GB1570075A

GB1570075A - Internal combustion engine air cleaners

Info

Publication number: GB1570075A
Application number: GB30798/76A
Authority: GB
Original assignee: General Motors Ltd
Current assignee: General Motors Ltd
Priority date: 1976-07-23
Filing date: 1976-07-23
Publication date: 1980-06-25
Also published as: DE2732165A1; AU511142B2; DE2732165C3; AU2701577A; DE2732165B2

Description

(54) INTERNAL COMBUSTION ENGINE AIR CLEANERS (71) We, GENERAL MOTORS LIMI TED, a British Company of High Sueet North, Dunstable, Bedfordshire, 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 particu- larly described in and by the following statement: This invention relates to internal combustion engine air cleaners.

It is known in the manufacture of internal combustion engine air cleaners to make provision for the air entering the intake pipe of the air cleaner to be drawn either from aunosphere, during normal operating conditions, or from a source of heated air, for example from a location adjacent the exhaust manifold of the engine, during low temperature conditions.

Such arrangements commonly consist of a pivotal valve member mounted in the intake pipe and movable to close one and open the other of two inlet openings one of which is adapted to draw air from atmosphere and the other of which is adapted to draw air from a source of heated air, such as a location adjacent the engine exhaust manifold, the valve commonly being manually adjustable so as to be retained in one or the other of its two positions.

The two positions in which the valve can be set are commonly designated as the "Winter" and "Summer" positions, and the two inlet openings are commonly referred to as the "warm air" and the "cold air" inlets and will be so referred to in the following description.

The use of such arrangements in an internal combustion engine air cleaner, when the valve member is retained in the "winter" position, in which the air is drawn into the cleaner intake conduit through the warm air inlet, may give rise to undesirable carburation of the engine during conditions of high air cleaner intake vacuum or high acceleration of the engine, an undesirably rich fuel/air mixture being drawn into the engine intake manifold under such conditions. It may also lead to loss of power in conditions of relatively high ambient temperature.

In an internal combustion engine air cleaner according to the present invention, in which a pivotal valve member in an intake pipe by which air enters the cleaner is selectively locatable so as to open one and close the other of two (cold air and warm air) inlet openings in said intake pipe which are res pectively intended for communication with atmosphere and a source of heated air, said valve member is adjustable so as to be retained in the "winter" position in which said cold air inlet opening is closed, and said valve member includes means associated therewith adapted when the valve is thus retained, to permit air to enter said intake pipe from said cold air inlet opening when the pressure within said pipe downstream of said valve member attains a predetermined sub-atmospheric value.

In a preferred embodiment of the present invention said valve member is manually operable to be latched so as to close either the cold air or warm air inlet opening and the valve member has an opening therein normally closed by a flexible flap which, when the valve is latched to close the cold air inlet, is adapted to be displaced from said valve opening upon the attainment of a predetermined sub-atmospheric pressure within the cleaner intake pipe downstream of said valve member, and thus permit air from atmosphere to be drawn in through the opening in the valve member from the cold air inlet opening in the pipe.The valve member is secured on a pivot pin having an extension arm to enable the valve member to be latched in either of its positions, and also mounted on the pivot pin and freely movable thereon is a further flap to which is attached one end of a coil spring the other end of which is anchored so as normally to retain the flap in a position permitting warm air to enter the intake pipe.

With this arrangement, when the pressure within the intake pipe downstream of the valve member reaches a predetermined subatmospheric value the flexible flap is displaced from the opening in the valve member which it overlies to permit cold air to enter the pipe; at the sarne time, the increased vacuum in the pipe acts on the flap in the warm air inlet and moves it, against the bias of the spring, towards the position in which it restricts the entry of warm air.

The valve member is preferably of arcuate form and the flexible flap, made of rubber or other elastomeric material, is secured along the edge thereof adjacent the pivot pin so that it is prestressed to overlie the opening in the valve member.

The scope of the invention is defined by the appended claims; and the invention and the method by which it is to be formed are hereinafter particularly described with reference to the accompanying drawing the single figure in which is a longitudinal section of the intake pipe of an internal combustion engine air cleaner according to the invention.

The drawing shows an air cleaner intake pipe 1, conveniently of rectangular section, having 2 integral extensions 2, 3 branching equi-angularly therefrom in "Y" form, the branch pipe 2 being the warm air inlet conduit which, in use of the air cleaner, will be located adjacent, or be connected to, a source of heated air, and the branch pipe 3 being the cold air inlet arranged to be open to, or to receive, unheated ambient air.

