Injection nozzle for injecting lubricating oil in engine cylinders and use thereof

Abstract

An injection nozzle for use in injecting lubricating oil into cylinders in large engines is provided. The nozzle is adapted for fastening in a cylinder wall with a nozzle rod extending through the cylinder wall and with a nozzle outlet at the inner end of the nozzle rod. The nozzle rod includes a cylindrical valve seat boring with a displaceable valve body having a cylindrical sealing face which interacts with the cylindrical valve seat boring of the nozzle rod, the valve body biased by a spring for effective closing of the valve. The valve body is formed by a cylindrical rod having a turned recess in the cylindrical sealing face of the valve body. The turned recess is arranged at the inner end of the valve body with parts of the cylindrical sealing face of the valve body at each side of the turned recess.

Claims

1. An injection nozzle for use in injecting lubricating oil into cylinders in engines and adapted with a mounting means for fastening in a cylinder wall, with a nozzle rod extending through the cylinder wall and with at least one nozzle outlet at an inner end of the nozzle rod, the nozzle rod including a valve with a cylindrical valve seat bore in which is provided a displaceable valve body having a cylindrical sealing surface which interacts with the cylindrical valve seat bore of the nozzle rod, the displaceable valve body having an enlarged head at an outer end of the displaceable valve body with a contact face for a spring disposed around the displaceable valve body for establishing a spring-loaded closing of the valve, the nozzle rod including a passage for pressurised oil for supplying pressurised oil to a pressure chamber in which the pressurised oil can exert a force on the displaceable valve body so that the displaceable valve body is displaced against the action of the spring for opening the valve and establishing an overpressure injection of oil through the nozzle outlet until the oil pressure drops such that the spring establishes a closing of the valve, wherein the displaceable valve body is formed by a cylindrical rod which has a turned recess in the cylindrical sealing surface of the displaceable valve body, the turned recess being arranged at an inner end of the displaceable valve body, with parts of the cylindrical sealing face of the displaceable valve body at each side of the turned recess, for being connected with the nozzle outlet at a forward displacement of the displaceable valve body towards an outlet end of the injection nozzle, against the action of the spring, to deliver the pressurized oil to the nozzle outlet, the pressure chamber of the nozzle rod being formed by a pressure chamber bore with a greater diameter than the valve seat bore for forming a pressure chamber in which the spring is located, and the pressure chamber via a pressurised oil supply duct being connected with the turned recess in the displaceable valve body.

2. The injection nozzle according to claim 1, wherein the displaceable valve body has at least one bevelled side for forming the pressurised oil supply duct together with the valve seat bore.

3. The injection nozzle according to claim 1, wherein the nozzle rod has at least one bore connecting the pressure chamber with the turned recess.

4. The injection nozzle according to claim 1, wherein the nozzle rod in the cylindrical valve seat bore has at least one longitudinal groove connecting the pressure chamber with the turned recess.

5. The injection nozzle according to claim 1, wherein the nozzle rod also includes a return oil passage for draining off a leak oil.

6. The injection nozzle according to claim 1, wherein the valve seat bore is open at the end such that a leak oil can be drained off via the open end.

7. The injection nozzle according to claim 1, wherein the displaceable valve body has two opposing bevelled sides.

8. The injection nozzle according to claim 1, wherein the bevelled sides of the displaceable valve body extend into the pressure chamber of the valve in which the spring is located.

9. The injection nozzle according to claim 1, wherein the contact face of the displaceable valve body is planar or spherical.

10. The injection nozzle according to claim 1, wherein a stop is provided for limiting the displacement of the displaceable valve body.

11. The injection nozzle according to claim 1, wherein a nut is provided for preloading the spring.

12. The injection nozzle according to claim 1, wherein a plurality of nozzle outlets are provided, disposed with varying orientations relative to a center axis through the nozzle rod.

13. A method comprising: utilizing an injection nozzle according to claim 1 in a system for use in injecting lubricating oil into cylinders in engines, arranged with injection nozzles, which are mounted in a cylinder wall, a lubricating apparatus with at least one pumping unit, connecting tubes for connecting the lubricating apparatus with the injection nozzles, wherein the injection nozzles are coupled in series and supplied with lubricating oil from a pump unit.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with reference to the following figures, wherein like designations denote like members, wherein:

(2) FIG. 1 illustrates a first embodiment of an injection nozzle according to the invention, including a nozzle rod with a valve seat boring and a valve body displaceable therein, and where lubricating oil is conducted to a turned recess in the valve body via ducts formed by bevelled sides on the valve body, and where possible leak oil is conducted into the cylinder;

(3) FIG. 2 is a detail of the injection nozzle shown in FIG. 1, where focus is on the front part of the injection nozzle;

(4) FIG. 3 illustrates an alternative embodiment of the injection nozzle where the lubricating oil is conducted to the turned recess via ducts in the nozzle rod;

(5) FIG. 4 illustrates an alternative embodiment of the injection nozzle where the lubricating oil is conducted to the turned recess via cutouts in the nozzle seat boring;

(6) FIG. 5 illustrates a second embodiment of an injection nozzle where possible leak oil is returned to an oil reservoir;

(7) FIG. 6 shows a partial section through an injection nozzle with adjustable stop for the valve body;

(8) FIGS. 7-9 show schematic views of an injection nozzle.

