JPS5837112B2 - hydraulic striking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic impact device used for destroying and crushing rocks, roads, buildings, etc.

Conventionally, impact devices using compressed air as a power source have been used as a means of destroying or crushing rocks, roads, buildings, etc., but when the air is released after the impact stroke, a loud bursting sound is generated, making it difficult to destroy or crush rocks, roads, buildings, etc. Since there are problems that cause noise pollution in the machine, there is a tendency to use striking devices that use hydraulic pressure, which generates less noise. However, striking devices that use hydraulic pressure as a power source are generally A piston is slidably arranged in a cylinder built into the main body, and this piston is reciprocated by hydraulic pressure, and a tool such as a chisel is struck by the piston itself or a hammer at the lower end of the piston rond directly connected to it. However, the switching mechanism that automatically switches the flow of hydraulic pressure to give reciprocating motion to the piston and the mechanism that controls this are complex, so the main body itself has a thick shape, and when the piston descends (impact stroke) The suction of hydraulic fluid in the low-pressure line causes pulsation, which causes large swings in the hose.To prevent pulsation, a special pulsation-absorbing accumulator is required in addition to the pressurizing accumulator, and this is installed on the side of the main body. Since it protrudes greatly, it has the disadvantage that it becomes large as a whole and is not easy to handle or use.

In addition, even when the introduction and discharge parts of the hydraulic fluid to the cylinder and the cylinder are provided in a far-separated relationship, and the device is not operated,
Since the hydraulic oil is discharged through the nohistone operating circuit within the main body, there is a large resistance to return to the hydraulic oil tank, which has the drawback of unnecessarily increasing power loss.

The present invention was created through repeated research in view of the above-mentioned circumstances, and its purpose is to provide a mechanism for automatically switching the flow of hydraulic pressure to provide reciprocating motion to a piston, and a mechanism for controlling this. Another object of the present invention is to provide a hydraulic impact device that has a simple mechanism for preventing suction of hydraulic fluid in a low pressure line when a piston is lowered, has a slender and simple shape as a whole, and is easy to handle and manufacture.

Another object of the present invention is that there is no need for an accumulator for pulsating suction, and that the accumulator for adding force also serves as the upper cap of the main body and can be easily removed from the main body, allowing inspection of various parts within the main body and replacement of parts. It is an object of the present invention to provide a hydraulic impact device having a structure that allows the accumulator to be easily operated and to be immediately replaced with another accumulator in the event of failure or gas filling.

A further object of the present invention is that the inlet and outlet of the hydraulic fluid are very close to each other, the hoses are well organized, and when the device is not in operation, the hydraulic fluid is directly supplied without passing through the hydraulic circuit inside the main body. It is an object of the present invention to provide a hydraulic impact device capable of minimizing power loss by discharging air from an inlet to an outlet.

Furthermore, the present invention allows the hydraulic fluid to flow directly from the inlet to the outlet as described above when the device is not in operation, and when the device is in operation, the flow of the hydraulic fluid is interrupted and the fluid flows through a circuit within the main body to the outlet. It is an object of the present invention to provide a valve for this type of device that has an automatic pressure return type.

Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 10 show a hydraulic impact device according to the present invention. In the drawings, 1 is a main body with a cylindrical part 1' fitted in the lower part, and a chisel or the like is attached to the cylindrical part 1l. The tool 2 has operating handles 3, 3 on the upper side of the main body, and an accumulator 4 is mounted on the top.

5 is a double-acting cylinder installed vertically on the lower bottom 6 of the main body 1, and has a piston 7 inside, and a lower piston 19 is connected to the lower surface of the piston 7 coaxially with the tool 2,
The lower piston 19 protrudes into the cylindrical portion, and has the hammer 8 firmly connected to its tip.

Further, on the upper surface of the piston 1, a lower piston 1''.9
A rod-shaped upper piston 18 is provided coaxially with the piston 7.
As shown in FIG. 5, the lower piston 19 and the upper piston 18 are configured such that their respective diameters are in the relationship W>W, >W2, and inside the double-acting cylinder there is an upper piston chamber 51 that can freely change its shape with the piston 7 as a boundary. A lower piston chamber 52 is formed.

