SE538237C2 - Liquid driven immersion drill with indexing by means of intermittent pressure setting - Google Patents

Abstract

SAMMANDRAG Foreliggande uppfinning avser en sankborrmaskin som via en borrstrang drivs av ett vatskeflode. Den innefattande ett hus med ett slagverk, en borrkrona axiellt rorligt monterad i en kronhylsa som Jr vridbart lagrad I huset, slagverket anordnat med en slagkolv med en kolvyta anordnad att si5 p5 en nacke p5 borrkronan, och en vend far att styra slagkolven fram och ater mellan ett utg5ngslage och ett andlage, varvid siagkolvens ventil vaxelvis trycksatter och avlastar ett tryckrum som vid tryckbelastning driver slagkolven fram5t, huset vidare innefattande en vatskedriven rotationsmotor av vingmotortyp innefattande tryckrum med vingar som Yid tryckbelastning roterar borrkronan. En flodesvag for fiddet till rotationsmotorns tryckrum oppnas ay slagkolyens ventil nar ventilen stanger flociesvagen till slagkolyens tryckrum. SUMMARY The present invention relates to a submersible drilling machine which is driven by a drilling rig via a drill string. It comprises a housing with a percussion device, a drill bit axially movably mounted in a crown sleeve which is rotatably mounted in the housing, the percussion device arranged with a percussion piston with a piston surface arranged to sit on a neck on the drill bit, and a flange father to guide the percussion piston back and forth between a starting stroke and a bearing, wherein the valve of the sieve piston alternately pressurizes and relieves a pressure chamber which, under pressure load, drives the percussion piston forward, the housing further comprising a water-driven rotary motor of wing motor type comprising pressure chambers with wings which Yid pressure load rotates the drill bit. A flood wave for the feed to the pressure chamber of the rotary engine is opened in the percussion valve when the valve closes the float wave to the percussion pressure chamber.

Description

VATSKEDRIVEN SANKBORRMASKIN MED INDEXERING MEDELST INTERMITTENT TRYCKSATTNING. WATER SPRING SANK DRILLING MACHINE WITH INDEXING BY INTERMITTENT PRESSURE SETTING.

TEKNISKT OMRADE Foreliggande uppfinning avser en vatskedriven sankborrmaskin innefattande ett hus, en borrkrona vridfast monterad i en kronhylsa, ett slagverk med en slagkolv anordnad att sI5 p en nacke p5 borrkronan och en till huset anordnad vatskedriven vingmotor far rotation av borrkronan. TECHNICAL FIELD The present invention relates to a water-powered submersible drilling machine comprising a housing, a drill bit rotatably mounted in a crown sleeve, a percussion device with a percussion piston arranged to rotate a drill-driven wing motor rotating on a neck on the drill bit and a water-driven wing motor.

BAKGRUND Vatskedrivna sankborrmaskiner av detta slag anvands ofta med borror som skarvas ihop. BACKGROUND Water-powered submersible drills of this type are often used with drills that are spliced together.

Vatskan som driver slagen och rotationen leds genom (Oren. Ett annat satt att leda drivvatskan Sr genom s.k. coiled tubing, ett flexibelt borrrir som hasplas av en rulle. Fordelen med att anvanda ett flexibelt ror Sr att borrningens riktning kan styras, samt att borrningen gar snabbare tack vare att roret inte behover skarvas. The fluid that drives the strokes and rotation is guided through (Oren. Another way to guide the drive fluid Sr through so-called coiled tubing, a flexible drill pipe that is reeled by a roller. The advantage of using a flexible pipe is that the direction of the drilling can be controlled, and that the drilling goes faster due to the fact that the rudder does not need to be spliced.

Nackdelen med denna typ av vatskedrivna sankborrmaskiner Sr komplicerade ventilsystem m5ste anvandas for att 5stadkomma en sl5ende och roterande rorelse. En annan nackdel Sr att borrkronan kan med en s5dan rarelse dra borrester, s.k. borrkax med sig i rotationen, vilket innebar att borrkronan ncits kraftigt, samt att borrkronan riskerar att kilas fast. The disadvantage of this type of water-powered submersible drilling machine is that complicated valve systems must be used to create a sliding and rotating motion. Another disadvantage is that the drill bit can with such a rarity draw drilling residues, so-called drill cuttings with it in the rotation, which meant that the drill bit ncits sharply, and that the drill bit risks being wedged.