Mounted at the base of the angle at the junction between the pipes 2, 3 is a pivot pin 4 on which is secured a valve member 5 in the form of an arcuate plate which, as shown in the drawing, in one position of movement extends across the junction between the cold air branch pipe 3 and the intake pipe 1. The valve plate 5 has therein an opening 6 normally closed by a flexible flap 7 secured at one edge thereto, adjacent the pivot pin 4 as by rivets 8, the flap 7 normally overlying and closing the opening 6 in the valve plate 5.

Preferably the flap 7 is secured so that it is prestressed so as to conform to the curvature of the plate 5. The pivot pin 4 is formed with an extension arm (not shown) so that the valve plate 5 with the flap 7 thereon can be manually moved from the position shown to the position indicated by the broken line 9 in which the valve plate closes the junction between the warm air branch pipe 2 and the intake pipe 1. The extension arm is arranged, in known manner (not shown) to enable the valve plate 5 to be latched in either of its two positions of adjustment.

Also mounted on the pivot pin 4, and freely movable thereon, is a further valve plate or flap 10 to which is attached one end of a coil spring 11 the other end of which is anchored to the warm air branch pipe 2 so that the flap 10 is normally retained in a position in which it permits warm air to enter the intake pipe 1 but can be moved against the bias of the spring 11 towards a position in which it closes the warm air intake pipe 2.

In the use of the arrangement described above, in which the intake pipe 1 is connected to the air cleaner of an internal combustion engine so as to deliver air to the carburetter of the engine, and assuming that the valve plate 5 has been latched in the position in which it closes the cold air intake pipe 3, warm air will be drawn into the carburetter by way of the warm air intake pipe 2 and the intake pipe 1.When the pressure within the intake pipe 1 downstream of the valve plate 5 reaches a predetermined sub-atmospheric value, the flexible flap 7 will be displaced from the opening 6 in the valve plate 5 which it overlies and will thus permit cold air to enter the intake pipe 1; at the same time, the increased vacuum in the pipe 1 acts on the flap 10 in the warm air pipe 2 and moves it, against the bias of the spring 11, towards the position in which it restricts or prevents the entry of warm air into the intake pipe 1.

When an air cleaner intake pipe constructed and adapted to operate as described above, has the flap 5 secured in the "winter" position in which the cold air intake is closed thereby, then in conditions of high intake vacuum in the carburetter supplied by the air cleaner, or conditions of high acceleration of the engine, the flexible flap 7 will be deflected to allow a proportion of cold air, depending on the degree of intake vacuum, to be admixed with the warm air entering the intake pipe 2 and thus prevent an undesirably rich fuel air mixture being supplied to the engine under such conditions.

The "Y" pipe formed by the intake pipe 1 and the extensions 2, 3 is conveniently formed from an upper and a lower rectangular channel-form pressing or moulding in sheet metal or plastics, secured together at their edges; and the extensions 2 and 3 of the intake pipe 1 are conveniently at 300 to the longitudinal axis of the pipe 1.

WHAT WE CLAIM IS: 1. An internal combustion engine air cleaner in which a pivotal valve member in an intake pipe by which air enters the cleaner is selectively locatable to open one and close the other of two (cold air and warm air) inlet openings in said intake pipe which are respectively intended for communication with atmosphere and a source of heated air, said valve member including means associated therewith adapted when said valve member is located in the "winter" position in which said cold air inlet opening is closed, to permit air to enter said intake pipe from said cold air inlet opening when the pressure within said pipe downstream of said valve member attains a predetermined sub-atmospheric value.

2. An internal combustion engine air cleaner according to claim 1, in which said valve member has an opening therein nor mally closed by a flexible flap which, upon

