GB2063369A

GB2063369A - Compressed Air Control Mechanism for a Starter of Multi- cylinder Internal Combustion Engines

Info

Publication number: GB2063369A
Application number: GB8034969A
Authority: GB
Original assignee: Kloeckner Humboldt Deutz AG
Current assignee: Kloeckner Humboldt Deutz AG
Priority date: 1979-11-06
Filing date: 1980-10-30
Publication date: 1981-06-03
Also published as: JPS6128831B2; DE2944742C2; FR2468762A1; JPS5675917A; FR2468762B1; DE2944742A1; GB2063369B

Abstract

The mechanism comprises a connection plate (5) having air flow ducts (15) for connection to engine cylinders, a rotary distributor valve (8) for distributing compressed air from inlet pipe 9 to the air flow ducts (15), and a control plate (4) arranged between the distributor valve (8) and the connection plate (5), the control plate (4) having a first main face adjacent the distributor valve, a second main face adjacent the connection plate (5), and through bores (13) which at one end communicate with the distributor valve (8) and which at their other ends opens into respective ones of a number of recesses (14) disposed in the second main face of the control plate (4), each of the air flow ducts (15) in the connection plate registering with a respective one of the recesses (14) in the control plate (4). The mechanism can be used with engines having 6, 8 or 9 cylinders by using a control plate having a corresponding number of bores 13. <IMAGE>

Description

SPECIFICATION Compressed Air Control Mechanism for a Starter of Multi-cylinder Internal Combustion Engines This invention relates to a compressed air control mechanism for controlling the supply of compressed air to cylinders of a starter of a multicylinder internal combustion engine for the purpose of starting the engine, the mechanism serving to pressurise and vent cylinder feed lines, and comprising a rotary distributor valve and a connection plate with air connections for the cylinder feed lines.

Compressed air control mechanisms for multicylinder internal combustion engines starters are known (German Patent Application DE AS 11 76 931). The known mechanisms are invariably designed for use with an engine having a specified number of cylinders. As a result, every specific engine type within a series with a specific number and arrangement of cylinders requires a compressed air starter control all its own. Many different constructions of the individual component parts are consequently necessary.

An aim of the invention is the provision of a compressed air control mechanism which can be used, with minor modification, for engines having different numbers of cylinders.

According to the present invention there is provided a compressed air control mechanism for controlling the supply of compressed air to cylinders of a multi-cylinder internal combustion engine for the purpose of starting the engine, the mechanism comprising a connection plate having air flow ducts for connection to engine cylinders, a rotary distributor valve for distributing compressed air to the air flow ducts, and a control plate arranged between the distributor valve and the connector plate, the control plate having a first main face adjacent the distributor valve, a second main face adjacent the connection plate, and through bores which at one end open onto the first main face of the control plate to communicate with the distributor valve and which at their other ends open into respective ones of a number of recesses disposed in the second main face of the control plate, each of the air flow ducts in the connection plate registering with a respective one of the recesses in the control plate.

Preferably where the number of bores provides in the control plate is equal to x, the angular spacing between the bores =360/x, and the number of recesses provided in the control plate is equal to y, then the location of the recesses and their angular extent is so chosen that the number of bores x may be chosen to be equal to the number of recesses y, or may be chosen to be equal to at least one numberx less than y, and in both cases each bore will communicate with a recess, and no recess will communicate with more than one bore.

According to another aspect of this invention there is provided compressed-air control mechanism for controlling the supply of compressed air to cylinders of a multi-cylinder internal combustion engine for the purpose of starting the engine, the mechanism serving to pressurise and vent cylinder feed lines, and comprising a connection plate provided with air connections for the cylinder feed lines, a rotary distributor valve, and an interchangeable control plate arranged between the connection plate and the rotary distributor valve to be coaxial with these, the connection plate having a plurality of mutually alike air connections sufficient in number for the number of cylinders provided, the control plate having a plurality of control bores equal in number to the number of cylinders to be directly started and having mutually alike recesses equal in number to the number of air connections and open towards the connection plate, and each control bore being connected to an air connection via one of the recesses.

The advantages obtained include, on the manufacturer's side, the avoiding of parallel developments, saving of production equipment, reduction of preparation times and full utilisation of the production capacity. On the user's side the reserve stock needs are reduced, maintenance is made more uniform and the stock of tools etc.

required is harmonised. One work-intensive assembly operation during internal combustion engine manufacture is the fitting of lines and the bending of the line sections in accordance with templates and other devices. This operation cannot be automated and this is true more especially in the case of large engines produced in small numbers. It is precisely in the case of small numbers that investment and reserve stock costs for components specific to a particular type increase relative to material and production costs.

By making the components more uniform investment costs can be reduced considerably while the increase in component costs is often only small.

A compressed air starter control mechanism in accordance with the invention is shown, by way of example, in the accompanying drawings, in which Figure 1 shows a cross section of the complete compressed air starter control; Figure 2 shows a front elevation of Figure 1; and Figure 3 shows the control plates for engines with six, eight and nine cylinders.

