JPS6032033B2 - Starting and braking device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is a starting and braking device for internal combustion engines, in particular large diesel engines, which comprises a starting valve arranged in the area of each cylinder, which starting valve is loaded with pressure medium. with a control section delimited by two control greens corresponding to the starting control time, operable with a possible actuating piston, the pressure medium being movable in the respective direction of rotation of the internal combustion engine; The present invention relates to a type which can be supplied in the movement stroke of an internal combustion engine by means of a control device with a scannable control slide guide.

According to West German Utility Model No. 7218931, such a device is known.

In such devices, one control slide guide, for example a cam, is provided on the control shaft for starting in the main direction of rotation and for starting in the opposite direction of rotation or braking from the main direction of rotation. ing. These control barrel guides are scanned by appropriate feelers to properly control the starting valve. The control shaft is normally movable in the vertical direction for selective control, and the position of the control shaft predetermines whether the aforementioned forward cam or backward cam is acting. However, cases also arise where the internal combustion engine is stopped, for example in the main direction of rotation, and it is later desired to start it from this stopped state in the opposite direction of rotation. This is only possible in the device described in that the control shaft is moved from a position corresponding to the main direction of rotation to a position corresponding to the desired direction of rotation in the stationary state. However, this results in extremely high wear on the control cam of the control shaft and the roller actuated by this cam. Attempts have therefore been made to reduce this wear phenomenon by means of switching control aids. Furthermore, it is known, on the other hand, to provide a separate starting device with a forward cam and a reverse cam, in order to be able to start the internal combustion engine in any direction even if the position of the control shaft does not correspond to the desired direction of rotation. It is. However, this type of device requires conduits which are quite long and have different lengths from valve to valve. Such long control conduits introduce delays that prevent the necessary precise and rapid control. Starting from this, it is an object of the invention to avoid the known disadvantages and to make it possible to start this machine in the desired direction of rotation from any standstill, without any prior movement of the control shaft, at a low cost, but with a delay. An object of the present invention is to provide a starting device that can achieve a control time with a reduced amount of time. This task has a starting valve arranged in the area of each cylinder, which starting valve can be actuated by a working piston that can be loaded with a pressure medium, which pressure medium is used for the respective internal combustion engine. A control device with a scannable control slide guide, movable in the rotational direction, with a control section delimited by two control edges, corresponding to the starting control time, can be provided in the movement stroke of the internal combustion engine. In the starting device, two selectively actuatable pressure medium lines, each assigned to one direction of rotation, are provided, which are opened and closed by control valves that scan the same control slide guide. controllable, such that the scanning mechanism of these control valves is equal to the section corresponding to the starting or braking time movement angle between clockwise and counterclockwise rotation of the control ladder guide provided in the area of each cylinder. This was solved by placing them side by side at intervals.

Since this type of device is simple and inexpensive, it is possible to provide a control slide with one control slide guide and two scanning mechanisms in the area of each cylinder without great expense. In this case, the required length of the conduit is minimized and, moreover, can be of the same length everywhere. This provides accurate control times. Furthermore, in this case, the internal combustion engine can be started from any position in the desired direction of rotation by energizing the pressure medium line corresponding to the desired direction of rotation. The control shaft can then be moved, if appropriate, as soon as a predetermined critical rotational speed is achieved. While the control shaft is not brought to a position corresponding to the desired rotational speed, all cylinders of the engine cannot produce their full power, but there is already enough power to move the engine, and therefore the control shaft can now be moved while driving instead of at a standstill. Wear phenomena are correspondingly reduced. In one advantageous embodiment of the invention, the pressure medium lines enter a common pressure medium connection line in the area behind the control valve and can be mutually closed by a check valve.

This procedure allows the omission of parallel conduits which are used only as an alternative. Furthermore, it is advantageous if pressure medium connection lines are provided on both sides of the working piston.

This makes it possible to assist the opening and closing movements of the starter valve with the control medium. This is particularly advantageous for braking. Therefore, in most cases it is sufficient for at least one control slider to have a control green that controls the opening and closing operation of the starting valve. Advantageously, air is used as pressure medium.

This medium is inexpensive and easily applied to large machines. Furthermore, it is advantageous for this purpose if the pressure medium line is connected to the starting air cylinder via a throttle valve. This allows the pressure level present in the starting air cylinder to be reduced to the desired individual pressure level. Another aspect of the present invention
In the exemplary embodiment, a dam pressure valve is provided as a control slide.

