DE1272637B - Control device for gas turbine jet engines - Google Patents

Description

Control Apparatus for Gas Turbine Jet Engines The invention relates to a control device for gas turbine jet engines with afterburning device and variable thrust nozzle cross-section, in which the feed of the afterburning fuel is initiated with a manually operated control device and the nozzle cross-section can only be increased after ignition of the afterburning fuel.

In a known control device of the specified type is used for Initiation of the afterburning first of all the feeding in of the afterburning fuel initiated with a manually operated control device. After the automatic Ignition of the afterburning fuel is produced as a result of the exhaust nozzle Change in pressure an actuator switched on, the thrust nozzle cross-section increased from a normal value to a predetermined larger value.

In this known control device, the one with the afterburning generated thrust is not changed by the pilot, but only switched on or off will. If, on the other hand, you want a finer adjustment option for afterburning have generated thrust, so result in modern gas turbine jet engines certain difficulties arising from the fact that such modern engines operated near their maximum power close to the surge line of the engine will. Therefore, the fuel supply must depend on the operating conditions of the engine can be metered very precisely, even when going into operation passes with afterburning. When operating with post-combustion, the nozzle cross-section must be increased as much as possible that the pressure at the turbine outlet remains unchanged remain; both excessive pressure drops and, in particular, pressure increases easily cause the machine to get into the pumping area.

The present invention is therefore based on the object of a control device of the type specified at the beginning, in which a largely constant change of the additional thrust generated with the afterburning is possible and yet it is ensured in a simple and reliable manner that the nozzle cross-section can only be increased after ignition of the afterburning fuel.

According to the invention, the object is achieved in that a mechanical locking device is provided, which increases the thrust nozzle cross-section prevents a continued response to the ignition of the afterburning fuel Device for switching off the locking device is provided and that the nozzle cross-section via a lost motion device and a preloaded spring from the manually operated one Adjusting device is adjustable, with a movement of the manually operated adjusting device in the sense of an enlargement of the nozzle cross-section with the locking device switched on recorded by the lost motion device and with the locking device switched off is passed on by the force of the spring.

In the case of the control device according to the invention, there is therefore fundamentally a certain relationship between the setting of the manual actuator and the nozzle cross-section. However, the nozzle cross-section can only affect the Set the size specified by the manually operated setting device when the locking device is turned off as a result of the ignition of the afterburning fuel. As long as that is not is the case, the actuating movement of the manually operated actuating device is controlled by the Backlash device added, and the nozzle cross-section remains unchanged; as soon as however, after the fuel has been ignited, the locking device is activated solved, and the selected setting of the manually operated actuator can be by the action of the pretensioned spring on the nozzle cross-section adjusting device transfer. According to the invention, with very simple mechanical means in extremely the desired combination of continuous adjustment in a reliable manner of Post-combustion surge and avoidance of undesired operating conditions achieved.

In a further embodiment of the invention is with an engine several afterburners, which can be put into operation one after the other in order to increase thrust are provided that the nozzle flaps at different sizes of the thrust nozzle cross-section can be locked by the locking device and these locks are successive upon ignition Sets of burners are solvable one after the other.

Further features of the invention emerge from the subclaims.

The invention is illustrated below with reference to one in the drawings Embodiment described in more detail.

FIGS. 1 to 9 are schematic representations of the individual parts the device according to the invention; F i g. 10 shows the relationship between the F i g.1 to 9 parts shown.

The gas turbine jet engine cooperating with the control device is denoted by 1 in the figures. This engine can be known in any Be carried out in a manner; for convenience and simplicity of description it is assumed that the engine is of the simplest design and has a compressor and a turbine arranged on the same shaft and between the compressor and the turbine Contains combustion chambers. The invention is equally applicable to more complicated engines, z. B. turbofan engines, applicable. There are three in the nozzle 2 for afterburning Burner sets 3, 4, 5 provided. From these burner sets, fuel can be poured into the Thrust nozzle are sprayed in order to heat the turbine exhaust gases and thus the thrust of the Increase engine. To ensure that the To ensure the engine, the nozzle outlet cross-section is by means of two flaps 6 and 7 adjustable; these are mounted on pivot pins 8 and 9. The adjustment device for the flaps each consists of an angle lever 11 rotatably mounted at 12, one Member 13, which is articulated with one end of the angle lever with the associated flap connects, and a servo cylinder 14 with a servo piston 15, one of which is a piston rod 16 goes out, which by means of a pin-and-slot connection 17 to the other end of the Angle lever 11 is coupled. The adjustment devices for the flaps are such connected together so that the flaps move together. Two hydraulic lines 18 and 19 each lead to one of the two servo cylinders 14 to adjust the flap bring about. All cylinders 14 are hydraulically connected in parallel. On the piston rod 16 a lever 21 is attached to the movement of the flaps to other parts of the Control device transmits.

To control the supply of hydraulic fluid to the servo cylinders 14, a hydraulic pump 22 (FIG. 7) is provided which contains a return valve 23 connected in parallel. The pump 22 is driven by a motor. The return valve 23 ensures that the fluid for actuating the servo cylinder 14 is available under constant pressure. The pump 22 conveys via a pipe 24 to a servo valve 25. This consists of a fixed cylinder 26 in which a valve slide 27 with several webs 28, 29 and 31 is provided. The slide 27 cooperates with five openings 32, 33, 34, 35 and 36 in the wall of the cylinder 26. The delivery line 24 from the pump 22 ends in the opening 34, and the flow of liquid is controlled by the web 29. Lines 18 and 19 are connected to openings 33 and 35, respectively. The openings 32 and 36 are connected in parallel to a line 37 in order to convey liquid back to the pump 22 under low pressure.

At the two ends of the slide 27 there are springs 38 which hold the slide press to a middle position. The position of the slide 27 is through the Influenced pressures that prevail at the two ends of the cylinder 26 and over the Lines 39 and 41 are fed.

The lines 39 and 41 go from a control valve 42 (Fig. 6) the end. This valve consists of a cylinder 43, a sleeve 44 which is inside of the cylinder 43 is slidable, and a slide 45 that slides in the sleeve 44. The slide 45 has three webs 46, 47 and 48. There are five in the wall of the cylinder 43 Openings 49, 51, 52, 53 and 54 arranged. These openings correspond to openings 55, 56, 57, 58 and 59 in the sleeve. Within the range of motion of the sleeve 44 the openings in the sleeve can only be matched with the associated openings in the cylinder 43 get in touch. This fact is not apparent from the drawing which not to scale to reduce overall size. The sleeve 44 is through a single-piece with her upright piston 61 adjustable in the longitudinal direction. This piston is located in an adjusting cylinder 62, which operates on the principle of the nozzle flapper control is working. For this purpose, the end of the cylinder 62 adjacent to the sleeve 44 is used through the pipe 63 with liquid under the pressure of the delivery line 24 of the pump 22 fed. The end of the cylinder 62 remote from the sleeve 44 is of the line 63 is fed via a throttle 64. A small diameter extension 65 protrudes sealed from the end of the cylinder 62 remote from the sleeve 44. In this Approach is a channel 66. The end 67 of the approach 65 works with one Cams 68 together. When the end 67 of the lug 65 from the surface of the cam 68 is spaced, the channel 66 is open, whereby the pressure below the piston 61 is decreased. Then the higher pressure above the piston 61 pushes it down on the cam 68 until the end 67 almost touches the surface of the cam 68. In this position, the leakage current through channel 66 is reduced. The movement of the piston 61 comes to a standstill when the leakage flow through the channel 66 goes so far has decreased that the pressure below the piston corresponds to the higher pressure above the Piston, taking into account the different effective areas, the equilibrium holds.

