JPH0763940B2 - Impact tool - Google Patents
Impact toolInfo
- Publication number
- JPH0763940B2 JPH0763940B2 JP24107986A JP24107986A JPH0763940B2 JP H0763940 B2 JPH0763940 B2 JP H0763940B2 JP 24107986 A JP24107986 A JP 24107986A JP 24107986 A JP24107986 A JP 24107986A JP H0763940 B2 JPH0763940 B2 JP H0763940B2
- Authority
- JP
- Japan
- Prior art keywords
- chamber
- valve
- piston
- oil
- diameter portion
- 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.)
- Expired - Fee Related
Links
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
- B25D9/14—Control devices for the reciprocating piston
- B25D9/16—Valve arrangements therefor
- B25D9/20—Valve arrangements therefor involving a tubular-type slide valve
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25D—PERCUSSIVE TOOLS
- B25D2209/00—Details of portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously
- B25D2209/007—Details of portable percussive tools with fluid-pressure drive, i.e. driven directly by fluids, e.g. having several percussive tool bits operated simultaneously having a tubular-slide valve, which is not coaxial with the piston
Landscapes
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Percussive Tools And Related Accessories (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、油圧パワーショベル等の先端に取り付け、コ
ンクリート構造物の解体、岩石の破砕、岩盤掘削等に用
いる油圧作動の衝撃動工具に関するものである。TECHNICAL FIELD The present invention relates to a hydraulically-operated impact tool attached to the tip of a hydraulic power shovel or the like and used for dismantling a concrete structure, crushing rocks, excavating rock, etc. Is.
油圧作動の衝撃動工具は、大きく分けるとアキュームレ
ータ方式とガス方式に二分される。Hydraulically operated impact tools can be roughly divided into an accumulator system and a gas system.
アキュームレータ方式は、ピストンが上昇する時、アキ
ュームレータに油を蓄積しておいて、打撃行程でそれを
放出してピストンを加速する方式である。The accumulator method is a method of accumulating oil in the accumulator when the piston rises and discharging it in the striking stroke to accelerate the piston.
ガス方式は、ピストンが油圧によって上昇する時、ピス
トン上方のガスを圧縮することによりエネルギーを蓄積
し、打撃行程では、ガスの膨張するエネルギーを利用し
てピストンを加速する方式で、特公昭54−32192号公報
にこの方式が示されている。The gas system stores energy by compressing the gas above the piston when the piston rises due to hydraulic pressure, and accelerates the piston by utilizing the energy that expands the gas in the striking stroke. This method is shown in Japanese Patent No. 32192.
第７図に示す前記公報記載の発明は、中室が常に排油口
と繋がっているので、ピストンの打撃行程（下降行程）
ではバルブが上昇位置にあるため、下室はバルブの軸心
に設けられた連通孔と弁室を通って中室と低圧の排油口
とに連通している。In the invention described in the above-mentioned publication shown in FIG. 7, since the middle chamber is always connected to the oil discharge port, the striking stroke (lowering stroke) of the piston
However, since the valve is in the raised position, the lower chamber communicates with the middle chamber and the low-pressure oil discharge port through the communication hole provided in the axial center of the valve and the valve chamber.
従って、ピストンがチゼルを打撃して、次に激しく反撥
した時、下室の圧力は急激に低下し、作動油の中に含ま
れている気泡が急成長する現象、いわゆるキャビテーシ
ョン現象が発生する。Therefore, when the piston hits the chisel and then repels violently, the pressure in the lower chamber sharply drops, and a phenomenon called a cavitation phenomenon occurs in which bubbles contained in the hydraulic oil rapidly grow.
次にバルブが下降して給油口から圧油が下室に流入する
と、急成長した気泡が瞬間的に崩壊し、非常に高い圧力
と衝撃波を発生する。Next, when the valve descends and pressure oil flows into the lower chamber from the oil supply port, the rapidly growing bubbles momentarily collapse, generating extremely high pressure and shock waves.
この現象が一分間に数百回繰り返されるので、衝撃動工
具を長時間使用するとピストンとシリンダの表面に壊食
（エロージョン）が生じる。Since this phenomenon is repeated hundreds of times per minute, erosion occurs on the surfaces of the piston and the cylinder when the impact tool is used for a long time.
