JPH02298659A - Control device for stopping diesel engine - Google Patents

Abstract

PURPOSE: To rapidly stop an engine by connecting a suction valve and a feed valve in a feed pump to a switching member, and functioning the suction valve as the feed valve, and the feed valve as the suction valve when the switching member is operated to the stop position. CONSTITUTION: A feed pump 10 built in a fuel circulation route of a fuel injection pump of a diesel engine is provided with a feed piston 16 to be reciprocated in cooperation with a cam interlocked with the engine operation, and discharges the fuel sucked in a work chamber 22 through a suction valve 25 through a feed valve 28. A switching member 34 is connected to the valves 25, 28 by a coupling member 60, and the coupling member 60 is movable to the stop position by an adjustable member 62. At this stop position, valve springs 50, 80 of the valves 25, 28 are inoperative, and auxiliary springs 52, 58 are operative, and the suction valve 25 functions as the feed valve, and the feed valve 28 functions as the suction valve by the spring force of the auxiliary springs 52, 82.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention is a control device for stopping a diesel engine, which sucks fuel from a tank through a suction conduit, and pumps it during normal operation. A feed pump is provided which, during a stroke, delivers via a delivery conduit to the suction chamber of the fuel injection pump, the pump casing of the feed pump having at least one suction valve and a delivery valve in the working chamber, the feed pump A switching member is provided for influencing the effective direction of feed of the feed pump, the switching member being configured to switch from a normal operating position, which does not affect the fuel delivery of the feed pump from the suction conduit to the delivery conduit, to a stop during reversal operation. The present invention relates to a feed pump which can be switched to a stop position, in which the feed pump sucks fuel from the fuel injection pump suction chamber and guides it back to the tank.

[Conventional technology]

DE-O53014712 discloses that the feed pump is configured to be able to be controlled in reverse by a reversing valve in order to stop the internal combustion engine, and the suction chamber of the fuel injection pump is connected to the suction side of the feed pump. A type in which the delivery side is connected to a tank is disclosed. This known device is used to create a low pressure in the suction chamber with the aid of two low-pressure sealed check valves, one each installed on the inlet and outlet sides of the fuel injection pump. . As a result, fuel is removed from the suction chamber of the fuel injection pump to such an extent that the fuel injection pump no longer supplies fuel and the diesel engine is stopped.

[Problem of invention]

However, in this known control device, the reversing valve is
A separate component separate from the feed pump, in which a number of conduits are associated with the connections, and a number of tube connections are provided for connecting the number of conduits. These tube connections therefore have the disadvantage that they are susceptible to failures of the internal combustion engine, especially when taking into account the vibrational stresses of the diesel engine and the resulting loads on the line connections. The object of the invention is therefore to eliminate this drawback.

[Means to solve the problem]

According to the invention, this object is solved in that the switching element is integrated in the feed pump and is connected by means of a coupling element to at least two valves, namely a suction valve and a delivery valve, said coupling element being connected by an adjustment element to at least two valves. movable into a rest position, in which the suction valve and the delivery valve have reached a position in which the valve springs of these valves are inactive and one auxiliary spring is applied in each case; The spring force of the auxiliary spring causes the suction valve to act as a delivery valve, and the delivery valve to act as a suction valve, whereby the feed pump is configured to suck fuel from the delivery conduit and deliver it to the suction conduit.

〔effect〕

The control device according to the invention has the advantage that the conduits required in conventional control devices of this type are dispensed with, and thus the costs thereof are reduced. The arrangement and configuration of the control device according to the invention, which is configured as a component integrated in a feed pump, increases the operating and driving reliability of the injection system of the internal combustion engine on the one hand and reduces the maintenance costs. On the other hand, the simplified construction of the control device results in reduced material and assembly costs and structural advantages.