Reference numeral 9 denotes a valve chamber formed between the double-acting cylinder 5 and the partition wall 17, and the upper piston 18 extends through the partition wall 17 into the center thereof.

A switching valve 1o is installed in the valve chamber 9 so as to be slidable relative to the upper piston 18, which automatically switches the flow of hydraulic pressure by moving the piston up and down.

Reference numeral 11 denotes an inclined protrusion connected to the lower side of the top of the main body 1, and the inclined protrusion 11 has an inlet passage 13 that can communicate with an upper chamber 12 formed between the accumulator 4 and the valve chamber 9.
is bored therein, and an outlet passage 14 is bored parallel to and adjacent to the inlet passage 13.

An operating valve 15 is installed in the inlet passage 13 and the outlet passage 14 in a relationship perpendicular thereto, and an operating lever 16
The inlet passage 13 and the outlet passage 14 are directly connected, or the inlet passage 13 and the outlet passage 14 are not communicated with each other, so that the hydraulic oil flows through the main body and is then discharged through the outlet passage 14. .

Thus, the upper chamber 12 opens at the top surface of the main body 1, and the accumulator 4 fits into the inner diameter surface 121 of the upper chamber 12 with the annular projection 41 as shown in FIG. A large number of through holes 42 for the upper chamber 12 are formed inside, and an oil storage chamber 45 with a diaphragm 44 stretched therein is recessed in the inner part of the through holes 42 .

Vertical holes 47 are formed in each corner of the accumulator 4 and communicate with the female threaded holes 46 formed at the same position in the main body 1. By inserting and rotating bolts 48 into each of the vertical holes 47, the accumulator 4 is removably attached to the main body 1.

Next, the upper piston 18, the valve chamber 9 and the switching valve 1
0 are arranged coaxially, and first, as shown in FIG. 5, a spool-shaped duct 20 is bored in the upper piston 18, with one end opening on the upper end face and the other end opening on the side wall.
Below this duct, there is a recessed duct 21 which normally opens into the partition wall portion.

On the other hand, the valve chamber 9 has a cylindrical valve chamber bottom section 94 that accommodates the lower flange 22 of the switching valve 10 at the bottom, and a ring-shaped first or second section that extends from the top to the bottom inside. Three recesses 91, 92, 93 are formed.

In contrast to such a valve chamber 9, the switching valve 10 has a lower flange 22 like a heron, and an upper flange 23 facing the lower flange 22 at a predetermined distance.

This upper flange 23 comes into contact with the bottom surface of the second recess 92 during rising to reach its upper limit, and is made to have the same outer diameter as the lower flange 22. It is in contact with a protruding peripheral surface 95 between the location 92 and the third recess 93 to block both of the recesses.

A relay path 96 is formed between the lower flange 22 and the upper flange 23 by communicating the second recess 92 and the third recess 93.
A cylindrical recess 24 is formed to obtain the following.

The upper flange 23 is connected with an annular head 25 for blocking the connection between the first recess 91 and the upper chamber 12 in the normal state and during the piston rising period.

Further, a ring-shaped hole 26 having a predetermined depth from the lower end is formed on the inner diameter side of the switching valve 10.

A passage 27 communicating between the upper chamber 12 and the lower piston chamber 52 is bored inside the main body outside the valve chamber 9, and the outlet passage 14 is communicated with the second recess 92. A discharge passage 28 is branched from an intermediate position of the discharge passage 14, and the other end of this passage is connected to a recess 29 formed concentrically with the upper piston between the cylindrical space 94 and the partition wall 17.

This recess 29 communicates with the duct 21 of the upper piston 1B only at the time of switching the piston up and down, and is for guiding the hydraulic oil in the cylindrical space of the valve chamber to the discharge passage 28.

Further, the main body is provided with a passage 30 that communicates the first recess 91 and the upper piston chamber 51 at a different cross-sectional position from the passages 27 and 28, and a passage 30 that connects the third recess 93 and the upper piston chamber 51. A passage 31 connecting the chambers 51 is bored.

Next, the operating valve 15, which is one of the features of the present invention, is shown in detail as shown in FIGS. 1 and 2 a and b.