SAMMANFATTNING AV UPPFINNINGEN Syftet med den fareliggande uppfinningen Sr att erbjuda en vatskedriven sankborrmaskin av det slag som har en intermittent roterande motor som trycksatts av flode frAn slagverket. SUMMARY OF THE INVENTION The object of the present invention is to provide a water-powered submersible drilling machine of the type which has an intermittent rotary motor pressurized by flood from the percussion device.

Detta syfte 5stadkomnnes genom att rotationsmotorn och slagverket Sr sammanbyggda I ett maskinhus till vilket flodet leds och via ventiler intermittent trycksatter rotationsmotorn. This object is achieved by the rotary motor and the percussion mechanism being assembled in a machine housing to which the flow is directed and via valves intermittently pressurizing the rotary motor.

FIGURBESKRIVNING Figur 1 visar en sidovy av en sankborrmaskin enligt uppfinningen Figur 2 visar ett snitt taget genom rotationsmotorn hos sankborrmaskinen fran figur 1 1 BESKRIVNING AV UTFORINGSFORMER Den vatskedrivna sankborrmaskinen 1 som visas i figur 1 uppvisar ett maskinhus 2 med ett slagverk 3, en rotationsmotor 4 och en borrkrona 5. Maskinhuset 2 innefattar ett I5ngstrackt ror med en kopplingsdel eller anslutning 6 till vilken en ej visad borrstrang, exempelvis i form av ett borror eller en coil, är ansluten. En trycksatt fluid, exempelvis vatten, luft eller mud, harefter kallad vatska, leds fran en ej visad kalla via borrstrangen in i anslutningen 6 for drivning av sankborrmaskinen 1. Vid borrning Jr saledes hela maskinhuset 2 infort i borrh5let med borrkronan riktad mot borrh5lets botten och borrstrangen strackande sig ut ut borrhalet sammankopplad med en [calla far en trycksatt fluid. DESCRIPTION OF THE FIGURES Figure 1 shows a side view of a submersible drilling machine according to the invention. Figure 2 shows a section taken through the rotary motor of the submersible drilling machine from Figure 1. a drill bit 5. The machine housing 2 comprises an elongated pipe with a coupling part or connection 6 to which a drill string (not shown), for example in the form of a drill or a coil, is connected. A pressurized fluid, for example water, air or mud, hereinafter referred to as liquid, is led from a cold (not shown) via the drill string into the connection 6 for driving the submersible drill 1. Thus, when drilling, the entire machine housing 2 enters the borehole with the drill bit facing the bottom of the borehole and the drill string extending out of the drill tail connected to a pressurized fluid.

Till maskinhusets 2 ena ande 7, i anslutning till kopplingsdelen 6, är ett slagverk 3 anordnat. To one end 7 of the machine housing 2, in connection with the coupling part 6, a percussion device 3 is arranged.

Slagverket 3 innefattar en slagkolv 8 som drivs via vatskeflodet. Slagkolven 8 är utformad som en axel med en ansats A och en genomg5ende kanal 9. Vatskeflridet leds via en ventil 10 som omvaxlande oppnar och stanger flodet nar slagkolven 8 frirflyttas mellan sitt utg5ngslage 11 och sitt andlage 12, och darmed omvaxlande trycksatter och avlastar ett tryckrum 13. Ventilen 10 kan innefatta en slidventil, men aven andra typer av ventiler kan anvandas. Exempelvis kan en port oppnas av slagkolven nar slagkolven bringas i rorelse. Tryckrummet 13 Jr 55 utformat att trycket fra'n vatskan driver slagkolven 8 mot borrkronan 5. Slagkolven 8 är axiellt styrd med hjalp av exempelvis bussningar 14 som till5ter att slagkolven 8 forflyttas mellan sitt utg5ngslage 11 och sitt andlage 12. Andlaget 12 uppvisar ett sate S mot vilket slagkolvens ansats bottnar. The percussion device 3 comprises a percussion piston 8 which is driven via the liquid river. The percussion piston 8 is designed as a shaft with a shoulder A and a through-going channel 9. The liquid flow is led via a valve 10 which alternately opens and closes the flow when the percussion piston 8 is moved between its outlet stroke 11 and its base 12, thereby alternating pressure sets and relieving a pressure chamber. 13. The valve 10 may comprise a slide valve, but other types of valves may also be used. For example, a port can be opened by the percussion piston when the percussion piston is agitated. The pressure chamber 13 Jr 55 is designed so that the pressure from the liquid drives the percussion piston 8 against the drill bit 5. The percussion piston 8 is axially controlled by means of, for example, bushings 14 which allow the percussion piston 8 to be moved between its outlet 11 and its abutment 12. The abutment 12 has a set S against which the stroke of the percussion piston is based.