本発明は、このキャビテーション現象の発生を防止し、
ピストンとシリンダの表面に発生する壊食（エロージョ
ン）を無くすことを目的としている。The present invention prevents the occurrence of this cavitation phenomenon,
The purpose is to eliminate erosion that occurs on the surface of the piston and cylinder.
上記の問題となっているピストンがチゼルを打撃した直
後に下室の油中の気泡が成長する原因は、打撃において
下室が排油口に連絡しているため打撃時の下室の圧力が
低く、ピストンが反撥した瞬間に下室の圧力が急減する
ことによる。The cause of the bubbles in the oil in the lower chamber growing immediately after the piston hitting the chisel, which is the problem above, is that the pressure in the lower chamber at the time of impact is because the lower chamber is in contact with the oil drain port during impact. Low, due to a sudden decrease in pressure in the lower chamber at the moment the piston repels.
従って、気泡が成長しない程度に下室の圧力を上げてお
けば、キャビテーションは発生しない。Therefore, if the pressure in the lower chamber is raised to the extent that bubbles do not grow, cavitation does not occur.
そのため、本発明はピストンの打撃行程でバルブが上昇
して最上昇位置近くになると、下室は中室とのみ通じて
排油口との連通が遮断されるようにするとともに、下室
に常に給油口からの圧油を流入させる極小径油路を設け
て、打撃時の下室の圧力を上昇させる回路構成とする。Therefore, according to the present invention, when the valve rises in the striking stroke of the piston and is close to the maximum raised position, the lower chamber communicates only with the middle chamber and the communication with the oil drain port is blocked, and the lower chamber is always closed. An extremely small-diameter oil passage into which pressure oil from the oil supply port is made to flow is provided to increase the pressure in the lower chamber upon impact.
従ってピストンが打撃直後に反撥しても、下室の圧力
は、下室の油中の気泡が成長する程には低くならず、キ
ャビテーションの発生はなくなる。次にバルブが下降
し、圧油が下室に供給されて下室の圧力が上昇しても気
泡の崩壊現象は生じないので、衝撃動工具を長時間使用
しても壊食（エロージョン）が発生することはない。Therefore, even if the piston repels immediately after the impact, the pressure in the lower chamber does not become so low that bubbles in the oil in the lower chamber grow, and cavitation does not occur. Next, the valve descends, pressure oil is supplied to the lower chamber, and the collapse of the bubbles does not occur even if the pressure in the lower chamber rises, so even if the impact tool is used for a long time, erosion will occur. It never happens.
まず、第一実施例について第１図乃至第４図に基づき説
明する。First, the first embodiment will be described with reference to FIGS.
第１図において、１は衝撃動工具、２はシリンダであ
り、このシリンダ２内にピストン３が摺動自在に組み込
まれている。In FIG. 1, 1 is an impact tool, 2 is a cylinder, and a piston 3 is slidably incorporated in the cylinder 2.
ピストン３は上下にそれぞれ直径の等しい上部小径部４
と下部小径部５を有し、中央に直径の等しい上部大径部
６と下部大径部７を形成し、その間に中部小径部８を一
体に形成する。The piston 3 has an upper small-diameter portion 4 having the same diameter vertically.
And a lower small-diameter portion 5, an upper large-diameter portion 6 and a lower large-diameter portion 7 having the same diameter are formed in the center, and a middle small-diameter portion 8 is integrally formed between them.
シリンダ２内には、ピストンの上部大径部６の上面に中
室９を、下部大径部７の下面に下室10を形成し、上部小
径部４の上方には、窒素ガスを封入した上室11を形成す
る。Inside the cylinder 2, a middle chamber 9 is formed on the upper surface of the upper large-diameter portion 6 of the piston, a lower chamber 10 is formed on the lower surface of the lower large-diameter portion 7, and nitrogen gas is filled above the upper small-diameter portion 4. The upper chamber 11 is formed.
シリンダ２の下端には、一定範囲で摺動自在にチゼル12
を嵌装して、ピストン３の下端がチゼル12の上端を打撃
するようにする。At the lower end of the cylinder 2, a chisel 12 is slidable within a certain range.
So that the lower end of the piston 3 strikes the upper end of the chisel 12.