The cam 68 is activated by the movement of a feedback member 71 rotated, which proceeds from the feedback lever 21 on the exhaust nozzle. The movement of the link 71 is set on the cam 68 by a reversing lever 72 and a link 73 transfer.

The slide 45 of the valve 42 is rotatably connected at 74 to a lever 75 which has a fixed pivot point 76. A piston 77 sliding in guides 78 is connected to the lever 75 via a pin 79. The piston 77 in turn is connected to a levitation lever 82 by an articulation connection 81. The end of the lever 82 opposite the articulation connection 81 is connected by a pin 83 to a member 84 which ends in a pin 85 which engages in a control cam 86 of a turntable 87. The plate 87 is rotatably mounted in a fixed position and can be adjusted by turning a hand lever 88 of the pilot. This hand lever is used by the pilot to adjust the additional thrust generated by the afterburning. The parts 84 to 88 form a hand-operated adjusting device for the thrust nozzle cross-section. The central fulcrum 89 of the lever 82 is - as seen in the drawings (FIG. 6) - pressed downwards against an end plate 92 carried by a rod 93 by means of a piston 91 which is pressed downwards by a pretensioned spring will. The parts 89, 91 form a lost motion device. The rod 93 slides in guides 94 and has two cam followers 95 and 96 which engage cams 97 and 98, respectively. The cam disk 97 is firmly connected to a shaft 99 which rests in bearings 101 and 103. The cam disk 98 is connected to the shaft 99 via a lost motion connection 104 composed of a pin and slot and a spiral spring 105. The shaft 99 is connected to the member 71 by means of a rotary connection (not shown), the rotation of the shaft 99 being proportional to the feedback movement of the feedback lever 21 . The cam disk 97 has four constant zones with different radii at 100, 106, 107 and 108. These constant zones are interconnected by the slopes 102, 109 and 111, so that the rotation of the cam causes the plunger 95 to move upwards. The cam disk 98 also has four zones 110, 112, 113, 114, the radii of which are equal to the zones 100, 106, 107 and 108 of the cam disk 97, respectively. In the case of the cam disk 98, the zones are separated from one another by radial steps.

The activation of the fuel supply to the burner sets 3, 4 and 5 is controlled by three control openings 115, 116 and 117, respectively. These openings include locking elements 118 or 119 or 121 with fixed pivot points 122 or 123 or 124. A spring-loaded bolt 125, 126 or 127 cooperates with each of the locking elements, the task of the locking elements being to hold the locking elements either in a completely closed or completely open position with respect to their control openings. Each closing element has a nose 128 or 129 or 131, which can interact with one of three cross bars 132, 133 and 134 that are slidably arranged in the bar 93 in the transverse direction. The distance between the cross bars 132, 133 and 134 is slightly larger than the distance between the noses 128, 129 and 131, so that the cross bars 132, 133 and 134 come into contact with the noses 128, 129 and 131 one after the other within a short axial movement of the bar 93. The transverse rods 132, 133 and 134 are each pressed to the right in the sense of the drawing by a spring 135 which extends from the rod 93 and engages a flat surface of the transverse rod.

Each of the cross bars 132, 133 and 134 has a head 136 which is in engagement with a bar 137 which is arranged parallel to the bar 93. The rod 137 is held by a piston rod 138 attached to a servo piston 139. The servo piston 139 is located within a servo cylinder 141 and, under the action of hydraulic pressure, can perform a small movement that is only sufficient to move the rod 137 transversely and thereby move the three transverse rods 132, 133 and 134 simultaneously from the three lugs 128, 129, 131 move away. The cylinder 141 is fed with pressure from the line 63 at its end on the left in the sense of the figure. The effective area of the piston 139 on the left is reduced by a piston rod 142 that extends to the left end of the cylinder 141 . The right end of the cylinder 141 is fed from a line 143 with hydraulic pressure. The effective area on the right side of the piston 139 is greater than the effective area on the left side, due to the relatively small diameter of the piston rod 138 exiting on the right, so that the piston 139 moves to the left when the pressure in the line 143 is the same as that in line 63.

The piston 77 extends through a chamber 144 between the guides 78, and the piston rod 142 extends into this chamber with a direction of movement transverse to that of the piston 77. The piston 77 contains three spaced apart grooves 145, 146 and 147, the upper portions of which are perpendicular to the direction of movement of the piston 77 and the lower portions thereof extend obliquely to the direction of movement of the piston 77. A spring-loaded pawl 148 can snap into each of the grooves 145, 146, 147 at right angles to the direction of movement of the piston 77. The upper edge of the pawl 148 in the drawing runs at right angles to the direction of movement of the piston 77, while the lower edge runs obliquely to it. The arrangement is such that the pawl blocks a movement of the piston 77 in the downward direction when it enters one of the grooves 145, 146 and 147, but permits it in the upward direction. An extension 149 of the piston rod 142 is arranged so that when the piston 139 moves to the left, the pawl 148 is tensioned and pushed back out of the groove 145, 146 and 147 into which it was approximately locked.

The computer 151 (FIG. 5) represents the device which responds to the ratio of the pressures at the inlet and outlet of the turbine of the engine. A chamber 152 is arranged in the computer 151, in which two bellows 153 and 154 are attached to opposite walls. Their free ends are connected by a rod 155. A lever 156 is hinged within the chamber to a fixed pin 157, extends between the bellows 153 and 154, and is attached to the rod 155 by a pin 158. The bellows 153 is evacuated and the bellows 154 is connected to a small chamber 161 via a duct 159. The bellows 153 and 154 have exactly the same cross-sectional area so that the force exerted on the pin 158 on the lever 156 is exactly proportional to the pressure in the bellows 154.

At the opposite end of the lever 156 are two bellows 162 and 163 which are attached to the opposite walls of the chamber 151. The free ends of these bellows are connected by a rod 164 which is hinged to the lever 156 by a pin 165. The bellows 162 is evacuated and the bellows 163 is connected by a line 166 to the turbine outlet. The bellows 162 and 163 have the same cross-sectional areas, so that a force is exerted on the lever 156 at the pin 165, which is exactly proportional to the turbine output pressure. The forces exerted on pins 158 and 165 act in opposite directions.

A servo cylinder 167 located laterally of chamber 152 contains a sliding servo piston 168. From piston 168, piston rods 169 and 171 extend in opposite directions through the ends of cylinder 167; suitable seals are provided to prevent leaks. Liquid supplied under pressure by the pump 22 is fed through the line 63 to the relevant ends of the cylinder 167 through the two throttles 172 and 173, respectively. The channels 174 and 175 run from the two ends of the cylinder 167 to two oppositely directed control openings 176 and 177 which are arranged on opposite sides of the lever 156. The relative flow resistances in the openings 176 and 177 determine the pressure losses occurring at the throttles 172 and 173 and the pressures that exist on both sides of the cylinder 167. Only in one particular position of the lever 156 are the pressures in both ends of the cylinder 167 equal, and movement of the lever 156 in one or the other direction from this particular position causes the piston 168 to move in one direction or the other. The end 178 of the piston rod 179 is conical and enters the chamber 161 through an opening 179. A duct 181 leads to opening 179. A line 182 directs air from the outlet of the engine compressor into duct 181. The air which has passed through opening 179 enters chamber 161, from which it flows through a throttle 183 into a low pressure zone can, such as B. the fuselage. The throttle 183 is designed so that it works in a throttled state under all operating conditions of the engine, ie the "dimensionless" speed value through the throttle, formed by the product of the mass flow per unit of time Q and the square root of the absolute temperature T divided by the product from the square of the clear throttle diameter d and the pressure P in front of the throttle is constant and independent of the pressure prevailing in the chamber 161. The free cross-section of the opening 179 is created by axial movement. the piston rod 169 is set. At any position of the piston rod 169, the pressure in the chamber 161 is a constant fraction of the compressor output pressure, regardless of the change in such pressure. The movement of the piston rod 169 changes the fraction of the compressor output pressure in the chamber 161.