Till maskinhusets 2 andra ande 15 Jr anordnat en borrkrona 5 med en hals 16 som sticker in i maskinhuset 2. Borrkronans 5 hals 16 uppvisar en genomg5ende axiell kanal 17 och avslutas med en nacke 18. Slagkolven 8 uppvisar en kolvyta 19 och är axiellt rarligt anordnad att sI5 p5 borrkronans 5 nacke 18. Slagkolven 8 är kopplad till vatskeflodet som via ventilen omvaxlande fyller och tommer ett eller flera tryckrum 13 med vatskan under tryck, som via kolvytan 19 sl5r kolven 8 mot borrkronans 5 nacke 18. Borrkronan 5 är vid sin mot berget vanda ande forsedd med utlopp 31 for returflodet. Nar slagkolven har utfort sitt slag mot borrkronan, satts tryckrummet 13 under I5g tryck, varvid slagkolven bringas att utfora sitt returslag och ken/ander till sitt utgangslage 11. 2 Borrkronans 5 hals 16 har en splineforbindning 20 med en borrkronhylsa 21, vilket ger borrkronan 5 en styrd fram och 5tergaende rorelse enligt pilen i figur 1, och Jr lagrat monterad p5 sa satt att borrkronans 5 hals 16 kan rotera inne i maskinhuset 2 och medfOlja rotationsmotorns 4 rotation. Borrkronhylsans 21 lagring 22 Jr fastskruvad, fastpressad eller p annat satt fastsatt i maskinhuset 2. Borrkronans 5 hals 16 monteras i borrkronhylsan 21 varefter en stoppring 23 monteras p5 borrkronans 5 hals 16 for att forhindra att borrkronan 5 kan falla ut fr5n hylsan 21. Darefter monteras borrkronhylsan 21 i maskinhusets 2 ande 7. Borrkronan 5 kan i en annan utforingsform vara forsedd med endast ett sp8r for att styra den fram och Atergaende rorelsen. Arranged to the second end 15 Jr of the machine housing 2 is a drill bit 5 with a neck 16 projecting into the machine housing 2. The neck 16 of the drill bit 5 has a continuous axial channel 17 and terminates with a neck 18. The percussion piston 8 has a piston surface 19 and is axially arranged that the pendulum 5 of the drill bit 5 is connected to the fluid piston 8 which via the valve alternately fills and empties one or more pressure chambers 13 with the liquid under pressure, which via the piston surface 19 slides the piston 8 against the neck 18 of the drill bit 5. berget vanda ande provided with outlet 31 for the return flood. When the percussion piston has made its stroke against the drill bit, the pressure chamber 13 is put under I5g pressure, whereby the percussion piston is made to perform its return stroke and ken / ander to its initial stroke 11. The neck 16 of the drill bit 5 has a spline connection 20 with a drill bit sleeve 21, which gives the drill bit 5 a controlled reciprocating movement according to the arrow in Figure 1, and Jr mounted mounted p5 so that the neck 16 of the drill bit 5 can rotate inside the machine housing 2 and follow the rotation of the rotary motor 4. The bearing 22 of the drill bit sleeve 21 is screwed, pressed or otherwise fastened in the machine housing 2. The neck 16 of the drill bit 5 is mounted in the drill bit sleeve 21, after which a stop ring 23 is mounted on the neck 16 of the drill bit 5 to prevent the drill bit 5 from falling out of the sleeve 21. the drill bit sleeve 21 in the spirit 7 of the machine housing 2. In another embodiment, the drill bit 5 can be provided with only one groove for guiding the forward and return movements.

Rotationsmotorn 4, som visas i genomskarning i figur 2, är placerad mellan borrkronan 5 och slagverket 3 p5 sa satt att borrkronans 5 hals 16 loper axiellt genom rotationsmotorns 4 centrum 24. Ventilen 10 vid anslutningen 6 uppvisar kanaler 25 genom vilka flodet leds n5r ventilen 10 oppnar flodesvagen till kanalerna 25 som leder floclet till rotationsmotorn 4. Rotationsmotorn 4 innefattar en allmant kand vingmotor av den typ som innefattar ett hus H med radiellt rorliga vingar 26 anordnade p5 en rotoraxel 27 omgiven av ett tryckrum 28. The rotary motor 4, shown in section in figure 2, is placed between the drill bit 5 and the percussion device 3 p5 so that the neck 16 of the drill bit 5 runs axially through the center 24 of the rotary motor 4. The valve 10 at the connection 6 has channels 25 through which the flow is directed near the valve 10 opens the river carriage to the channels 25 leading the floc to the rotary motor 4. The rotary motor 4 comprises a generally known wing motor of the type comprising a housing H with radially movable wings 26 arranged on a rotor shaft 27 surrounded by a pressure chamber 28.