(9) FIG. 10 shows a curve for illustrating pressure conditions in an injector;

(10) FIG. 11 shows a schematic view of a lubricating oil system in which is used injection nozzles coupled in parallel; and

(11) FIG. 12 is a view corresponding to FIG. 11, but illustrating a lubricating oil system with serially coupled injection nozzles.

DETAILED DESCRIPTION

(12) FIG. 1 shows an embodiment of the injection nozzle where possible leak oil is conducted into the cylinder. The injection nozzle includes a nozzle rod divided into an inner part 1 which contains a valve body 3 and an outer part extending through a cylinder wall 102 (see FIG. 11) and formed by an inner tube 5 and an outer tube 6. Alternatively, the nozzle rod can be made in one piece.

(13) On FIG. 1 the following components are seen:

(14) 101—injection nozzle

(15) 1—nozzle rod

(16) 2—spring

(17) 3—valve body

(18) 3a, 3b—cylindrical sealing face on valve body

(19) 4—stop for valve body

(20) 4a—passage through stop 4

(21) 5—inner tube

(22) 6—outer tube

(23) 7—mounting flange

(24) 8—oil supply flange

(25) 9—screws for fastening oil supply flange

(26) 10—threaded hole for oil supply union

(27) 11—head of valve body 3

(28) 20—bevelled sides of valve body for forming a pressurised oil supply duct

(29) 21—valve seat boring interacting with valve body sealing faces 3a, 3b

(30) 20a—pressurised oil supply ducts formed by bevelled sides 20 and the valve seat boring 21

(31) 22—cavity for innermost end of reciprocating valve body

(32) 22a—opening from cavity into cylinder

(33) 23—turned recess for oil supply

(34) 24—edge/transition between sealing face and turned recess

(35) 25—nozzle outlet

(36) 26—duct for supplying lubricating oil to pressure chamber

(37) 27—pressure chamber

(38) 28—annular chamber formed by turned recess 23 and valve seat boring 21

(39) 29—one or more spray(s)/jet(s) (through one or more nozzle outlets)

(40) The injection nozzle 101 operates in that a dose of pressurised lubricating oil is delivered through the union 10 and on down in the duct 26 and the pressure chamber 27. A pressure build-up occurs in the duct 26 and in the pressure chamber 27 as the valve seat boring 21 acts as a sealing face interacting with the sealing faces 3a and 3b of the valve body. Displacement of the valve body 3 only takes place when the pressure in the lubricating oil exerts a force which is large enough to overcome the force from the spring 2. The head 11 will hereby leave the stop 4 such that the oil flows into the pressure chamber 27. The oil also flows through the pressurised oil supply ducts 20a.

(41) The interaction between the sealing faces and the valve seat boring ensures that the pressurised oil can only be delivered out through the nozzle outlet 25 when the valve body 3 is pressed so far to the right in FIG. 1 that the front edge 24 of the turned recess 23 passes the nozzle outlet 25 so that communication is formed between the annular chamber 28 and the nozzle outlet 25.

(42) After the first filling of the duct 26, the pressure chamber 27 and the pressurised oil supply duct 20a with oil, there are established pressure conditions so that the head 11 is not moved so far back as to establish contact against the stop between successive oil injections.

(43) FIG. 2 shows the foremost part of the injection nozzle 101 shown in FIG. 1. In this embodiment, possible leak oil will be conducted into the cylinder itself as pressurised lubricating oil possibly passing by the sealing face 3b and into the cavity 22 will flow out of the opening 22a.

(44) The function is as follows: a) Pressurised lubricating oil is conducted to the duct 26 via the union 10. b) The lubricating oil is conducted through the passage 4a in the stop 4 and into the pressure chamber 27 past the spring 2. The pressurised oil is conducted via the two pressurised oil supply ducts 20a down to the annular chamber 28. c) The pressurised oil acts on the active area of the valve body 3 which is the difference between the largest area of the valve body minus the core area of the valve body. The core area is defined by the diameter of the turned recess 23. d) When the force exerted by the pressure in the lubricating oil is sufficiently large to surmount the force from the spring 2, the valve body 3 is pressed to the right. e) When the valve body 3 is displaced sufficiently to the right such that the front edge 24 of the turned recess 23 is aligned with the nozzle outlet 25, the pressurised oil can be delivered freely through the nozzle outlet. No dead volume will appear between the annular chamber and the nozzle outlet. The pressure in the annular chamber 28 will thus be maintained in the lubricating oil when the latter is delivered through the nozzle outlet 25.

