GB2155995A

GB2155995A - I.C. engine with induction manifold heating

Info

Publication number: GB2155995A
Application number: GB08503436A
Authority: GB
Inventors: Herbert Ampferer
Original assignee: Dr Ing HCF Porsche AG
Current assignee: Dr Ing HCF Porsche AG
Priority date: 1984-02-10
Filing date: 1985-02-11
Publication date: 1985-10-02
Also published as: GB2155995B; IT1184859B; FR2559548A1; DE3404773A1; ES540245A0; IT8519274A0; FR2559548B1; GB8503436D0; ES8606576A1

Abstract

When the engine is below its operating temperature the induction manifold 3 is heated by part of the liquid by-passing the cooler 5 of the main engine cooling circuit 7. A thermostat 9 controls flow through the cooler by-pass circuit 8 and 20 to 40% of this flow passes through the manifold heating circuit 10 which has its supply and return lines 11 and 12 connected adjacent the pump outlet and inlet connections 15 and 16. When the engine reaches its operating temperature the thermostat 19 closes the circuit 8 and a thermostat 21 diverts the majority of the liquid passing through the line 11 to the main circuit 7 upstream of the cooler 5, e.g. 10% of the coolant passes through the manifold 3. <IMAGE>

Description

SPECIFICATION Internal combustion engine with an induction manifold heating apparatus The invention relates to an internal combustion engine having an induction manifold heating apparatus.

Tests with an internal combustion engine which has been installed in a vehicle and has a heated induction manifold have shown that its driving ability is considerably increased by a rapid heating of the manifold after starting from cold. In addition, this induction manifold heating has a beneficial effect upon the emission of exhaust gases and the fuel consumption.

In the case of a known heating apparatus for an induction manifold (German Patent 22 35 857) a parallel line connected to a cooler by-pass line is provided for heating the manifold. Since the connexions of the parallel line are provided on the by-pass line at a distance from the cooling-water pump and in addition the quantity of liquid circulating in the parallel line is not defined, the described rapid heating of the manifold to be aimed for is difficult to achieve with this apparatus.

The object of the invention is therefore to provide a heating apparatus for an induction manifold of an internal combustion engine in such a way that the manifold is rapidly heated during the warming-up phase of the internal combustion engine and, after the engine has reached the operating temperature, is at a temperature which supports efficient operation of the engine.

The present invention consists in an internal combustion engine having a heating apparatus and a liquid cooling system comprising a pump and a main circuit provided with a cooler for controlling the operating temperature of the internal combustion engine and a cooler by-pass circuit controlled by means of a thermostat and which operates during the warming-up phase of the internal combustion engine, an induction manifold heating circuit being connected to the cooler by-pass circuit, wherein the manifold heating circuit has feed and return lines connected adjacent to the compression and suction connexions of the pump positioned in a line of the main circuit a proportion of between 20 and 40% of the entire quantity of liquid circulating in the cooler by-pass circuit and in the manifold heating circuit flows through the manifold heating circuit, and a three-way thermostat is arranged in the manifold heating circuit which, after the operating temperature of the internal combustion engine has been reached, diverts the liquid flow from the manifold heating circuit into the main circuit except for a residual quantity which is used for partially heating the manifold.

The advantages principally achieved with the invention are that by connecting the feed and return lines of the manifold heating circuit to the cooling-medium pump and by virtue of the proportion of the quantity of liquid circulating in the heating circuit, an optimum heating of the manifold is made possible in the warming-up phase.In addition, after the operating temperature of the internal combustion engine has been reached, the three-way thermostat ensures that the quantity of liquid circulating in the heating circuit is diverted into the main cirucit except for a residual which is used for the partial heating of the manifold, as a result of which even in this operating state of the internal combustion engine the manifold is maintained at a temperature which ensures an efficient running performance, since the partial hating improves the emission of exhaust gases, the dynamic performance and the fuel consumption of the internal combustion engine in this state.

In the accompanying drawings:- Figure 1 is a diagrammatic perspective view of an internal combustion engine with an induction manifold heating apparatus according to the invention, and Figure 2 is a diagram showing the operation of the induction manifold heating apparatus.

Referring to Fig. 1, an internal combustion engine 1 comprises an engine block 2 having an induction manifold 3, the block 2 being connected to a liquid coder 4. Further details of the internal combustion engine such as additional units, electrical equipment and the fuel supply system are not illustrated.