According to the features of claim 2, a more reliable drive type is obtained, and according to the features of claim 3, the main components of the control device, that is, the two valve seat supports, are constructed in a stationary manner; Due to the movable design of the correspondingly arranged spring catch as switching element, on the one hand, the movable mass is reduced and, on the other hand, there are no disadvantageous effects caused by tilting or misalignment; Therefore, manufacturing with coarse manufacturing tolerances is possible.

〔Example〕

Next, the configuration of the present invention will be specifically explained with reference to the embodiments shown in the drawings.

The embodiment shown schematically in FIG. 1 shows a known feed pump 10 that is integrated into the fuel circulation path of a fuel injection pump leading to the drive of an internal combustion engine. This feed pump 10 is mounted in the engagement area of the cam 11 relative to the injection pump in normal use. The displacement operates according to the principle that the feed pump 10 is surrounded by a pump casing 12, the stroke of the cam 110 introduces a force into the feed pump IO, which is transmitted via the piston rod 14 to the feed piston 16,
This feed pump 16 moves in the ↓8 directions of arrows.

The feed piston 16 is moved inward in the direction of the arrow 18 against the return force of the preloaded operating spring 20, and at this time the feed piston 1
6 feeds fuel into the working chamber 22 when the feed pump IO is in a drive ready state.

The working chamber 22 is located inside the pump casing 12 and is located between the end face side of the feed pump 16 and the suction valve 25 (this suction valve 2
5 is delimited in the closed state by a working chamber 22 (which in the closed state is isolated from a suction conduit 26 which connects to a tank 27 ) and a delivery valve 28 and has a stationary bearing block 24 .

The other end side of the feed piston 16 in the pump casing 12 opens into a delivery conduit 32 which closes off a chamber 30 , which is connected to a suction chamber 33 of the fuel injection pump 9 .

The suction valve 25 is rigidly connected to the delivery valve 28 by a coupling element 60 and forms a switching element 34 . The suction valve 25 has a first valve seat body 35 , which forms an interior chamber 36 .
A base body 4 configured as a plate within this inner chamber 36
A valve closing body 38 with 0 is arranged. Base body 4
0 is a closed surface 42.44 configured as an annular seat on both sides.
, on the one hand a front closing surface 42 facing the suction conduit 26 and on the other hand a rear closing surface 44 facing the working chamber 22 . These two closing surfaces 42
44 is the corresponding valve seat 43. of the first valve seat support 35.
45 respectively. That is, the front closing surface 42 faces the valve seat 43 and the rear closing surface 44 faces the valve seat 45. A guide member 46 is attached to the center portion of the base body 40 facing the support block 24 side. This guide member 46 is connected to the support block 24.
is guided in the first bore 48 of the valve spring 50 and forms a first spring seat 51 for the valve spring 50. This valve spring 5
0 partially surrounds the guide member 46 and biases the rear closing surface 44 of the base body 40.

The front closing surface 4 of the base body 40 opposes the valve spring 50
An auxiliary valve spring 52 is arranged on the second side. This auxiliary valve spring 52 is supported by a first auxiliary spring receiver 53 fixed to the casing. The length of this auxiliary valve spring 52 is
The first embodiment shown in FIG. 1 is insufficient to act on the base body 40.

The first valve seat support 35 has an outer contour that slides tightly within the working chamber 22 . Furthermore, the first valve seat support 35 can be moved by means of a coupling element 60 (which coupling element 60 is connected to an adjustment element 62 for the movement of the first guide element 46 in the bearing of the bearing block 24). (which is movable in the direction) and is rigidly connected to a part of the delivery valve 28, ie to the second valve seat body 65.

The delivery valve 28 is constructed similarly to the suction valve 25 and has a similar arrangement and corresponding structure. That is, the second valve seat body 65, the inner chamber 66, the valve closing body 68, the base body 70, the annular front closing surface 72, the front valve seat 73, and the annular rear closing surface 74. , a rear valve seat 75 , and a guide member 76 , which includes a second valve seat 75 extending into the pump casing 12 .
The valve spring 80 is guided in the hole 78 of the valve spring 80, and includes a valve spring 80, a second spring receiver 81, and an auxiliary valve spring 82. This auxiliary valve spring 82 is supported by a second auxiliary spring receiver 83 formed on the valve body 24, and its length is such that it acts on the base body 70 in the first embodiment shown in FIG. It is insufficient to do so.