(45) The injection nozzle is typically supplied with oil at a pressure of 30-70 bar which is also the pressure at which the valve is opened. The opening pressure of this injection nozzle is determined by the compression of the spring 2. By this embodiment, this compression of the spring 2 is not adjustable but is given by the spring characteristic and the geometry of the stop 4 and the nozzle rod 1. These two determine how great force is needed for the spring 2 to be compressed enough in order to open for passage of the lubricating oil from the annular chamber 28 to the nozzle outlet 25.

(46) Each injection nozzle 101 can have two or more nozzle outlets 25.

(47) FIG. 3 is a view corresponding to FIG. 2, though illustrating a second embodiment of an injection nozzle 101a. This embodiment differs from the one described above by a different design of the pressurised oil supply ducts 62. The pressurised lubricating oil is supplied to the annular chamber 28 from the pressure chamber 27 around the valve body 67 and the spring 2 via the pressurised oil supply ducts 62 formed as borings in the wall of the nozzle rod. The bevellings 20 in the valve body 3 can hereby be omitted. By this embodiment, the head 11a of the valve body 3 is cylindrical with flat end face for contact against the stop 4 (not shown in FIG. 3).

(48) The other elements and functions will be as described for the injection nozzle shown in FIGS. 1 and 2.

(49) FIG. 4 is a view corresponding to FIG. 2, but illustrating a third embodiment of an injection nozzle 101b. This embodiment differs from the above description by a different design of the pressurised oil supply ducts 66 which are here formed by the nozzle rod 1 in the cylindrical valve seat boring 21 having at least one longitudinal groove 67, which together with the cylindrical sealing face 3a of the valve body form pressurised oil supply ducts 66 connecting the pressure chamber 27 with the annular chamber 28.

(50) FIG. 5 shows a fourth embodiment of an injection nozzle 101c. In this embodiment, a dose of pressurised lubricating oil is delivered through the union 10 and on into the duct 26 and the pressure chamber 27. The valve body 3 is pressed in direction towards the nozzle outlet when the force from the oil pressure is large enough to surmount the force from the spring 2. This part of the injection nozzle operates in the same way as the injection nozzle shown in FIGS. 1a and 1b.

(51) The difference from the first embodiment is that this injection nozzle does not conduct possible leak oil from the sealing face 21 into the cylinder, but collects this leak oil in a cavity 45 formed in front of the valve body 3 as the cavity is closed at the end. The leak oil is conducted from the cavity 45 through the valve body 41 via the opening 44 and through the ducts 43 and 42. From here, the oil is conducted via one or more ducts 40 out through the side of the nozzle rod 1. Cavities/ducts 39 and 38 ensure that the leak oil can be conducted to the head of the injection nozzle. The oil is conducted from the duct 38 to a cavity 36 and through a passage 37 into a turned recess/cavity 35 around an inner separating element 46 (separating pressurised oil from leak oil). From this point the oil is conducted through a passage 34 in an outer separator element 47 to the discharge union 31 for leak oil via the ducts 33 and 32.

(52) FIG. 6 shows a fifth embodiment of the injection nozzle 101d. In this embodiment, the opening pressure for the injection nozzle is adjustable. The nozzle rod 1 and the stop 4 are designed according to the same principle as the corresponding elements in the embodiments with “fixed” and predefined opening pressure. But in this embodiment, the compression of the spring 2 can be adjusted steplessly in that the valve body 51 has a screw thread 51a at one end. An adjusting nut 50 can be screwed on this thread. The spring compression can hereby be changed by adjusting/rotating the adjusting nut 50. Hereby is achieved an embodiment enabling uniformity in the spring compression without need for applying very fine tolerances (under 5/100 mm) on the components involved. At the same time, this embodiment is also advantageous in that there is no need for the spring to meet very strict requirements.

(53) FIGS. 7, 8 and 9 show the most important operating positions of the injection nozzle.

(54) FIG. 9 shows the injection nozzle with the lubricating oil 52 in unpressurised condition. The valve body 3 is disposed farthest from the nozzle outlet 25 under the action of the force from the spring 2. At this position, the sealing surface 23 is not in contact with the nozzle outlet 25. The valve body 3 rests on the stop 4 in this position.

(55) FIG. 8 shows the injector with pressurised lubricating oil 52, but in rest position, in which it remains until the lubricating oil pressure amounts to a size that can surmount the spring force In this position, the front edge 24 of the turned recess 23 is disposed such that there is no passage between the nozzle outlet 25 and the annular chamber 28. The lubricating oil is still. However, a minor leak can occur across the sealing face 21.