ピストン３の上部大径部６と下部大径部７が摺動するシ
リンダ２の内側には、上方より順に内周溝13,14,15を設
ける。Inside the cylinder 2 along which the upper large-diameter portion 6 and the lower large-diameter portion 7 of the piston 3 slide, inner circumferential grooves 13, 14, 15 are provided in order from above.
前記各大径部6,7により各内周溝は、ピストン３が下降
位置にあるときは、内周溝14と15が連通し、内周溝15と
16は遮断され、ピストンが上昇位置にあるきは、内周溝
15と16が連通し、内周溝14と15が遮断されるように形成
する。When the piston 3 is in the lowered position, the inner peripheral grooves 14 and 15 communicate with each other by the large diameter portions 6 and 7, and the inner peripheral groove 15 and the inner peripheral groove 15 communicate with each other.
16 is shut off and the piston is in the raised position,
It is formed so that 15 and 16 communicate with each other and the inner circumferential grooves 14 and 15 are blocked.
17は、シリンダ２の一側に固定した弁箱で、この弁箱17
内に弁室18を設け、バルブ19を摺動自在に嵌装する。弁
室18の上部には、室20を設け、プランジャ21を摺動自在
に嵌装し、プランジャ21の下端をバルブ19の上端に当接
させる。17 is a valve box fixed to one side of the cylinder 2, and this valve box 17
A valve chamber 18 is provided inside, and a valve 19 is slidably fitted therein. A chamber 20 is provided above the valve chamber 18, and a plunger 21 is slidably fitted in the valve chamber 18, and a lower end of the plunger 21 is brought into contact with an upper end of a valve 19.
バルブ19は、上方に大径部22と下方の小径部23を有し、
弁室18の大径部と小径部に進退自在に嵌装され、大径部
22の下端面と弁室18の間にはアクチュエイト室24を形成
する。The valve 19 has a large diameter portion 22 on the upper side and a small diameter portion 23 on the lower side,
It is fitted in the large diameter part and the small diameter part of the valve chamber 18 so that it can move back and forth.
An actuate chamber 24 is formed between the lower end surface of 22 and the valve chamber 18.
バルブ小径部23の下方には外周溝25を形成し、軸心には
弁室18の上部と下部を連通させる連通孔26を形成する。
なおバルブ19の大径部と小径部の断面積の差は前記プラ
ンジャ21の断面積より大きくする。An outer peripheral groove 25 is formed below the small-diameter portion 23 of the valve, and a communication hole 26 for communicating the upper part and the lower part of the valve chamber 18 is formed in the shaft center.
The difference in cross-sectional area between the large-diameter portion and the small-diameter portion of the valve 19 is made larger than that of the plunger 21.
弁室18の大径部には上方から順に内周溝27,28を形成
し、小径部には内周溝29,30,31を形成する。なお前記弁
室18の上部は、油路32によりシリンダ２の内周溝13と連
通し、内周溝14は油路により内周溝27に連通させる。シ
リンダの他の内周溝15,16は、それぞれ油路33,34により
弁室18の内周溝28,31に連通させる。Inner circumferential grooves 27, 28 are formed in the large diameter portion of the valve chamber 18 in order from above, and inner circumferential grooves 29, 30, 31 are formed in the small diameter portion. The upper part of the valve chamber 18 is communicated with the inner peripheral groove 13 of the cylinder 2 by an oil passage 32, and the inner peripheral groove 14 is communicated with the inner peripheral groove 27 by an oil passage. The other inner circumferential grooves 15, 16 of the cylinder are communicated with the inner circumferential grooves 28, 31 of the valve chamber 18 by oil passages 33, 34, respectively.
また油路33から分岐した小径の油路35は内周溝29に接続
し、油路34から分岐した極小径油路38は内周溝30に接続
する。36は低圧の排油口であって内周溝27に繋がり、油
路によって常時内周溝14に連通させる。37は給油口で、
油路により常時弁室の内周溝30と室20に繋がる。The small-diameter oil passage 35 branched from the oil passage 33 is connected to the inner circumferential groove 29, and the extremely small-diameter oil passage 38 branched from the oil passage 34 is connected to the inner circumferential groove 30. A low-pressure oil discharge port 36 is connected to the inner peripheral groove 27 and is always connected to the inner peripheral groove 14 by an oil passage. 37 is a filler port,
An oil passage constantly connects the inner circumferential groove 30 of the valve chamber and the chamber 20.