According to the structure of the embodiment described above, the following functions and modes of operation are obtained.

Starting from the cam-controlled inward stroke of the feed piston 16, the feed piston 16 reduces the volume of the working chamber 22 in the direction of the arrow 18, thereby increasing the pressure in the working chamber 22. This also further assists the closing action in the course of the intake valve 25 , where the front closing surface 42 is pressed against the front valve seat 43 by the prestressing of the valve spring 50 .

On the other hand, in the course of the delivery valve 28 , in which the front closing surface 72 is pressed against the front valve seat 73 due to the preload of the valve spring 80 , the valve closing member 68 is actuated against the return force of the valve spring 80 . This causes the feed piston 16 to perform its normal working stroke, causing the delivery valve 28 to open.

However, the fuel volume flowing out of the working chamber 22 does not reach the delivery conduit v32. This is because this volume, displaced by the feed piston [6], compensates for the low pressure level approximately left in the chamber 30.

As feed piston 16 makes a cam-controlled outward stroke in the direction opposite to arrow 18, piston rod 14
is frictionally connected to the retracting cam surface by the return force of the operating spring 20 acting indirectly on this piston rod 14. At this time, a low pressure is created in the working chamber 22 which keeps the delivery valve 28 in the closed position and opens the suction valve 25.

As the feed piston 16 moves outward, the volume within the chamber 30 is reduced. By closing the delivery valve 28 , the fuel is not guided back into the working chamber 22 , but is forced via the delivery conduit 32 of the feed pump 10 into the suction chamber 33 of the fuel injection pump 9 .

Thereby, the working cycle consisting of an inward stroke and an outward stroke of the feed piston 16 is completed when the switching member 34 is in the normal operating position, in which case fuel is supplied during the inward stroke of the feed piston 16. During the outward stroke of the feed piston 16, fuel is forced out of the working chamber 22 and into the suction chamber 33 of the fuel injection pump 9, and at the same time, fuel is removed from the tank 27. It flows into the chamber 22.

This forms a feed circuit from the tank 27 to the fuel injection pump 9 via the feed pump 10.

The feed direction of the feed pump 10 can be changed from the normal operating position shown in FIG. It is switched to the stop position shown in Figure 2.

The two valve seat supports 35,65 are moved from the position shown in FIG. 1 to the position shown in FIG. 2, in which the delivery valve 28 acts as a suction valve and the suction valve 25 acts as a delivery valve. By shifting the two valve seat supports 35.65, the position of the two valve closing members 38.68 also changes, with the two base bodies 40.70 moving towards their front closing surfaces 4.
2.72 moves away from the front valve seat 40.70, its rear closing surface 44.74 abuts the rear valve seat 45, 74, the force connection with the valve spring 50.80 is released, and the auxiliary valve spring 52
．． 82 and is operatively connected.

When the feed piston 16 performs an inward stroke in the direction of the arrow 18, the pressure in the working chamber 22 increases, the delivery valve 28 acting as a suction valve is maintained in its closed state, and the suction valve 25 acting as a delivery valve becomes an auxiliary valve. The fuel flows around the base body 40 against the return force of the spring 52 and flows into the working chamber 2.
2 until it reaches tank 27. As a result, the pressure within the working chamber 22 drops again. On the other hand, as the feed piston 16 makes an inward stroke and is pushed back, the volume within the chamber 30 increases, thereby creating a low pressure. This low pressure is not compensated for via the working chamber 22 when the delivery valve 28, which acts as a suction valve, is closed and draws fuel from the suction chamber 33 of the fuel injection pump 9 into the delivery conduit 3.
2 to the chamber 30.

