GB1588568A - Apparatus for the optional supply of hot air or cold air into the induction air filter of an internal combustion engine - Google Patents

Description

(54) APPARATUS FOR THE OPTIONAL SUPPLY OF HOT AIR OR COLD AIR INTO THE INDUCTION AIR FILTER OF AN INTERNAL COMBUSTION ENGINE (71) We, FILTERWERK MANN & BR< HUMMEL GmbH of Postbox 409, D-7140 Ludwigsburg, Germany (Fed Rep); a German body corporate, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to an apparatus for the optional supply of hot or cold air to an induction air filter of an internal combustion engine having a control flap or butterflv valve eccentrically mounted in the unfiltered air passage. The flap in its first end position closes the cold air supply and in its second end position. closes the hot air supply.From the second end position. the throttle moves against a return force and progressively exposes the cold air supply upon reaching a predetermined operating condition of the internal combustion engine with increasing pressure difference between the sides of the control valve flap. The throttle has a pivot axle passing through a boss of the control flap and extending from the air inlet passage and being engageable in either end position.

Such apparatus may be readilv operated.

by means of the pivot lever which has only to be engaged in the summer or winter position. depending on the season. A visual check from the outside is always possible.

Moreover. in the winter position it is ensured that the internal combustion engine having a high air requirement additionally receives cold air to improve the degree of admission. Undesired "carburetter icing' may be reliably prevented since after the running engine has warmed-up. sufficient hot air is always supplied during winter operation so that the temperature of induced air cannot reach the vicinitv of freezing point.

German Gebrauchsmuster 77 01 582 discloses an induction air filter having a valve in which the throttle flap is fixedly connected to the pivot axle to move therewith.

A valve opening is covered by a valve plate and during winter operation, with the pivot lever engaged in the first end position with rising pressure difference on both sides of the throttle, is progressively released for the supply of cold air. Thus, the return force is created by the bending of the rubber-elastic valve plate.

An object of the invention is the simplification of the aforesaid apparatus and to improve the function.

According to the present invention there is provided an apparatus for the optional supply of heated air or unheated air into an induction air filter of an internal combustion engine including a throttle valve eccentrically mounted in the unfiltered air intake passage wherein the throttle valve in a first end position closes the unheated air supply and in a second end position closes the heated air supply, and above a predetermined operating condition of the internal combustion engine with which the apparatus is to be used. the throttle valve, if initially in the first end position. progressively releases the unheated air supply against the action of a return bias means with rising pressure difference between the two sides of the throttle valve as it moves from the first end position out of the unheated air passage said throttle valve being mounted on a pivotal axle which passes through a boss of the throttle valve which axle has an angled pivot lever extending outward of said intake passage and engageable in either of two positions corresponding to the end positions of the throttle valve wherein the throttle valve is pivotally mounted on the pivotal axle, and said throttle valve is biassed by the return force of a spring engaged thereon and on the air intake passage. the throttle valve being adapted to be pivoted away from its first end position, and wherein with the pivot lever engaged in a position corresponding to the second end position of the throttle valve the pivotal axle has a first engaging member or means adapted to act on a first stop of the throttle valve to retain said throttle valve in the second end position.

The valve plate or throttle thus saves a hitherto essential additional component of the known device. The metal spring may be determined and manufactured with far greater precision to produce the return force so that the operational limits of the device may be more precise. By pivoting the throttle itself away from its first end position a greater cross-section is exposed than was possible in the known valve. This permits the flow resistance to accordingly be kept smaller.

The limiting of the cold air supply with the pivot lever engaged in the winter position may also be obtained by development and positioning of-the throttle between the openings for hot air and cold air supply and/or by a return force rising steeply with the pivoting away from the opening for cold air supply.

According to a feature of the invention, the supply of cold air is preferably restricted in that the throttle has a second stop for a second engaging member of the pivotal axle which limits the swing away of the throttle from the first end position with the pivotal lever engaged in the first end position.