Tryckrummet bildas med fordel av huset H och rotationsaxelns mantel M. Rotoraxelns 27 centrum 24 är utformad med splines eller spar 29 motsvarande splinsen eller sparen 20 hos borrkronan 5, sa att borrkronans 5 hals 16 kan rora sig fram och 5ter p5 ett styrt s5tt och medfolja rotationen. The pressure chamber is formed with the advantage of the housing H and the mantle M of the rotary shaft M. The center 24 of the rotor shaft 27 is formed with splines or grooves 29 corresponding to the spline or grooves 20 of the drill bit 5, so that the neck 16 of the drill bit 5 can move forward and follow a controlled path. the rotation.

Tryckrummen 28 är s5 utformade att volymen akar i borjan av rotationsrorelsen, far att minska i slutet av rotationsrorelsen. Tack vare att vingarna 26 är radiellt rorliga foljer vingarna 26 tryckrummens 28 form och far p5 sa satt en okande area thr att i slutet av rotationsrorelsen f5 en minskande area. Nar den trycksatta vatskan leds in i tryckrummen 28 trycker den vingen framfor sig varvid rotationen 5stadkommes. Med fordel Jr tryckrummen placerade symmetriskt kring rotorn. Vatskan leds in p5 bada sidor av rotoraxeln 27, och clamed undviks snedbelastning. Nar rotationsmotorn 4 roterar foljer borrkronan 5 med i rotationen. The pressure chambers 28 are so designed that the volume increases at the beginning of the rotational movement, may decrease at the end of the rotational movement. Due to the fact that the wings 26 are radially movable, the wings 26 follow the shape of the pressure chambers 28 and have an increasing area so that at the end of the rotational movement there is a decreasing area. When the pressurized liquid is led into the pressure chambers 28, it pushes the wing in front of it, whereby the rotation is effected. Advantageously, the pressure chambers are placed symmetrically around the rotor. The fluid is led into both sides of the rotor shaft 27, and the clamed avoids oblique loading. When the rotary motor 4 rotates, the drill bit 5 follows the rotation.

Borrkronans 5 och slagkolvens 8 genomg5ende kanaler 9,17 leder returfloclet fra'n slagkolvens 8 tryckrum 13 till borrkronan 5 for spolning av borromradet. Rotationsmotorn 4 innefattar vidare ett eget utlopp 30 Mr vatskeflodets returflode. Utloppet 30 Jr placerat mellan anslutningen 6 och borrkronan 5. Detta ger fordelen att returflodet, som rensar borrh5let fran 3 s.k. borrkax, far tillskott fran tv5 hall. DeIs fran borrkronans returflode 33., som aven rensar omradet kring borrkronans omedelbara narhet, dels frail rotationsmotorns returflodesutlopp 30, vilket ger en effektiv rensning av borrhalet. The through passages 9,17 of the drill bit 5 and the percussion piston 8 guide the return floc from the pressure chamber 13 of the percussion piston 8 to the drill bit 5 for flushing the drill string. The rotary motor 4 further comprises its own outlet 30 Mr the return flow of the liquid river. The outlet 30 Jr is located between the connection 6 and the drill bit 5. This gives the advantage that the return flow, which cleans the drill hole from 3 so-called drill cuttings, father addition from tv5 hall. It is from the return flow 33 of the drill bit, which also cleans the area around the immediate vicinity of the drill bit, and partly from the return flow outlet 30 of the rotary motor, which provides an effective cleaning of the drill tail.