As feed piston 16 makes an outward stroke in the opposite direction of arrow 18, fuel is forced out of chamber 30. At this time, the delivery valve, which functions as a suction valve, opens and the delivered fuel flows into the working chamber. In this working chamber, the fuel sufficiently compensates for the low pressure caused by the increased volume of the working chamber 22.

In the stop position according to the first embodiment shown in FIG. 2, which is changed from the normal operating position of the first embodiment shown in FIG. Fuel is fed during the directional stroke. At this time, fuel is fed in the direction from the suction chamber 33 of the fuel injection pump 9 to the tank 27 via the feed pump IO.

FIG. 3 shows a modified embodiment of the first embodiment shown in FIGS. 1 and 2. In FIG. The operation of the device according to this second embodiment is the same as that of the first embodiment.

FIG. 3 shows a normal operating position of the coupling member 160, which corresponds to that in FIG. The operating state of the feed pump 110 is the same as that of the first embodiment shown in FIG. 2, so the stop position is not shown. This second
In embodiments, the suction valve 125 and the delivery valve 128
In this case, two valve seat supports 135.165 are fixed to the housing and a movable spring support 151.181 is installed.
Alternatively, the switching action of the auxiliary spring supports 153, 183 (which can also be arranged offset by 90") is taken into account.

Spring receiver 151.181 or auxiliary spring receiver 153.
183 is connected to a coupling member 160, which is moved by the adjustment member 62 from the illustrated normal operating position to the rest position.

Shown in FIG. 3 is the valve spring 150 in the normal operating position.
．． 180 loads the base body 140, 170, so that the suction valve 125 and the delivery valve 128 are initially closed.

When the feed piston 16 makes an inward stroke in the direction of arrow 18 against the return force of the preloaded operating spring 20, fuel is forced out of the working chamber 22 and into the chamber 30 while the delivery valve 128 opens. When the fuel moves, whereas the feed piston 16 performs an outward stroke in the direction opposite to the arrow 18, the fuel on one side of the fuel injection pump 9 is forced out of the chamber 30 via the delivery conduit 32. on the other hand, fuel is released via the suction conduit 26;
It is supplied to the working chamber 22 through the suction valve 125.

When the coupling member 160 moves from the normal operating position to the stop position in the direction of arrow 190, the spring receivers 151, 181
Alternatively, the auxiliary spring receiver 153.183 moves and the base body 140.170 no longer receives the spring force from the valve spring 150.180, but instead receives the spring force from the auxiliary valve spring 152.182, so that the suction valve 125 and at the delivery valve 128 and also at the feed pump 11
Operation switching is also performed at 0.

When fuel is supplied from the fuel injection pump 9 to the tank 27 by the feed pump 110, the basic fuel supply position of the fuel injection pump 9 is released and the internal combustion engine is thereby reliably shut off.The control device switches the feed pump 10. 11
0, the operational and drive reliability of the injection system for internal combustion engines is improved, and economic advantages are achieved through reduced material and assembly costs. It was done.

[Brief explanation of drawings]

1 is a schematic sectional view of a control device according to a first embodiment of the present invention in a normal operating position, FIG. 2 is a schematic sectional view of the control device of FIG. 1 in a stopped position, and FIG. 3 is a schematic cross-sectional view of a control device according to a second embodiment of the invention in a normal operating position; FIG. 9...Fuel injection pump, 10,110...Feed pump, 11...Cam, 12...Pump casing, 14...Piston rod, 16...Feed pump, 18...Arrow, 20...operation spring, 22...
Working room, 24...Support block, 25.125...
Suction valve, 26... Suction conduit, 27... Tank,
28,128... Delivery valve, 30... Push-back chamber, 32... Delivery conduit, 33... Suction chamber, 34
...Switching member, 35...Valve seat support, 36...
・Inner chamber, 38... Valve seat closing member, 40, 140...
Base body, 42.44...Closing surface, 43.45...
Valve seat, 46... Guide member, 48... Hole, 50...
・Valve spring, 51.151...Spring receiver, 52...Auxiliary valve spring, 53.153...Auxiliary spring receiver, 60.1
60... Coupling member, 62... Adjustment member, 6
5... Valve seat support body, 66... Inner chamber, 68... Valve closing member, 70.170... Base body, 72.74...
・Closing surface, 75... Valve seat, 76... Guide member, 7
8... Hole, 80... Valve spring, 81, 181... Spring receiver, 82... Auxiliary valve spring, 83.183... Auxiliary spring receiver, 190... Arrow

