EP2076364A1 - Hydraulic impact device - Google Patents
Hydraulic impact deviceInfo
- Publication number
- EP2076364A1 EP2076364A1 EP07835133A EP07835133A EP2076364A1 EP 2076364 A1 EP2076364 A1 EP 2076364A1 EP 07835133 A EP07835133 A EP 07835133A EP 07835133 A EP07835133 A EP 07835133A EP 2076364 A1 EP2076364 A1 EP 2076364A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- impact
- piston
- impact piston
- end portion
- low pressure
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
- 238000004891 communication Methods 0.000 claims abstract description 8
- 230000004913 activation Effects 0.000 claims abstract description 7
- 239000012530 fluid Substances 0.000 claims description 22
- 238000013016 damping Methods 0.000 description 8
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000001627 detrimental effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000020169 heat generation Effects 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/04—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously of the hammer piston type, i.e. in which the tool bit or anvil is hit by an impulse member
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D17/00—Details of, or accessories for, portable power-driven percussive tools
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D17/00—Details of, or accessories for, portable power-driven percussive tools
- B25D17/11—Arrangements of noise-damping means
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/14—Control devices for the reciprocating piston
- B25D9/145—Control devices for the reciprocating piston for hydraulically actuated hammers having an accumulator
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D9/00—Portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D9/14—Control devices for the reciprocating piston
- B25D9/16—Valve arrangements therefor
- B25D9/18—Valve arrangements therefor involving a piston-type slide valve
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D2217/00—Details of, or accessories for, portable power-driven percussive tools
- B25D2217/0011—Details of anvils, guide-sleeves or pistons
- B25D2217/0019—Guide-sleeves
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D2250/00—General details of portable percussive tools; Components used in portable percussive tools
- B25D2250/365—Use of seals
Definitions
- Hydraulic impart, device.
- the invention relates to a hydraulic impact device of the type comprising an impact piston reciprocally driven in a cylinder bore and intended to deliver repeated impact energy to a working implement, wherein the impact piston is provided with a central drive portion to be pressurized via a distribution valve for reciprocating the piston in the cylinder, and an anvil arranged to transfer impact energy from the impact piston to the working implement .
- Impact devices of this type normally suffer from a couple of problems such as leakage and/or mechanical wear of piston seals, i.e. impact devices have been provided either with seal elements with a moderate contact force and a risk for leakage or very tight seal elements with friction losses, heavy mechanical wear and heat development as a result. Heat generated by such tight seal elements could be of such a magnitude that the surface hardening of the piston disappears and the mechanical wear of the piston increases drastically.
- the invention aims to create a hydraulic impact device by which the above described problems are avoided. This is accomplished by an improved impact device wherein the impact piston operates without any mechanical seal elements, which means that there are no friction losses, no limited service life due to worn down seal elements, and no heat generation in the impact piston. By the invention there is also accomplished an impact device wherein the impact piston is sealed off from the atmospheric air and thereby protected against rust attacks, which means that a cheaper material may be used in the impact piston.
- Fig. 1 A shows a hydraulic impact device according to one embodiment of the invention and illustrates the impact piston in its rear end position.
- Fig. 1 B shows the impact device in Fig. 1 A but illustrates the impact piston in its forward impact delivering position.
- Fig. 2 A shows an impact device according to an alternative embodiment of the invention and illustrates the impact piston in its rear end position.
- Fig. 2 B shows the impact device in Fig. 2 A but illustrates the impact piston in its forward impact delivering position.
- Fig. 3 shows an impact device according to a slightly different embodiment of the invention and illustrates the impact piston in its rear end position.
- Fig. 4 shows an impact device according to still another embodiment of the invention and illustrates the impact piston in its rear end position.
- the impact device shown in Figs. 1 A and IB comprises a housing with a cylinder bore 10, an impact piston 12 reciprocally guide in the cylinder bore 10, and an anvil 13 also guided in the cylinder bore 10 and arranged to transfer impact energy from the impact piston 12 to a working implement 14 inserted in the forward end of the cylinder bore 10.
- the cylinder bore 10 has a central larger diameter activation section 16, a rear guide section 17, and a forward guide section 18, and the impact piston 12 has a central drive portion 20 sealingly guided in said activation section 16 of the cylinder bore 10, thereby forming a working stroke drive chamber 21 and a return stroke drive chamber 22 on opposite sides of the impact piston drive portion 20.
