JPS6031633B2 - Hydraulic driven striking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a hydraulically driven striking device equipped with a piston-type hammer that applies impact energy to a working tool such as a chisel through reciprocating motion.

In order to improve the work efficiency of hydraulically driven impact devices such as rock drills and crushers, it is necessary to impact working tools such as chisels at high speed, but in this case, the return speed of the hammer is If it becomes too large, the next striking stroke will begin before the drop in discharge volume or pressure of the hydraulic pump or accumulator due to the release of large amounts of energy during the striking stroke has been recovered, causing individual striking forces to fluctuate, which in turn will reduce work efficiency. This will lead to a decline in efficiency.

This invention has been made in view of the above points, and is based on hydraulic pressure that allows the time required for the upward stroke, which is the return stroke, of the hammer to be longer, relative to the time required for the downward stroke, which is the striking stroke, of the hammer. It is an object of the present invention to provide a driving striking device.

In this invention, hydraulic pressure mainly refers to oil pressure, but other liquids other than hydraulic oil may be used if desired. A first embodiment of the present invention will be described below with reference to FIG.

In the figure, the housing extends to 1', and a hammer 3 is housed in a cylinder 2 provided in the housing so as to be freely movable in the vertical direction.

4 is the upper piston part of the hammer, 5 is the lower piston part, 6
is the upper small diameter part of the hammer, 7 is the middle small diameter part, and 8 is the lower small diameter part.

The diameter of the lower small diameter portion 8 is smaller than that of the upper portion 4 and the flap portion 6, and therefore the area of the rising pressure receiving surface 9 of the lower piston portion is larger than the area of the descending pressure receiving surface 10 of the upper piston portion. cylinder 2
An upper chamber 11 and a lower chamber 12 of variable volume, and a middle chamber 13 of constant volume are formed in the cylinder 2 by the inner wall surface of the hammer 3 and each piston portion of the hammer 3 . 20 is a slide valve for controlling the reciprocating motion of the hammer 3, and its spool 21
is installed inside a valve hole 22 provided in the housing so as to be able to freely slide vertically.

Reference numeral 23 indicates an annular groove for switching the hammer drive circuit provided on the spool, 24 indicates an upper pressure receiving surface of the spool, and 25 indicates a lower pressure receiving surface, and the area of each pressure receiving surface is equal.

An upper pilot oil chamber 26 and a lower pilot oil chamber 27 are formed by each pressure receiving surface and the valve hole 22. On the other hand, 14 is a high-pressure pipeline for supplying pressure oil, which passes through the upper chamber 11 of the cylinder and an annular inlet chamber 28 provided in the valve hole, and the inlet 15 is connected to an external pressure supply source such as a hydraulic pump. 16. Reference numeral 17 denotes a low-pressure pipe for return oil, which passes through the middle chamber 13 of the sill and an annular outlet chamber 29 provided in the valve hole.
is connected to tank 19. It is a supply and discharge pipe that is suitable for the lower chamber 12 of the three-way cylinder and the annular supply and discharge chamber 31 provided in the valve hole.

Further, 32 is a conduit that connects the upper pilot boat 33 and the upper pilot oil chamber 26 that open into the cylinder 2;
3 is a conduit that connects the lower pilot boat 35 and the lower pilot oil chamber 27 that open into the cylinder 2; 36 is a conduit that connects the high-pressure pipe 14 and the upper pilot oil chamber 26;
Reference numeral 7 designates a conduit connecting the high-pressure conduit 14 and the lower pilot oil chamber 27, and each of these conduits is a pongee pipe having its own resistance. Note that 40 is inserted into the housing 1 so as to be able to move up and down, and 41 is a stopper. Note that in the above configuration, the housing 1 has a hammer 3
Also, the portion accommodating the spool 21 may be divided into parts that can be fixed. Next, the operation of the hydraulically driven striking device constructed as described above will be explained.

Figure 1 shows the moment when hammer 3 hits chisel 40,
Hydraulic pressure P from the high pressure pipe line 14 is acting on the lowering pressure receiving surface 1 of the hammer.