The piston rod 171 extends into a chamber 184, the part of the rod located within the chamber 184 being provided with a flattened surface 185 which runs parallel to the axis of the piston rod 171. Within the supporting structure 186 between the cylinder 167 and the chamber 184, two annular grooves 187 and 188 running around the piston rod 171 are arranged, with channels 189 and 191 inside the piston rod 171-. work together. These. Channels end as control openings 192 and 193 in the flat surface 185. In the vicinity of the flat surface 185, a cam disk 194 is rotatably mounted on an axle 195. The cam 194 has a flat side that moves in close proximity to the flat surface 185. The axis of rotation is perpendicular to the flat surface 185, so that the distance between the cam disk and the flat surface 185 remains constant. The control opening 192 cooperates with the curved profile 196 of the cam 194 so that the opening is either open, partially open or substantially closed depending on the relative positions of the rod 171 and the profile 196. The control opening 192 is fed with hydraulic fluid from the line 63 via a throttle 197 and a channel 198. The channel 198 extends to one side of the servo cylinder 199, which contains a servo piston 201. The other side of the cylinder 199 receives pressurized fluid directly from the line 63. A piston rod 202 passes through the end of the cylinder 199 in a sealed manner, which receives pressurized fluid directly from the line 63, thereby creating a difference in the effective areas on the two sides of the piston 201 The piston 201 therefore moves over the control opening 192 depending on the closed position of the cam profile 196. The piston rod 202 is connected to a rod 203 which is used to regulate the fuel supply to the afterburner sets 3, 4 and 5.

The cam disk 194 is rotated by means of a pinion 204 which is attached to the disk axis 195 and meshes with a toothed rack 205 . The rack is attached to a piston 206 which slides in a cylinder 207. The hydraulic pressure applied to one side or the other of the cylinder 207 to control the movement of the piston 206 is determined by an electro-hydraulic valve 208 of conventional design. This valve is connected via an electrical line 209 to an electrical temperature sensor at the inlet of the compressor. This temperature sensor can only work slowly.

The afterburning fuel is supplied to the burners 3, 4 and 5 by a centrifugal pump 511 (FIG. 3). Within the pump housing 512, a jacketed impeller 513 is driven by a drive shaft 514 mounted in the housing. The drive shaft 514 extends from the gas turbine. The housing 512 is provided with a conventional spiral that terminates in an exit channel 215. Liquid fuel enters the center of the pump impeller 513 through a multiplicity of radial openings 516 formed in a cylindrical sleeve 517. The fuel enters the sleeve through passage 518 under boost pressure. The end of the sleeve 517 remote from the pump is closed by a wall 519 through which a piston rod 521 passes in a sealed manner. On the opposite side of the wall 519 an adjusting cylinder 522 is arranged, in which an adjusting piston 523 with the piston rod 521 is accommodated in a sliding manner. Inside the sleeve 517, the piston rod 521 carries a sliding sleeve 524 which fits tightly in the sleeve 517. The adjustment movement of the rod 521 causes the sliding sleeve 524 to change the free cross section of the openings 516. The sleeve 524 can be moved by the piston 523 so that the openings 516 are completely closed.

For the purpose of adjusting piston 523 and sleeve 524, high pressure fuel from the main fuel system is supplied through line 525 to the end of cylinder 522 that is closer to pump rotor 513. The side of cylinder 522 remote from pump rotor 513 is fed high pressure fuel from line 525 through a throttle 526. From the side of the cylinder 522 remote from the rotor 513, a pipe 527 goes to a control opening 228 of a nozzle flapper control 229 (FIG. 9). The fuel flow escaping from the opening 228 determines the pressure drop across the throttle 526 and thus the pressure in the end of the cylinder 522 remote from the rotor 513. At the other end of the cylinder 522, the full fuel pressure acts, but on a small area of the piston 523 Adjustment of the control opening 228 therefore determines the position of the piston 523 in the cylinder 522 and the free cross section of the openings 516. The speed of the pump rotor 513 and its size are designed so that the fuel within the pump housing 512 becomes one in the range of the regulated flow rates of the fuel Forms ring, the radial depth of which determines the discharge pressure of the liquid. The center of this ring is completely isolated from the atmosphere so that the pressure within the ring is the vapor pressure of the fuel. The fuel is fed to input 51.8 under the boost pressure of the aircraft. This is a relatively low pressure, but it is sufficient to operate the various fuel pumps. The pressure drop of the fuel at the openings 516 is approximately equal to the boost pressure, since the fuel vapor pressure is normally quite small, so that the fuel supply to the pump is determined by the free cross section of the openings 516. The radial depth of the fuel ring within the pump housing 512 is automatically adjusted depending on the flow rate of the liquid entering the rotor 513. This ensures that the flow takes place under a pressure which is sufficient for the flow through the supply channel 215.

A shut-off valve is used to shut off the fuel supply to the pump 511 531 provided. The channel 518 starts from a chamber 532 in the valve 531. The fuel enters chamber 532 through entrance port 533. Inside the chamber 532, a valve body 534 can lie on a seat 535, so that the flow is blocked from the opening 533 in the channel 518. Closes to chamber 532 An actuating cylinder 536, which contains an actuating piston 537, adjoins. From the piston a piston rod 538 passes into the chamber sealed by one end of the cylinder 536 532, and within chamber 532, valve 534 is attached to piston rod 538. A spring 539 is provided in the cylinder 536, which pushes the piston in the closing direction of the valve body 534 pushes. The end of the cylinder 536 that contains the spring 539, is connected by a pipe 541 to the chamber 532, which is below the low Boost pressure of the aircraft is. Pressurized fuel is released from the line 525 through the throttle 542 into the end of the cylinder 536 adjacent to the chamber 532 directed. From this end of the cylinder 536 a pipe 376 leads to the control port 117 (Fig. 6).

