JP5841015B2 - Impact tool - Google Patents

Description

  The present invention relates to an impact moving tool such as a hydraulic breaker used for dismantling a concrete structure, crushing a rock, excavating a rock, or the like.

  A piston having a large-diameter portion is slidably fitted in the cylinder, an upper chamber is provided above the large-diameter portion of the piston, and a lower chamber is provided below the large-diameter portion. Oil is supplied to raise the piston, and in the upward stroke, the high-pressure gas in the gas chamber formed on the upper side of the piston is compressed to store energy, and the piston is lowered by the energy of the gas expansion to lower the chisel. In the impact moving tool that strikes the upper end of the piston, the switching valve is operated in conjunction with the lifting and lowering movement of the piston, and the lifting and lowering movement of the piston is controlled by the switching valve.

  As described in Patent Document 1, the switching valve employed in the impact tool has a round shaft shape with an annular groove formed on the outer periphery, and the annular groove is pivoted by the up-and-down movement of the valve body. There are a spool type that is displaced in the direction to switch the flow path of the hydraulic oil, and a cylindrical type that is made to flow the hydraulic oil inward as described in Patent Document 2. .

Japanese Utility Model Publication No. 61-2224 Japanese Patent Laid-Open No. 2003-71744

  By the way, in the switching valve described in Patent Document 1, the working oil from the oil supply port is introduced into the upper chamber in the annular groove for introducing the hydraulic oil from the oil supply port into the lower chamber when the valve body is in the stopped state and the lower chamber. Since it is necessary to provide a plurality of annular grooves such as annular grooves to be introduced at intervals in the axial direction of the valve body, in order to secure a sufficient flow path, the total length of the switching valve becomes longer and larger, and the weight There is an inconvenience that the switching valve becomes difficult to control.

  Also, during the stroke when the piston descends, when hydraulic fluid flows from the lower chamber to the upper chamber or the oil outlet, the hydraulic fluid flows along an annular groove formed in the valve body, and the flow rate is limited by the annular groove. Therefore, the flow resistance is increased, the smooth flow of the hydraulic oil is hindered, and the impact efficiency of the piston is lowered. In order to improve the impact efficiency, if the diameter of the valve body is increased to form a deep annular groove and the stroke is made longer, the valve body becomes longer and heavier and the valve body moves smoothly. This makes it difficult to control the valve body.

  In addition, since it is necessary to increase the processing accuracy of the groove so as not to hinder the sliding of the valve body, it takes time to manufacture.

  On the other hand, in the switching valve described in Patent Document 2, hydraulic oil in the lower chamber flows into the inside from the lower end opening of the valve body and flows into the upper chamber from a plurality of small-diameter holes formed at the top during the piston stroke. Therefore, it is necessary to increase the inner diameter of the valve body in order to secure a sufficient flow path at that time and to improve the fluidity of the hydraulic oil. As the inner diameter increases, the outer diameter also increases, making the valve body heavier and heavier, more likely to cause oil leakage, unstable operation of the valve body, and failure to occur. Inconvenience occurs in that the operating efficiency of the apparatus decreases.

  Also, when hydraulic fluid flows from the upper chamber to the lower chamber vigorously due to the reaction applied to the piston immediately after hitting the chisel, the hydraulic fluid flows downward through the small diameter hole from the top of the valve body, so the valve A pressing force is applied to the body and the operation becomes unstable, which affects the control of the piston and may cause unevenness.

  An object of the present invention is to provide an impact moving tool capable of securing a sufficient hydraulic fluid conduit in a state where the axial length of the valve body in the switching valve is reduced in size and reduced in diameter. is there.

