, the second valve chamber is reliably maintained at low pressure, and the high pressure oil is supplied to the second valve chamber by the operation of the hammer. The hammer will not be reversed until it is released. When the spool moves to the first valve chamber side due to the high pressure in the second valve chamber due to the hammer operation, the upper chamber is switched to the high pressure by this movement, and the second valve chamber has the high resistance oil supply / discharge passage. Since it is communicated with the high pressure upper chamber via the high pressure chamber, the second valve chamber is reliably maintained at high pressure, and the hammer is not inverted until the second valve chamber becomes low pressure by the operation of the hammer.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, the same parts as those in FIG. 4 are designated by the same reference numerals as those in FIG. 4, and detailed description thereof will be omitted. Reference numeral 61 is a high resistance oil discharge passage in the form of a thin groove engraved on the outer periphery of the upper large diameter portion 24 of the spool 21.
It extends in the spool axial direction, and its length is set so that the second valve chamber 34 and the low pressure chamber 38 communicate with each other when the spool 21 moves to the second valve chamber 34 side as shown in the first illustration. .
Reference numeral 62 is a thin tubular high-resistance oil supply passage provided in the housing 22, one end of which is connected to the high-pressure pipe passage 33, and the other end of which the spool 21 is moved to the first valve chamber 31 side as shown in the second illustration. At the position above the large pressure receiving surface 29 of the spool, the opening is formed in the peripheral wall surface of the spool hole 44. The high resistance oil discharge passage 61 and the high resistance oil supply passage 62 are respectively connected to the pilot conduit.
It has a small flow passage cross-sectional area so that the flow passage resistance becomes larger than 35.

In the striking device 60 having the above structure, as shown in the first illustration, immediately after the hammer 2 strikes the chisel 18, the pilot chamber 15
Communicates with the low pressure chamber 14 via the annular groove 7 of the hammer, and the spool 21 of the switching valve rises from the previous position on the first valve chamber 31 side to the position on the second valve chamber 34 side shown in the drawing. Accordingly, the switching pipe 40 communicates with the low pressure pipe 36 via the annular groove 26, and the hammer 2 is driven upward by the high pressure in the lower chamber 12 and rises. After the pilot chamber 15 is closed by the lower large-diameter portion 4 while the hammer 2 is rising, the high-pressure oil in the lower chamber 12 is removed from the pilot chamber 15 by the clearance between the lower large-diameter portion 4 and the piston hole 10.
Even if the second valve chamber 34 of the switching valve communicates with the low pressure pipe 36 via the high resistance oil discharge passage 61, the inside of the second valve chamber 34 is maintained at a low pressure and the spool 21 The hammer 2 is held at the position on the second valve chamber side (ascended position) shown in the figure, and accordingly, the hammer 2 is reliably ascended by a predetermined stroke without being reversed during ascending. As a result, the hammer 2 is surely raised to the predetermined ascending end position, the acceleration distance of the hammer 2 in the subsequent descending stroke is sufficient, and the chisel 18 can be given a sufficient striking force.

When the hammer 2 reaches the rising end position shown in FIG. 2, the pilot chamber 15 communicates with the lower chamber 12, so the second valve chamber of the switching valve 20.
A high pressure is applied to 34, and the spool 21 is driven to descend and cut to the position on the side of the first valve chamber 31 as illustrated. At this time, the high resistance oil discharge passage 61 has a higher resistance than the pilot pipe passage 35, so that the pressure increase in the second valve chamber 34 and accordingly the start of the lowering of the spool 21 are performed quickly and smoothly.

While the hammer 2 is descending, the pilot chamber 15 is closed by the lower large-diameter portion 4, and the second valve chamber 34 of the switching valve to the upper large-diameter portion is closed.
24 and spool hole 44 clearance and upper small diameter part 27 and spool hole
Even if the high-pressure oil flows out to the low-pressure line 36 through the clearance of 45,
Since high pressure oil is supplied to the second valve chamber 34 from the high resistance oil supply passage 62, the inside of the second valve chamber 34 is maintained at a high pressure and the spool 21 is held at the position on the first valve chamber 31 side (down position). Therefore, the hammer 2 is surely lowered by a predetermined stroke without being reversed during the lowering. As a result, the hammer 2 is surely lowered to a predetermined lower end position, sufficiently accelerated, and a predetermined striking force can be applied to the rattle 18, and the occurrence of idle driving is reduced.