以上の構成においてバルブ19が下降位置にある時は、内
周溝30と31は外周溝25により連通し、内周溝29と30及び
内周溝31と弁室18の下部は遮断される。バルブ19が上昇
を始めると、まず内周溝30と31の連通が遮断され、同時
に内周溝29と30、内周溝31と弁室18の下部が連通する。
さらに上昇すると、バルブ19の大径部が内周溝27を弁室
18の上部から遮断し、排油口と弁室との連通を断つ。In the above configuration, when the valve 19 is in the lowered position, the inner peripheral grooves 30 and 31 communicate with each other by the outer peripheral groove 25, and the inner peripheral grooves 29 and 30, the inner peripheral groove 31 and the lower portion of the valve chamber 18 are blocked. When the valve 19 starts to rise, the communication between the inner peripheral grooves 30 and 31 is first interrupted, and at the same time, the inner peripheral grooves 29 and 30, the inner peripheral groove 31 and the lower portion of the valve chamber 18 communicate with each other.
When it further rises, the large diameter portion of the valve 19 moves the inner circumferential groove 27 into the valve chamber.
Shut off from the upper part of 18 and cut off the communication between the oil drain and the valve chamber.
次に作動について説明する。Next, the operation will be described.
第１図は、ピストン３もバルブ19も下降位置にある状態
を示し、アクチュエイト室24は内周溝15,14、油路、弁
室上部を介して排油口36に繋がっている。この状態で給
油口37に圧油を供給すると、圧油は内周溝30→外周溝25
→内周溝31→油路34→下室10と流れ、ピストン３の下部
大径部７の下端面に油圧を加える。この時中室９は、油
路32,弁室18の上部，内周溝27を介して排油口36と連通
しているので、ピストン３は上室11内の窒素ガスを圧縮
しながら上昇する。同時に給油口37からの圧油は室20に
も流入し、プランジャ21を下方に押し付けるので、バル
ブ19も下方に押し付けられている。FIG. 1 shows a state in which both the piston 3 and the valve 19 are in the lowered position, and the actuate chamber 24 is connected to the oil discharge port 36 through the inner circumferential grooves 15, 14, the oil passage, and the upper portion of the valve chamber. If pressure oil is supplied to the oil supply port 37 in this state, the pressure oil will flow from the inner peripheral groove 30 to the outer peripheral groove 25.
-> Inner peripheral groove 31-> Oil passage 34-> Lower chamber 10, and hydraulic pressure is applied to the lower end surface of the lower large diameter portion 7 of the piston 3. At this time, since the middle chamber 9 communicates with the oil discharge port 36 through the oil passage 32, the upper portion of the valve chamber 18 and the inner circumferential groove 27, the piston 3 moves upward while compressing the nitrogen gas in the upper chamber 11. To do. At the same time, the pressure oil from the oil supply port 37 also flows into the chamber 20 and presses the plunger 21 downward, so that the valve 19 is also pressed downward.
次にピストン３が上昇して、下部大径部７の下端面が内
周溝15と下室10を連通させ、内周溝14と15を遮断する第
２図の状態になると、下室10の圧油が内周溝15→油路33
→アクチュエイト室24と流れ、バルブ19の大径部22の下
端面に油圧が働く。バルブ19のこの部分の作用面積は、
プランジャ21の断面積より大きいのでバルブ19は上方に
動き始める。Next, when the piston 3 rises and the lower end surface of the lower large-diameter portion 7 connects the inner circumferential groove 15 and the lower chamber 10 to each other and shuts off the inner circumferential grooves 14 and 15, the lower chamber 10 is closed. Pressure oil of inner peripheral groove 15 → oil passage 33
→ Flows with the actuating chamber 24, and hydraulic pressure acts on the lower end surface of the large diameter portion 22 of the valve 19. The working area of this part of the valve 19 is
Since it is larger than the cross-sectional area of the plunger 21, the valve 19 starts moving upward.