Since this dam pressure valve operates without contact and is not exposed to pressure and friction forces, it usually has relatively short connection times and, moreover, it is possible to provide the control slide guide with a relatively simple design. Become. Since only a small amount of pressure medium always escapes in the dam pressure valve, it is particularly advantageous in this case to use air as the pressure medium. An advantageous embodiment of the dam pressure valve is such that it has a pressure medium dam chamber that can be closed sufficiently tightly by means of a control grate guide, which pressure medium dam chamber can be loaded with respect to the pressure in the dam chamber. It can be restricted by a slider, which slider has a ring groove for controlling the opening and closing of the pressure medium conduit. Advantageously, the chamber formed by the ring groove is connected to the stop chamber via a throttle hole in the slider. This eliminates the need for a separate part for supplying the pressure medium to the dam chamber. Insofar as in the device of the invention a cam fixed to the control shaft is provided to form a common control slide guide, according to the basic idea of the invention, the length of the cam is approximately equal to the switching control distance. It is. In this case, it is advantageous if the control edge extends curvedly between the end regions of the control gauze guide. This results in a continuous transition of the shape of the silk guide between the positions assigned to both rotational directions. Such an extension of the control slide guide is necessary in practice whenever the control slide guide is moved for switching control purposes. However, it is also conceivable that the control pin guide is actuated electromagnetically and without the need for movement, in which case it is possible to control the control pin guide corresponding to one of the desired rotational directions by means of an electronic circuit. The invention will now be explained with reference to the drawings. In FIG. 1, reference numeral 1 designates a starting and/or braking valve which is arranged, for example, in a valve cage 2 of a cylinder 3 of a large marine diesel engine.

When the starting valve 1 is released from the valve seat, the starting air is routed through a main starting air conduit 4 connected to a starting air cylinder and guided through holes 5 in the valve cage into a flow path controlled by the starting valve 1. Main starting air is supplied to the main starting air cylinder 3. This makes it possible to start the engine from a standstill or to brake it against the direction of rotation in which it was previously rotating. During normal engine operation, the starter valve 1 is kept in the closed position by a spring 6. For actuating the starting valve, an actuating piston 7 is provided which is loaded with a pressure medium, preferably air. In the embodiment shown, one pressure chamber 8 or 9 is provided on each side of the working piston 7. These pressure chambers 8 or 9 are loaded via connecting channels 10 or 11 with a pressure medium, here compressed air. When the pressure chamber 8 is loaded, the starting valve 1 is opened in the illustrated embodiment, and when the pressure chamber 9 opposite the pressure chamber 8 is loaded, the actuating piston 7 is loaded in the closing direction. This helps the force of the spring 6. This is advantageous when braking the engine, ie when the cylinder 3 acts as a compressor and dissipates the energy. Compressed air is supplied via a connecting conduit 12 to the connecting conduit 10' for opening the starting valve 1, with the stroke of the internal combustion engine provided by a control device, which has not yet been described. To close the starter valve 1, the downstream channel 11 is supplied with compressed air in the same manner via the connecting line 13. This pump also starts with an air bong. Compressed air taken from the tank is used.

This compressed air can optionally be reduced to a low pressure level, for example 1 bar, by means of a throttle valve. In engines which are operated both clockwise and counterclockwise, a pressure medium supply line 14 or 15 is provided in each direction of rotation, which is connected to a starting air cylinder. The opening and closing of both pressure medium supply conduits can be controlled by control valves 16 and 17. In this case, the pressure medium supply line 15 can be loaded, for example, for starting the engine in the main direction of rotation.
The pressure medium supply conduit 14 serves for starting in the opposite direction of rotation and at the same time for braking from the main direction of rotation. It is clear from this that the pressure medium supply line 14 or 15 and the associated control valve 16 or 17 need not be operated simultaneously. Therefore pressure medium supply conduit 1
4 or 15 in the area behind the associated valve 16 or 17 into a connecting line leading to the working chamber of the actuating piston 7; this passage can be connected to the connecting line 12 for actuating the actuating piston 7 in the opening direction. can. In the illustrated embodiment, therefore, the outlet 18 of the control valve 17 is connected to the connecting conduit 1.
9 is connected to the outlet 21 of the control valve 16 via a check valve 20. A common connecting conduit 12 is connected to the two check valves. Such an arrangement can also be provided in the area of the connecting line 13, as long as braking of the engine from both rotational directions is desired and envisaged. However, in this embodiment the closing movement of the starting valve 1 is assisted by compressed air only when braking from the main direction of rotation. For this reason, the connecting line 13 for loading the actuating piston 7 in the closing direction is connected only to the control valve 16 and can therefore be loaded exclusively via the pressure medium supply line 14. In this case, control valve 16 is provided with a further control edge than control valve 17 for controlling the closing air. Activating or disconnecting the pressure medium supply conduit 14 or 15 can be effected from the command station by means of a switch that can be easily activated. The control valve 16 or 17 has an associated scanning mechanism 22 or 23. This scanning mechanism 22 or 23
scans a cam fixed to a control fluid guide 24, in this embodiment a control rod 25, movable with the stroke of the internal combustion engine. When the control rod guide 24 moves into the area of the scanning mechanism 22 or 23, the scanning mechanism activates the associated control valve 16 or 1 in order to load the working piston 7 in the opening or closing direction.
Give a signal to 7. This corresponds therefore to the control section 28 of the control slide guide 24, which is limited by the control edges 26 and 27, or to the filling time during braking. scanning mechanism 22,
The lateral spacing 23 corresponds to the angular distance of the control sperm guide 24, which corresponds to the starting or braking time movement angle between left and right rotation. The angular distance of this pawl and the control slide guide 24 is the same as the control section 28. In this embodiment, when the control shaft 25 rotates clockwise, the control valve 16 cooperates with the scanning mechanism, and when the control shaft 25 rotates counterclockwise, the control valve 17 cooperates with the scanning mechanism 2.
I would like to collaborate with 3. Therefore, in one example, the control edge 26
determines the start of control, and the control green 27 determines the end of the control edge. When the rotation direction is reversed, the start of control is related to the control edge 27, and the end of control is related to the control green 26. It has become. The control shaft 25 is normally movable in the axial direction in internal combustion engines that are switched controlled. In the previous arrangement, therefore, only two cams were provided which were arranged next to each other and which acted on a common scanning mechanism. However, in this embodiment of the invention two scanning mechanisms 22, 23 are provided which scan a common control gauze guide 24, which are arranged side by side in one plane with the same spacing as the control greens 26 and 27. There is. This makes it possible to control the scanning mechanism, which is already assigned to the desired direction of rotation, and thus also the pressure medium line, which is assigned to the desired direction of rotation, without having to move the control shaft 25 in the axial direction. It becomes like this. In this way, the machine can be started in the desired direction of rotation even if the control shaft is in a position opposite to the desired direction of rotation. The control shaft 25 can then be moved during rotation in order to protect the control cam fixed thereon and the roller actuated thereby. In order to be able to operate the desired scanning mechanism during or even after the control shaft 25 is moved in the enemy direction, as shown in FIG. The cam is configured as a vertically long cam.