- the impact piston 12 further comprises a forward end portion 23 guidingly supported in said forward guide section 18 and forming a clearance seal 24 therewith, and a rear end portion 25 guidingly supported in said rear guide section 17 and forming a clearance seal 26 therewith.
- the return stroke drive chamber 22 is continuously connected to a pressure fluid source 27, whereas the working stroke drive chamber 21 is alternatingly connected to the pressure fluid source 27 and to a tank 28 by means of a distribution valve 30 so as to reciprocate the piston 12 in the cylinder bore 10.
- the working stroke drive chamber 21 is connected to the tank 28 during return strokes via a passage 31 and the valve 30.
- a rear low pressure chamber 34 continuously communicating with the rear end of the piston 12, and at the forward end of the cylinder bore 10 there is provided a forward low pressure chamber 35, The latter is penetrated by the forward end section 23 of the impact piston 12 during the working strokes.
- the forward and rear low pressure chambers 34 and 35 are continuously connected to each other via a communication passage 36 and to the tank 28 and form together with the communication passage 36 a low pressure circuit which is supplied with pressure fluid from the return stroke drive chamber 22 via a feed passage 38 as the piston 12 occupies its rear end position, as illustrated in Fig. 1 A. Due to a certain flow resistance in a drain passage 39 to the tank 28 there will always remain a certain pressure in the low pressure circuit 34, 35, 36 which results in a maintained pressure in the forward low pressure chamber 35, and a forward directed force on the anvil 13 is thereby maintained during operation of the impact piston 12. This force will keep the anvil 13 in continuous contact with the working implement 14 and no metallic striking sound will be generated.
- a pressure accumulator 41 is connected to the pressure fluid supply line to reduce pressure transients in the drive system, and another pressure accumulator 42 is connect to the low pressure circuit to smoothen out the pressure therein.
- the annular groove 46 acts as a damping chamber as it is connected to the tank 28 via a flow restriction 47. This will dampen the piston 12 and preventing it from hitting the anvil 13 with metallic contact .
- the working stroke drive chamber 21 is supplied with pressure fluid from the pressure fluid source 27 via the distribution valve 30, as illustrated in Fig. 1 A, whereas the return stroke drive chamber 22 is continuously pressurized. Due to the fact that the annular piston surface at the rear end of the central drive portion 20 is larger than that at the forward end thereof, the force acting on the rear surface will dominate during the working strokes, despite the same fluid pressure acting on the oppositely facing surface.
- An impact stroke is started with the impact piston 12 is in its rear end position where the pressure in the return stroke drive chamber 22 is conducted to the rear low pressure chamber 34 to pressurize the low pressure circuit, including the communication passage 36 and the forward low pressure chamber 35. Then, the piston 12 accelerates forwards towards the anvil 13, and when having passed through the forward low pressure chamber 35 a high pressure cushion 44 is enclosed between the piston 12 and the anvil 13 to transfer the kinetic energy of the piston 12 to the anvil 13 and the working implement 14. The minor leakage that occurs from the high pressure cushion 44 via the clearance seal 24 will be collected in the low pressure chamber 35 and in the damping groove 46 and returned to the tank 28. As the forward end position of the piston 12 is reached, see Fig.
- the rear low pressure chamber 34 has been expanded and momentarily received some fluid from the forward low pressure chamber 35 as the latter has decreased. Since the distribution valve 30 has now stopped directing pressure fluid to the working stroke drive chamber 21 the full pressure in the return stroke drive chamber 22 will drive the piston 12 in the opposite direction.
- the anvil 13 is provided with an annular flange 48 which is received in an enlarged portion 49 of the bore 10, and an enclosed air volume will dampen forward movement of the anvil 13 at occurring idle blows, i.e. when no working implement is attached.
- the impact device is identical to the one described above except for the low pressure circuit communication passage 50 which is located inside the impact piston 12.
- the passage 50 In order to have the passage 50 communicate with the forward low pressure chamber 35 the piston 12 is provided with an annular groove 51 adjacent its forward end. The rest of the design and the operation order is the same as for the above described embodiment .
- the impact device illustrated in Fig. 3 is identical with the above described devices except for the arrangement of a high pressure damping volume 55 at a forward facing end surface 56 of the anvil 53.
- the damping volume 55 is continuously connected to the pressure fluid source 27 via a passage 57. This arrangement will ensure a safe damping and protection of the device in case of idle blows, as described above .