バルブ19の変位が所定量になると同時に内周溝30と31の
連通が断され、内周溝29と30、内周溝31と弁室18の下部
が連通するので、下室10は油路34→内周溝31→弁室18の
下部→連通孔26→排油口36と繋がり圧力が低下するの
で、上室11内の窒素ガスの圧力によってピストンは下降
を始める。At the same time when the displacement of the valve 19 reaches a predetermined amount, the communication between the inner circumferential grooves 30 and 31 is cut off, and the inner circumferential grooves 29 and 30, the inner circumferential groove 31 and the lower portion of the valve chamber 18 communicate with each other, so that the lower chamber 10 has an oil passage. 34 → inner peripheral groove 31 → lower part of valve chamber 18 → communication hole 26 → oil discharge port 36, and the pressure drops, so the piston begins to descend due to the pressure of nitrogen gas in upper chamber 11.
この時下室には、極小径油路38を介して給油口37から少
量の圧油が供給されているが、ピストンの下降運動を妨
げることなく弁室を通って中室及び排油口に流れる。At this time, a small amount of pressure oil is supplied to the lower chamber from the oil supply port 37 via the extremely small oil passage 38, but passes through the valve chamber to the middle chamber and the oil discharge port without hindering the downward movement of the piston. Flowing.
下降途中でピストン下部大径部７の下端が内周溝15を下
室10より遮断しても、圧油が内周溝30→内周溝29→小径
の油路35→油路33→アクチュエイト室24と供給され続け
るので、バルブ19は上昇を続ける。バルブ19がさらに上
昇して、最上昇位置近くになると、大径部22が弁室の上
部を排油口36より遮断するので、下室10の油は弁室下
部，連通孔26,弁室上部を通って中室９に流入する。こ
の状態を第３図に示す。Even if the lower end of the large diameter portion 7 of the lower part of the piston shuts off the inner circumferential groove 15 from the lower chamber 10 while descending, the pressure oil is still in the inner circumferential groove 30 → inner circumferential groove 29 → small diameter oil passage 35 → oil passage 33 → actuator. The valve 19 continues to rise because it is continuously supplied with the eight chamber 24. When the valve 19 further rises and approaches the maximum raised position, the large diameter portion 22 shuts off the upper portion of the valve chamber from the oil discharge port 36, so that the oil in the lower chamber 10 is lower in the valve chamber, the communication hole 26, the valve chamber. It flows into the middle chamber 9 through the upper part. This state is shown in FIG.
また上記の作動の間中、給油口37からの圧油が内周溝30
→極小径油路38→油路34→下室10と流入しているので、
バルブの上昇により排油口36と弁室18上部の連通が遮断
されると、下室10の圧力は上昇する。この時、ピストン
の上部小径部４と上部大径部６の断面積差は下部小径部
５と下部大径部７の断面積差に等しいので、下室10と中
室９は連通によって圧力が共に同圧となり、ピストン３
の下向きの運動には支障を及ぼさない。Also, during the above operation, the pressure oil from the oil supply port 37 is kept in the inner circumferential groove 30.
→ Since it is inflowing from the extremely small diameter oil passage 38 → the oil passage 34 → the lower chamber 10,
When the communication between the drain port 36 and the upper portion of the valve chamber 18 is cut off due to the rise of the valve, the pressure in the lower chamber 10 rises. At this time, since the difference in cross-sectional area between the upper small diameter portion 4 and the upper large diameter portion 6 of the piston is equal to the difference in cross-sectional area between the lower small diameter portion 5 and the lower large diameter portion 7, the lower chamber 10 and the middle chamber 9 are connected by Both have the same pressure, and piston 3
It does not interfere with the downward movement of the.
ピストン３がさらに下降して、第４図の位置になり、ピ
ストンの中部小径部８が内周溝14と15を連通すると、ア
クチュエイト室24は、内周溝28,油路33,内周溝15,内周
溝14を介して油路により排油口36に連通するので、アク
チュエイト室24の圧力が低下し、バルブ19はプランジャ
21の働きで第１図に示す下降位置に押し下げられる。こ
の間瞬間的に小径の油路35から圧油が供給される状態に
なるが、小径の油路35が絞りの効果を発揮し、アクチュ
エイト室24への流入量を制限するのでバルブ19の動きに
重大な影響を及ぼすことはない。When the piston 3 further descends to the position shown in FIG. 4 and the middle small diameter portion 8 of the piston communicates with the inner circumferential grooves 14 and 15, the actuate chamber 24 becomes the inner circumferential groove 28, the oil passage 33, and the inner circumferential groove. Since the oil passage communicates with the oil discharge port 36 through the groove 15 and the inner peripheral groove 14, the pressure in the actuate chamber 24 is reduced, and the valve 19 is connected to the plunger.