Vatskeflridet till rotationsmotorn 4 paborjas nar slagkolven 8 befinner sig i sitt utgangslage 11, det lage nar kolven 8 befinner sig narmast anslutningen 6. I detta lage är borrkronan avlastad fr5n batten i borrhalet. Nar den det trycksatta vatskeflodet nat. slagkolven 8 oppnas ventilen 10 som leder en del av flridet till rotationsmotorn 4 varvid motorn 4 roterar medtagande borrkronan 5 i rotationen. Resterande del av floclet leds saledes till slagkolven 8 som slar p5 borrkronans nacke 18. Nar slagkolven 8 lamnar sitt utgangslage 11 i sin rorelse mot dess andlage 12, stanger ventilen 10 kanalerna 25 till rotationsmotorns 4 tryckrum 28 varvid rotationsmotorn stannar. Med stillast5ende rotationsmotor utfrir slagkolven 8 sitt arbetsslag och slar slagkolvens 8 kolvyta 19 mot borrkronans 5 nacke 18, varvid borrkronan 5 slar mot berget. Nar slagkolven 8 ror sig tillbaks i riktning mot sitt utgangslage 11, lyfter borrkronan 5 fran berget, och nar slagkolven 8 nar sitt utgangslage 11 sa oppnas ventilen och flodet leds till rotationsmotorn 4. The water flow to the rotary motor 4 is drilled when the percussion piston 8 is in its initial position 11, the layer when the piston 8 is closest to the connection 6. In this layer the drill bit is relieved from the bat in the drill tail. When it the pressurized river flood night. the percussion piston 8 opens the valve 10 which leads a part of the flow to the rotary motor 4, the motor 4 rotating taking the drill bit 5 in the rotation. The remaining part of the floc is thus led to the percussion piston 8 which strikes the neck 18 of the drill bit. When the percussion piston 8 leaves its initial bearing 11 in its movement towards its abutment 12, the valve 10 closes the channels 25 to the pressure chamber 28 of the rotary motor 4 whereby the rotary motor stops. With a stationary rotary motor, the percussion piston 8 performs its working stroke and strikes the piston surface 19 of the percussion piston 8 against the neck 18 of the drill bit 5, the drill bit 5 striking the rock. When the percussion piston 8 moves back in the direction of its initial stroke 11, the drill bit 5 lifts from the rock, and when the percussion piston 8 reaches its initial stroke 11, the valve is opened and the flow is directed to the rotary motor 4.

I en annan utforingsform leds det trycksatta flodet till slagkolven 8 som driver borrkronan 5 mot berget. Nar borrkronan 5 genomfort sitt slag, och slagkolven 8 är p5 vag mot sitt utgingslage 11, oppnas ventilen 10 varvid rotationsmotorn 4 roterar medtagande borrkronan 5 i rotationen. Nar slagkolven 8 nar sitt utgangslage 11 sa stangs ventilen 10 varvid rotationen stannar. Detta upprepas sa lange det trycksatta vatskeflodet leds ner genom borrstrangen fran den ej visade Ulan for den trycksatta vatskan. Dessa bada utforingsformer ger en form av indexerande borrning eller rorelse, dar borrkronan slat- mot berget i botten av borrhalet pa nya, ororda platser varje gang. In another embodiment, the pressurized flood is directed to the percussion piston 8 which drives the drill bit 5 towards the rock. When the drill bit 5 carries out its stroke, and the percussion piston 8 is p5 vague towards its starting stroke 11, the valve 10 is opened, the rotary motor 4 rotating taking the drill bit 5 in rotation. When the percussion piston 8 reaches its initial stroke 11, the valve 10 is closed, whereby the rotation stops. This is repeated as long as the pressurized liquid stream is led down through the drill string from the Ulan (not shown) of the pressurized liquid. These two embodiments provide a form of indexing drilling or movement, where the drill bit strikes the rock at the bottom of the borehole in new, unspoiled locations each time.

Anslutningen är anordnad med ej visade dysor I flodesvagen i syfte att styra motorns rotationshastighet genom att begransa flridet. The connection is provided with nozzles (not shown) in the river trough in order to control the rotational speed of the motor by limiting the flow.

Foreliggande uppfinning är inte begransad till det ovan beskrivna och pa ritningarna visade, utan kan andras och modifieras p5 en rad olika satt inom ramen for den i de efterfoljande patentkraven angivna uppfinningstanken. 4 The present invention is not limited to the one described above and shown in the drawings, but can be modified and modified in a number of different ways within the scope of the inventive concept stated in the appended claims. 4

Claims (7)