  In order to solve the above problems, in the present invention, the upper end portion of the chisel is slidably inserted into the lower end portion of the cylinder, and a slidable piston for hitting a chisel having a large diameter portion is incorporated inside the cylinder. An inner chamber of the cylinder is provided with an upper chamber on the upper surface side of the large-diameter portion, a lower chamber on the lower surface side of the large-diameter portion, and a gas chamber filled with high-pressure gas on the upper end surface side of the piston, The cylinder is provided with a communication passage communicating the upper chamber and the lower chamber, and a valve chamber continuous above the communication passage, and a valve body for opening / closing control of the communication passage is slidably incorporated in the valve chamber. A large-diameter portion that is slidable in a large-diameter chamber formed in the upper portion of the valve chamber is provided at an upper portion of the valve body, and the cylinder is connected with pressure oil from an oil supply port at a lowered position of the valve body. And the pressure from the oil supply port A pressure applying passage for introducing a hydraulic pressure to the upper end surface of the valve body by introducing the pressure oil into the valve regulating chamber formed in the upper portion of the valve chamber, and introducing pressure oil to the bottom of the large diameter chamber during the upward stroke of the piston A valve switching control oil passage that raises the valve body in a state slightly before the piston reaches the upper limit position, and an oil discharge passage that communicates the upper portion of the large-diameter chamber and the oil discharge port when the valve body is lowered. The communication passage extends in the vertical direction, and has a vertical hole portion at which the lower end portion of the valve body that moves up and down in the valve chamber is movable forward and backward, and the valve body is connected to the upper end portion of the vertical hole portion. A configuration was adopted in which a closed state in which communication between the upper chamber and the lower chamber was blocked by the entry of the lower end portion was adopted.

  In the impact tool having the above-described configuration, the lower end portion of the valve body enters the vertical hole portion of the communication passage, and pressure oil is supplied to the oil supply port in a lowered state of the valve body that blocks communication between the lower chamber and the upper chamber. Then, the pressure oil flows from the piston raising oil supply passage to the communication passage and flows into the lower chamber, the piston rises, and the high-pressure gas in the gas chamber is compressed.

  During the upward stroke of the piston, when the piston rises to a position slightly before reaching the upper limit position, pressure oil is introduced into the lower portion of the large-diameter chamber through the valve switching control oil passage, and the valve body is caused by the pressure oil. Ascending, the lower end part comes out of the vertical hole part of the communication passage, the piston descends due to the expansion of the compressed high-pressure gas in the gas chamber, and hits the chisel. At this time, the pressure oil in the lower chamber flows into the upper chamber through the open communication path.

  In addition, the lower chamber and the valve switching control oil passage are blocked from communication by lowering the piston, the supply of pressure oil to the lower portion of the large-diameter chamber is shut off, and the lower portion of the large-diameter chamber communicates with the oil discharge port, The pressure oil in the upper chamber and the lower portion of the large-diameter chamber is discharged from the oil discharge port. Further, since the pressure oil is supplied from the oil supply port to the valve regulating chamber through the pressure applying passage, the valve body is lowered. Due to the lowering, the lower end portion of the valve body enters the vertical hole portion of the communication passage, closes the communication passage, and blocks communication between the lower chamber and the upper chamber. Thereafter, the above operation is repeated.

  As described above, the valve body opens and closes the communication passage by its up-and-down movement, and when opened, the communication passage enters a state in which the lower chamber and the upper chamber communicate with each other, and the lower chamber hydraulic fluid flows into the upper chamber. The valve body does not need to be formed with a constricted portion such as an annular groove for allowing the hydraulic oil in the lower chamber to flow into the upper chamber, and the axial length of the valve body can be shortened.

  In addition, since the lower chamber hydraulic oil can have a sufficient flow path diameter without passing through the constricted portion of the valve, it smoothly flows from the communication path into the upper chamber, and the valve body does not give resistance to the flow of hydraulic oil. Therefore, the diameter of the valve body can be reduced. As described above, the hydraulic oil conduit can be secured in a state where the weight of the valve body is reduced by shortening and reducing the diameter of the valve body.

