DE3304682C2 - Carburetors for internal combustion engines - Google Patents

Abstract

Carburetor for internal combustion engines, with at least one primary and one secondary stage, the secondary throttle element of which can be separated from the opening movement of the primary throttle element by a pneumatically or electromagnetically operated coupling device.

Description

The invention relates to a carburetor for internal combustion engines, with at least one primary and one secondary stage, whose primary throttle device, which can be activated by an Indian device in such a way connected with the Sekuitdärdrossclorga. ", that the secondary throttle member opens only after a certain amount of opening of the primary throttle member.

Such a carburetor is from the information leaflet of the Deutsche Vergaser Gesellschaft. Ncuss den Solex downdraft double gister gasifier (4Al) pertaining to, with printing date 11/76, known.

In this carburetor, the primary stage is equipped with a pre-throttle valve arranged upstream of the primary throttle element, with which in connection with a starting device in a known manner a fuel mixture enrichment for the cold operation of the engine can be achieved.

Since the secondary stage does not have such a device, the cold operation is based on the use of the Primary stage is limited to the opening of the secondary stage, since the use of the secondary stage makes the fuel mixture supplied to the engine lean would result, whereby the engine, especially at low speed and full load, tend to stall would.

This going-out is prevented by locking the secondary stage while the starting device is functioning, i. H. the starting device controls one Locking pawl which engages on a shoulder of the shaft provided for the attachment of the secondary throttle; the mechanical device! will.

By overpressing the resilient means increases however, the actuation force for the arbitrarily actuatable primary throttle organ is considerably reduced when it is used of the engine in a motor vehicle must be applied by the driver as Pcdalkraft, what of this as

is felt to be uncomfortable.

The object of the invention is therefore to provide an initially called carburettor so that the actuating force in the for actuation without locking usual framework is kept.

According to the invention, this object is achieved by that the .Sekundärdrosselorgan by a clutch lever in the mechanical device as a function from the engine temperature from the primary throttle

ίο is detachable The clutch lever can be removed from a pneumatic actuator operated via a The intake pressure of the internal combustion engine can be applied to the thermal valve or it can be actuated by an electromagnetic actuator which

is moschalter with voltage is bcaufschlagbar.

The invention also has the advantage that the carburetor can be operated easily and has not been customary up to now has become attainable during cold operation and, moreover, it has been achieved that the blocking the secondary level is no longer actuated by the starting device, which means that the locking is also possible with modern, electronically controlled carburettors (DE-OS 29 27 881) in which the Vordrossclklappcn is driven by an electric motor The actuator can be actuated over the entire operating range of the engine if the engine needs to enrich or lean the combustion mixture.

An embodiment of the invention is shown in the drawing and is described below

jo bcn. It shows

F i g. 1 a carburetor according to the invention. 2 shows an alternative actuator for the actuation the clutch.

Fig. I shows a carburetor 1 with a primary

Intake duct 2 and a secondary intake duct 3, the primary intake duct 2 being on a shaft 4 attached primary throttle member 5 and upstream of it a Vordrossclklappe 6, which is not of a shown starting device or by a likewise not shown electromotive. Actuator operated will.

The .secondary intake duct 3 has a Sckundärdrosselorgan 8 fastened on a shaft 7 and various other devices for mixture formation on which however, it is not included as it is not directly related to the invention. A lever 9 with a clutch lever 11 loaded by a spring 10 is attached to the shaft 7, the lever 9 from a spring 12 in the closing direction of the secondary throttle organs 8 is loaded The clutch lever 11 has egg nen stop tabs 13 for a pneumatic actuator 14 that the clutch lever 11 in the closed position of the Sckundärdrossclorgans 8 against the effect of Spring 10 adjusted by a pin 25 so that it is in a Recess 15 of a middle to the shaft 7 on the carburetor 1 stored Zwischenhcbcls 16 engages when the opening of the Sckundärdrossclorgans 8 is desired. If the pin 25 of the actuator 14 does not load the clutch lever 11, then an opening is not possible.

W) wishes, so that the clutch lever 11 is held out of the recess 15 of the intermediate lever 16 under the action of the spring 10 and against a stop 17 of I lubcl.s 9 is applied. The intermediate hcbcl 16 is via a connecting rod 18 with a

b'j Ic 4 of the primary throttle member 5 attached operating lever 19, the connecting rod 18 in an elongated hole 20 of the actuating lever 19 is held. whereby is achieved. that the operating lever only

after a certain opening amount of the primary throttle body 5 on the connecting rod 18 and thus the opening of the secondary throttle organ 8 acts when the clutch lever U is engaged in the recess 5 of the intermediate lever 16.

The actuator 14 is supplied with the suction pressure via a thermal valve 21 acted upon by the motor cooling switch of the engine is applied when a predetermined molar temperature is reached, so that below the predetermined engine temperature of the pin 25 of the actuator 14 the stop tab 13 of the clutch lever 11 not loaded and loaded above the predetermined engine temperature.

In Fig.2 is an alternative to the pneumatic actuator 14, an electromagnetic actuator 22 is shown, which in the same direction of action via a thermal switch 23 with electrical voltage can be applied when the operating switch 24 of the internal combustion engine is closed

20 Description of functions

If the engine has cooled down from the operating temperature to below a predetermined Temperature operated, then the actuator 14,22 is such urged that the pin 25 of the actuator is retracted.

The clutch lever 11 is by the spring 10 to the Stop 17 of the lever 9 applied so that the clutch lever 11 is not in the recess 15 of the Intermediate lever 16 is located. If the primary throttle element 5 is now actuated to open, the connecting rod then transmits 18 the movement of the actuating lever 19 on the intermediate lever 16, which readily this movement can follow.

After the predetermined temperature has been exceeded, the actuator 14 or 22 is acted upon by the thermal valve 21 or the thermal switch 23 in such a way that the pin 25 of the actuator 14, 22 executes, whereby the clutch lever 11 is so loaded via the stop tab 13, that the spring 10 is overpressed and thus the clutch lever 11 engages in the recess 15 of the intermediate fog 16. Thus, the movement of the actuating lever 19 is transferred to the lever 9 on the shaft 7 of the secondary throttle body 8, whereby the latter is opened.

1 sheet of drawings

50

bO

Claims (3)

Patent claims: 1. Carburetor for internal combustion engines, with at least one primary and one secondary stage, whose arbitrarily beiätigbaren primary throttle member by a mechanical device in such a way with the Secondary throttle member is connected. that the secondary throttle body only after a certain The opening amount of the primary throttle element opens, characterized in that the secondary throttle element (8) is actuated by a coupling lever (11) in the mechanical device (9,16,18,19) in Can be separated from the primary throttle element (5) as a function of the engine temperature. 2. Carburetor according to claim 1, characterized in that the clutch lever (11) of one pneumatic actuator (14) is operated. the upper a thermal valve (21) with the suction pressure of the Internal combustion engine can be acted upon. 3. Carburetor according to claim 1, characterized in that the clutch lever (11) of one electromagnetic actuator (22) is operated. voltage can be applied to it via a thermal switch (23).