Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
  • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
  • F02M3/00—Idling devices for carburettors
  • F02M3/06—Increasing idling speed
  • F02M3/062—Increasing idling speed by altering as a function of motor r.p.m. the throttle valve stop or the fuel conduit cross-section by means of pneumatic or hydraulic means

Definitions

• Control device for the idle speed of internal combustion engines in particular spark-ignited injection internal combustion engines
• the invention relates to a control device of the type described in the preamble of claim 1.
• the object of the invention is to improve the control device according to the preamble of claim 1 in such a way that no excessive speed increase occurs even in such operating conditions.
• the invention solves this problem by the characterizing features of claim 1.
• This configuration of the control device reliably prevents a disturbingly high idle speed increase in any operating state of the internal combustion engine or such a speed increase within narrow limits, e.g. 1,500 / min, because the largest possible opening cross section of the bypass valve is adapted to the highest possible power requirement of the machine when idling, which is significantly influenced by the operating state.
• O full diaphragm stroke of the servomotor can be used for the control range and the bypass valve can be kept small.
• the idle channel prevents the maximum speeds determined by the stop from being changed when setting the idle flow rate.
• 1 is a central longitudinal section of a control device for the idle speed of internal combustion engines with a schematic representation of their connections with respect to the intake manifold,
• FIG. 2 is a partial view of the control device in the direction of arrow II in FIG. 1,
• FIG. 3 shows a central longitudinal section of another exemplary embodiment of the control device shown in FIG. 1,
• FIG. 4 shows a central longitudinal section of a further exemplary embodiment of the control device according to FIG. 1,
• FIG. 3 shows a section along the line V-V of the control device according to FIG. 3 on an enlarged scale
• FIG. 6 is a section along the line VI-VI of the control device according to Fig. 5 and FIG. 7 shows a section similar to FIG. 5 of a further exemplary embodiment of the control device.
• bypass valve 1 shows as a control device a bypass valve 1 with its connections to a collecting suction pipe 2 with oscillating pipes 3 and to the suction pipe 4 with the throttle valve 5.
• the bypass valve 1 is located in a bypass line 6, which is seen in the suction flow direction, is connected in front of the throttle valve 5 and opens into the manifold 2 behind it.
• the bypass valve 1 comprises a membrane box 7, the chamber 8 of which can be acted upon by the intake manifold pressure via a line 9, and a housing 10.
• the housing 10 has a bore 11 and, perpendicularly thereto, a further bore 12.
• a circular insert 13 is fitted into the bore 11 adjacent to the bore 12.
• the insert 13 is designed similar to an aperture and has an opening 14 as a control cross section, the width of which increases progressively starting from the upper edge region of the insert 13 parallel to the bore 12.
• the bore 12 is designed as a gradually narrowing blind hole. With its widest section 15 it crosses the bore 11. The wide section 15 is followed by a threaded section 16 which merges into a short smooth-walled section 17. The short, smooth-walled section 17 merges with the formation of a shoulder 18 into the narrowest section 19 of the blind hole, which is crossed by a transverse bore 20.
• connecting pieces 21 are connected to openings 21 formed by the transverse bore 20, via which the narrowest section 19 is included in the coolant circuit of the machine.
• the housing 23 of an expansion element 24 projects into the narrowest section 19 of the stepped bore 12 and is supported on the shoulder 18 with the interposition of a sealing ring 25.
• the expansion element 24 is held by means of a retaining ring 26 which is provided with an external thread and which is screwed into the threaded section 16.
• a lifting pin 27 of the expansion element 24 projects through the retaining ring 26 and forms a stop for an actuating rod 28 of a cylindrical valve body 29 which is guided in the widest section 15 of the bore 12.
• the actuating rod 28 protrudes through a seal 30 out of the housing 10 into the membrane box 7, in which it is attached to the membrane 31 thereof.
• a compression spring 32 is arranged in the membrane box 7, which counteracts the effect of the intake manifold pressure.
• the identifier of the compression spring 32 is matched to the idling behavior of the machine with regard to all possible load cases in such a way that a relatively flat identifier is associated in the area which is associated with lower loads in idle mode and one in the area which is associated with higher loads results in a relatively steep identifier with a continuous transition.
• the compression spring 32 is adjustable in the chamber 8 of the membrane box 7 with the interposition of a spring plate 33 by means of an adjusting screw 3 * ⁇ in its pretension.
• O PI Adjusting screw 35 enables the setting of a minimum opening in the interaction of an idling stop bolt 36 with a "second spring plate 37, which is connected to a triple actuating rod 28 and thus to the valve body 29.
• an idle speed of about 700 rpm, for example, of the unloaded machine it is additionally loaded by switching on or engaging an auxiliary unit.
• the idle speed drops by a small amount.
• This causes a simultaneous increase in the intake manifold pressure in the manifold intake manifold 2.
• This increased value of the intake manifold pressure comes into effect in the chamber 8 of the bypass valve 1 and, in conjunction with the compression spring 32, results in the valve body 29 being adjusted in the opening direction.
• the thus enlarged cross section of the opening 14 also results in a further increase in the intake manifold pressure, with an increase in the filling and thus the performance of the machine and an increase in the speed.
• the expansion element 24 is increasingly heated by the coolant when the machine is warmed up.