As shown in Figure 1 the crankcase 1 of an engine is formed with an aperture which is closed off by a cover plate 2. The cover plate 2 is formed with a stepped opening or bore 3 into which extends an end region of a shaft 6 which is driven by means of a toothed gear wheel 7. An apertured valve disc member 8 is mounted fast on the rotary shaft 6 adjacent the extreme end of the shaft The outer portion of the valve disc 8 lies in the wider portion of the stepped bore 3 and defines a annular chamber 11 between itself and a shoulder formed where the wider portion of the stepped bore 3 joins the narrower portion.

Compressed air can be fed to the chamber 11 by way of a bore 10 in the cover plate. A compressed air supply line 9 is connected to the bore 10 by way of a conventional union. The outer region of the valve disc member 6 is formed with at least one through opening which may comprise an arcuate slot 12, (but could instead comprise a plurality of ports) the center of curvature of this slot 12 being the axis of rotation of the valve disc 8.

An apertured control plate 4 overlies the valve disc 8 and is retained in place by being trapped between the cover plate 2 and a connection plate 5 bolted to the cover plate 2 by means of four bolts 22 (Figure 2). For the purpose of accurately centering the control plate 4, a portion of such plate is designed to be a close fit within the wider portion of the stepped bore 3. The control plate 4 has a number of through bores 1 3 (e.g. nine through bores). At one main face of the control plate 4 the bores 13 serve to communicate with the slot 12 in the rotary disc 8. The other ends of the bores 13 open into respective ones of a number of recesses 14 disposed angularly spaced apart around another main face of the control plate 4.

The connection plate 5 has a number of through bores 1 5 equal to the number of recesses 14. These bores 15 each open at one end in registry with a respective one of the recesses 14 to communicate therewith. The other ends of the bores 1 5 are each connected to a respective cylinder feed pipe 1 6. The bores 1 5 serve as air flow ducts. The cylinder feed pipes 1 6 are bunched together and formed or combined into one part 17 of a connector. The connector part 17 is connected to a co-operating connector part 1 8 which in turn is connected to cylinder feed pipes 19.

Operation of the mechanism is as follows. In order to supply compressed air to the engine cylinders (not shown) for starting the engine the line 9 is pressurised and the shaft 6 is rotated by means of the gear wheel 7. As the shaft 6 rotates, the valve disc 8 rotates, and compressed air in the annular chamber 11 is caused to flow in turn through the bores 13 in the control plate 4 by way of the slot 12. The compressed air is fed from the bores 13, via the recesses 14 and bores 15, to the cylinder feed lines 1 6 and 19. At the same time as air is being fed to one of the cylinders, air may be returning from another cylinder. For example, the returning air may enter the lowermost bore 15, may flow from there through the lowermost bore 13, and from there be vented to a region within the crankcase by way of a port or recess 20 in the valve disc 8 and a bore 21 in the shaft 6.

The precise locations of recesses 14 and their arcuate extent is carefully chosen so that a combination of the connection plate 5 and a blank for the control plate can be used to provide a mechanism for starting a six cylinder engine, an eight cylinder engine, or a nine cylinder engine.

The said blank for the control plate will be formed with the recesses 14 illustrated, but will not be provided with any bores. Figure 3 comprises three views of the control plate 4 showing three different ways in which the control plate blank can be bore. In the lowermost view, nine bores 1 3 are provided, one bore communicates with each recess 14, and the angular spacing between the bores 13 is 400. In the central view, only eight bores are provided, spaced apart by 450. In this case, eight of the recesses with have bores communicating with them, but one of the recesses will have no bore 1 3. In the uppermost view, six bores 13 are spaced 600 apart. In this case only six of the recesses 14 will communicate with bores 13.

The positions and sizes (angular extents) of the recesses 14 are so chosen that whether six, eight, or nine bores 1 3 are equally spaced apart around the control plate 4, each bore 13 will communicate with one of the recesses 14 and no recess 14 will communicate with more than one bore.

It is even possible to construct the connection plate 15, the pipes 16, and the connector 1 7 as an assembled unit which can be used with six, eight, or nine cylinder engines. In this case, there will be nine pipes 1 6 each connected to an opening 1 5 in the connection plate 5. In this case, when the mechanism is used with a six or eight cylinder engine it will not matter that there are extra pipes 16 provided, because these pipes are isolated from the air distributor valve 8 by the unbored portions of the control plate 4. Thus it is possible to manufacture and stock only one assembly of connection plate 5, feed pipes 1 6 and connector part 1 7 which can be used with all engines, i.e. the six, eight and nine cylinder engines.This is clearly a great advantage.

In a modification, not illustrated, the connection plate 5 could be formed, on its face remote from the control plate 4 with a connector part corresponding to connector part 17.