  In addition, since the valve body can be shortened, the lift stroke of the valve body can be reduced, and since the valve body is light, the control of the valve body can be facilitated. Further, unlike the structure in which the hollow hole of the valve body is used as a flow path, the valve body can have a small diameter, so that a reduction in efficiency due to oil leakage at the time of operation can be suppressed, and the impact efficiency can be improved.

  In addition, when the piston strikes the chisel and the hydraulic fluid in the upper chamber flows toward the lower chamber due to the momentary lift of the piston due to the reaction, the valve body is still in the raised position, and the hydraulic fluid is directly connected to the communication path. Since it passes through the lower chamber through the valve body, the valve body is not affected by the flow of hydraulic oil, and the impact of the piston can be stabilized as compared with the conventional type that passes through the inside of the valve body.

  In the impact moving tool according to the present invention, the piston raising oil passage is formed in the valve body in the annular high-pressure import formed in the inner periphery of the valve chamber and communicating with the oil filler, and the valve body is lowered. It may be composed of an annular high-pressure out-port that communicates with the high-pressure import through the constricted portion, and a bypass that communicates the high-pressure out-port with the middle of the communication path. In this case, the valve switching control oil passage is formed in the cylinder between the lower chamber and the upper chamber, and the annular valve control import that communicates with the lower chamber at a position slightly before the piston reaches the upper limit position, The valve control import may be formed of a valve body ascending oil passage that has one end communicating with the valve control import and the other end communicating with the bottom of the large-diameter chamber formed at the top of the valve chamber.

  Further, the piston raising oil supply passage may be composed of an inlet-side passage whose opening end is the oil supply port. In this case, the valve switching control oil passage is formed on the inner circumference of the cylinder between the lower chamber and the upper chamber, and the annular valve control import that communicates with the lower chamber at a position slightly before the piston reaches the upper limit position; A valve control outport that is formed on the upper side of the valve control import and that communicates with the valve control import via a valve switching annular groove formed in the large diameter portion of the piston when the piston is lowered. And one end in communication with the valve control import, and the other end in communication with the bottom of the large-diameter chamber formed at the top of the valve chamber, and one end in communication with the valve control outport. An oil passage for lowering the valve body that is always in communication with the oil discharge port via a constricted portion formed in the valve body, and a valve body that is formed in the valve body, It is comprised from the oil passage hole which connects the lower part of a diameter chamber, and the said communicating path It can be as.

  Here, the constricted portion formed in the valve body may be formed of an annular groove, or may be formed of a plurality of cutout portions formed at intervals in the circumferential direction. When the plurality of cutout portions are constricted portions, the outer periphery between adjacent cutout portions forms a sliding guide surface, so that the valve body can be moved up and down smoothly in the valve chamber.

  In the present invention, as described above, the communication passage that communicates the lower chamber and the upper chamber is opened and closed by the valve body that is moved up and down in the valve chamber, and the hydraulic oil in the lower chamber flows into the upper chamber when the valve is opened. Therefore, it is not necessary to form a constricted portion such as an annular groove for allowing the hydraulic oil in the lower chamber to flow into the upper chamber in the valve body, and the axial length of the valve body can be shortened. In addition, compared with the case where the inner diameter of the cylindrical valve body is used as the flow path, the valve body does not give resistance when the hydraulic oil flows from the lower chamber to the upper chamber, and a sufficient flow path is secured. The hydraulic oil line can be secured in a state where the weight of the valve body is reduced by shortening and reducing the diameter of the valve body.

  Furthermore, the oil moves instantaneously by connecting the upper chamber and the lower chamber through the direct communication path without going through the annular groove and the inner diameter flow path, so the resistance when the piston descends is eliminated and the hitting is performed smoothly. . In addition, the cylinder itself that accommodates the valve body portion can be reduced in size, and the impact moving tool itself can be reduced in weight.