The invention will be described further, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view, partly in section, of an apparatus for the optional supply of heated air or unheated air; Figure 2 is a plan view on an enlarged scale and partly in section of the throttle used in Figure 1; Figure 3 is a cross-section taken on the line 3-3 of Figure 2 and on an enlarged scale of the boss of the throttle; Figures 4 and 5 are cross-sections through the boss of the throttle of Figure 3 in different operating positions; and Figure 6 is a cross-section through a boss of an alternative embodiment of the apparatus.

An induction air filter 1 of which only a portion is shown has an unfiltered air inlet passage 2 with which there communicates an unheated air passage 3 which in use is arranged to lead in from the front, and with which a heated air passage 4 communicates leading-in from below. A throttle 5 is provided having a horizontal pivotal axle 6 and is eccentrically mounted in the intake air passage. In the first end position shown in full lines, the throttle 5 prevents the supply of unheated air through the cold air passage 3 and in the second end position shown in dotted lines it prevents the supply of heated air through the hot air passage 4.

The pivotal axle 6 extends laterally out of the fresh air passage 2 and is bent over to form a pivot lever 30. A side wall of the fresh air passage 2 on the outside is provided with grooves or stop notches 7 and 8 in which the pivot lever 30 may be engaged in the two end positions. A metal spring 9 operating as a tension spring is secured at one end to the fresh air passage 2 and engages at the other end with an eyelet 10 on the throttle 4.

The throttle 5 comprises a throttle plate 21 having the eyelet 10 for receiving the end of the spring 9 and a boss 22. The boss 22 has a through bore 23 and a recess 23a formed as an elongate groove which is closed at one end face 24 and is open at the other end face 25 for the introduction of the pivot axle 6 into the boss 22. The recess 23a has a first stop flank 34 and a second stop flank 35. The recess 23a may be replaced by an elongate slot extending from the bore 23 to the outer circumference of the boss 22.

The pivot axle 6 includes a pivot pin 28 which extends through the bore 23 of the boss 22. The axle 6 is pivotally mounted at one end by means of the end of the pivot pin 28 projecting beyond the boss 22, and at the other end by means of a collar 29 in suitable recesses of the side wall of the fresh air passage. Barbs (not shown) are located on the free end of the pivot pin 28 and spread radially outwards outside the adjacent side wall of the fresh air passage 2 having the throttle 5 mounted thereon; the pivotal axle 6 is thus prevented from slipping out sideways. As a means for the lateral fixing of the pivotal axle, such barbs may be replaced by a toothed disc firmly gripping in the pivot pin.The pivot pin 28 of the pivotal axle 6 has a radial projection 31 which extends in the longitudinal direction and which, with its flanks forms a first engaging member 32 and a second engaging member 33 for the throttle 5. In the embodiment shown the two engaging members are combined into the common, radial projection 31. The members may also be located in the longitudinal extension of the pivot axle 6 and be spaced apart or be separate projections at varying angular positions relative one another on the pivot pin 28. As shown in Figures 3 to 5, the engaging members 32 and 33 of the pivot axle 6 co-operate with stop surfaces 34 and 35 in the boss 22 of the throttle 5 in a manner not described in detail.

In the second end position of the throttle 5 shown in dotted lines in Figure 1 and which corresponds to the summer position, the pivot lever 30 of the pivotal axle 6 is engaged in the stop groove 8 and the throttle 5 closes the hot air inlet passage 4 during all operating states of the internal combustion engine. Consequently, the air filter 1 only receives cold air. In this position in accordance with Figure 3, the first engaging member 32 of the pivotal axle 6 abuts against the first stop 34 of the throttle 5 and the throttle 5 is retained in this end position against the return force of the spring 9.

In the first end position shown in full lines in Figure 1 wherein the throttle 5 is caused by the spring 9 to assume a position closing unheated air passage 3, and the pivot lever 30 is engaged in the stop groove 7. In this end position, which corresponds to the winter position, heated air only is supplied to the air filter 1 below a predetermined operating point of the internal combustion engine. Figure 4 shows that in this operating state of the internal combustion engine the first stop 34 of the throttle 5 has a small spacing from the first engaging member 32 of the pivotal axle 6. In this first end position the throttle 5 is retained by the spring 9 only as long as the pressure difference between the two sides of the throttle does not exceed a predetermined value.