That is, this operating valve 15 has a valve chamber 32 formed to cross the inlet passage 13 and outlet passage 14 which are parallel to each other as described above, and an upper and lower chamber slidably housed in this valve chamber 32. A sleeve-shaped valve body 33 has a through hole 34 extending through it, and its lower end is connected within the through hole of the valve body 33 by a pin 36, and has a stepped part 37 in the middle part and an inclined protrusion above it. It has an actuation rod 35 projecting through the wall.

The valve chamber 32 is formed by connecting in series a valve upper chamber 321 that intersects with the inlet passage 13 and a valve lower chamber 322 that intersects with the outlet passage 14 and is partially recessed outside the outlet passage 14. A step 38 is provided around the boundary between the chamber 321 and the lower chamber 322.

On the other hand, the valve body 33 has a stopper part 331 on its outer diameter that can come into contact with the step part 38, and a valve lower chamber 322 in the bottom part.
A flange portion 332 that can come into contact with the inner wall of the recess is provided, and between the flange portion 332 and the stopper portion 331,
A reduced diameter cylindrical portion 333 is provided to configure the valve intermediate chamber 323.

Next, the operation of the hydraulic impact device of the present invention will be explained.

First, if the operating rod 35 is not pushed down with the operating lever 16 as shown in FIG. 33 through holes 34 directly out of the outlet passage 14 and back into the tank.

Therefore, the device does not operate, and the hydraulic oil is immediately discharged from the starting end of the inlet passage 13 to the outlet passage 14 without passing through the interior of the main body 1, and returns to the tank with almost no resistance, minimizing power loss. be able to.

In the above state, the valve chambers 321, 322, 3
23 are all connected, each valve chamber has a low pressure only due to the back pressure.

Therefore, the pressures applied to the upper area S1, s2 and the lower area s3 of the valve body and the stopper area S4 are canceled out, and the operating rod 3
The actuating rod is pushed upward by the low pressure applied to the lower area S5 of the actuating rod 3, the valve body 33 also moves upward, and the actuating rod stepped portion 37 acts as a stopper to stop and remain as it is.

Next, the actuating rod 35 is pressed against the valve body 33 by the pressing portion of the operating lever 16 until the stopper portion 331 is locked with the stepped portion 38.
When the valve is lowered, the passage between the inlet passage 13 and the outlet passage 14 is closed by the flange portion 332 of the valve body 33 (see Fig. 2b), and the high-pressure hydraulic oil flowing from the inlet passage becomes flow A. After flowing into the main body and actuating it, it becomes a flow B that passes through the outside of the reduced diameter cylinder part of the valve body 33 and enters the outlet passage 14.
flows out from.

That is, as shown in Fig. 6, high-pressure hydraulic oil flows into the upper chamber 1.
2 and the passage 27 to the lower piston chamber 52, and the force generated by the difference in area between the lower piston chamber 52 and the upper piston 18 pushes the piston 7 and the hammer 8 upward.

At the same time, the upper piston 18 located above the piston 7 is also pushed upward.

At this time, the hydraulic oil in the upper piston chamber 51 becomes a flow B and flows out from the passage 31 through the relay passage 96 constituted by the second and third recesses 92 and 93, and from the outlet passage 14.

In addition, high-pressure hydraulic oil is supplied to the spool-shaped duct 20 and the switching valve 1.
0 through the ring-shaped hole 26 into the valve chamber bottom 94, bringing this and the upper chamber 12 to the same pressure.

Since the area of the lower part of the switching valve 10 is larger than that of the upper part, the switching valve 10 is stably maintained in the upper position as shown by the force generated by this difference in area.

Furthermore, the high pressure hydraulic oil flowing from the inlet passage 13 is
As shown in the figure, at the same time as the piston I is pushed up, the upper chamber 12
It passes through the through hole 42 and becomes a flow D, which pushes up the diaphragm 44 while compressing the gas (nitrogen gas, etc.) sealed in the accumulator, and the pressure is accumulated in the oil storage chamber 45.

On the other hand, when the upper piston 18 is pushed up together with the piston 7 and the duct 21 installed therein is raised until it connects the valve chamber bottom (valve lower chamber) 94 and the recess 29, the switching valve 10 is maintained at the upper limit position. The high-pressure hydraulic oil flows through flow C.
The liquid then flows out from the valve chamber bottom 94, passes through the duct 21 and the discharge passage 28, and exits the outlet passage 14.