The action of 21 pushes it down to the lowered position shown in FIG. During this time, the pressure oil is momentarily supplied from the small-diameter oil passage 35, but the small-diameter oil passage 35 exerts a throttling effect and limits the amount of inflow into the actuate chamber 24, so that the valve 19 moves. Has no significant effect on
給油口37から圧油が供給されている限り、上記の作動を
繰り返す。As long as the pressure oil is supplied from the oil supply port 37, the above operation is repeated.
次に第二実施例について第５図に基づき説明する。Next, a second embodiment will be described with reference to FIG.
第一実施例では、バルブ19を常に下向きに押し付ける手
段として、室20とプランジャ21を利用している。これに
代わる手段として第二実施例では、バルブ19の上部に中
径部39を付加し、弁室18の上部と中径部39の段部とで室
40を形成し、この室を油路にて常時給油口37に連通させ
る。またバルブ19の大径部22と中径部36の断面積差は、
大径部22と小径部23の断面積差より小さくする。その他
の構成は第一実施例と同じであり、作動については第一
実施例と全く同様になる。In the first embodiment, the chamber 20 and the plunger 21 are used as means for constantly pressing the valve 19 downward. As an alternative means, in the second embodiment, a medium diameter portion 39 is added to the upper portion of the valve 19, and the chamber is provided at the upper portion of the valve chamber 18 and the step portion of the medium diameter portion 39.
40 is formed, and this chamber is always communicated with the oil supply port 37 through the oil passage. The difference in cross-sectional area between the large diameter portion 22 and the medium diameter portion 36 of the valve 19 is
The cross-sectional area difference between the large diameter portion 22 and the small diameter portion 23 is made smaller. The other structure is the same as that of the first embodiment, and the operation is exactly the same as that of the first embodiment.
次に第三実施例について第６図に基づき説明する。Next, a third embodiment will be described with reference to FIG.
第一実施例、第二実施例では、ピストンが上昇して下部
大径部７の下端面が内周溝15と下室10を連通させる位置
になると、圧油がアクチュエイト室24に流入しバルブ19
を上方に移動させる。更に、バルブ19の上方への移動及
び上昇位置の保持を確実にするために、圧油を内周溝30
→内周溝29→小径の油路35→油路33→アクチュエイト室
24と流入させている。In the first and second embodiments, when the piston rises and the lower end surface of the lower large-diameter portion 7 reaches the position where the inner peripheral groove 15 and the lower chamber 10 communicate with each other, the pressure oil flows into the actuate chamber 24. Valve 19
Move upwards. Further, in order to ensure the upward movement of the valve 19 and the holding of the raised position, pressure oil is supplied to the inner circumferential groove 30.
→ Inner peripheral groove 29 → Small diameter oil passage 35 → Oil passage 33 → Actuate chamber
It is inflowing with 24.
これに代わる手段として第三実施例では、バルブ押し下
げ手段として、バルブの上端に中径部39を付加して室40
を形成するとともに、上昇位置保持手段として、バルブ
19の大径部22が摺動する弁室18に内周溝41を形成し、こ
れを小径の油路42にて給油口37に連通させる。As an alternative means, in the third embodiment, as a means for pushing down the valve, a medium diameter portion 39 is added to the upper end of the valve to add a chamber 40.
And the valve as a rising position holding means.
An inner peripheral groove 41 is formed in the valve chamber 18 on which the large diameter portion 22 of 19 slides, and the inner peripheral groove 41 is communicated with the oil supply port 37 through an oil passage 42 of a small diameter.
内周溝41は、バルブ下降位置においては、大径部22によ
ってアクチュエイト室24から遮断されており、バルブ19
が上昇した時に、アクチュエイト室24と連通するように
形成する。The inner circumferential groove 41 is cut off from the actuate chamber 24 by the large-diameter portion 22 at the valve lowering position.
Is formed so as to communicate with the actuation chamber 24 when is raised.