- FIG. 4 An alternative damping means is illustrated in Fig. 4 wherein the anvil 63 has been provided with a larger annular flange 60 with a forward facing end surface 66, and the damping chamber 61 is continuously connected via a passage 64 to the low pressure circuit and the tank 28.
- the inevitable flow restrictions in the drain passages to the tank 28 will provide a sufficient damping effect.
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
- Percussive Tools And Related Accessories (AREA)
Abstract
Description
Claims
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE0602237A SE530617C2 (en) | 2006-10-25 | 2006-10-25 | Hydraulic percussion |
PCT/SE2007/000932 WO2008051146A1 (en) | 2006-10-25 | 2007-10-24 | Hydraulic impact device |
Publications (2)
Publication Number | Publication Date |
---|---|
EP2076364A1 true EP2076364A1 (en) | 2009-07-08 |
EP2076364A4 EP2076364A4 (en) | 2012-11-14 |
Family
ID=39324851
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP07835133A Withdrawn EP2076364A4 (en) | 2006-10-25 | 2007-10-24 | Hydraulic impact device |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP2076364A4 (en) |
SE (1) | SE530617C2 (en) |
WO (1) | WO2008051146A1 (en) |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE534794C2 (en) | 2010-04-01 | 2011-12-27 | Atlas Copco Rock Drills Ab | Hydraulic striking device, piston control, and drilling rig |
JP6438897B2 (en) * | 2014-01-31 | 2018-12-19 | 古河ロックドリル株式会社 | Hydraulic striking device |
CN110107220B (en) * | 2019-05-05 | 2020-12-04 | 三峡大学 | Percussion device and rock drilling equipment |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB814240A (en) * | 1957-05-24 | 1959-06-03 | Industrikompaniet Ab | Vibrator |
DE3229309C2 (en) * | 1982-08-05 | 1987-05-21 | Institut Avtomatiki Akademii Nauk Kirgizskoj Ssr, Frunze, Su |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4231434A (en) * | 1978-02-21 | 1980-11-04 | Justus Edgar J | Hydraulic impact device |
SE433821B (en) * | 1979-11-29 | 1984-06-18 | Vni I P Konstrukt | Impact-action machine |
JPH03208215A (en) * | 1990-01-10 | 1991-09-11 | Izumi Seiki Seisakusho:Kk | Hydraulic breaker |
SE506400C2 (en) * | 1995-03-23 | 1997-12-08 | Goeran Nilsson | Device which forms connection between fittings on components |
-
2006
- 2006-10-25 SE SE0602237A patent/SE530617C2/en unknown
-
2007
- 2007-10-24 WO PCT/SE2007/000932 patent/WO2008051146A1/en active Application Filing
- 2007-10-24 EP EP07835133A patent/EP2076364A4/en not_active Withdrawn
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB814240A (en) * | 1957-05-24 | 1959-06-03 | Industrikompaniet Ab | Vibrator |
DE3229309C2 (en) * | 1982-08-05 | 1987-05-21 | Institut Avtomatiki Akademii Nauk Kirgizskoj Ssr, Frunze, Su |
Non-Patent Citations (1)
Title |
---|
See also references of WO2008051146A1 * |
Also Published As
Publication number | Publication date |
---|---|
SE530617C2 (en) | 2008-07-15 |
WO2008051146A1 (en) | 2008-05-02 |
EP2076364A4 (en) | 2012-11-14 |
SE0602237L (en) | 2008-04-26 |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
17P | Request for examination filed |
Effective date: 20090326 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LI LT LU LV MC MT NL PL PT RO SE SI SK TR |
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DAX | Request for extension of the european patent (deleted) | ||
A4 | Supplementary search report drawn up and despatched |
Effective date: 20121012 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B25D 9/18 20060101ALI20121008BHEP Ipc: B25D 9/14 20060101ALI20121008BHEP Ipc: B25D 9/04 20060101AFI20121008BHEP Ipc: B25D 17/11 20060101ALI20121008BHEP |
|
17Q | First examination report despatched |
Effective date: 20130422 |
|
RAP1 | Party data changed (applicant data changed or rights of an application transferred) |
Owner name: CONSTRUCTION TOOLS PC AB |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
INTG | Intention to grant announced |
Effective date: 20141217 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
18D | Application deemed to be withdrawn |
Effective date: 20150429 |