A longitudinal sectional view showing an embodiment of an impact tool according to the present invention Sectional drawing which expands and shows the switching valve part of FIG. Sectional drawing which shows the state which the piston rose to the upper limit position Sectional view showing the switching state of the switching valve Sectional view showing the lowered state of the piston Longitudinal sectional view showing another embodiment of the impact tool according to the present invention Sectional drawing which expands and shows the switching valve part of FIG. Sectional view showing the switching state of the switching valve Front view showing another example of valve body Sectional drawing which shows other example of a valve body (A) is sectional drawing along the XI-XI line of FIG. 10, (b) is sectional drawing which shows the other example of a constriction part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIGS. 1 and 2, the upper portion of the chisel 2 is slidably fitted in the lower end portion of the cylinder 1, and the piston 3 and the piston 3 are slidably guided in the cylinder 1 above the chisel 2. A sleeve 4 is incorporated. The sleeve 4 is positioned in the axial direction and forms a part of the cylinder 1.

  The piston 3 has a large-diameter portion 3a in the central portion in the axial direction. In the cylinder 1, a lower chamber 5 is provided on the lower surface side of the large-diameter portion 3a, and an upper chamber is provided on the upper surface side of the large-diameter portion 3a. 6 are provided. A gas chamber 7 is provided on the upper end surface side of the piston 3 in the upper part of the cylinder 1, and high-pressure gas is sealed in the gas chamber 7.

  The lower chamber 5 and the upper chamber 6 communicate with each other through a communication path 8 formed in the cylinder 1. The communication path 8 has a vertical hole portion 8a extending in the vertical direction, and a switching valve 10 for controlling the up and down movement of the piston 3 is provided above the vertical hole portion 8a.

  The switching valve 10 incorporates a valve body 12 in a valve chamber 11 provided continuously above the vertical hole portion 8 a of the communication passage 8 so as to be movable up and down, and the piston 3 is moved up and down by the movement of the valve body 12. It comes to control.

  The lower end portion of the valve chamber 11 communicates with the upper end portion of the communication passage 8, and the valve body 12 incorporated in the valve chamber 11 has a large diameter portion 12 a at the upper portion. The large-diameter portion 12a can be raised and lowered in a large-diameter chamber 11a formed in the upper portion of the valve chamber 11, and the lowering position of the valve body 12 is brought into contact with the bottom surface of the large-diameter chamber 11a by the lower surface of the large-diameter portion 12a. The lower end portion of the valve body 12 enters the communication path 8 and closes the communication path 8 at the lowered position of the valve body 12. The communication between the lower chamber 5 and the upper chamber 6 is blocked by the closure.

  Further, the rising position of the valve body 12 is restricted by the abutment of the upper end surface of the large diameter portion 12a with respect to the upper surface of the large diameter chamber 11a. The lower chamber 5 and the upper chamber 6 are maintained in communication with each other.

  A plunger 12b having a smaller diameter than the large-diameter portion 12a is provided on the upper end surface of the large-diameter portion 12a in the valve body 12, and the upper end portion of the plunger 12b is provided in a valve regulating chamber 13 provided above the large-diameter chamber 11a. It is slidably inserted inside.

  The cylinder 1 is provided with an oil supply port 14 on the side of the valve chamber 11 and an oil discharge port 15 on the lower side of the oil supply port 14.

Further, the cylinder 1 has a piston raising oil passage T ₁ for introducing the pressure oil from the oil filler port 14 into the communication passage 8 at the lowered position of the valve body 12, and the pressure oil from the oil filler port 14 to the valve regulating chamber 13. a pressure applying passage T ₂ which always impart oil supply pressure to the upper end face of the valve body 12 is guided, slightly before the piston 3 by introducing pressurized oil at the bottom of the large-diameter chamber 11a during upstroke of the piston 3 reaches the upper limit position a valve switching Goyu path T ₃ to increase the valve body 12 in the state, drain oil passage T ₄ communicating the oil outlet 15 and the upper large-diameter chamber 11a in lowered position of the valve body 12 is provided, respectively Yes.