The fuel in supply line 215 (Fig. 9) flows through a flow regulator 216 before entering a line 217 leading to the first set of afterburner. The regulator 216 includes a cylinder 218 in which a sleeve 219 slides. The line 215 ends in an opening 221 in the wall of the cylinder 218. The fuel outflow takes place through an opening 222 which is provided in the wall of the cylinder 218 and which leads to the line 217. A plurality of openings 223 are provided in the sleeve 219, which more or less cover the opening 222 and thereby determine a throttle cross section for the fuel entering the channel 217. The sleeve 219 can be adjusted in the axial direction by means of a piston 224 which slides in an adjusting cylinder 225. A piston rod 226 connects the piston 224 to the sleeve 219 and passes through one end of the cylinder 225 in a sealed manner. Another piston rod 227 passes through the other end of the cylinder 225 in a sealed manner and carries a spring end cap 240 against which a compression spring 230 presses. The spring 230 and the end cap 240 are arranged in a chamber 231 which is formed within the system part containing the cylinder 218. A lever 232 is rotatably mounted on a pin 233 within the chamber 231. The compression spring 230 acts on one end of the lever 232. At the other end of the lever 232, two bellows 234 and 235 are attached to opposite walls of the chamber 231. The free ends of these bellows are moved by a rod 236 which is connected to the lever 232 by a pivot pin 237. The bellows 234 is evacuated and the bellows 235 is connected to a line 238 to receive a control pressure proportional to the compressor output pressure. The actuating piston 224 is actuated by pressurized fuel from the main fuel system which is supplied through line 525. Pressurized fuel is supplied to the two ends of the cylinder 225 through two throttles 239 and 241. Two channels lead from the two ends of the cylinder 225 to two control openings 244 and 245, one of which is arranged on each side of the lever 232. The position of the lever 232 between the openings 244 and 245 determines the ratio of the leakage currents from these openings and thereby the relative values of the reduced pressure in the two ends of the cylinder 225. The piston 224 reaches an equilibrium position when the spring 230 on the The load acting on the lever 232 compensates for the load exerted on the bellows 235 by the pressure applied via the line 238. When the pressure in the line 238 increases, the openings 223 coincide more and more with the opening 222, as a result of which more fuel can flow through the line 217 to the first afterburner set.

In order to accurately determine the flow through regulator 216, there are devices provided to keep the pressure drop across ports 222 and 223 at a fixed, constant Worth holding. A nozzle flapper control 229 is provided for this purpose. It contains a body that surrounds a pair of separate chambers 246 and 247. A pivotable Lever 248 extends through a sealed hole 249 in the wall between the two chambers 246 and 247; the sealing of the hole takes place by means of a metal membrane. The pivot 251 of the lever 248 is in the Hole arranged. In the chamber 248 a bellows 252 is provided in which a compression spring 253 is attached, which via a pivot 254 a certain load on the Lever 248 exercises. The interior of the bellows 252 is through a conduit 255 with the Port 222 connected to take the pressure on the downstream side of the throttle. The chamber 246 is connected to the fuel pressure line 215 via a line 256. The pressure drop across the bellows 252 is that of the overlapping openings 222 and 223 occurs. Within the chamber 247 opens an opening 228, the more effective Cross-section controlled by a hemispherical valve 257 carried by the lever 248 will. If the pressure drop increases at the overlapping openings 222 and 223, so the bellows 252 contracts and moves the lever 248 so that the Hemisphere 257 places on opening 228. This way, an increase in the Flow rate the outflow at the opening 228 in the pump rotor 513 facing away End of the cylinder 222 so that the pressure rises and the sleeve 524 through the piston 523 is moved so that the effective cross section of the openings 516 is reduced.

The fuel supply to the second afterburner set is regulated by a flow regulator 258 (FIG. 4). A branch line 259 of the supply line 215 enters an opening 261 in the wall of a cylinder 262. This opening is relatively long in the axial direction and has a straight delimiting edge 263 parallel to the axis of the cylinder 262. An opening 264 in the wall of the cylinder 262 is connected to a line 265 which conducts fuel from the valve 258 to the second burner set. A sleeve 266, the ends of which are closed, is provided within the cylinder 262. At the right end of the cylinder 262 - as can be seen from the drawing - the sleeve 266 is provided with a pinion 267 which is in engagement with a rack 268. The rack is attached to a piston rod 269, which passes through the wall of the cylinder 262 in a sealed manner and extends into an actuating cylinder 271 which is arranged transversely to the cylinder 262. A piston 272 is attached to the piston rod 269 in the cylinder 271. From the other end of the piston 272, a rod 273 extends into a chamber 274 to which the cylinder 262 is attached. Inside the chamber 274, the rod 273 ends in the spring end cap 275. A lever 276, which is mounted at the pivot point 277, is also located in the chamber 274. A compression spring 273 acts between lever 276 and rod 273. In the chamber 274, a pair of bellows 279 and 281 are attached to opposite walls. The bellows 279 is evacuated and the bellows 281 is connected to a line 2S2 from which it receives a control pressure which is a fraction of the compressor output pressure. The bellows 279 and 281 are connected by a rod 283 which is connected to the lever 276 by a pivot 284.

In order to adjust the piston 272, the pump 511 delivers Fuel through line 285 and filter 286 to a pair of restrictors 287 and 287 288 headed. From these throttles, fuel flows out on both sides of the cylinder 271 a. A line 289 and 291 each leads from both sides of the cylinder 271 a pair of openings 292 and 293, one on either side of the lever 276 is arranged. The relative leakage losses that occur at openings 292 and 293 occur depending on the position of the lever 276, determine the pressure difference in the two ends of the cylinder 271, each pressure difference being a movement of the Piston 272 and a corresponding rotation of the sleeve 266 causes. The movement of the Piston 272 is returned to lever 276 by a spring 278, whereby the the The rotation imparted to sleeve 266 is proportional to the pressure in bellows 281.

The rotation of the sleeve 266 determines the overlap of the opening 294 in the sleeve 266 and the opening 261; this overlap occurs at straight edge 263 so that axial movement of sleeve 266 does not change the overlap of opening 294. The rotary movement of the sleeve 266 determines the effective cross section of the opening 294 depending on the control pressure in the line 282, the axial movement of the sleeve 266 causing an adjustable cover between the openings 295 in the sleeve and the opening 264 in the cylinder 266. Here, the longitudinal movement is adjusted so that there is a certain pressure drop at the opening 294. A nozzle flapper control 296, which contains two chambers 297 and 298, is provided for this purpose. A lever 299 passes in a sealed manner through a hole 301 in the wall between the chambers and is pivotably mounted on the pin 302 arranged transversely to the hole 301. The hole is sealed by means of a membrane attached between the lever and the hole 301. The chamber 297 contains a bellows 303 with a compression spring 304. The bellows 303 is attached to the wall of the chamber 297 and connected at its free end to the lever 299 by a pivot 305. The chamber 297 is placed under fuel delivery pressure by the pump 511 via the line 256, while the interior of the bellows 303 is subjected to the pressure prevailing inside the sleeve 266 through the line 306. Such a pressure is achieved through the interacting openings 307 and 308 in the sleeve 266 and the cylinder 262, respectively. On the downstream side of the filter 285, fuel is conveyed through a line 285 via two throttles 309 and 311 to the left and right side of the cylinder 262, respectively. Lines 312 and 313 bring liquid from the left and right ends of cylinder 262, respectively, to two openings 314 and 315, respectively, which are located within chamber 298 on either side of lever 299. The relative outflow losses of the openings 314 and 315 determine the pressures in the ends of the cylinder 262. These pressures cause the axial movement of the sleeve 266 and a corresponding change in the overlap of the openings 295 and 264, until the restriction of the fuel flow from the opening 264 is so great Pressure drop across the overlapping surfaces of openings 294 and 261 creates that it corresponds to the load on spring 304 in bellows 303. In this way, regardless of the pressure in the line 259 from the delivery side of the pump 511, any desired flow rate of the fuel to the second burner set corresponding to the pressure transmitted through the line 282 into the bellows 281 can be achieved.