On the other hand, since the annular groove 23 of the spool of the slide valve 20 communicates the outlet chamber 29 and the supply/discharge chamber 31, the pressure receiving surface 9 for raising the hammer has a low pressure conduit 17 whose Po is equal to 0. Hydraulic pressure is working. In the illustrated position of the hammer 3, the upper pilot boat 33 is blocked by the upper piston part 4, so that the pressure P acts on the upper pilot oil chamber 26 of the slide valve via the conduit 36.
On the other hand, since the lower pilot boat 35 is closed to the middle chamber 13, the pressure oil at pressure P flows from the high pressure pipe 14 through the pipe 37 to the lower pilot oil chamber 27, and then passes through the pipe 34 and the middle chamber 13 to the low pressure pipe. 17 to the outside. Therefore, the lower pilot oil chamber 27 has a pressure P, (P>P,>
The spool 21 is driven downward by the difference between this pressure P and the pressure P in the upper pilot oil chamber 26. When the spool 21 descends and the annular groove 23 connects the supply/discharge chamber 31 and the inlet chamber 28, the hammer 3
The pressure P of the high-pressure pipe 14 begins to build up on the rising pressure receiving surface 9, and since the area of the rising pressure receiving surface 9 is larger than the area of the descending pressure receiving surface 10, it acts on the descending pressure receiving surface 10. pressure P
The hammer 3 rises by overcoming the pressing force. Hammer 3
As the lower pilot boat 35 rises, the lower piston part 5 blocks the lower pilot boat 35, and then the upper pilot boat 33
opens into the middle chamber 13 and connects to the low pressure pipe 17. As a result, pressure P acts on the lower pilot oil chamber 27 of the slide valve through the conduit 37, while pressure oil at pressure P flows into the upper pilot oil chamber 26 through the conduit 36, and low pressure oil flows through the conduit 32. It flows out from the conduit 17.
Therefore, the upper pilot oil chamber 26 mainly includes a conduit 32,
Pressure P2 ( determined by the pipe resistance of 36 and pressure P
P>P2>Po), and the spool 21 is driven upward by the difference between this P2 and the pressure P in the lower pilot oil chamber. When the spool 21 rises and the annular groove portion 23 moves between the supply and discharge chamber 31 and the outlet chamber 29,
The lower chamber 12 is connected to a low pressure line 17 via a supply and discharge line 30.
The pressure acting on the lifting pressure receiving surface 9 of the hammer is P
Since the pressure is lowered to 0, the hammer 3 is driven downward by the pressure P acting on the lowering pressure receiving surface, and the above movement is repeated thereafter. In this way, the pressure acting on the upper pressure receiving surface 24 and the lower pressure receiving surface 25 when the slide valve 20 is operated is suppressed by the pipe resistance of each conduit 32, 34, 36, 37, so the resistance value of each of these pipes is By appropriately setting the above-mentioned pressure relationship P,>P2, the descending speed of the spool 21 becomes smaller than the ascending speed, extending the time until the hammer 3 starts rising, and increasing the rising speed of the hammer 3. As a result, the time required for the hammer 3 to rise is extended. Note that FIG. 1 shows both pressure receiving surfaces 24 and 25 of the spool and the low pressure pipe 17.
The two conduits 32 and 34, which are connected to each other, are alternately blocked by the position of the hammer 3, but instead
Both conduits 36, 37 which connect 4, 25 and the high pressure pipeline 14
Even if the configuration is such that the conduits 32 and 34 are alternately cut off depending on the position of the hammer 3 and the conduits 32 and 34 are always connected to the low-pressure conduit 17, the same effect as in the first embodiment can be obtained by setting the conduit resistance value of each conduit. be able to.

However, in this case, the spool 21 will be driven in each direction by the difference between the pressures P and Po, or the difference between the pressures P2 and Po. Figure 2 is the second example of this invention.
Embodiments are shown, and parts with the same reference numerals as in FIG. 1 indicate the same or equivalent parts as in FIG. 1.