Upon exceeding a predetermined operating condition of the internal combustion engine, i.e. upon exceeding a predetermined intake air supply, the throttle 5 with the pivot lever 30 engaged in the stop groove 7 begins to move away out of the first end position against the return force of the spring 9 engaging thereon. With rising pressure difference across the throttle it progressively opens the unheated air passage 3 and hence the supply of unheated air into the air filter 1 until the position shown in chain-dotted lines in Figure 1 is finally attained. As shown in Figure 5 which corresponds to this mentioned position, the throttle 5 pivots to such an extent until its second stop 35 abuts against the second engaging member 33 of the pivotal axle 6.

The pivotal movement of the throttle 5 from the first end position is so limited by the stop 35.

The limitation of the unheated air supply by the pivot lever 30 engaged in the stop groove 7 in the winter position may also be attained by suitable arrangement of the return force of the spring 9. The spring 9 would then have to be so dimensioned and possibly pre-tensioned that the total forces occurring at the throttle 5 would only lead to the restricted opening of the unheated passage 3 in the winter position. It would then be possible to omit the second stop 35a of the throttle 5 and the second engaging member 33 of the pivot axle 6 or for such to be so arranged that it becomes ineffective.

A cross-section through the boss of a throttle so fashioned with inserted pivot axle is shown in Figure 6 shown in the position indicated by chain-dotted lines in Figure 1.

It would be conceivable to cause such flow ratios around the throttle 5 that they substantially influence the position of the throttle 5 shown by chain-dotted lines in Figure 1. The only purpose of the spring 9 would then be to determine the operating point beyond which the throttle 5 begins to open the unheated air passage in winter position.

The structural elements used for the aforesaid apparatus, with the exception of the spring 9, may instead of being made of metal be made wholly or partly of plastics material.

WHAT WE CLAIM IS: 1. An apparatus for the optional supply of heated air or unheated air into an induction air filter of an internal combustion engine including a throttle valve eccentrically mounted in the unfiltered air intake passage wherein the throttle valve in a first end position closes the unheated air supply and in a second end position closes the heated air supply, and above a predetermined operating condition of the internal combustion engine with which the apparatus is to be used, the throttle valve, if initially in the first end position, progressively releases the unheated air supply against the action of a return bias means with rising pressure difference between the two sides of the throttle valve as it moves from the first end position out of the unheated air passage, said throttle valve being mounted on a pivotal axle which passes through a boss of the throttle valve which axle has an angled pivot lever extending outward of said intake passage and engageable in either of two positions corresponding to the end position of the throttle valve wherein the throttle valve is pivotally mounted on the pivotal axle, and said throttle valve is biassed by the return force of a spring engaged thereon and on the air intake passage, the throttle valve being adapted to be pivoted away from its first end position, and wherein with the pivot lever engaged in a position corresponding to the second end position of the throttle valve the pivotal axle has a first engaging member or means adapted to act on a first stop of the throttle valve to retain said throttle valve in the second end position.

2. An apparatus as claimed in claim 1 in which the throttle valve has a second stop for a second engaging member or means of the pivotal axle which limits the pivoting away of the throttle valve from the first end position with the pivot lever engaged in the position corresponding to said first end position.

3. An apparatus as claimed in claim 2, in which the first engaging member and the

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (6)