When the hammer 2 reaches the descending end position shown in the first drawing, the second valve chamber 34 of the switching valve becomes low pressure as described above, the spool 21 is driven upward, and the hammer 2 is reversed in the upward direction.
At this time, the high resistance oil supply passage 62 exhibits a higher resistance than the pilot pipe passage 35, so that the pressure drop in the second valve chamber 34, and accordingly the spool.
The start of climb of 21 will be done quickly and smoothly.

Since both the high resistance oil discharge passage 61 and the high resistance oil supply passage 62 are provided in the above-described embodiment, the hammer 2 reciprocates reliably with a predetermined stroke both upward and downward, which is particularly preferable. As a result, one of the high resistance oil discharge passage and the high resistance oil supply passage may be omitted. The high resistance oil supply passage 62 may be provided not only in the housing 22 but also across the housing 22 to the cylinder 1.

Next, FIG. 3 shows another embodiment of the present invention, in which one high resistance oil supply / discharge passage 71 is provided in place of the high resistance oil supply passage 61 and the high resistance oil supply passage 62 of the above embodiment. Is. The high resistance oil supply / drain passage 71 is in the form of a thin tube having a flow passage resistance larger than that of the pilot pipe passage 35, and one end thereof is located in the upper chamber 11 of the cylinder 1.
The other end is connected to the second valve chamber 34 of the switching valve 20.

In the striking device 70 of this embodiment, when the hammer 2 is moving upward, the pressure in the second valve chamber 34 is low, and the spool 21 is located on the side of the second valve chamber 34, the upper chamber 11 in which the hammer is moving upward has a switching pipe. The second valve chamber 34 communicates with the low pressure upper chamber 11 through the high resistance oil supply / drain passage 71 because the second valve chamber 34 communicates with the low pressure pipe 36 through the passage 40. The inside of 34 is reliably maintained at a low pressure, and the lowering of the spool 21 and the halfway inversion of the hammer 2 are prevented. Further, when the hammer 2 is descending and the inside of the second valve chamber 34 is at high pressure and the spool 21 is at the position of the first valve chamber 31 side, the upper chamber 11 during descending the hammer is connected to the high pressure pipe 33 via the switching pipe 40. The second valve chamber 34 is connected to the
It is in communication with the high pressure upper chamber 11 via 71,
The inside of the second valve chamber 34 is reliably maintained at a high pressure, and the rise of the spool 21 and the halfway reversal of the hammer 2 are prevented.

According to this embodiment, since only one high resistance oil supply / drain passage 71 needs to be provided, there is an advantage that the device is simple.
In the above embodiment, the high resistance oil supply / drain passage 71 was directly connected to the upper chamber 11 and the second valve chamber 34. However, both ends or one end of the high resistance oil supply / drain passage 71 are connected to the switching pipe 40 and / or the pilot pipe. Alternatively, the upper chamber and the second valve chamber may be indirectly connected to each other through a high resistance oil supply / discharge passage via these pipes.

The present invention is not limited to the above embodiments, and the spool of the switching valve may have a shape other than the above.

[Effect of device]

As described above, according to the present invention, the spool that has moved to the second valve chamber side of the switching valve reliably moves to the second valve chamber side position by the oil draining action of the high resistance oil drain passage or the high resistance oil drain passage. The spool that is held at the first valve chamber side and is moved to the first valve chamber side is reliably held at the first valve chamber side position by the high-pressure oil replenishment action by the high-resistance oil supply passage or the high-resistance oil supply and drain passage, so the hammer moves up and down. Predetermined rise and / without reversal in the middle of the stroke
Alternatively, it is possible to reciprocate with a descending stroke, and to reliably apply the desired impact force to the working tool.