The piston raising oil passage T ₁ is formed on the inner periphery of the valve chamber 11 and communicated with the oil filler port 14. The constricted portion formed in the valve body 12 when the valve body 12 is lowered. 16, an annular high-pressure out port 22 that communicates with the high-pressure import 21 via 16, and a bypass path 23 that communicates with the high-pressure out port 22 at one end and communicates with the other end in the middle of the communication path 8. Here, as the constricted portion 16 formed in the valve body 12, a constricted portion 16 is shown.

The pressure applying passage T ₂ are an annular pilot port 31 formed on the inner peripheral upper portion of the valve restraining chamber 13 communicates at one end to the pilot port 31, consisting of the pilot hole 32 and the other end communicates with the oil supply port 14 .

Valve switching Goyu path T ₃ is formed in the inner periphery of the cylinder between the lower chamber 5 and an upper chamber 6, for import annular valve control which communicates with the lower chamber 5 at a position slightly before the piston 3 reaches to the upper limit position 41 and its valve control import 41, one end communicates with, and the other end communicates with an annular valve control outport 42 formed on the inner periphery of the bottom of the large-diameter chamber 11a of the valve chamber 11 It consists of road 43.

The drain oil passage T ₄ has a oil discharge port 51 formed on the inner peripheral upper portion of the large diameter chamber 11a, the oil discharge hole 52 having one end to the oil discharge port 51 are communicated, and the other end communicates with the oil discharge port 15 Consists of.

  In the communication path 8, an annular groove 8 b is formed on the inner periphery at a position facing the lower end portion of the valve body 12 in the lowered position, and the annular groove 8 b communicates with the oil discharge port 15.

The impact moving tool shown in the embodiment has the above-described structure. FIG. 2 shows that the piston 3 is lowered, the valve body 12 of the switching valve 10 is lowered, and the lower end portion thereof is a vertical hole portion of the communication passage 8. 8a is entered, and the communication between the lower chamber 5 and the upper chamber 6 is blocked. Further, the high pressure import 21 and the high pressure out port 22 of the piston raising oil supply passage T ₁ are in communication with each other through a constricted portion 16 formed in the valve body 12.

In lowered position of the valve body 12 as described above, when the pressure oil is supplied to the fuel supply port 14, the pressure oil flows into the lower chamber 5 flows from the piston-increasing oil supply passage T ₁ in the communication passage 8, the piston 3 rises. Further, as the piston 3 moves up, the hydraulic oil in the upper chamber 6 flows through the annular groove 8 b formed in the upper part of the communication path 8 to the oil discharge port 15 and is discharged.

  In the upward stroke of the piston 3 as described above, the high-pressure gas in the gas chamber 7 formed on the upper side of the piston 3 is further compressed to accumulate energy.

3, the piston 3 is shown elevated until the upper limit position, the lower chamber 5 in position slightly before reaching the upper limit position is communicated to a valve control for import 41 Bensetsu-over Goyu path T _3. By its communication, hydraulic oil in the lower chamber 5 flows into the lower portion of the large diameter chamber 11a of the valve chamber 11 through the valve switching Goyu path T _3. The valve body 12 by a pressing force applied to the lower surface of the large diameter portion 12a of the valve element 12 rises, hydraulic fluid in the large diameter chamber 11a is and is discharged from the oil discharge port 15 through the oil discharge passage T ₄ .

  FIG. 4 shows a state in which the valve body 12 is raised to the upper limit position, and the lower end portion of the valve body 12 is pulled out from the vertical hole portion 8a of the communication passage 8 due to the rise of the valve body 12 and the communication passage 8 is opened. The lower chamber 5 communicates with the oil discharge port 15 via the communication passage 8 and the lower chamber 5 is in a low pressure state. At this time, the piston 3 rapidly descends due to the expansion of the compressed high-pressure gas in the gas chamber 7.

  Due to the rapid lowering of the piston 3, the piston 3 strikes the upper end of the chisel 2 as shown in FIG. At this time, most of the hydraulic oil in the lower chamber 5 flows into the upper chamber 6 through the communication passage 8 and prevents the upper chamber 6 from becoming a negative pressure, thereby smoothly moving the piston 3 downward.