The discussion now follows of the flow regulator 321 (FIG. 2), which regulates the flow of fuel from the line 259 into the line 322 leading to the third afterburner set 5. The structure of the controller 321 is similar to that of the controller 258; however, the drawing shows the operating state in which the fuel supply to the third burner set is interrupted. The regulator 321 contains a cylinder 32, 3 in which a sleeve 324 with closed end faces is arranged. There are two openings 320 and 325 in the wall of the cylinder 323. The opening 320 is connected to the feed line 259 and has a straight edge 326 parallel to the axis of the cylinder 323. The opening 325 runs in the circumferential direction with an edge 327 which extends in a plane perpendicular to the axis of the cylinder 323 lies. A small opening 328 is arranged in the sleeve 324 and cooperates with the opening 320. As shown, the opening 328 is in the closed position, in which an overlap of the edge 326 of the opening 320 is just avoided. In the sleeve 324 there are also openings 329 which interact with the opening 325. The overlap area reaching over the edge 327 forms an adjustable throttle for regulating the fuel flow. The sleeve 324 can be rotated by means of a toothed pinion 331 engaged by a toothed rack 332. The toothed rack 332 is at the same time the piston rod of a piston 333 which is slidably arranged in an adjusting cylinder 334, the adjusting cylinder being arranged to the side of the cylinder 323. The piston rod 332 passes through one end of the cylinder 334 in a sealed manner, and from the other side of the piston 333 another rod 335 passes through the other end of the cylinder 334 in a sealed manner and terminates in a spring end cap 336. The spring end cap 336 is housed in a chamber 337 . A lever 338 rotatably mounted on a fixed pivot point is arranged within the chamber 337. A spring 341 acts between the end cap 336 and one end of the lever 338. Two bellows 342 and 343 are arranged in the chamber on opposite walls, the free ends of which are connected by a rod 344 which is connected to that of the spring 341 by a pin 345 opposite end of the lever 338 is connected. The bellows 343 is evacuated, while the bellows 342 is connected to a Ro gel pressure line 346. The two bellows 34.2 and 343 have the same diameter. Two lines 347 and 348 lead from both ends of the cylinder 334 to two openings 349 and 351 on both sides of the lever 338.

The line 353 leads via two throttles 354 and 355 to the two ends of the cylinder 334. In normal operation - that is, not in the switched-off state - determines the position; of the lever 338 between the openings 349 and 3 51, the relative Ausströmungsverluste exiting these openings, and so that the relative flow rates through the restrictors 354 and 355. This in turn is determined the ratio of the pressures on both sides of the cylinder 334, in turn, the Determine the movement of the piston 333. A position of equilibrium is reached when the return force exerted by the piston 333 via the spring 341 on the lever 338 is kept in equilibrium by the load exerted on the lever 338 by the bellows 342 and 343. The position of the piston 333 is therefore directly proportional to the pressure prevailing in the line 346 and in the bellows 342. The position of the piston 333 determines the overlap of the openings 328 and 320 via the rack and pinion 331 and 332. In the drawing, the opening 328 does not of course cover the opening 320 Nozzle flapper control 356 is provided which is built like unit 296. It contains two chambers 357 and 358 which are separated by a wall with a hole 359. A lever 361 passes through the hole 359 and is rotatably supported by means of a pivot pin 362 which extends transversely through the hole 359. A metal diaphragm seals hole 359 to prevent fluid from spilling between chambers 357 and 358. A bellows 363, which is internally tensioned by a spring 364, is arranged in the chamber 357. The bellows is attached to the chamber wall at one end and is connected to the lever 361 at the other end by a pin 365. The bellows is in communication with an opening 367 in the wall of cylinder 323 through conduit 366. This opening cooperates with openings 368 in sleeve 324 so that line 366 always receives pressure from within sleeve 324. The chamber 357 is connected to the line 256 and receives the pressure of the delivery line 215 of the pump 511 via this. In this way, the bellows 363 responds to the pressure drop that occurs at the throttle formed by the overlap of the openings 320 and 328. In the chamber 358 there are two openings 369 and 371 on both sides of the lever 361. arranged. The opening 369 is connected to a line 372 which leads to the right end of the cylinder 323 (in the drawing). The opening 371 is connected to a line 373 which leads to the left end of the cylinder 323.

The line 372 is filled with hydraulic fluid via a throttle 374 the line 353 fed, while the line 373 through a throttle 375 with hydraulic fluid is supplied from line 353.

The position of the lever 361 between the openings 369 and 371 determines the relative outflows from the two openings 369 and 371. and thus also the flow through the two throttles 374, 375 Cylinder 323 act, and the sleeve is caused to axially adjust the overlap of the openings 329 with the opening 325 so that the pressure drop occurring at the overlap of the openings 320 and 328 is kept constant at the value determined by the tension of the spring 364. By maintaining the pressure drop at these openings, the flow through the line 322 leading to the third burner is regulated to a desired value.

The actual release or shut-off of the fuel supply to the three burner sets 3, 4 and 5 is determined by the closing and opening of the three nozzle baffle controls 115, 116 and 117 . The opening 117 of the baffle plate control for the first burner set is connected to a line 376, which extends from the cylinder 536 in the shut-off unit 531. When the opening 117 is closed, the piston 537 moves upwards in the sense of the figures as the pressure rises below it. This movement lifts the valve body 534 from its seat and allows the admission of fuel under boost pressure to the pump 511. The pump 511 then pumps the fuel through the line 215 to the flow regulator 216 which controls the amount of fuel dispensed into the line 217 regulates by acting on the piston 523 of the pump 511. Similarly, the nozzle opening 116 of the nozzle flapper control for the second burner set is connected via line 377 to the one shown in FIG. 4 upper end of the actuating cylinder 271 of the regulator 258 connected.

When the opening 116 is closed, the piston 272 adjusts itself automatically, as described, in accordance with the pressure prevailing in the line 282. When port 116 is open, the pressure above piston 272 decreases to a very low level. This rotates the sleeve 266 into a position in which the opening 294 does not cover the opening 261, whereby the flow to the second burner set is blocked. The opening 115 for the third burner set is connected to the line 378 which leads to the upper end of the actuator cylinder 334 of a regulator 321. When the opening 115 is closed, the piston 333 adjusts itself automatically according to the pressure supplied by the line 346. When the opening 115 is open, the pressure above the piston 333 decreases to a very low value, so that the sleeve 324 is rotated into the position shown, in which the openings 328, 320 do not overlap. In this way, the fuel supply to the line 322 leading to the third burner set is shut off.

A curve control system 381 (FIG. 8) is provided for entering the control pressures into lines 238, 282 and 346. In this system, three three-dimensional control bodies 382, 383 and 384 rotate on a common shaft 385 which rests in bearings 386. The shaft 385 carries a gear 387 which meshes with a long pinion 388 so that the longitudinal movement of the shaft 385 can take place without separating the gear 388 and the pinion 389. The pinion 388 is rotated from the feedback lever 21 by a feedback member 389. At the end of the shaft 385 that faces away from the transmission, a levitation lever 391 is provided, which acts axially against the end of the shaft 385. The end of the lever 391 facing away from the point of application on the shaft 385 is connected via a pivot 392 to a piston 393 guided in the bearing 394. The piston 393 is moved in the longitudinal direction by the joint 203 which is actuated by the actuating piston 201. The pivot point of the lever 391 is formed by the contact point on a cam 395. The cam 395 is rotatable about an axis 396 and is adjustably rotated by a device which is responsive to the compressor inlet temperature of the engine. The rotation of the cam 395 displaces the fulcrum of the lever 391 in a direction transverse to the length of the lever 391.