As a result, the automatic switching valve 10 becomes free, and the upper chamber 12
is pushed down along the upper piston 18 by the action of high pressure, and the lower limit position, that is, the lower flange 22
It is stabilized at a position where the upper 7 flange 23 contacts the bottom of the valve chamber and the valve chamber protruding peripheral surface 95.

(See Fig. 8) Fig. 8 shows the downward phase of the piston, and when the switching valve 10 reaches the lower limit position like a rabbit, the upper flange 23
The space between the second recess 92 and the third recess 93 is closed, and at the same time, the annular head 25 is lowered to close the upper chamber 12 and the first recess 93.
The recess 91 is in communication with the recess 91 .

Therefore, the high-pressure hydraulic oil becomes a flow E, and the upper chamber 12
From there, it flows into the upper piston chamber 51 through the first recess 91 and the passage 30.

The area of the upper piston chamber 51 is much larger than that of the lower piston chamber 52.

Therefore, the lower piston 19 is suddenly pushed downward by a force corresponding to the area difference.

Moreover, at this time, the hydraulic oil stored in the accumulator 4 is released as a flow E, which passes through the upper chamber 12 and accelerates the upper piston 18.

Further, the hydraulic oil in the piston lower chamber 52 is pushed out to the passage 2.
7, flows back into the upper chamber 12 as a flow F, and presses the upper piston ton 18.

In this way, in the present invention, the upper histone 18 accelerates at the same time as the lower piston 19, and the hammer 8 is rapidly accelerated downward due to the resultant force of the pressure on the entire upper and lower areas. Piston chamber 5
The passage 31 connecting the first and third recesses 93 is the upper flange 2.
3 and the lower flange 22, and the outlet passage 14 is isolated from both the upper piston chamber 51 and the lower piston chamber 52.

Therefore, there is no suction of hydraulic oil from the outlet passage 14 during the downward movement of the piston I, which reduces the pulsation of the hydraulic oil, eliminates the need for an accumulator to absorb pulsation, and reduces the shaking of the hose. It becomes possible to extend the life of the hose.

Then, as the piston 7 further descends rapidly,
A hammer 8 connected to the tip of the lower piston 19 strikes the tool 2.

This is the state shown in Fig. 9, and almost at the same time when the hammer 8 strikes the tool 2, the spool-shaped duct 20 of the lowered upper piston 18 and the ring-shaped hole 26 of the switching valve 1o are connected, and this causes high pressure to flow. The hydraulic oil becomes a flow G and flows into the valve chamber bottom 94.

At this time, since the space between the valve chamber bottom 94 and the recess 29 is closed by the upper piston circumferential surface, the discharge passage 28 is blocked, and there is no fear that the hydraulic oil will leak into the outlet passage 14.

When high-pressure hydraulic oil flows into the valve chamber bottom 94, the switching valve 10 is pushed up by the force due to the difference in area between the upper and lower sides of the switching valve 10, as shown in FIG. 10, and returns to the state shown in FIG. Since the first recess 91 is closed by the portion 25, the passage 30 from the upper chamber 12 to the upper piston chamber 51 is blocked, and at the same time, the passage 30 from the upper chamber 12 to the upper piston chamber 51 is closed, and at the same time, the second recess 9 is closed by the cylindrical recess 24 of the switching valve 10.
2 and the third recess 93, the upper piston chamber 51 communicates with the outlet passage 14 through the passage 31, and the upper piston chamber 1
The piston 1 is pushed up by high-pressure hydraulic oil from the flow path 27 connecting the piston 2 and the lower piston chamber 52.

Thereafter, by repeating the same operation, the tool 2 is continuously hit.

Note that when the main body 1 described above is operated, the operating valve 15
The valve upper chamber 321 and the valve lower chamber 322 are at high pressure, and the valve intermediate chamber 323 is at low pressure, which is only the back pressure.

At this time, high pressure acts on the valve body upper areas S1, S2 and lower area S3, and the lower area S of the actuating rod, and the area S4 of the valve stopper part is increased by the duct D1 into the valve intermediate chamber 3.
Since it is connected to 23, only low back pressure acts on it.