Further, as the piston 3 descends, the upper chamber 6 communicates with the oil discharge port 15 via the communication passage 8 and the valve control import 41 communicates with the upper chamber 6. It will be lead to the oil discharge port 15 via the Bensetsu-over Goyu path T _3, of the valve body upper end surface of the hydraulic fluid supplied to the valve regulating chamber 13 through the pressure applying passage T ₂ from the fuel supply port 14 The valve body 12 is lowered by the pressing force. As shown in FIGS. 1 and 2, the lower end of the valve body 12 enters the communication path 8 and closes the communication path 8, thereby blocking communication between the lower chamber 5 and the upper chamber 6. Thereafter, the above operation is repeated.

  As shown in the embodiment, the vertical hole portion 8a of the communication passage 8 that communicates the lower chamber 5 and the upper chamber 6 is opened and closed by the rod-like lower end portion of the valve body 12 that is moved up and down in the valve chamber 11, and the opening is opened. Since the hydraulic oil in the lower chamber 5 is sometimes allowed to flow into the upper chamber 6 from the communication passage 8, the valve body 12 has a constricted portion such as an annular groove for allowing the hydraulic oil in the lower chamber 5 to flow into the upper chamber 6. Therefore, the axial length of the valve body 12 can be shortened. In addition, the valve body 12 does not give resistance when the hydraulic oil flows from the lower chamber 5 to the upper chamber 6 as compared with the type in which the inner diameter of the hollow valve body is a flow path, and the outer diameter of the valve body is reduced. it can. By shortening and reducing the diameter of the valve body 12, it is possible to secure a hydraulic oil conduit having a sufficient flow path in a state where the weight of the valve body 12 is reduced.

  In addition, the shortening of the valve body 12 can reduce the lifting stroke of the valve body 12, and since the valve body 12 is lightweight, the switching control of the valve body 12 can be performed quickly and reliably. Furthermore, since the diameter of the valve body 12 can be reduced, it is possible to suppress a malfunction of the switching valve and a decrease in efficiency due to oil leakage during operation, and to improve the impact efficiency.

  Here, when the piston 3 strikes the chisel 2, the piston 3 rapidly rises due to the reaction caused by the impact, and the hydraulic oil in the upper chamber 6 instantaneously flows toward the lower chamber 5. Also at this time, the hydraulic oil does not pass through the inside of the valve body 12 or the annular groove and directly reaches the lower chamber 5 through the communication path, so that the valve body 12 is not affected by the flow of the hydraulic oil, and the piston 3 Can be stabilized.

6 and 7 show another embodiment of the impact moving tool according to the present invention. Impact dynamic tool shown in impact dynamic tool and FIGS. 1 and 2 shown in this embodiment, the position of the fuel supply port 14 and the drain oil port 15 as the arrangement of the upside down, the piston rises oil supply passage T _1, the open end There points are formed only at the inlet-side passage 25 and the communication path 8 which is the fuel supply port 14, and is different in that it the valve switching Goyu path T ₃ with the following configuration. For this reason, the same code | symbol is attached | subjected to the part same as embodiment shown in FIG. 1 and FIG. 2, and description is abbreviate | omitted.

In the valve switching Goyu path T ₃ shown in the embodiment shown in FIGS. 6 and 7, it is formed in the cylinder inner periphery between the lower chamber 5 and the upper chamber 6, the position of just before the piston 3 reaches the upper limit position The annular valve control import 41 communicated with the lower chamber 5 and the valve control import 41 are formed on the upper side of the valve control import 41 so as to be spaced apart and formed in the large-diameter portion 3a of the piston 3 when the piston 3 is lowered. The valve control outport 46 communicates with the valve control import 41 via the valve switching annular groove 45, and one end communicates with the valve control import 41 and the other end is the valve control out of the lower part of the large-diameter chamber 11a. One end communicates with the valve body raising oil passage 47 communicating with the port 42 and the valve control outport 46 on the inner circumferential side of the cylinder, and the other end is disposed through the constricted portion 16 formed in the valve body 12. The valve body is always in communication with 15 The oil passage 48 includes an oil passage hole 49 that is formed in the valve body 12 and communicates the lower portion of the large-diameter chamber 11a and the communication passage 8 when the valve body 12 is raised.