A throttle unit 397 works together with the control body 382. In this throttle unit there is a chamber 398, to which the output pressure of the engine compressor is located via the channel 399 and the line 182. An opening 401 regulates the entry of air into the chamber 398. A conical pin 402 is adjustable in the opening, which is slidably mounted in a guide 403 in the wall of the chamber. The pin 402 is provided at its end with a nose 404 which is in engagement with the surface of the control body 382. A spring 405 presses the tapered pin 402 outward so that the nose 404 remains in constant contact with the control body 382. The air flows from the chamber 398 through a throttle 406 into a low pressure zone, such as the engine body. The throttle 406 throttles under all operating conditions. This means that the "dimensionless" speed value through the throttle 406, formed by the product of the mass flow per unit of time Q and the square root of the absolute temperature T divided by the product of the square of the internal throttle diameter d and the pressure P in front of the throttle is substantially constant regardless of the pressure applied and that therefore, in any position of the taper pin 402, the pressure within the chamber 398 is directly proportional to the compressor output pressure provided by the line 182. This proportionality changes depending on the position of the taper pin 402 which follows the rotation of the cam. The line 238 is connected to the chamber 398 so that the pressure in the chamber 398 forms a control pressure for the bellows 235 of the flow regulator 216 for the first set of burners.

Another throttle unit 407 (FIG. 8), the structure of which is similar to that of the unit 397, works together with the control body 383. In particular, it contains a chamber 408 which is fed from the line 182 via an opening 409. Inside the opening 409, a conical pin 411 slides in the guide 412, which forms part of the wall of the chamber 408. Outside the chamber, the taper pin 411 has a nose 413 which is pressed into engagement with the control body 383 by a spring 414. A throttle 415, which is constantly operating under throttling conditions, discharges air from the chamber 408 into a low pressure zone. As described in connection with unit 397, the pressure in chamber 408 is proportional to the compressor output pressure supplied through line 182 in any position of taper pin 411. The proportionality changes with the axial position of the conical pin 411. The chamber 408 is connected to the line 282 so that the pressure in the chamber 408 forms the control pressure which acts in the bellows 281 of the regulator 258 and determines the fuel supply to the second burner set .

Another throttle unit 416 (FIG. 8) works together with the control body 384. This unit is similar to units 397 and 407. It contains a chamber 417 to which the compressor output pressure is applied via line 182 and an opening 418. A conical pin 419 guided in a guide 421 is axially displaceable within the opening 418. The taper pin 419 has a nose 422 which rests on the control body 384; the pin is pressed against the control body 384 by the spring 423. The throttle 424 discharges air from the chamber 417 to the low pressure zone and is designed to operate continuously in the throttling state. In any position of the taper pin 419, the pressure in the chamber 417 is proportional to the compressor outlet pressure. The change in the axial position of the taper pin 419 changes the proportionality. The pressure in the chamber 417 acts via the line 346 in the bellows 342 of the flow regulator 321 and thus determines the flow of the fuel through the line 322 to the third burner set 5.

During normal operation of the engine without post-combustion, the pilot's post-combustion controller 88 (FIG. 6) belonging to the manually operated control device is held in the end position rotated counterclockwise in the sense of the figure. The piston 77 is raised to an upper position, moving the adjustable nozzle flaps 6 and 7 into their innermost position via the valve 42, the servo valve 25 (FIG. 7) and the servo pistons 15. The cam disks 97 and 98 are set in this state so that the cam followers 95 and 96 are seated on the lowermost zones 100 and 11.0. Openings 115, 116 and 117 are exposed, members 118, 119 and 121 being held away from these openings by latches 125, 126 and 127. Keeping the opening 117 open means that only a low pressure can be present in the line 376 and in the lower end part of the actuating cylinder 536 (FIG. 3) of the shut-off system 531; as a result, the valve body 534 closes its seat 535 and no fuel enters the pump 511. Since no fuel can then leave the pump 511 through the delivery line 215, no fuel flows through the overlapping openings 222 and 223 of the flow regulator 216 (FIG. 9), and accordingly there is also no pressure drop there. The bellows 252 of the nozzle baffle control 229 therefore expands completely and opens the opening 228. This in turn leads to a reduction in the pressure in the left end of the actuating cylinder 522 of the pump 511 (FIG a maximum expansion of the openings 516 in the middle of the pump impeller 513 results.

Since openings 114 and 115 for the second and third burner sets are also open, sleeves 266 and 324 of flow regulators 258 and 321 close their openings 294 and 328, respectively, thereby ensuring that the second and third burner sets are not admitted. The fuel system of the main engine is provided with a locking device which ensures that the pilot can only switch on the afterburning when the engine is running at the highest attainable speed. When the engine speed is increased to its maximum, the piston 168 (Fig. 5), responsive to the pressure ratio of the turbine, rises, and at the maximum speed the orifice 193 in the piston rod 171 comes off the rim 196 of the cam 194 free. This reduces the pressure on the right side of the piston 139 (FIG. 6) and brings the pawl 148 into engagement with the piston 77. When operating without post-combustion, the piston 77 is in its uppermost position and when the pawl is released it engages in the recess 145 and holds the piston 77 in place. The selection of a low degree of post-combustion by the pilot by actuating the lever 88 in a clockwise direction results in the right-hand end of the lever 82 being raised around the pin 81 as the pivot point. The spring-loaded piston 91 of the lost motion device 89, 91 gives way, and the rod 93 is raised by the action of the compression spring 90 . The initial lifting of the rod 93 brings the transverse rod 134 into engagement with the nose 131 of the locking member 121, as a result of which this is rotated clockwise against the action of the bolt 127 and closes the opening 117. After the closing member 121 is seated on the opening 117, the engagement of the cross rod 134 with the nose 131 prevents further movement of the rod 93 under the action of the spring 90. The closing of the opening 117 blocks the outflow from the line 376. In this line and A pressure builds up in the lower end of the cylinder 536 (FIG. 3) of the shut-off valve 531. This increase in pressure lifts the actuating piston 537 and the valve body 534 from its seat 535. As a result, fuel can flow under boost pressure from the connection 533 through the channel 518 into the pump 511. Since the openings 516 are initially completely open, there is a considerable flow through the supply line 215. As soon as this flow passes through the overlapping openings 222 and 223 of the flow regulator 216 , a pressure drop occurs, which is transmitted to the bellows 252 of the nozzle baffle control 229. The hemispherical valve 257 immediately begins to regulate the opening 228 in order to adjust the actuating piston 523 in the pump 511 so that the delivery of the pump 511 is reduced to the value at which the predetermined pressure drop at the overlapping openings 222 and 223 of the flow regulator 216 enters. Then the flow rate of the fuel is at a minimum value and is mainly controlled by the setting of the conical pin 402 in the throttle unit 397 , which determines the regulating pressure existing in the bellows 235 of the flow regulator 216. This pressure is at a minimum value because it is regulated by the feedback lever 21, the link 389, the pinion 388, the gear 387 and the control body 382. Such a flow of fuel is then sprayed into the exhaust nozzle from the first set of burners. This afterburning fuel is ignited in a conventional manner. When the fuel is ignited, there is a significant increase in pressure in the exhaust nozzle which acts on piston 168 (Fig. 5) causing it to indicate a decrease in the pressure ratio of the turbine. The effect is to increase the pressure in the bellows 163 and upset the balance of the lever 156 so as to decrease the pressure under the piston 168 to cause it to move downward and the opening 193 to be covered by the rim 196 of the cam 194. This increases the pressure on the right side of the piston 139, since the outflow loss through the associated throttle 190 is reduced to a low value. The piston 139 (FIG. 6) moves to the left, at the same time releasing the pawl 148 from the recess 145 and pulling the rod 137 on. The rod 137 engages the cross rod 134 and disengages it from the nose 131 of the locking member 121. As a result, the rod 93 moves upward under the action of the spring 90 until the pivot point 89 against the piston 91 of the lost motion device 89 .91 bumps. The pressure of the spring-loaded piston 91 against the fulcrum 89 also causes the lever 82 to move downward with its left end, thereby carrying the piston 77 with it. Such a movement is transmitted to the slide 45 of the control valve 42. The fluid under pressure in the line 63 can then flow from the line 63 through the opening 57 between the webs 47 and 48 into the line 39 to the upper end of the cylinder 26 of the servo valve 25. In a similar manner, the lower end of the servo cylinder 26 is connected to the return flow circuit 40 through the opening 56 with a space between the webs 47 and 46 and through the opening 55. The valve slide 27 then moves downwards, and pressure from the line 24 is transmitted through the space between the webs 28 and 29 to the line 19, causing a movement of the piston 15 (FIG. 1) to the left and an opening movement of the nozzle flaps 6 and 7 is effected. The movement of the nozzle flaps naturally moves the feedback lever 21, which acts on the piston 61 via the link 71, the lever 72, the member 73 and the cam 68, moving it downwards and canceling the relative displacement between the slide 45 and the sleeve 44 when the movement of the nozzle flaps 6 and 7 is proportional to the selected movement of the pilot lever 88. Opening the nozzle flaps reduces the resistance of the exhaust nozzle, so that the discharge pressure of the turbine can drop and the pressure ratio of the turbine increases. The pressure ratio of the turbine is now regulated to a value at which the opening 192 provided in the piston rod 171 (FIG. 5) is partially closed by the edge of the cam 194. The task of the opening 192 is to regulate the position of the actuating piston 201 in its cylinder and thereby the setting of the piston 393 (FIG. 8), by means of which the shaft 385 and the control bodies are set in the longitudinal direction. The longitudinal adjustment of the shaft 385 changes the setting of the conical pin 402 in its opening 401 and thereby the cone pressure acting on the bellows 235, which controls the overlap of the openings 222 and 223 and thus changes the throttling of the fuel supplied to the first set of afterburner. The entire arrangement is such that an equilibrium position is reached in which the fuel supply to the first burner set is adjusted so that the opening 192 is partially closed by the edge 196 of the cam 194, that is, the fuel flow is adjusted so that at the Turbine a predetermined pressure ratio is kept constant. This predetermined pressure ratio can be changed by changing the inlet temperature of the compressor, and for this purpose the electrohydraulic valve 208 (FIG. 5), which acts via the servo piston 206, adjusts the cam 194 so that the pressure ratio of the turbine is maintained Compressor inlet temperature is appropriate.