The actuating rod is then pushed upward by a large force due to the high pressure applied to the area S5, so in order to continuously operate the device, the actuating rod 35 must be pushed down against said force to maintain it in the position shown. Well, working rod 35
When the pressure is released, the oil pressure automatically returns to the state shown in Fig. 2a.

Therefore, there is no need for a return spring, and the structure can be simplified accordingly.

In addition, in the present invention, a stopper portion 331 is provided on the outer periphery of the valve body 33 in order to reduce the force pushing down the actuating rod 35.

The force pushing the valve body 33 and the actuating rod 35 upward in the state shown in Fig. 2b is Phx (S5 + S3) + Pi x (S4), where the high pressure is Ph and the back pressure is PI, and the force is downward. The pushing force is PhX (S1+S2).

Therefore, the relationship between each area is S5>(St +S2)”
If the setting is made so that 3=S4, the force pushing the valve body 33 and the actuating rod 35 upward is PhX(Ss S4)+
It becomes PhX(S+).

PI is much smaller than pH (can be ignored, so Ph
X (S5 S4) is the force for pushing upward, so no matter how large the flow pressure becomes, by appropriately setting (S5S4), the force for manually pushing down the actuating valve 35 can be arbitrarily adjusted.

According to the present invention as described above, an inlet passage 13 and an outlet passage 14 are provided on the upper side of the main body 1 and are directly connected to each other by an operating valve 15, and at the end of the inlet passage 13 there is an upper chamber communicating with the lower side of the cylinder via a passage 27. 12, an accumulator 4 is mounted directly above the upper chamber, and a rod-shaped upper piston 18 is provided in the piston 7 in the double-acting cylinder provided in the main body to allow the flow of hydraulic pressure around the piston 7. A switching valve 10 that automatically switches as the piston moves up and down and a valve chamber 9 that controls the movement of the switching valve 10 are provided on the same axis, and the valve chamber 9 normally cooperates with an annular head 25 on the upper side of the switching valve. The communication between the upper chamber 12 and the valve chamber 9 is cut off, and the upper chamber 12 and the upper piston chamber 5 are connected by the passage 30 only during the downward movement of the piston.
The first recess 91 communicates with the first recess 91 which communicates with the upper piston 51 during the piston rising period, allowing the hydraulic fluid to flow out from the upper piston 51 to the outlet passage 14, and the upper 7 flange 23 of the switching valve 10 communicating with the first recess 91 during the piston rising period. Second and third recesses 92 and 93 are provided to block the passage 31 connecting the upper piston 51 and the outlet passage 14, and to connect the valve chamber 9 and the upper piston chamber 5.
A recess 29 is formed between the valve chamber 9 and the outlet passage 14 through the duct 21 of the upper piston 18 to discharge the switching valve position holding pressure only during the piston up/down switching period. In addition to the simple mechanism to automatically switch between the two to give reciprocating motion to the piston and the mechanism to control it, there is also a dedicated accumulator and operating valve to prevent hydraulic fluid from being sucked into the low-pressure line during the piston's descent phase. Since no return valve is required, the overall shape can be made slender and simple.

Furthermore, it has a good pulsation prevention effect, so there is no vibration of the main body due to pulsation or hose vibration, and the hydraulic fluid inlet and outlet are located very close to each other, so the hose does not fall apart and is well-organized. what you can do,
When the device is not in operation, the hydraulic fluid is discharged directly from the inlet to the outlet without passing through the passage inside the main body, which minimizes power loss.The accumulator also serves as the cap of the main body and can be removed freely. This makes it easy to inspect each circuit inside the main body, install/remove the switching valve, and replace the accumulator.
Excellent effects such as very good handling and usability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing an embodiment of the hydraulic impact device according to the present invention, FIGS. 2 a and b are cross-sectional views showing the structure and operation of the operating valve according to the present invention, and FIG. 3 is a main body according to the present invention. FIG. 4 is a sectional view showing the top structure; FIG. 4 is a plan view thereof, and FIGS. 5 to 10 are sectional views showing step-by-step how the device of the present invention is used. 1...Body, 2...Tool, 4.1...
...Accumulator, 5...Double acting cylinder, 7
...Piston, 8...Hammer, 9.
...Valve chamber, 10...Switching valve, 121...
...Upper chamber, 13...--Entrance passage, 14...-
...Outlet passage, 15...--Operating valve, 18...
... Upper piston, 19 ... Lower piston, 22 ... Lower flange, 23 ... Upper flange, 25 ... Annular head, 27, 28,
30, 31... passage, 29... recess,
51... Upper piston chamber, 52... One lower piston chamber, 91, 92, 93, 94... Recess.