(The same applies to each of the following embodiments.) In this embodiment, when the hammer 3 is approximately at the bottom dead center position, the high pressure pipe 14 is in a state where the hammer 3 is approximately at the top dead center position. In this case, an upper pilot boat 51 is provided which communicates with the low pressure line 17, and the pressure P, P is supplied to the upper pilot oil chamber 26 of the slide valve by means of a line 52 in relation to the position of the hammer 3.

This embodiment differs from the first embodiment only in that it is made to act alternately. In the illustrated state of the spool 21, a pressure P acts on the upper pressure receiving surface 24 and a pressure P acts on the lower pressure receiving surface 25, and the spool is driven downward by the difference between them. On the other hand, when the hammer 3 is at the top dead center position, the upper pilot boat 51 passes through the low pressure pipe 17.
The spool 21 is driven upward at a speed that depends on the resistance of the conduits 34, 37 and the mass of the spool. Therefore, for example, by making the pipe resistance of the conduit 37 smaller than that of the conduit 34, the descending speed of the spool 21 can be made smaller than the ascending speed, and the same effect as in the first embodiment can be obtained. The third embodiment of the present invention shown in FIG. 3 differs from the second embodiment only in that the lower pilot oil chamber 27 is directly connected to the low pressure line 17 through a conduit 61.

In this embodiment, pressure oil always flows out from the high-pressure pipe 14 to the low-pressure pipe 17 via the pipe 37, the lower pilot oil chamber 27, and the pipe 61, and the pressure is adjusted according to the pipe resistance of the pipes 37 and 61. It acts on the lower pilot oil chamber 27. This pressure and the alternating pressure acting on the upper pilot oil chamber 26 drive the spool 21 up and down.Similar to the second embodiment, if the line resistance of the conduit 37 is made smaller than the line resistance of the conduit 61. The descending speed of the spool 21 can be made 4 times slower than its ascending speed. In the fourth embodiment of the present invention shown in FIG. 4, the pilot piping to the lower pilot oil chamber 27 is only the conduit 37, and the area (denoted as A) of the upper pressure receiving surface 24 of the spool 21 is connected to the lower pressure receiving surface. The difference from the third embodiment is that the area is larger than 25 (assumed to be a).

That is, the upper flea part 71 provided on the subur 21 is thinner than the lower flea part 72, and each of the small flea parts has holes 73 and 74 drilled in the housing to fit the bales, and 75 is an oil escape hole. Note that instead of providing this escape hole 75, the hole 73
, 74 may be passed through the low pressure pipe 17. At the illustrated hammer position, pressure P acts on the upper and lower pressure receiving surfaces 24 and 25, and the spool 21 is driven downward due to the difference in the pressure receiving areas. On the other hand, when the hammer 3 is approximately at the top dead center position, the upper pilot oil chamber 26 is fully connected to the low pressure pipe line 17, so the spool 21 is driven upward. In order to make the descending speed of the spool 21 smaller than the ascending speed, for example, if a>A/2, based on the condition of upward driving force (P・a)>downward driving force (P・A−P・a). good. In this embodiment, the pilot piping for the slide valve 20 is simple. In the first to third embodiments, the areas of the upper pressure receiving surface 24 and the lower pressure receiving surface 25 of the spool 21 are the same, but these embodiments It is also possible to use spools with different pressure-receiving areas as in the fourth embodiment, and the difference in the pressure-receiving areas is multiplied by the difference in the driving pressure in the upward and downward directions of the spool, thereby increasing the driving speed in the vertical direction of the spool 21. can make a further difference.

In addition, in this embodiment, the upper small portion 71 and the lower small portion 72
This slide valve may be used in the first to third embodiments by making the upper pressure receiving surface 24 and the lower pressure receiving surface 25 have the same area, and in this case, only a small amount of oil is required for operating the slide valve.
Furthermore, the spool is prevented from being driven at an unnecessarily high speed and colliding with the housing. FIG. 5 shows a modification of the fourth embodiment, in which the area a of the upper pressure receiving surface 24 is defined as the area a of the lower pressure receiving surface 25.
is smaller than the area A, and a<A/2.