この構成によりバルブが上昇すると、圧油が小径の油路
42を通って、内周溝41からアクチュエイト室24に流入
し、バルブ19をストロークエンドまで上方に押し続け、
上昇位置を確実に保持する。その他の構成及び作動につ
いては、第一実施例と同様である。With this configuration, when the valve rises, the pressure oil is
After passing through 42, it flows into the actuate chamber 24 from the inner peripheral groove 41, and continues pushing the valve 19 upward to the stroke end,
Hold the rising position securely. Other configurations and operations are similar to those of the first embodiment.
上記の各実施例においては、ピストン３の上部小径部４
と下部小径部５を同径とした場合について述べたが、上
部の径を下部より幾分小さくしてもよい。この場合は、
打撃行程においてピストンの上端面には、ガス圧に加え
て上部小径部と下部小径部の断面積差による油圧が働く
ので、打撃力をより大きくすることができる。In each of the above embodiments, the upper small diameter portion 4 of the piston 3
Although the case where the lower small diameter portion 5 has the same diameter has been described, the diameter of the upper portion may be somewhat smaller than that of the lower portion. in this case,
In the striking stroke, not only the gas pressure but also the hydraulic pressure due to the difference in sectional area between the upper small diameter portion and the lower small diameter portion acts on the upper end surface of the piston, so that the striking force can be further increased.
本発明の衝撃動工具は、ピストンの打撃行程（下降行
程）で、ピストンがチゼルを打撃する少し前に下室と排
油口の連通を遮断するとともに、給油口からの圧油を下
室に流入させ、下室の圧力を上昇させるようにしてい
る。従って、ピストンが打撃直後に急反撥しても、下室
内には油中の気泡が成長するほどの圧力低下はなくな
り、キャビテーションの発生を防止することができる。The impact tool of the present invention cuts off the communication between the lower chamber and the oil discharge port just before the piston strikes the chisel in the striking stroke (lowering stroke) of the piston, and the pressure oil from the oil supply port to the lower chamber. The pressure in the lower chamber is increased by inflowing. Therefore, even if the piston suddenly repels immediately after the impact, the pressure drop to the extent that bubbles in the oil grow in the lower chamber does not occur, and the occurrence of cavitation can be prevented.
従ってシリンダやピストンの表面に生じるキャビテーシ
ョンによる壊食（エロージョン）が減り、耐久性が著し
く向上するとともに工具全体の信頼性が高まり、面倒で
大変な取替修理作業を減らすことができるという効果が
ある。Therefore, erosion due to cavitation that occurs on the surface of the cylinder or piston is reduced, durability is significantly improved, the reliability of the entire tool is improved, and troublesome and troublesome replacement work can be reduced. .
第１図から第４図は本発明の第一実施例の作動を説明す
る断面図、第５図は第二実施例の断面図、第６図は第三
実施例の断面図、第７図は従来例の衝撃動工具の断面図
である。 １……衝撃動工具、２……シリンダ ３……ピストン、４……上部小径部 ５……下部小径部、６……上部大径部 ７……下部大径部、８……中部小径部 ９……中室、10……下室 11……上室、12……チゼル 13,14,15,16……シリンダ内周溝 18……弁室、19……バルブ 20……室、21……プランジャ 22……バルブ大径部、24……アクチュエイト室 26……連通孔 27,28,29,30,31……バルブ内周溝 32,33,34……油路 35,42……小径油路 36……排油口、37……給油口 38……極小径油路、40……室1 to 4 are sectional views for explaining the operation of the first embodiment of the present invention, FIG. 5 is a sectional view of the second embodiment, FIG. 6 is a sectional view of the third embodiment, and FIG. FIG. 6 is a cross-sectional view of a conventional impact tool. 1 ... Impact tool, 2 ... Cylinder 3 ... Piston, 4 ... Upper small diameter part 5 ... Lower small diameter part, 6 ... Upper large diameter part 7 ... Lower large diameter part, 8 ... Medium small diameter part 9 …… Middle chamber, 10 …… Lower chamber 11 …… Upper chamber, 12 …… Chisel 13,14,15,16 …… Cylinder inner circumferential groove 18 …… Valve chamber, 19 …… Valve 20 …… Room, 21 …… Plunger 22 …… Valve large diameter part, 24 …… Actuate chamber 26 …… Communication hole 27,28,29,30,31 …… Valve inner circumferential groove 32,33,34 …… Oil passage 35,42… … Small oil passage 36 …… Draining port, 37 …… Refueling port 38 …… Extra small oil passage, 40 …… Room
Claims (1)
装着し、シリンダ（４）の内部には下降時にチゼルを打
撃するピストン（３）を摺動自在に嵌装し、前記ピスト