The feedback of the movement of the nozzle flaps is also given to the shaft 99 which rotates the cams 97 and 98. The cam disk 97 is driven directly by the shaft 99, and the cam disk 98 contains a lost motion connection of pin and slot 104. The spring acts on the cam disk 98 in such a way that, in the representation selected in the drawing, it turns counterclockwise to one end of the dead corridor is rotated. When the post-combustion is switched off, the two cam followers 95 and 96 rest on the lowermost zones 100 and 110 of the two cams. As soon as the first burner is ignited and the locking of the piston 77 is released, the nozzle flaps 6 and 7 move and the feedback on the shaft 99 rotates the cam disk 97 in a counterclockwise direction. The slopes 102 between the zones 100 and 106 grip the cam follower 95 and try to push it upwards. However, the step between the rest zones 110 and 112 of the cam 98 engages the side of the follower 96 and prevents rotation of the cam 98, allowing relative rotation between the cams due to their lost motion. For normal flow control of the fuel during operation with only the first set of afterburner, the cam follower 95 sits on the zone 106 and a part of the slope 102 between the rest zones 100 and 106 . As soon as the nozzle flaps have moved a sufficient distance and the cam disk 97 has rotated so far that the zone 106 supports the tappet 95, the cam disk 98 rotates by the spring pressure until the end of its lost motion, so that the zone 112 is under the tappet 96 is located. In order to change the size of the additional thrust generated during operation with the first set of afterburner, the lever 88 can be moved backwards and forwards in approximately the first third of its range of motion. Within this sub-area, the lever 88 controls the position of the nozzle flaps directly.

All nozzle openings of the flapper controls of the illustrated Embodiment are located in chambers in which the leakage is collected and returned to a low pressure zone. In the case of chambers 247, 298, 358, 231, 274 and 337 are the collected amount of escaped fluid for the The boost pressure input 533 of the pump 511 is fed back. In the case of chambers 152 and 184 is the collected escaped fluid through pipes to the inlet 37 of the Oil pump 22 returned.

In each selected position of the flaps 6 and 7, the fuel supply automatically adjusted so that the pressure ratio of the turbine on the predetermined Value is held. This is accomplished by opening 192 in piston 168 is always partially closed by cam 194. This effect is made possible by the scheme the flow of fuel out of the opening 192 by means of the actuating piston 201, the member 203, the longitudinal movement of the shaft 385 and the adjustment of the taper pin 402 and so that the control pressure supplied to the bellows 235 in the flow regulator 216 is reached.

After moving the control lever over about a third of its total movement, the additional thrust achieved by the afterburning essentially requires the maximum fuel supply to the first afterburner set, and the arrangement is such that in this position the pawl 148 moves into the recess 146 in the piston 77, whereby this piston is blocked against further movement in the sense of enlarging the nozzle. A further movement of the lever 88 in the sense of opening the nozzle rotates the lever 82 about the pivot pin 81, whereby the pivot point 89 moves upwards against the pressure of the spring-loaded piston 91. The spring 90 acting on the rod 93 presses this rod upwards until the transverse rod 1.33 engages the nose 129 of the closing element 119, moves it against the tension of the locking device 126 and closes the opening 116. Thereafter, the stop of the cross rod 133 on the nose 129 prevents further movement of the rod 93. The closure of the opening 116 prevents outflow from this opening and creates a pressure increase in the upper end of the actuating cylinder 271 of the flow regulator 258. The actuating piston 272 is then under the The control influence of the lever 276 moves downwards in the sense of the figure and rotates the sleeve 266 so that the openings 294 and 261 overlap. The fuel can then flow through the overlapping openings from line 215 via line 265 to the second burner set. The position of the piston 272 is determined by the control pressure which is fed to the bellows 281 from the chamber 408 of the throttle unit 407 . The nozzle flapper control 296 regulates the longitudinal movement of the sleeve 266 and ensures that a set pressure drop occurs at the overlapping openings 294 and 261.

The additional amount of fuel required for the second burner is selected so that it can be easily supplied by the pump 511 within the scope of its delivery capacity. The additional flow briefly reduces the flow to the first burner set, as a result of which there is a reduction in the pressure drop at the overlapping openings 222 and 223 of the first flow regulator.