The induction manifold 3 is provided with a heating apparatus 6 connected to the liquid cooling system. The liquid cooling system comprises a main circuit 7 and a cooler bypass circuit 8. The main circuit 7 comes into operation at the operating temperature of the internal combustion engine 1 whilst the cooler by-pass circuit 8 comes into operation in the warming-up phase of the internal combustion engine.The circuit 8 is controlled by a thermostat 9 and is connected to a manifold heating circuit 10 comprising a feed line 11 and a return line 1 2 which are connected respectively at one end 1 3 and 1 4 to the induction manifold 3 and at their other ends, spaced at a short distance A, to compression and suction connexions 1 5 and 1 6 of a pump 1 7. The pump 1 7 is connected in the line 1 8 which is both part of the main circuit 7 and of the cooler by-pass circuit 8.

The manifold heating circuit 10 is formed in the region of the induction manifold by an integrated annular line 1 9 (indicated by dashdot lines) and at 20 comprises a three-way thermostat 21 which opens into a line 22 connected to the main circuit 7 at 23. The thermostat 21 can, if desired, be integrated in the induction manifold 3.

When the internal combustion engine 1 is operating in the warming-up phase the thermostat 9 controls the cooler by-pass circuit 8 so that the stream of liquid circulated through the pump 1 7 flows in the direction of the arrow B indicated in broken lines and enters the engine block 2 at 24.

At the same time the induction manifold 3 is supplied with liquid medium by way of the feed line 11, as a result of which the induction manifold 3 is heated by way of the annular line 1 9 of the heating apparatus 6.

The medium again enters the return line 1 2 at 14 and the medium 25 flowing through the engine block 2 returns to the cooler by-pass circuit 8 through an outlet socket 26.

Between 20 to 40% of the entire quantity of liquid circulating in the circuits 8 and 10 circulates in the manifold heating circuit 10, and this is made possible by selecting the cross-sections in the line system, in particular to the induction manifold 3, of the circuit 10.

After the operating temperature of the internal combustion engine 1 has been reached, the thermostat 9 blocks the cooler by-pass circuit 8, and the liquid medium circulates in accordance with the arrow C indicated by dash-pot lines in the main circuit 7, the medium now flowing through the cooler 4. In this operating state of the internal combustion engine has the thermostat 21 also partially blocks flow in the direction of the induction manifold 3, so that the major part of the quantity of liquid of the heating circuit 10 flows along the path indicated by the arrow D symbolized by dots. The main quantity of the liquid is supplied to the main circuit 7 by way of the line 22.

A partial quantity, approximately 10% of the quantity of liquid of the heating circuit 10, further flows through the induction manifold 3, as a result of which a partial heating of the manifold 3 is made possible. In order to effect this, openings (not shown) are provided only on the closure valve of the thermostat 21 which act in the direction of the induction manifold 3.

The warming-up speeds of a known induction manifold and of the manifold 3 according to the invention are illustrated with reference to the diagram according to Fig. 2. For this purpose the temperature t is recorded on the ordinate and the time s is recorded on the abscissa. The line E clearly shows the warming-up speed of the known manifold, i.e. it lasts nine minutes, until it reaches the desired operating temperature of 86"C. In contrast, the manifold 3 according to the invention reaches this operating temperature after four minutes, which is shown by the line G.

Claims

1. An internal combustion enging having a heating apparatus and a liquid cooling system comprising a pump and a main circuit provided with a cooler for controlling the operating temperature of the internal combustion- engine and a cooler by-pass circuit controlled by means of a thermostat and which operates during the warming-up phase of the internal combustion engine, an induction manifold heating circuit being connected to the cooler by-pass circuit, wherein the manifold heating circuit has feed and return lines connected adjacent to the compression and suction connexions of the pump positioned in a line of the main circuit a proportion of between 20 and 40% of the entire quantity of liquid circulating in the cooler by-pass circuit and in the manifold heating circuit flows through the manifold heating circuit, and a three-way thermostat is arranged in the manifold heating circuit which, after the operating temperature of the internal combustion engine has been reached, diverts the liquid flow from the manifold heating circuit into the main circuit except for a residual quantity which is used for partially heating the manifold.

2. An internal combustion engine substantially as described with reference to, and as illustrated in, Fig. 1 of the accompanying drawings.