The length of this cam, marked 1, corresponds approximately to the travel distance with a slight addition in the green. Control greens 26 and 27 are therefore moved from the plane containing the scanning mechanisms 23 and 24 when the machine rotates to the right, indicated at 29, to the scanning mechanism 23 and 24 when the machine rotates to the left, indicated at 30. 24. It can be seen from this that in the device of the invention each scanning mechanism can be operated in any position of the control shaft. For example, it is also possible for the scanning mechanism assigned to the left-hand rotation of the machine to operate in the area of the plane 29 assigned to the right-handed rotation of the machine, and to be moved during rotation through the plane 30' assigned to the left-hand rotation. Control green 26 and 27 range 29
The continuity from 30 to 30 provides another advantage during braking, in that this is possible independently of the position of the control shaft and already during the travel process. control valve 16
and 17 are advantageously constructed as contact-free dam pressure valves. Therefore, as shown in Figure 3,
The scanning mechanisms 22 and 23 have a dam chamber 32 or 33. Pressure medium can flow out of this dam chamber 32 or 33 via a nozzle 34 or 35 which can be closed periodically by means of the control slide guide 24. When the nozzle 34 or 35 is closed by the control gutter guide 24, the pressure in the dam chamber 32 or 33 increases, so that the control valve 16 with a control green controls the opening and closing of the pressure medium supply conduit 14 or 15. Or 17
slider 36 or 37 is moved. Sliders 36 and 37 are best shown in FIG.
The dam chamber 32 or 33 can be supplied with pressure medium in a simple manner by closing off the main pressure medium supply conduit. In this preferred embodiment, a small throttle hole 39 is provided for this purpose in the piston 38 of the slider 36 or 37 facing the relevant dam chamber. The pressure medium is supplied to the pressure medium supply conduit 14 through this throttle hole 39.
Alternatively, it reaches the damming chamber via the cooling chamber 40 connected to the dam 15. However, embodiments are also conceivable in which the dam chamber can be loaded by its own conduit. Such an arrangement is suitable for machines in which only one control valve is provided with a scanning mechanism assigned to two different rotational directions of the machine, as in the present invention, to control all functions. ,
is particularly advantageous. Good results show that the scanning mechanism has a diameter of approximately 8
The skin is achieved in an embodiment configured as a simple tube. This pawl, nozzle 34 or 35 can have a diameter of 6 mm. Advantageously, the gap between the outlet of the nozzle 34 or 35, designated 41, and the surface of the control gauze guide 24 is approximately 0.5 skin in size. Although one most advantageous embodiment of the invention has been described in detail above, the invention is not limited thereto and can be implemented in various different ways.

