Pneumatic hammer mechanism and control method
원문보기
IPC분류정보
국가/구분
United States(US) Patent
등록
국제특허분류(IPC7판)
E21B-001/38
B25D-011/12
B25D-011/00
출원번호
US-0697066
(2010-01-29)
등록번호
US-9132541
(2015-09-15)
우선권정보
DE-10 2009 008 189 (2009-01-30)
발명자
/ 주소
John, Alexander
Schulz, Reinhard
Pfeiffer, Eduard
출원인 / 주소
Hilti Aktiengesellschaft
대리인 / 주소
Crowell & Moring LLP
인용정보
피인용 횟수 :
3인용 특허 :
4
초록▼
A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston, which limits a movement of the flying mass
A pneumatic hammer mechanism is disclosed. The hammer mechanism features: a flying mass, which is movable along an impact axis; an impact surface, which limits a movement of the flying mass along the impact axis in the impact direction; an exciting piston, which limits a movement of the flying mass along the impact axis opposite from the impact direction; a pneumatic chamber between the flying mass and exciting piston; a drive for periodically moving the exciting piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and exciting piston. The stroke is selected as a function of a maximum length of the pneumatic chamber such that the periodic movement of the flying mass on the path between an impact on the impact surface and a minimum approach of the exciting piston intermittently has a velocity of zero.
대표청구항▼
1. A pneumatic hammer mechanism, comprising: a flying mass which is movable along an impact axis;an impact surface which limits a movement of the flying mass along the impact axis in an impact direction;an exciting piston which limits the movement of the flying mass along the impact axis opposite fr
1. A pneumatic hammer mechanism, comprising: a flying mass which is movable along an impact axis;an impact surface which limits a movement of the flying mass along the impact axis in an impact direction;an exciting piston which limits the movement of the flying mass along the impact axis opposite from the impact direction;a pneumatic chamber disposed between the flying mass and the exciting piston; anda drive for periodically moving the exciting piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and a minimum approach of the exciting piston in a cycle with a first phase and a second phase, wherein the first phase is a movement from the minimum approach of the exciting piston to the impact surface and the second phase is a movement from the impact surface to the minimum approach of the exciting piston, and wherein a graph of the movement of the first phase differs from a graph of the movement of the second phase;wherein the stroke is a function of a maximum length of the pneumatic chamber such that the flying mass decelerates, accelerates, and then decelerates again during the second phase, wherein due to the deceleration, acceleration, and then deceleration again of the flying mass a duration of a period of time for the second phase is greater than a duration of a period of time for the first phase and the flying mass has a greater velocity during the first phase than during the second phase. 2. The pneumatic hammer mechanism according to claim 1, wherein the stroke is a function of the maximum length of the pneumatic chamber such that the flying mass changes a direction of movement at least once during a movement between the impact surface and a following minimum approach of the exciting piston. 3. The pneumatic hammer mechanism according to claim 1, wherein the stroke is a function of the maximum length of the pneumatic chamber such that the flying mass touches the impact surface at least twice between two successive minimum approaches of the exciting piston. 4. The pneumatic hammer mechanism according to claim 1, wherein a mass (m2) of the flying mass, a cross-sectional area (A) of the pneumatic chamber, a maximum length (L) of the pneumatic chamber, the stroke (H) of the exciting piston and an impact coefficient (q) fulfill the following inequality, if the hammer mechanism has an impact frequency (f) during percussive operation: Lk2(L-H)k·kL-H+(Lk2(L-H)k-1)·1-qqN2πH≥!m2A·p0·N2f2wherein N is at least 4, po designates an ambient pressure and K an isentropic coefficient of gas in the pneumatic chamber. 5. The pneumatic hammer mechanism according to claim 4, wherein the impact coefficient (q) is 0.22 if a ratio m1/m2 of a mass (m1) of a snap die to the mass (m2) of the flying mass is greater than 1.2 and otherwise the impact coefficient (q) is 0.12. 6. The pneumatic hammer mechanism according to claim 4, wherein N is greater than 5. 7. The pneumatic hammer mechanism according to claim 4, wherein N is greater than 7. 8. The pneumatic hammer mechanism according to claim 1, wherein the flying mass decelerates to a velocity of zero. 9. A method of operating a pneumatic hammer mechanism, wherein the pneumatic hammer mechanism comprises: a flying mass which is movable along an impact axis;an impact surface which limits a movement of the flying mass along the impact axis in an impact direction;an exciting piston which limits the movement of the flying mass along the impact axis opposite from the impact direction;a pneumatic chamber disposed between the flying mass and the exciting piston; anda drive for periodically moving the exciting piston with a stroke along the impact axis, wherein the flying mass is excited to a periodic movement between the impact surface and a minimum approach of the exciting piston in a cycle with a first phase and a second phase, wherein the first phase is a movement from the minimum approach of the exciting piston to the impact surface and the second phase is a movement from the impact surface to the minimum approach of the exciting piston and wherein a graph of the movement of the first phase differs from a graph of the movement of the second phase;and comprising the step of:decelerating, accelerating, and then decelerating the flying mass again during the second phase, wherein due to the deceleration, acceleration, and then deceleration again of the flying mass a duration of a period of time for the second phase is greater than a duration of a period of time for the first phase and the flying mass has a greater velocity during the first phase than during the second phase. 10. The method according to claim 9, further comprising the step of changing a direction of movement of the flying mass during the second phase. 11. The method according to claim 9, further comprising the step of touching the impact surface at least twice by the flying mass between two successive minimum approaches of the exciting piston. 12. The method according to claim 9, wherein the flying mass decelerates to a velocity of zero.
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이 특허에 인용된 특허 (4)
Kolgan Jury N. (Planernaya ; 14 ; korpus 2 ; kv.13 Moscow SUX) Kirjushin Nikolai M. (Kolomensky proezd ; 3 ; korpus 1 ; kv. 63 Moscow SUX) Prokhorov Ivan A. (ulitsa Smuryakova ; 9 ; kv. 48 oblast ; I, Compression-vacuum percussive action machine.
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