Claims (1)

[Claims] 1. A control device for stopping a diesel engine, which sucks fuel from a tank (27) through a suction conduit (26) during normal operation and sends it to a fuel injection pump (27) through a delivery conduit (32) during a feed stroke. A feed pump (10) is provided to feed the suction chamber (33) of the feed pump (10) to the suction chamber (33) of the feed pump (10).
2) in the working chamber (22) at least one suction valve (
25) and a delivery valve (28), a switching element (34) is provided for influencing the effective delivery direction of said feed pump (10), said switching element (34) comprising a suction conduit (26) to the delivery conduit (3
2) can be switched from a normal operating position that does not affect fuel delivery of the feed pump (10) to a stop position during reverse operation, and in the stop position, the feed pump (10) injects fuel. Suction chamber of pump (9) (
33) and is guided back to the tank (27), the switching member (3
4) is incorporated in the feed pump (10),
A coupling member (60) connects at least two valves, namely a suction valve (25) and a delivery valve (28), said coupling member (60) being brought into a stop position by an adjustment member (62). movable, and in the stop position the suction valve (25) and the delivery valve (
28) have reached a position in which the valve springs (50, 80) of these valves are in the inactive state and one auxiliary spring (52, 82) in each case is activated;
The spring force of the suction valve (25) acts as a delivery valve and the delivery valve (28) acts as a suction valve, which causes the feed pump (10) to draw fuel from the delivery conduit (32) and into the suction conduit ( 26) A control device for stopping a diesel engine. 2. The two valves (25, 28) each have one valve seat support (35, 65), and the valve seat support (3
5, 65) along its outer contour.
0), the first valve seat support (35) delimits the working chamber (22) to the tank (27) and the second valve seat support (35) limits the working chamber (22) to the tank (27) The seat support (65) connects the working chamber (22) to the suction chamber (3) of the fuel injection pump (9).
3), and each valve seat support (35, 65
) with two valve seats facing each other (43,45:73,7
5) and a valve closing member (36, 66) which acts doubly on the sealing surface of these valve seats.
8, 68) are adapted to abut alternately. 3. Two valves (125, 128) are connected to valve springs (150,
180) and a spring receiver (151, 153; 181,
183) and these spring receivers (151, 153; 181
.
6) Two valve seats (43, 45; 73) facing each other within
, 75), and these valve seats (43, 45; 7
One valve closing member (1, 75) on each sealing surface of each
38, 168) are brought into contact with each other alternately, and the coupling member (1
valve spring (150) when the valve spring (150) is in the normal operating position.
, 180) or by switching the coupling member (160) by the adjustment member to reach its stop position under the spring force of the auxiliary springs (152, 182); 4. Control device according to claim 1. The valve closing members (38, 68) of the suction valve (25) and the delivery valve (28) are configured identically to each other and have two closing surfaces (42, 44) facing each other.
; 72, 74), the base body (40, 70) extending on at least one side along the longitudinal axis of the valve (25, 28) and having a valve spring ( 50, 80) or an auxiliary valve spring (52, 82) with a guide member (46, 76) guided in the pump casing (12), which passes through the pump casing (12) with play;
The control device according to claim 1 or 2. 5. Base body (40, 70) of valve closing member (38, 68)
) has two flat closing surfaces (42,44:72,74) and each valve seat (43,45:73,75) has an associated closing surface (42,44:72,74). 5. The control device as claimed in claim 4, further comprising annular surfaces arranged symmetrically about the longitudinal axis, which produce a form-locking connection.