  In the impact tool having the above-described configuration, when pressure oil is supplied to the oil supply port 14 in a state where the piston 3 and the valve body 12 are in the lowered position, the pressure oil flows into the lower chamber 5 from the communication hole 8. Then, the piston 3 rises.

  At this time, the hydraulic oil in the upper chamber 6 flows into the valve chamber 11 from the upper part of the communication passage 8, flows around the constricted portion 16 of the valve body 12 and is discharged from the oil discharge port 15, and the piston 3 smoothly moves. To rise.

When the piston 3 is raised to near the upper limit position, the lower chamber 5 communicates with the valve control import 41, hydraulic oil in the lower chamber 5 of the large diameter chamber 11a of the valve chamber 11 flows into the Bensetsu-over Goyu path T ₃ It flows into the lower part, a pushing force is applied to the lower surface of the large diameter part 12a of the valve body 12, and the valve body 12 rises. At this time, the valve control outport 46 is disconnected from the valve control import 41 at the large diameter portion 3 a of the piston 3.

  FIG. 8 shows a state in which the valve body 12 is raised, and when the valve body 12 is raised, the lower end portion of the valve body 12 comes out of the vertical hole portion 8a of the communication path 8, and the communication path 8 is opened. 5 and the communication path 8 are maintained in a communicating state and are in an equal pressure state. Then, the piston 3 descends due to the accumulated energy of the high-pressure gas in the gas chamber 7 compressed by the ascent of the piston 3 and strikes the chisel 2.

When the piston 3 descends, the communication between the lower chamber 5 and the valve control import 41 is cut off, the supply of the pressure oil to the large-diameter chamber 11a is cut off, and the valve body raising oil passage 47 is connected to the valve control outport. The valve body lowering oil passage 48 communicated with the oil discharge port 15 is connected via 46. Therefore, the valve body 12 is pushed down by the pressure oil flowing from the pressure applying passage T ₂ communicating with the oil supply port 14 in the valve regulating chamber 13 is lowered, as shown in FIG. 7, the lower end of the valve element 12 is communicated It enters into the passage 8 and blocks communication between the lower chamber 5 and the upper chamber 6. Thereafter, the above operation is repeated.

  The oil passage hole 49 supplies oil for holding the valve body 12 in the raised position when the valve body is raised.

  As shown in FIG. 9, when the plunger 12b of the valve body 12 is divided with respect to the valve body 12 with the upper surface of the large-diameter portion 12a as the dividing surface, the sliding portion of the valve body 12 and the sliding portion of the plunger 12b are coaxial. Since it is not necessary to increase the degree, the processing of the valve chamber 11 and the valve body 12 can be facilitated.

  In FIG. 2, the constricted portion 16 of the valve body 12 is an annular groove. However, as shown in FIGS. 10 and 11A, the constricted portion 16 includes a plurality of notches formed at intervals in the circumferential direction. As a result, the outer periphery between the adjacent notch portions 16 forms the sliding guide surface 17, so that the valve body can be moved up and down smoothly in the valve chamber 11.

  Here, the side surface of the constricted portion 16 formed of the notch portion may be a concave curved surface as shown in FIG.