Claims (1)

[Claims] 1. A double-acting cylinder is provided in the main body 1 to which a tool is attached at the bottom, and a lower piston 19 with a hammer 8 suspended coaxially with the tool is protruding from the piston 7 in the double-acting cylinder. , the device is designed to strike the tool 2 with the hammer 8 by the reciprocating motion of the piston, and on the same axis as the upper piston 18 protruding from the histone I, the flow of hydraulic pressure is automatically controlled by raising and lowering the piston. A switching valve 10 to be switched and a valve chamber 9 for controlling the movement of the switching valve 10 along with the reciprocating movement of the piston are provided externally, while a parallel inlet passage 13 and an outlet that can be directly connected to the upper part of the main body 1 with an operating valve 15 are provided. A passage 14 is provided, and an upper chamber 12 communicating with a lower piston chamber 52 via a passage 27 is formed at the top of the main body beyond the inlet passage, and
An accumulator 4 is attached to the upper chamber 12, and an accumulator 4 is attached to the valve chamber 9, which cooperates with the annular head 25 of the switching valve to shut off the upper chamber 12 and the valve chamber 9 in the normal state. A first recess 91 that communicates between the upper chamber 12 and the upper piston chamber 51 through the passage 30 only during the piston rising period, and a first recess 91 that communicates with the upper piston chamber 51 through the outlet passage 1 during the piston rising period.
4, and during the piston descending period, the switching valve 10
The upper flange 23 of the valve chamber 9 and the upper piston chamber 51 are provided with second and third recesses 92 and 93 that block mutual communication and close the passage 31 connecting the upper piston chamber 51 and the outlet passage 14. In between, there is a recess 29 that allows the valve chamber 9 and the outlet passage 14 to communicate through the duct 21 of the upper piston 18 only when switching the piston up and down, and discharges the switching valve holding pressure.
A hydraulic impact device characterized by being provided with. 2. The accumulator 4 is attached to the top surface of the main body by an annular projection 41 in contact with the inner diameter surface of the upper chamber, and is removably fixed to the main body 1 by bolts 4B and 48 arranged on the outer peripheral area of the annular projection 41. A hydraulic impact device according to claim 1, wherein: 3. The switching valve 10 includes a lower flange 22 that fits in the lower space of the valve chamber, and an upper flange 22 that faces the lower flange 22 at a predetermined distance and is locked at the bottom of the second recess of the valve chamber 9 when rising. and a cylindrical recess 24 which is located between the upper and lower flange portions and defines a relay passage 96 that communicates the upper piston chamber 51 and the outlet passage 14 during the piston rising period, and which is connected to the upper surface of the upper flange and which connects the upper chamber 12 and the 2. The hydraulic impact device according to claim 1, further comprising an annular head 25 that opens the communication recess 91 of the piston chamber 51 only during the downward movement of the piston. 4. A valve chamber 32 in which the operating valve 15 is formed so as to cross the inlet passage 13 and the outlet passage 14 which are parallel to each other.
It is slidably housed in this valve chamber and has a through hole 3 inside.
4, and an operating rod 35 whose lower end is connected to the upper space of the valve element and whose upper part protrudes from the main body 1. By holding the valve body 33 in the raised position, the through hole 34 communicates with the inlet passage 13 and the outlet passage 14, and while the actuating rod 35 is pressed, the bottom flange portion 332 of the valve body 33 and the bottom of the valve chamber are connected to each other. The contact blocks the through hole 34 and the hydraulic fluid in the main body flows around the outer recess of the valve body and flows into the outlet passage 14, and when the actuating rod 35 stops pressing, the hydraulic pressure acting on the bottom of the valve chamber closes the valve body 33. The hydraulic impact device according to claim 1, wherein the hydraulic impact device is constructed in such a manner that the force phase dynamically returns to the normal state.