Further, piping is arranged so that pressure P is applied to the upper pressure receiving surface 24 and alternating pressure of Po and P (pressure of the lower chamber 12) is applied to the lower pressure receiving surface 25. Although a detailed explanation will be omitted, the spool 2
1 is driven downward by the force P×a, and P×(A−a
), and a large upward driving speed can be obtained. In each of the above embodiments, the resistance of the conduit itself is utilized, so the structure is simple and easy to manufacture. However, instead of this, a fixed throttle valve or a fixed throttle valve or A variable throttle valve may be provided to utilize its resistance.

The sixth embodiment shown in FIG. 6 has a valve hole 22 in the spool 21.
This differs from each of the above embodiments in that a constricted portion 81 with a diameter close to the inner diameter of is provided. This constriction portion 81 is provided at a position facing the entrance chamber 28 only when the spool 21 is in the lowest position (not shown). Further, the conduits 82 and 83 are arranged so that an alternating pressure of P or Po is applied to each pressure receiving surface of the spool 21 depending on the position of the hammer 3, respectively. That is, in the illustrated state, pressure P acts on the upper pressure receiving surface 24 and pressure Po acts on the lower pressure receiving surface 25, the spool 21 is driven downward, and the high pressure pipe 14 passes through the supply/discharge pipe 30. However, the constricted part 81 of the spool is connected to the inlet chamber 28.
Since the hammer 3 is opposed to the lower chamber 12, the pressure oil flowing into the lower chamber 12 is throttled by the throttle part 81, and the rising speed of the hammer 3 itself becomes slow.

After the hammer 3 is raised, the pressure P of the lower chamber 12 acts on the lower pressure receiving surface 25 of the spool, and the pressure Po acts on the upper pressure receiving surface 24, causing the spool to rise as shown in the figure. The flow path resistance between the outlet chamber 29 and the outlet chamber 29 is 4.
Therefore, the hammer 3 is rapidly driven downward. In the first to fifth embodiments described above, the aperture portion 81 may be provided in the annular groove portion 23 of the spool to further reduce the upward driving speed of the hammer 3.

In addition, in FIG. 6, the converging part 81 may be provided in two or more steps, and instead of being stepped, it may be in the form of a continuous surface extending to the deepest diameter part of the annular groove part 23, as shown by a chain line 84. good. As explained above, according to the present invention, the time required for the hammer to rise can be made relatively longer than the time required for the hammer to descend, so even if the hammer's descending speed is sufficiently increased, the pump pressure will increase during the hammer's upward stroke. The drop in accumulator pressure can be recovered and the next descending stroke can be performed in the optimal system state, making it possible to perform highly efficient striking work.

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show embodiments of the hydraulically driven striking device according to the present invention, and FIGS. 1 to 6 are longitudinal sectional views showing the first to sixth embodiments, respectively.

2...Cylinder, 3...Hammer, 4.
...Upper piston part, 5...Lower piston part, 9...Pressure receiving surface for rising, 10...
Lowering pressure receiving surface, 11... Upper chamber, 12...
...Lower chamber, 14...High pressure pipe, 17...
...Low pressure pipe, 20...Slide valve, 21...
... Spool, 23 ... Annular groove, 24 ...
Upper pressure receiving surface, 25...Lower pressure receiving surface, 30...
... Supply and discharge pipe line, 32 ... conduit, 34 ... conduit,
36... conduit, 37... conduit, 52... conduit,
61... conduit, 81... constriction section, 82... conduit, 83... conduit.

Traditional/Illustration Figure 5 *Z diagram Many 3 figures Figure 4 Figure 6

Claims (1)