(56) FIG. 7 shows the injection nozzle with pressurised lubricating oil 52 where the pressure in the lubricating oil is at a level surmounting the spring force. In this position, pressurised lubricating oil flows from the annular chamber 28 out through the nozzle outlet 25. There is only a limited risk of leaking in this position since the oil will mostly pass through the nozzle outlet 25. From this point, the lubricating oil will be delivered either in atomised form or as a jet, depending on nozzle geometry, viscosity, flow conditions, pressure etc.

(57) FIG. 10 is a curve showing an example of how the lubricating oil pressure varies during an injection with an injection nozzle according to embodiments of the present invention. On the Figure there is an area HP called “holding pressure”. This corresponds to the position of the injection nozzle in FIG. 8 where the oil is pressurised, but where no lubricating oil is delivered through the nozzle outlet 25. Here it can be seen that there is a certain leakage of lubricating oil until the dosing of a portion of pressurised lubricating oil when opening for delivery of pressurised lubricating oil through the nozzle outlet. Depending on the design of the injection nozzle, there may thus occur a small and marginal leaking of lubricating oil which may cause a loss of pressure between successive activations and consequently a pressure drop between the activations. This can be seen on the curve by the occurrence of a rise in pressure from about 40 bar to 52 bar. This part of the pressure curve corresponds to the position of the injection nozzle in FIG. 7 where pressurised lubricating oil is delivered directly through the nozzle outlet 25.

(58) FIG. 11 shows a traditional system with a number of valves 101 coupled in parallel and located in a cylinder wall 102. The injection nozzles 101 are mounted in mounting holes 127 which are oriented radially in the cylinder wall in this embodiment.

(59) The injection nozzles 101 are via hydraulic pipes or via flexible oil hoses 103 connected with a lubricating apparatus 104 which includes individual pump units for respective injection nozzles 101 and is connected with an oil tank 105.

(60) At one end, each injection nozzle 101 has a nozzle outlet 106 disposed in the cylinder wall immediately within the inner surface of the cylinder wall 102. Through the nozzle outlet 106, the oil is atomised/jetted when the pressure in the oil pipe 103 reaches a predetermined level.

(61) At the parts provided outside the cylinder wall 102, the injection nozzles are connected with hydraulic pipes or with flexible return hoses/pipes 107 for oil to be returned to the oil tank 105.

(62) The injection nozzles are discharging an oil mist or injection jet 108 transversely to the valve stem, covering an area 109 of the cylinder wall against which the oil mist/oil delivery is directed.

(63) As lubricating apparatus 104 various pumping apparatuses can be applied, possibly using conventional lubricating apparatuses powered by the chain drive of the motor or hydraulic lubricating apparatuses that are electrically controlled. The pump units of the lubricating apparatus are to dose and pressurise in a way such that the oil pressure surmounts the force from the spring incorporated in the injection nozzle.

(64) In FIG. 11 is shown an embodiment where the injection nozzles 101 are supplied via each their oil pipe 103 by individual pump units in a lubricating apparatus 104. Such a lubricating apparatus 104 will have several pump units, each feeding one injection nozzle 101; in large engines there will typically be a system where injection nozzles in a cylinder is lubricated by one lubricating apparatus 104.

(65) FIG. 12 shows a lubricating oil system with a number of serially coupled injection nozzles 101 provided in a cylinder wall 102. By this system, the injection nozzles 101 are coupled in series and supplied by one pump unit in a lubricating apparatus 104′ whereby piping is simplified appreciably. Thereby only one oil pipe 103′ is used for supplying oil to the injection nozzles 101. Similar to the system shown in FIG. 11, the injection nozzles 101 are connected by hydraulic pipes or by flexible return hoses/pipes 107 for oil to be returned to the oil tank 105.

(66) In this system it is required that the supply pressure is carefully set as identical for the coupled injection nozzles 101 since the supplied amounts otherwise can vary too much. Other conditions greatly influence the variation of the supplied portions (disposition of pipes, pipe length, etc.) as well, though the supply pressure is the most important condition.

(67) The injection nozzles do not have any valve seat such as known from traditional injection nozzles, which can change in character over time due to the influence of wear/dirt/etc. These are parameters that will influence opening conditions for the valve of the injection nozzle. This means that an injection nozzle according to embodiments of the present invention will have more uniform, operationally reliable, robust and continuous (over time) injection portions.

(68) Although the present invention has been disclosed in the form of preferred embodiments and variations thereon, it will be understood that numerous additional modifications and variations could be made thereto without departing from the scope of the invention.

(69) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements. The mention of a “unit” or a “module” does not preclude the use of more than one unit or module.