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. pipe; at the sarne time, the increased vacuum in the pipe acts on the flap in the warm air inlet and moves it, against the bias of the spring, towards the position in which it restricts the entry of warm air. The valve member is preferably of arcuate form and the flexible flap, made of rubber or other elastomeric material, is secured along the edge thereof adjacent the pivot pin so that it is prestressed to overlie the opening in the valve member. The scope of the invention is defined by the appended claims; and the invention and the method by which it is to be formed are hereinafter particularly described with reference to the accompanying drawing the single figure in which is a longitudinal section of the intake pipe of an internal combustion engine air cleaner according to the invention. The drawing shows an air cleaner intake pipe 1, conveniently of rectangular section, having 2 integral extensions 2, 3 branching equi-angularly therefrom in "Y" form, the branch pipe 2 being the warm air inlet conduit which, in use of the air cleaner, will be located adjacent, or be connected to, a source of heated air, and the branch pipe 3 being the cold air inlet arranged to be open to, or to receive, unheated ambient air. Mounted at the base of the angle at the junction between the pipes 2, 3 is a pivot pin 4 on which is secured a valve member 5 in the form of an arcuate plate which, as shown in the drawing, in one position of movement extends across the junction between the cold air branch pipe 3 and the intake pipe 1. The valve plate 5 has therein an opening 6 normally closed by a flexible flap 7 secured at one edge thereto, adjacent the pivot pin 4 as by rivets 8, the flap 7 normally overlying and closing the opening 6 in the valve plate 5. Preferably the flap 7 is secured so that it is prestressed so as to conform to the curvature of the plate 5. The pivot pin 4 is formed with an extension arm (not shown) so that the valve plate 5 with the flap 7 thereon can be manually moved from the position shown to the position indicated by the broken line 9 in which the valve plate closes the junction between the warm air branch pipe 2 and the intake pipe 1. The extension arm is arranged, in known manner (not shown) to enable the valve plate 5 to be latched in either of its two positions of adjustment. Also mounted on the pivot pin 4, and freely movable thereon, is a further valve plate or flap 10 to which is attached one end of a coil spring 11 the other end of which is anchored to the warm air branch pipe 2 so that the flap 10 is normally retained in a position in which it permits warm air to enter the intake pipe 1 but can be moved against the bias of the spring 11 towards a position in which it closes the warm air intake pipe 2. In the use of the arrangement described above, in which the intake pipe 1 is connected to the air cleaner of an internal combustion engine so as to deliver air to the carburetter of the engine, and assuming that the valve plate 5 has been latched in the position in which it closes the cold air intake pipe 3, warm air will be drawn into the carburetter by way of the warm air intake pipe 2 and the intake pipe 1.When the pressure within the intake pipe 1 downstream of the valve plate 5 reaches a predetermined sub-atmospheric value, the flexible flap 7 will be displaced from the opening 6 in the valve plate 5 which it overlies and will thus permit cold air to enter the intake pipe 1; at the same time, the increased vacuum in the pipe 1 acts on the flap 10 in the warm air pipe 2 and moves it, against the bias of the spring 11, towards the position in which it restricts or prevents the entry of warm air into the intake pipe 1. When an air cleaner intake pipe constructed and adapted to operate as described above, has the flap 5 secured in the "winter" position in which the cold air intake is closed thereby, then in conditions of high intake vacuum in the carburetter supplied by the air cleaner, or conditions of high acceleration of the engine, the flexible flap 7 will be deflected to allow a proportion of cold air, depending on the degree of intake vacuum, to be admixed with the warm air entering the intake pipe 2 and thus prevent an undesirably rich fuel air mixture being supplied to the engine under such conditions. The "Y" pipe formed by the intake pipe 1 and the extensions 2, 3 is conveniently formed from an upper and a lower rectangular channel-form pressing or moulding in sheet metal or plastics, secured together at their edges; and the extensions 2 and 3 of the intake pipe 1 are conveniently at 300 to the longitudinal axis of the pipe 1. WHAT WE CLAIM IS:

1. An internal combustion engine air cleaner in which a pivotal valve member in an intake pipe by which air enters the cleaner is selectively locatable to open one and close the other of two (cold air and warm air) inlet openings in said intake pipe which are respectively intended for communication with atmosphere and a source of heated air, said valve member including means associated therewith adapted when said valve member is located in the "winter" position in which said cold air inlet opening is closed, to permit air to enter said intake pipe from said cold air inlet opening when the pressure within said pipe downstream of said valve member attains a predetermined sub-atmospheric value.

the attainment of a predetermined sub-atmospheric pressure within the cleaner intake pipe downstream of said valve member, is adapted to be displaced from the opening which it overlies and thus permit air from atmosphere to be drawn in through the opening in the valve member from the cold air inlet opening in the pipe.

3. An internal combustion engine air cleaner according to claim 2 in which said valve member is secured on a pivot pin having an extension arm to enable the valve member to be latched in either of its positions, and also mounted on the pivot pin and freely movable thereon is a further valve member to which is attached one end of a coil spring the other end of which is anchored so as normally to retain said further valve member in a position permitting warm air to enter the intake pipe but permit movement of said further valve member towards a position closing said warm air inlet opening in response to increasing vacuum in said intake pipe.

4. An internal combustion engine air cleaner according to claim 2 or 3, in which said valve member is of arcuate form and the flexible flap made of rubber or other elastomeric material, is secured along the edge thereof adjacent the pivot pin so that it is prestressed to overlie the opening in the valve member.

5. An internal combustion engine air cleaner according to any of claims 1 to 4, in which said intake pipe is formed as a pipe with said cold air and warm air inlets in integral extensions of the intake pipe each extending at an angle to the longitudinal axis thereof.

6. An internal combustion engine air cleaner constructed and adapted to operate substantially as hereinbefore particularly described with reference to and as shown in the accompanying drawings.