[Brief explanation of drawings]

The drawings show an embodiment of the invention, in which FIG. 1 shows a sectional view of a starting and/or braking device with a control device according to the invention, and FIG. 2 shows a control boar configured as a control shaft cam. A perspective view of the guide, FIG. 3 is a partial view showing one embodiment of the scanning mechanism according to the invention. 1... Start and/or brake valve, 2...
... Valve cage, 3 ... Cylinder, 4 ... Main starting air conduit, 5 ... Hole, 6 ... Spring, 7 ... Working piston,
8, 9... Pressure chamber, 10, 11... Connection passage, 12
, 13... Connection conduit, 14, 15...
Pressure medium supply conduit, 16, 17...control valve, 1
8... Outlet, 19... Connection conduit, 20...
Check valve, 21... Outlet, 22, 23...
・Scanning mechanism, 24... Control slide guide, 25...
Control axis, 26, 27... Control edge, 28...
... Control section, 32, 33... Dam room, 34
, 35... Nozzle, 36, 37... Slider, 38...
Piston, 39... throttle hole, 40... ring chamber. Fig. "Fig.2 F:9.3

Claims (1)

Claims: 1. Switchable starting and braking device for an internal combustion engine, with a linearly movable control shaft for the injection valve and possibly the gas exchange valve, operable with compressed air pressure. The starting and braking valve 1 is provided with two control conduits (12, 14; 13, 15) for controlling the opening of the starting and braking valve 1, and these control conduits 12, 14; 13, 15)
can be selectively and periodically controlled to open and close by brake valves 16, 17 each assigned to one direction of rotation and actuated by one pneumatic force, the control valves 16, 1
7 scans a control slide guide 24 via a scanning mechanism 22, 23, which control slide guide 24 is movable according to the respective direction of rotation and corresponds to the starting or braking control time; In the version with two control sections 28 delimited by one control edge 26, 27, both control valves 16, 17 are constructed as pneumatic dam pressure valves, with each dam being The stop pressure valves are connected to pressure medium supply conduits 14, 15 which carry the pressurized air for actuating the starting and braking valves;
, 15 is provided with a dam tube having compressed air dam chambers 32, 33, which can be closed by means of a control slide guide 24, through which compressed air branches off from the compressed air dam chamber 3.
The pressure present at 2, 33 acts on slides 36, 37 arranged inside the dam pressure valve, which control the opening and closing of the pressure medium supply conduits 14, 15 at the control edge, so that the scanning The dam tubes forming the mechanisms 22, 23 are assigned to a single common control slide guide 24 and are arranged at intervals along the outer circumference of this control slide guide 24, the spacing being The starting or braking time between clockwise and counterclockwise rotation corresponds to the spacing provided between the two control edges 26, 27 of the phase shift angle, so that the control slide guide 24 is connected to the injection pump and, if appropriate, is the control shaft 25 that operates the gas exchange valve.
The control slide guide 24 is located at both control edges 2.
It has a control section 28 arranged on the cam limited by 6, 27, which control section 28 passes at a small distance in front of the outlet of the dam tube 22, 23 and is connected to the control slide. It is along an arc centered on the axis of the control shaft 25 when viewed in the circumferential direction of the child guide 24, and the control slide guide 24 has a length corresponding to at least the movement section of the control shaft 25 when viewed in the axial direction. A starting and braking device for an internal combustion engine, characterized in that: 2. The slider 36, 37 in the dam pressure valve has a ring groove 40 which is limited by two control edges;
0 forms a chamber for receiving compressed air from the pressure medium supply conduit 14, 15, from which the compressed air is led via a throttle 39 to the associated dam tube 22, 23. Starting and braking devices according to scope 1. 3 The outlet on the control slide guide side of the compressed air dam pressure chambers 32, 33 formed in the dam pipes 22, 23 is the nozzle 34, 3.
5. A starting and braking device according to claim 1, comprising: 5. 4 the control section 28 of the control slide guide 24 and the dam pipe 22,
The starting device according to claim 1, wherein a gap 41 of approximately 0.5 mm is provided between the compressed air dam chambers 32, 33 formed in the compressed air dam chambers 32, 33 and the outlet on the control slide guide side. and braking equipment. 5. Starting and braking device according to claim 1, wherein the pressure medium supply conduits 14, 15 are connected via a throttle valve to a starting air cylinder of the internal combustion engine. 6 Pressure medium supply conduits 14, 15 are dammed pressure valves 16, 1
2. The starting and braking device according to claim 1, which opens into a common pressure medium supply conduit 12 in the rear region of 7 and can be mutually isolated by a check valve 20. 7. At least one of the two weir pressure valves 16, 17 is a 3-port 2-position valve, which 3-port 2-position valve has one inlet connected to the pressure medium supply conduit 14, 15 and two
one outlet 21 is connected via a supply conduit with the opening pressure chamber 8 of the starting and braking valve, and the other outlet is connected with the closing pressure chamber 9 of the starting and braking valve. A starting and braking device according to claim 1.