[Scope of Claims] 1. An upper piston part which is disposed in a cylinder so as to be able to reciprocate in the vertical direction so as to strike a working tool such as a chisel, and has a descending pressure receiving surface and an area larger than the descending pressure receiving surface. a hammer including a lower piston portion having a rising pressure receiving surface; an upper chamber formed by dividing the cylinder by the descending pressure receiving surface; a high pressure pipe communicating with the upper chamber;
A lower chamber is formed by dividing the cylinder by the rising pressure receiving surface, a supply/discharge pipe communicating with the lower chamber, and a spool that is hydraulically driven in relation to the position of the hammer. The discharge pipe is alternately connected to the low pressure pipe and the high pressure pipe and is provided with a slide valve that drives the hammer up and down, and the spool is connected to the supply and discharge pipe when the supply and discharge pipe is connected to the high pressure pipe. A hydraulically driven striking device characterized in that a moving speed of the spool is smaller than a moving speed of the spool when connecting the supply/discharge pipe to the low-pressure pipe. 2. A separate conduit communicating with the high-pressure pipeline and a separate conduit communicating with the low-pressure pipeline are connected to both pressure-receiving surfaces of the spool of the slide valve, respectively, and both conduits communicating with the low-pressure pipeline are connected to the position of the hammer. 2. The hydraulically driven striking device according to claim 1, wherein the spool is alternately shut off by the flow path resistance of each of the conduits so that the moving speed in both directions of the spool is made different. 3. A separate conduit communicating with the high-pressure pipeline and a separate conduit communicating with the low-pressure pipeline are connected to both pressure-receiving surfaces of the spool of the slide valve, respectively, and both conduits communicating with the high-pressure pipeline are connected to the position of the hammer. 2. The hydraulically driven striking device according to claim 1, wherein the spool is alternately shut off by the flow path resistance of each of the conduits so that the moving speed in both directions of the spool is made different. 4 One pressure receiving surface of the spool of the slide valve is connected with a conduit that alternately communicates with the high pressure pipe and the low pressure pipe depending on the position of the hammer, and the other pressure receiving surface of the spool is provided with a conduit that communicates with the high pressure pipe, and when one of the pressure-receiving surfaces communicates with the high-pressure pipeline, a conduit communicating with the low-pressure pipeline is connected, and the speed of movement of the spool in both directions is made different depending on the distribution of flow path resistance of each conduit. Claim 1
Hydraulic-driven striking device as described in . 5 One pressure receiving surface of the spool of the slide valve is connected with a conduit that alternately communicates with the high pressure pipe and the low pressure pipe depending on the position of the hammer, and the other pressure receiving surface of the spool is connected with a conduit that communicates with the high pressure pipe, The hydraulically driven striking device according to claim 1, wherein conduits are connected to the low-pressure conduit and the spool is moved at different speeds in both directions by distributing flow path resistance of each conduit. 6. The hydraulically driven striking device according to claim 1, 2, 3, 4, or 5, wherein both pressure receiving surfaces of the spool of the slide valve have the same area. 7. The hydraulically driven striking device according to claim 1, 2, 3, 4, or 5, wherein the pressure receiving surfaces of the spool of the slide valve have different areas. 8 The areas of both pressure receiving surfaces of the slide valve spool are different, and the conduit communicating with the high pressure pipe is connected to the small pressure receiving surface, and the high pressure pipe and the low pressure pipe are connected to the large pressure receiving surface depending on the position of the hammer. 2. A hydraulically driven striking device according to claim 1, wherein conduits alternately communicate with the spool, and the moving speeds of the spool in both directions are made different depending on the difference in the pressure receiving area. 9. The hydraulically driven striking device according to claim 1, wherein the spool of the slide valve is provided with a constriction portion that causes a pressure loss in the fluid flowing from the high-pressure pipe to the supply/discharge pipe through the slide valve. 10 It is disposed within the cylinder so as to be able to reciprocate vertically in a manner that strikes a working tool such as a chisel, and has an upper piston portion having a descending pressure receiving surface and a rising pressure receiving surface having a larger area than the descending pressure receiving surface. a hammer having a lower piston portion; an upper chamber formed by dividing the cylinder by the lowering pressure receiving surface; a high pressure pipe communicating with the upper chamber; A separate lower chamber, a supply/discharge pipe communicating with the lower chamber, and a spool hydraulically driven in relation to the position of the hammer connect the supply/discharge pipe to a low-pressure pipe and a high-pressure pipe. slide valves alternately connected to the pipe to drive the hammer up and down; and a resistance that causes a pressure loss in the liquid flowing from the high pressure pipe to the supply/discharge pipe via the slide valve. A hydraulically driven striking device characterized by: 11. The hydraulically driven striking device according to claim 10, wherein the resistance is a constriction provided on the spool of the slide valve.