Such a momentary decrease causes the opening 228 to be momentarily released, which results in a considerable displacement of the sleeve 524 in the center of the pump impeller 513 , so that the openings 516 which supply the fuel to the pump are enlarged. The fuel emerging from the second burner set is ignited by the burning fuel from the first burner set. Immediately after ignition, the pressure in the jet pipe rises and the turbine pressure ratio drops. The piston 168 then moves downward so that the opening 193 is closed by the cam 194. This increases the pressure in the right-hand end of the cylinder 141 , and at the same time the pawl 148 is released from the recess 146 and the rod 137 is moved away from the rod 93. As a result, the cross rod 133 is released from the nose 129 and the rod 93 is moved upwards under its spring pressure. As a result of the release of the pawl 148 , the pretensioning of the piston 91 can act on the lever 82, move the piston 77 downwards and - as explained above - cause a further movement of the nozzle flaps 6 and 7 outwards. As soon as the flaps move, the feedback of this movement via the lever 21 and the pinion 388 rotates the shaft 385. The shapes of the control bodies are selected in comparison to one another so that a subsequent adjustment of the fuel flow takes place. It is ensured that the further rotation of the pinion 388 does not cause any significant change in the axial position of the conical pin 402 of the throttle unit 397. However, the control body 383 acts on the axial position of the conical pin 411 . The feedback of the movement of the flaps 6 and 7 is also given to the shaft 99, and as soon as movement occurs, the cam disk 97 is rotated so that it tries to lift the plunger 95 onto the slope 109 between the rest zones 106 and 107. The movement of the parts that results when the pawl 148 is released is sufficient to guide the next zone of the cam disk under the plunger 95. During the rotation of the cam 97 with the aim of bringing the zone 107 under the plunger 95 , the step between the zones 112 and 113 of the cam 98 engages the side of the plunger 96 so that rotation of the cam 98 is prevented, the mutual rotation of the discs 97 and 98 is absorbed by the lost motion connection. As soon as the plunger 95 has been lifted onto the zone 107 , the cam disk 98 rotates as a result of the spring tension so far that the zone 113 lies under the plunger 96. The fuel supply to the first burner set then remains at the value selected by the control element 382 , and the adjustment movement of the piston 168, through which the opening 192 is more or less covered by the cam disk 1.94, is controlled via the actuating piston 201, the member 203 , the piston 393 and the longitudinal movement of the axis 385 for the purpose of adjusting the control body 383, the pressure in the chamber 408 and the flow to the second burner set.

While the first and second burner sets are in operation and the hand lever 88 is moved within the second third of its travel, the control element 383 regulates the fuel inflow.

To further increase the thrust generated by afterburning, the hand lever 88 is moved into the last third of its travel range. The process that then takes place is essentially the same as when the hand lever is moved into the second third of its travel, with the exception that the third burner set is supplied with fuel due to the closure of the opening 115 and the regulation of the fuel supply thereby advances to the third burner set that in the new position of the control bodies there is a setting in which the control bodies 382, 383 keep their conical pins constantly in maximum setting and the control pressure in chamber 417 and bellows 342 is set by the movement of the conical pin 419 generated by the control body 384 .

When the supply of afterburning fuel is increased by moving the hand lever 88, the increase in thrust is essentially continuous, with the exception of small interruptions. The interruptions are due to the locking action of the pawl 148 , which is required during the ignition of the successive sets of torches. During the decrease in the supply of afterburning fuel, the pawl is unable to fix the piston 77 because of the inclined surfaces of the pawl and the recesses 145, 146 and 147, so that when the hand lever 88 is moved backward, the fuel supply to the burner sets continuously decreases to zero. When adjusting the afterburning fuel supply, if the pilot attempts to move the lever 88 to and fro in a position corresponding to switching the fuel supply to a burner set on and off, the cam disks 97 and 98 give the control a hysteresis effect in the following manner : Assume that the control is in the state shown, in which the fuel flows to the first and second, but not to the third burner set. The pilot now operates his hand lever188 to reduce the fuel supply. Since the movement of the hand lever controls the position of the flaps 6 and 7, it causes the two cam disks 97 and 98 to rotate clockwise to a position in which the zone 107 has moved away from the tappet 95 and the tappet 95 is above the slope 109 is arranged. In this position, however, the plunger 96 still remains on the zone 113 of the disc 94 close to the step between the two adjacent zones. The rod 93 cannot descend and cause the opening 116 to be released until the nozzle area has been reduced to such an extent that the cam follower 96 reaches the step between the zones 113 and 112, so that a sudden movement of the rod 93 and a sudden release the opening 116 enters through the closing member 119. If the pilot immediately decides at this point to increase the fuel supply again, the procedure is the same as that described for the start-up of the second burner set. The result is that during the downward movement of the hand lever 88 the position in which the fuel supply of a burner set is blocked differs from the position in which the fuel supply of this burner set begins during an increase in the afterburning thrust. Therefore, small swaying movements of the hand lever 88 by the pilot cannot result in continued switching on and off of the fuel supply to a burner set.

It can be seen that in the described embodiment of the invention the movement of the hand lever 88 basically controls the nozzle cross-section and that the adjustment of the thrust nozzle cross-section for coarse adjustment of the fuel supply serves to the afterburners, which by the action of the control body with fuel be fed. The fine adjustment of the fuel supply is carried out by the the turbine pressure ratio responsive piston 168, via port 192 and the cam disk 194 closing it adjusts the fuel flow so that the turbine pressure ratio depends on the compressor inlet temperature Assumes value.

In the embodiment described, a supply of afterburning fuel only be switched on when the engine is at the maximum that can be maintained Speed is running. It is within the scope of this invention to provide the arrangement to be taken so that a supply of afterburning fuel at any operating speed the machine can be initiated, with a fine adjustment device then with a device responding to the pressure ratio of the turbine interacts in such a way that that the selected pressure ratio, that of this device by appropriate setting after-fuel flow is maintained, both by engine speed as well as the compressor inlet temperature.

Claims (4)

Claims: 1. Control device for gas turbine jet engines with afterburning device and variable thrust nozzle cross-section, where the feed of the afterburning fuel is introduced with a manually operated control device and the nozzle cross-section can only be enlarged after the afterburning fuel has been ignited is, characterized in that a mechanical locking device (148) is provided that prevents an enlargement of the nozzle cross-section that continues a device (139, 151) responsive to the ignition of the afterburning fuel is provided for switching off the locking device and that the nozzle cross-section via a lost motion device (89, 91) and a preloaded spring from the manually operated one Standing device (84 to 88) is adjustable, with a movement of the manually operated Standing device in the sense of an enlargement of the nozzle cross-section when switched on Locking device taken from the lost motion device and switched off Locking device is passed through the force of the spring. 2. Apparatus according to claim 1 for an engine with several afterburners which can be put into operation one after the other for the purpose of increasing thrust, characterized in that the nozzle flaps (6, 7) can be locked at different sizes of the thrust nozzle cross-section by the locking device (148) and these detents ( 145, 146, 147) can be released one after the other when successive sets of burners are ignited. 3. Apparatus according to claim 1 or 2, characterized in that the spring-loaded lost motion device (89, 91) engages a rod part (82) of the manually operated adjusting device (82 to 88), which acts on both a metering device for the afterburning fuel also acts on a nozzle cross-section adjusting device, and that a return (97, 98, 99) actuated by the setting of the nozzle flaps (6, 7) after ignition is provided to maintain the supply of the afterburning fuel. 4. Apparatus according to claim 3, characterized in that the return (97, 98, 99) contains a hysteresis device (98) which blocks the fuel supply at different positions of the manually operated actuating device (88) when the thrust is reduced or the outlet cross-section is enlarged or releases. Documents considered: German Auslegeschrift No. 1099 273; French Patent No. 1230 868; U.S. Patent No. 2,737,016.