ンには中程に上部大径部（６）と中部小径部（８）と下
部大径部（７）を設け、シリンダ（２）の内部には、ピ
ストン上部大径部の上面側に中室（９）を、下部大径部
の下面側に下室（10）を形成し、下室及び中室と給油口
（37）及び排油口（36）の間に設けた弁室（18）には、
摺動自在のバルブ（19）を嵌装し、中室と下室と給油口
と排油口の連通をバルブと油路によって制御し、油圧と
ガス圧によりピストンを昇降させる衝撃動工具におい
て、排油口（36）はバルブ（19）が下降位置にある時は
弁室を介して中室（９）に連通し、バルブが上昇位置少
し手前から上昇位置にある時は弁室（18）と遮断される
ような位置に設けて中室（９）及び下室（10）と排油口
（36）との連通を断つとともに、下室（10）を常に給油
口（37）に連通させる極小径油路（38）を設け、さらに
バルブ（19）が上昇位置にある時アクチュエイト室（2
4）を給油口（37）に通じる小径油路（35），（42）を
設けて、ピストンがチゼルを打撃する下降行程の間中バ
ルブ（19）が上昇位置を保持するようにする油路を構成
したことを特徴とする衝撃動工具。1. A tool such as a chisel (12) is attached to a lower end of the piston (3) so as to move back and forth, and a piston (3) for striking the chisel when descending is slidably fitted inside the cylinder (4). An upper large diameter portion (6), a middle small diameter portion (8) and a lower large diameter portion (7) are provided in the middle of the cylinder, and inside the cylinder (2), a middle chamber is provided on the upper surface side of the piston upper large diameter portion. A lower chamber (10) is formed on the lower surface of the lower large diameter portion (9), and a valve chamber (18) is provided between the lower chamber and the middle chamber and the oil supply port (37) and the oil discharge port (36). Has
In a shock tool in which a slidable valve (19) is fitted, the communication between the middle chamber, the lower chamber, the oil supply port and the oil discharge port is controlled by the valve and oil passage, and the piston is moved up and down by hydraulic pressure and gas pressure, The oil drain port (36) communicates with the middle chamber (9) through the valve chamber when the valve (19) is in the lowered position, and the valve chamber (18) when the valve is in the raised position from slightly before the raised position. The lower chamber (10) and the lower chamber (10) are connected to the oil supply port (37) at all times by disconnecting the middle chamber (9) and the lower chamber (10) from the oil discharge port (36). A very small oil passage (38) is provided, and when the valve (19) is in the raised position, the actuation chamber (2
A small oil passage (35), (42) that connects 4) to the oil supply port (37) is provided so that the valve (19) maintains the raised position during the downward stroke in which the piston strikes the chisel. Impact tool that is characterized by being configured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24107986A JPH0763940B2 (en) | 1986-10-08 | 1986-10-08 | Impact tool |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24107986A JPH0763940B2 (en) | 1986-10-08 | 1986-10-08 | Impact tool |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6393577A JPS6393577A (en) | 1988-04-23 |
| JPH0763940B2 true JPH0763940B2 (en) | 1995-07-12 |
Family
ID=17068977
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24107986A Expired - Fee Related JPH0763940B2 (en) | 1986-10-08 | 1986-10-08 | Impact tool |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0763940B2 (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003071744A (en) * | 2001-09-05 | 2003-03-12 | Nippon Pneumatic Mfg Co Ltd | Impact dynamic tool |
| JP6470058B2 (en) * | 2014-01-30 | 2019-02-13 | 古河ロックドリル株式会社 | Hydraulic striking device |
| JP6495672B2 (en) * | 2015-01-30 | 2019-04-03 | 古河ロックドリル株式会社 | Hydraulic striking device, valve timing switching method and valve port setting method |
| JP7171035B2 (en) * | 2018-11-22 | 2022-11-15 | 株式会社テイサク | hydraulic percussion device |
-
1986
- 1986-10-08 JP JP24107986A patent/JPH0763940B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6393577A (en) | 1988-04-23 |
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