[Brief description of drawings]

1 and 2 are longitudinal sectional views of a striking device showing an embodiment of the present invention, FIG. 3 is a longitudinal sectional view of a striking device showing another embodiment of the present invention, and FIG. 4 is a conventional striking device. It is a longitudinal cross-sectional view of an apparatus. 1 ... cylinder, 2 ... hammer, 8 ... lowering pressure receiving surface,
9 ... Ascending pressure receiving surface, 11 ... Upper chamber, 12 ... Lower chamber, 18
…… Bug, 20 …… Switching valve, 21 …… Spool, 22 …… Housing, 24 …… Upper diameter part, 29 …… Large pressure receiving surface, 30 ……
Small pressure receiving surface, 31 ...... First valve chamber, 33 ...... High pressure line, 34 ...... Second valve chamber, 35 ...... Pilot tube line, 36 ...... Low pressure line, 40 ...
… Switching line, 44… Spool hole, 60… Striking device, 61…
… High resistance drainage passage, 62 …… High resistance oil feed passage, 70 …… Striking device, 71 …… High resistance oil drainage passage.

Claims (3)

[Scope of utility model registration request] 1. A hammer having an ascending pressure receiving surface and a descending pressure receiving surface larger than the area of the pressure receiving surface is reciprocated vertically in a cylinder so as to strike a working tool such as a chisel during the descending motion. The lower chamber, which is freely fitted and applies hydraulic pressure to the ascending pressure receiving surface, is connected to the high pressure line, and the upper chamber, which applies hydraulic pressure to the descending pressure receiving surface, is hydraulically driven in relation to the position of the hammer. A striking device which is alternately connected to a high pressure line and a low pressure line by a switching operation of a spool of a switching valve to drive the hammer up and down. The small pressure receiving surface and the large pressure receiving surface are provided to face each other, the first valve chamber for applying hydraulic pressure to the small pressure receiving surface is connected to the high pressure pipe line, and the hammer is provided for the second valve chamber for applying hydraulic pressure to the large pressure receiving surface. By reciprocating motion of, it connects to the high pressure line and the low pressure line alternately. In a striking device connected to an erase pipe, a high-resistance drainage passage communicating the second valve chamber with the low-pressure pipe in a state where the spool has moved to the second valve chamber side is provided with an outer peripheral portion of the spool. A striking device characterized by being provided. 2. A hammer having an ascending pressure receiving surface and a descending pressure receiving surface larger than the area of the pressure receiving surface is reciprocated vertically in the cylinder so as to strike a working tool such as a chisel during the descending motion. The lower chamber, which is freely fitted and applies hydraulic pressure to the ascending pressure receiving surface, is connected to the high pressure line, and the upper chamber, which applies hydraulic pressure to the descending pressure receiving surface, is hydraulically driven in relation to the position of the hammer. A striking device which is alternately connected to a high pressure line and a low pressure line by a switching operation of a spool of a switching valve to drive the hammer up and down. The small pressure receiving surface and the large pressure receiving surface are provided to face each other, the first valve chamber for applying hydraulic pressure to the small pressure receiving surface is connected to the high pressure pipe line, and the hammer is provided for the second valve chamber for applying hydraulic pressure to the large pressure receiving surface. By reciprocating motion of, it connects to the high pressure line and the low pressure line alternately. In a striking device connected to an erase pipe, a high resistance oil supply passage for supplying high pressure oil to the second valve chamber in a state where the spool moves to the first valve chamber side is provided in the housing of the switching valve. A striking device. 3. A hammer having an ascending pressure receiving surface and a descending pressure receiving surface larger than the area of the pressure receiving surface is reciprocated vertically in the cylinder so as to strike a working tool such as a chisel during the descending motion. The lower chamber, which is freely fitted and applies hydraulic pressure to the ascending pressure receiving surface, is connected to the high pressure line, and the upper chamber, which applies hydraulic pressure to the descending pressure receiving surface, is hydraulically driven in relation to the position of the hammer. A striking device which is alternately connected to a high pressure line and a low pressure line by a switching operation of a spool of a switching valve to drive the hammer up and down. The small pressure receiving surface and the large pressure receiving surface are provided to face each other, the first valve chamber for applying hydraulic pressure to the small pressure receiving surface is connected to the high pressure pipe line, and the hammer is provided for the second valve chamber for applying hydraulic pressure to the large pressure receiving surface. By reciprocating motion of, it connects to the high pressure line and the low pressure line alternately. In percussion device connected to Irotsuto conduit, percussion device being characterized in that between the second valve chamber and the upper chamber is connected by a high-resistance supply and discharge oil passage.