Another advantage is that the same control plate blanks can be used for the six, eight and nine cylinder engines, the control plate being manufactured from the recessed blank merely by drilling the correct number of holes at the appropriate equi-angular spacing. The control plate 4 can easily be fitted in its seat in plate 2 during initial assembly, and can easily be replaced should this prove necessary.

In the embodiment illustrated, the control plate 4 is designed to be adjusted. For this purpose, the control plate has a projecting lobe 23, so that after slackening the bolts 22, the plate can be rotated by means of the lobe 23 to a desired position, whereafter the bolts will be tightened.

Adjustment of the plate 4 as described will effect a change in the timing of the supply of compressed air. This change in timing is thus effected very simply, and does not require bending of the pipes 1 6 which was necessary in previously known arrangements. The connector 17, 18 can be of the "quick connect" type, and the conector part 18 can, if desired, be made integrally with the pipes 1 9 to comprise a prefabricated component. Naturally, all connectors will be disposed to be readily accessible.

The air flow ducts in the connection plate 5 are in the illustrated embodiment constructed as through bores 1 5 which can be smooth or internally screw threaded. The pipes 1 6 can be soldered or bolted in place.

An important feature of the arrangement of the recesses 14 is that where the number of bores provided in the control plate is equal to x, the angular spacing between the bores=360/x, and the number of recesses 14 provided in the plate 4 is equal to y, then the location of the recesses and their angular extent is so chosen that the number of bores 1 3 may be chosen to equal the number of recesses, or may be chosen to be equal to at least one number x less than y, and in both cases, each bore 13 will communicate with a recess 14, and no recess 1 4 will communicate with more than one bore.

Claims

1. A compressed air control mechanism for controlling the supply of compressed air to cylinders of a multi-cylinder internal combustion engine for the purpose of starting the engine, the mechanism comprising a connection plate having air flow ducts for connection to engine cylinders, a rotary distributor valve for distributing compressed air to the air flow ducts, and a control plate arranged between the distributor valve and the connection plate, the control plate having a first main face adjacent the distributor valve, a second main face adjacent the connection plate, and through bores which at one end open onto the first main face of the control plate to communicate with the distributor valve and which at their other ends open into respective ones of a number of recesses disposed in the second main face of the control plate, each of the air flow ducts in the connection plate registering with a respective one of the recesses in the control plate.

2. A mechanism according to claim 1, in which, where the number of bores provided in the control plate is equal to x, the angular spacing between the bores=360/x, and the number of recesses provided in the control plate is equal to y, then the location of the recesses and their angular extent is so chosen that the number of bores x may be chosen to be equal to the number of recesses y, or may be chosen to be equal to at least one number x less that y, and in both cases each bore will communicate with a recess, and no recess will communicate with more than one bore.

3. A mechanism according to claim 2, in which the control plate is formed from a blank which has the said recesses formed in it, but does not have the said bores, whereby by chosing an appropriate value for the number of bores x, the combination of control plate blank and connection plate can be used in a mechanism to supply air to a number of cylinders x equal to y (for example equal to nine) or instead equal to less than y (for example equal to six or eight).

4. A mechanism according to any preceding claim, in which the rotary distributor valve, the control plate, and the connection plate are coaxial, and the control plate fits at least partly within an opening in an engine crankcase cover plate, the control plate being held in position by being trapped between the connection plate and cover plate.

5. A mechanism according to claim 4, in which the position of the control plate is angularly adjustable by rotating such plate whereby to adjust the timing of the compressed air supply to cylinders of the engine.

6. A mechanism according to claim 4 or claim 5, in which the control plate has a portion which is a close fit in the opening in the cover plate whereby to centre the control plate during assembly of the mechanism.

7. A mechanism according to any preceding claim in which cylinder feed pipes are connected to each and every air flow duct in the connection plate, and in which the feed lines are at their ends remote from the connection plate combined into a connector part.

8. A mechanism according to any of claims 1 to 6, in which the connection plate is formed with a connector as a one-piece component, to which may be connected a connector part into which cylinder feed lines are connected.

9. A mechanism according to any preceding claim, in which the air flow ducts in the connection plate are comprised by through bores.

10. A compressed air control mechanism substantially as described herein with reference to the accompanying drawings.

11. A compressed-air control mechanism for controlling the supply of compressed air to cylinders of a multi-cylinder internal combustion engine for the purpose of starting the engine, the mechanism serving to pressurise and vent cylinder feed lines, and comprising a connection plate provided with air connections for the cylinder feed lines, a rotary distributor valve, and an interchangeable control plate arranged between the connection plate and the rotary distributor valve to be coaxial with these, the connection plate having a plurality of mutually alike air connections sufficient in number for the number of cylinders provided, the control plate having a plurality of control bores equal in number to the number of cylinders to be directly started and having mutually alike recesses equal in number to the number of air connections and open towards the connection plate, and each control bore being connected to an air connection via one of the recesses.