PATE NTKRAVPATE NTKRAV 1. Sankborrmaskin (1) som via en borrstrang drivs av ett vatskeflode, innefattande ett hus (2) med ett slagverk (3), en borrkrona (5) axiellt rorligt monterad i en kronhylsa (21) som är vridbart lagrad i huset (2), slagverket (3) anordnat med en slagkolv (8) med en kolvyta (19) anordnad att sI5 p5 en nacke (18) p5 borrkronan (5), och en ventil (10) for att styra slagkolven (5) fram och ater mellan ett utg5ngslage (11) och ett andlage (12), varvid slagkolvens (8) ventil (10) vaxelvis trycksatter och avlastar ett tryckrum (13) som vid tryckbelastning driver slagkolven (8) framat, huset (2) vidare innefattande en vatskedriven rotationsmotor (4) av vingmotortyp innefattande tryckrum (28) med vingar (26) som vid tryckbelastning roterar borrkronan (5), 1(5 n n et ec k n a d av att den innefattar en flodesvag (25) far flodet till rotationsmotorns tryckrum (28) som oppnas av slagkolvens ventil (10) nar ventilen (10) stanger flodesvagen till slagkolvens (8) tryckrum (13).A submersible drilling machine (1) which is driven by a drilling string via a drill string, comprising a housing (2) with a percussion device (3), a drill bit (5) axially movably mounted in a crown sleeve (21) which is rotatably mounted in the housing (2). ), the percussion device (3) arranged with a percussion piston (8) with a piston surface (19) arranged to sI5 p5 a neck (18) p5 the drill bit (5), and a valve (10) for guiding the percussion piston (5) back and forth between an outlet stroke (11) and a bearing (12), the valve (10) of the percussion piston (8) alternately pressurizes and relieves a pressure chamber (13) which, when the load is pressed, drives the percussion piston (8) forward, the housing (2) further comprising a water-powered rotary motor (4) of wing motor type comprising pressure chamber (28) with wings (26) which under pressure load rotate the drill bit (5), 1 (5 nn et ec knad in that it comprises a tidal wave (25) the river flows to the rotary motor pressure chamber (28) which is opened of the percussion valve (10) when the valve (10) closes the river carriage to the pressure chamber (13) of the percussion piston (8). 2. Sankborrmaskin nagot av foregaende patentkrav, varvid ventilen (10) 5r anordnad i anslutning till slagkolven (8).A submersible drilling machine according to any one of the preceding claims, wherein the valve (10) is arranged in connection with the percussion piston (8). 3. Sankborrmaskin enligt nagot av foregaende patentkrav, varvid ventilen (10) oppnar flodesvagen (25) till rotationsmotorn (4) nar slagkolven (8) befinner sig i sitt andlage (12) nar slagkolven (8) utfort sitt arbetsslag.A submersible drilling machine according to any one of the preceding claims, wherein the valve (10) opens the river carriage (25) to the rotary motor (4) when the percussion piston (8) is in its abutment (12) when the percussion piston (8) performs its working stroke. 4. Sankborrmaskin enligt n5got av foreg5ende patentkrav, varvid ventilen (10) stanger flodesvagen (25) till rotationsmotorn (4) nar slagkolven (8) laminar sitt andlage (12) under forflyttningen I riktning Ster mot sitt utgangslage (11).A submersible drilling machine according to any one of the preceding claims, wherein the valve (10) closes the river carriage (25) to the rotary motor (4) when the percussion piston (8) laminar its bearing (12) during the movement in the direction of Ster towards its initial bearing (11). 5. Sankborrmaskin enligt patentkrav 2, varvid ventilen (10) oppnar flodesvagen (25) till rotationsmotorn (4) under slagkolvens (8) forllyttning i riktning mot utgangslaget (11).A submersible drilling machine according to claim 2, wherein the valve (10) opens the river trough (25) to the rotary motor (4) during the movement of the percussion piston (8) in the direction of the exit layer (11). 6. Sankborrmaskin enligt patentkrav 5, varvid ventilen (10) stanger flodesvagen (25) till rotationsmotorn (4) nar slagkolven (8) n5r sitt utgangslage (11).A submersible drilling machine according to claim 5, wherein the valve (10) closes the river trough (25) to the rotary motor (4) when the percussion piston (8) reaches its initial stroke (11). 7. Sankborrmaskin enligt patentkrav 1, varvid borrkronan (5) innefattar en hals (16) forsedd med spar eller splines (20). (16) stracker sig axiellt 7) är fOrsedd med spar s (16). 1:0I=' 2/2A submersible drilling machine according to claim 1, wherein the drill bit (5) comprises a neck (16) provided with spars or splines (20). (16) extends axially 7) is provided with spar s (16). 1: 0I = '2/2