DESCRIPTION OF SYMBOLS 1 Cylinder 2 Chisel 3 Piston 5 Lower chamber 6 Upper chamber 7 Gas chamber 8 Communication path 8a Vertical hole part 11 Valve chamber 11a Large diameter chamber 12 Valve body 12a Large diameter part 13 Valve regulation chamber 14 Oil supply port 15 Oil discharge port 16 Constriction part T ₁ Piston raising oil passage 21 High pressure import 22 High pressure out port 23 Bypass passage 25 Inlet side passage T ₂ Pressure applying passage T ₃ Valve switching control oil passage 41 Valve control import 42 Valve control out port 43 Oil for raising valve body Passage 45 annular groove 46 valve control outport 47 valve body raising oil passage 48 valve body lowering oil passage 49 oil passage hole T ₄ oil passage 51 oil drain port 52 oil passage hole

Claims (4)

  The upper end portion of the chisel is slidably inserted into the lower end portion of the cylinder, and a slidable piston for hitting a chisel having a large diameter portion is incorporated in the cylinder, and the large diameter portion is disposed on the inner periphery of the cylinder. An upper chamber is provided on the upper surface side, a lower chamber is provided on the lower surface side of the large-diameter portion, and a gas chamber filled with high-pressure gas is provided on the upper end surface side of the piston. The cylinder communicates with the upper chamber and the lower chamber. A communication passage and a valve chamber continuous above the communication passage are provided, and a valve body for controlling the opening and closing of the communication passage is slidably incorporated in the valve chamber, and the valve body is disposed above the valve chamber. A large-diameter portion that is slidable in the formed large-diameter chamber is provided, and the cylinder is provided with a piston raising oil passage that introduces pressure oil from the oil filler port into the communication passage at the lowered position of the valve body, and the oil filler port. The pressure oil from the valve body is led to the valve regulation chamber formed in the upper part of the valve chamber A pressure applying passage for applying a hydraulic pressure to the upper end surface, and valve switching for raising the valve body in a state just before the piston reaches the upper limit position by introducing pressure oil to the bottom of the large-diameter chamber during the upward stroke of the piston A control oil passage and an oil discharge passage that communicates the upper portion of the large-diameter chamber and the oil discharge port when the valve body is lowered are provided, the communication passage extends in the vertical direction, and the upper end of the valve chamber extends through the valve chamber. A closed state in which the lower end of the valve body that moves up and down has a vertical hole portion that can be moved forward and backward, and communication between the upper chamber and the lower chamber is blocked by the entry of the lower end portion of the valve body into the upper end portion of the vertical hole portion An impact-driven tool characterized by The piston raising oil supply passage is formed on the inner periphery of the valve chamber and communicates with the oil supply port, and in the lowered state of the valve body, the constricted portion formed in the valve body It consists of an annular high-pressure out-port that communicates with the high-pressure import, and a bypass that communicates the high-pressure out-port with the middle of the communication path.
The valve switching control oil passage is formed in a cylinder inner circumference between the lower chamber and the upper chamber, and an annular valve control import communicating with the lower chamber at a position slightly before the piston reaches the upper limit position; 2. The impact moving tool according to claim 1, comprising an oil passage for raising a valve body, one end communicating with the valve control import and the other end communicating with the bottom of the large-diameter chamber formed at the upper portion of the valve chamber. The piston raising oil supply path is composed of an inlet side passage whose opening end is the oil supply port,
A valve switching control oil passage is formed on the inner periphery of the cylinder between the lower chamber and the upper chamber, and an annular valve control import communicating with the lower chamber at a position slightly before the piston reaches the upper limit position; A valve control outport that is formed on the upper side of the valve control import and that communicates with the valve control import via a valve switching annular groove formed in the large diameter portion of the piston when the piston is lowered. One end of the valve control import, the other end of which communicates with the bottom of the large-diameter chamber formed at the top of the valve chamber, and one end of the valve control outport. A fluid passage for lowering the valve body, which is in communication with the other end of the valve body through a constricted portion formed in the valve body, and is formed in the valve body. It consists of an oil passage hole that communicates the lower part of the large-diameter chamber and the communication passage. Impact dynamic tool according to Motomeko 1.   4. The impact tool according to claim 2, wherein the constricted portion formed in the valve body includes an annular groove or a plurality of notches formed at intervals in the circumferential direction.

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