**WARNING** start of CLMS field may overlap end of DESC **. throttle 5 closes the hot air inlet passage 4 during all operating states of the internal combustion engine. Consequently, the air filter 1 only receives cold air. In this position in accordance with Figure 3, the first engaging member 32 of the pivotal axle 6 abuts against the first stop 34 of the throttle 5 and the throttle 5 is retained in this end position against the return force of the spring 9. In the first end position shown in full lines in Figure 1 wherein the throttle 5 is caused by the spring 9 to assume a position closing unheated air passage 3, and the pivot lever 30 is engaged in the stop groove 7. In this end position, which corresponds to the winter position, heated air only is supplied to the air filter 1 below a predetermined operating point of the internal combustion engine. Figure 4 shows that in this operating state of the internal combustion engine the first stop 34 of the throttle 5 has a small spacing from the first engaging member 32 of the pivotal axle 6. In this first end position the throttle 5 is retained by the spring 9 only as long as the pressure difference between the two sides of the throttle does not exceed a predetermined value. Upon exceeding a predetermined operating condition of the internal combustion engine, i.e. upon exceeding a predetermined intake air supply, the throttle 5 with the pivot lever 30 engaged in the stop groove 7 begins to move away out of the first end position against the return force of the spring 9 engaging thereon. With rising pressure difference across the throttle it progressively opens the unheated air passage 3 and hence the supply of unheated air into the air filter 1 until the position shown in chain-dotted lines in Figure 1 is finally attained. As shown in Figure 5 which corresponds to this mentioned position, the throttle 5 pivots to such an extent until its second stop 35 abuts against the second engaging member 33 of the pivotal axle 6. The pivotal movement of the throttle 5 from the first end position is so limited by the stop 35. The limitation of the unheated air supply by the pivot lever 30 engaged in the stop groove 7 in the winter position may also be attained by suitable arrangement of the return force of the spring 9. The spring 9 would then have to be so dimensioned and possibly pre-tensioned that the total forces occurring at the throttle 5 would only lead to the restricted opening of the unheated passage 3 in the winter position. It would then be possible to omit the second stop 35a of the throttle 5 and the second engaging member 33 of the pivot axle 6 or for such to be so arranged that it becomes ineffective. A cross-section through the boss of a throttle so fashioned with inserted pivot axle is shown in Figure 6 shown in the position indicated by chain-dotted lines in Figure 1. It would be conceivable to cause such flow ratios around the throttle 5 that they substantially influence the position of the throttle 5 shown by chain-dotted lines in Figure 1. The only purpose of the spring 9 would then be to determine the operating point beyond which the throttle 5 begins to open the unheated air passage in winter position. The structural elements used for the aforesaid apparatus, with the exception of the spring 9, may instead of being made of metal be made wholly or partly of plastics material. WHAT WE CLAIM IS:

1. An apparatus for the optional supply of heated air or unheated air into an induction air filter of an internal combustion engine including a throttle valve eccentrically mounted in the unfiltered air intake passage wherein the throttle valve in a first end position closes the unheated air supply and in a second end position closes the heated air supply, and above a predetermined operating condition of the internal combustion engine with which the apparatus is to be used, the throttle valve, if initially in the first end position, progressively releases the unheated air supply against the action of a return bias means with rising pressure difference between the two sides of the throttle valve as it moves from the first end position out of the unheated air passage, said throttle valve being mounted on a pivotal axle which passes through a boss of the throttle valve which axle has an angled pivot lever extending outward of said intake passage and engageable in either of two positions corresponding to the end position of the throttle valve wherein the throttle valve is pivotally mounted on the pivotal axle, and said throttle valve is biassed by the return force of a spring engaged thereon and on the air intake passage, the throttle valve being adapted to be pivoted away from its first end position, and wherein with the pivot lever engaged in a position corresponding to the second end position of the throttle valve the pivotal axle has a first engaging member or means adapted to act on a first stop of the throttle valve to retain said throttle valve in the second end position.

2. An apparatus as claimed in claim 1 in which the throttle valve has a second stop for a second engaging member or means of the pivotal axle which limits the pivoting away of the throttle valve from the first end position with the pivot lever engaged in the position corresponding to said first end position.

3. An apparatus as claimed in claim 2, in which the first engaging member and the

second engaging member are combined into a common radial projection of the pivotal axle, with the flanks of which axle forming the engaging members which co-operate with the flanks of a recess formed in the boss of the throttle and forming the stops.

4. An apparatus as claimed in claim 3, in which the projection extends in longitudinal extension of the pivot axle and the recess in the boss is formed as an elongate groove.

5. An apparatus as claimed in claim 4, in which the recess is closed at one end face.

6. A control apparatus for the supply of air to an air filter of an internal combustion engine constructed and arranged to operate substantially as herein described with reference to and as illustrated in the accompanying drawings.