• the lifting pin 27 serving as a stop is pushed forward more and more and thus prevents stood the machine that a too large opening cross section of the bypass valve 1 is released.
• the increase in speed which can occur due to a sudden drop in the idle load on the warm machine, is kept within narrow limits because only the narrower upper part of the opening 14 is available for regulation. As a result, the impression of a malfunction of the control device is reliably avoided.
• Special coolant lines to and from the housing 10 can be saved either by mounting the housing 10 on the machine (not shown) in such a way that the expansion element 24 projects into a space through which the coolant flows, or by heating a component having the operating temperature by heat transfer.
• the bypass valve 101 shown in FIG. 3 as a control device has essentially the same structure as the previously described bypass valve 1. It comprises a membrane box 107 as a servomotor with a chamber 108 which can be acted upon by the suction pipe pressure and a housing 110.
• the housing 110 has a bore 111 and perpendicularly to it a further bore 112.
• a guide bushing 113 is inserted into the bore 112. In the area of intersection of the bores 111 and 112, the bore 111 is continued on one side into the guide bush 113 and on the other side is in the wall
• Guide bush formed an opening 114 as a control cross section, so that the guide bush 113 forms a kind of aperture for the bypass.
• a cylindrical valve body 129 is arranged on the actuating rod 128 within the guide bushing 113. The top of the
• the actuator 124 is screwed into the housing 110 coaxially to the bore 112.
• the actuator 124 consists of an expansion element similar to that in FIG. 1 and a commercially available PTC resistor for heating it.
• the lifting pin 127 of the expansion element protrudes at one end of the actuator 124 in the direction of the valve body 129 and forms a stop for its stroke limitation.
• a contact tongue for the connection of an electrical line, not shown is arranged.
• the actuator 21 can be controlled via a time-dependent switching element, not shown. It is also possible to control it by logically linking several links.
• the resistance of the PTC resistor increases with increasing temperature and thus ensures a temperature limitation. Appropriate selection of the PTC resistance and the expansion material allows any time constants to be represented. To ensure the start at low outside temperatures, it is possible to provide for the heating of the expansion element to be switched on only when the
• the machine is in operation and the starter is no longer actuated and / or the cold start enrichment is switched off.
• the actuator 124 can also consist of a lifting magnet, not shown, which, like the expansion element, is arranged coaxially with the bore 112 and the core of which fulfills the function of the lifting pin 127.
• an actuator for the stroke limitation is to arrange a lifting magnet as an actuator laterally on the lower part of the housing 110.
• a core or an extension of the core of the lifting magnet can be moved in the movement path of the valve body 129 or an extension of the actuating rod.
• only relatively small holding forces are required which hold the core of the lifting magnet forming the stop in its position limiting the movement path of the valve body 129.
• the actuation of the actuator takes place essentially in the same way as the actuation of the actuator 124.
• the stopper between the actual bypass valve 201 and its membrane box 127 serving as a servomotor is an actuator 224 is arranged in the form of a vacuum servomotor or a further diaphragm box, which carries a stop sleeve 227 as a movable stop for limiting the stroke of the valve body 229.
• the stop sleeve 227 directly limits the path of movement of the diaphragm 231 when the actuator 224 is activated in a corresponding manner.
• Actuator 224 is controlled via a time-dependent solenoid-pneumatic valve and / or a temperature-dependent pneumatic valve in a vacuum line leading to actuator 224.
• further refinements of the control are possible, as described above in connection with the previous exemplary embodiments.
• an idle channel 140 parallel to its opening 114 in the form of a valve body 129 or its guide bushing 113 Groove incorporated.
• the free passage cross section of the idle channel 140 can be adjusted by means of an adjusting screw 141 which projects into the idle channel 140 perpendicular to the actuating rod 128 of the bypass valve 101.
• the guide bushing 313 of the valve body 329 which acts like a diaphragm, has a large wall thickness and is correspondingly received in a large bore 312.
• the idle channel 340 is machined into the outer circumference of the guide bush 313. It has the shape of an approximately semicircular-shaped groove, which extends from the part of the bore 311 which extends into the bushing 313 to the opening 314.
• the free passage cross section of the idle channel 340 is adjustable by means of an adjusting screw 3 1 projecting into the idle channel.
• an additional idle channel in the control device makes it possible to adjust the pretension of the compression spring 132 in the chamber 108 and thus the identifier of the control device during assembly, while adapting to each individual machine equipped with the control device and thus the idle setting can be carried out using the adjusting screw 141 or 341. This avoids deviations in the control behavior and the control path and thus the overall size of the control device are kept small, since the cross section for the idle throughput is separated from the passage cross section of the valve device.

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• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Control Of Throttle Valves Provided In The Intake System Or In The Exhaust System (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6087421

Family Applications (1)

Country Status (4)

Cited By (3)

Citations (5)

• 1979
  • 1979-12-01 DE DE2948501A patent/DE2948501C2/de not_active Expired
• 1980
  • 1980-11-04 EP EP80106786A patent/EP0029928B1/de not_active Expired
  • 1980-11-04 DE DE8080106786T patent/DE3067885D1/de not_active Expired
  • 1980-11-13 JP JP50012980A patent/JPS56501618A/ja active Pending
  • 1980-11-13 WO PCT/EP1980/000129 patent/WO1981001591A1/de unknown

Patent Citations (5)

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