JP4430025B2 - Common rail hydraulic system - Google Patents

Description

  The present invention includes at least two hydraulic pressure consumption sources, a first hydraulic power supply source, and a first common hydraulic pressure that connects the first hydraulic power supply source to at least two hydraulic consumption sources. And a hydraulic system comprising a supply line. This type of system is typically referred to as a “common rail” system because a number of hydraulic consumption sources are connected to a common supply line.

  An example of the use of a common rail hydraulic system as described above is in large electronically controlled diesel engines. In many large electronically controlled diesel engines, each cylinder is controlled by an “independent hydraulic cylinder unit”. The hydraulic cylinder unit (HCU) controls the movement of the exhaust valve and the operation of the fuel injection system via a hydraulic actuator. The hydraulic system that supplies hydraulic power to the hydraulic cylinder unit is typically a common rail system in which each HCU is connected to a single common hydraulic supply rail. In this way, it is not always necessary to run individual supply lines for each HCU. Thus, a common rail hydraulic system is less complex and less expensive than a conventional hydraulic supply system in which a separate supply line is provided for each hydraulic consumption source.

  However, the problem with the supply rail system is that if a leak occurs in a common supply line, all hydraulic sources supplied by that common supply line will depressurize and shut down. . In the above example of a large diesel engine, if a leak occurs in a common supply line, the HCU is deactivated and all engines are stopped. Accordingly, there is a need to reduce the severity of leaks in a common supply line.

  A number of different solutions to the above problem have been proposed in the prior art. For example, one solution is to cover the first common hydraulic supply line in a maintenance line having a larger diameter than the first common hydraulic supply line. If the first common supply line breaks, the maintenance line takes over the function of the first supply line. However, the cost of this system can be very high due to the cost of a larger diameter maintenance line. In addition, the larger diameter of the maintenance line increases the force placed on the end stops and valves. This can also increase the cost of the system.

Another solution common to automobiles and aerospace vehicles is to use redundant components. U.S. Pat. No. 4,860,781 shows an example of a brake system for a vehicle. In this system, two separate supply hoses are provided, each hose connected to an independent caliper. When the hose connected to the first caliper breaks, the oil supply to the first hose is stopped, and the hose connected to the second caliper takes over. However, this solution requires an extra caliper for each wheel. This is fine for relatively simple systems such as car brake systems, for example, but in systems such as diesel engines where there are very many sources of hydraulic consumption, the extra cost of supplying extra components. Greatly increases the cost of the system.

Thus, a first aspect of the present invention provides a hydraulic system as described above in the opening paragraph that is simple, robust and does not significantly increase the cost of the system.
The second aspect of the present invention provides a hydraulic pressure as described above in the opening paragraph in which the hydraulic consumption source continues to function even if the first common hydraulic supply line leaks or ruptures. A system is provided.

  The aspects described above are provided in part by a hydraulic system as referred to in the opening paragraph, the hydraulic system comprising a second hydraulic power source and the second hydraulic power source and And a second common hydraulic supply line connecting at least one two hydraulic consumption sources. In this system, at least two hydraulic consumption sources are connected to both the first and second common supply lines, and each common supply line is connected to its own power supply. Thus, even if one common supply line ruptures, hydraulic fluid will still be supplied to at least two hydraulic consumption sources. In this way, both hydraulic consumption sources continue to function.

  In addition, when a leak occurs in one of the supply lines, no action is required to keep the system running. In many other redundant systems, some action is required to run the system when a leak occurs. For example, the second power supply must be started, the valve must be closed, and so on. A good example of such a system is disclosed in US Pat. No. 6,769,251.

  Another positive feature of the system according to the invention is that during normal operation, the two supply lines both supply both at least two consumption sources, so that the first and second powers. The source can be reduced in size. This reduces the cost of the power supply. Furthermore, since the two common supply lines are similar in size, the cost of manufacturing the two supply lines is not much higher than manufacturing one line. Thus, the total cost of the system does not increase significantly.

  In a preferred embodiment of the hydraulic system, the system comprises a first hydraulic pressure supply line arranged in a first common hydraulic supply line between the first hydraulic power supply and at least two hydraulic consumption sources. A normally open valve, a second normally open valve disposed in a second common hydraulic supply line between the second hydraulic power supply and the at least two hydraulic consumption sources; It may further comprise one connection line and a normally closed valve arranged in the first connection line. A first end of the first connection line is connected to a first common hydraulic supply line at a position between the first hydraulic power supply and the first normally open valve; The second end of the first connection line is connected to the second common hydraulic supply line at a position between the second hydraulic power supply and the second normally open valve. Due to this configuration, if one of the supply lines causes a leak, the leaked supply line can be isolated from the system and the leak can be stopped. In addition, due to the first connection line, the system can be driven at full power output even if only one supply line is operating.

  It should be understood that the terms “normally open valve” and “normally closed valve” are understood in the context of this specification as describing valves that are each opened or closed during normal operating conditions. That is, the valves may be spring loaded valves that are each biased to an open or closed position (described later herein as shown in the drawings). However, the valve may be a manually operated valve that is manually opened or closed depending on the situation. The “normal” part of the term refers to the state of the valve during normal operating conditions.

  In order to protect the hydraulic power supply source, the system is arranged in a first common hydraulic pressure supply line between the first hydraulic power supply source and the first connection line and the first hydraulic pressure Disposed in a second common hydraulic supply line between the first check valve that allows flow away from the power supply, the second hydraulic power supply and the first connection line; A second check valve that allows flow in a direction away from the second hydraulic power supply.

  The hydraulic system may further comprise a third hydraulic power supply connected to the first common hydraulic supply line and / or the second common hydraulic supply line. In this way, the system can supply more flow to the consumer if a single power supply fails.

  In a preferred embodiment, the hydraulic system is connected to the first common hydraulic supply line at a position between the first hydraulic power supply and the first connection line, or the second hydraulic system The apparatus further includes a third hydraulic power supply source connected to the second common hydraulic pressure supply line at a position between the pressure power supply source and the first connection line.

  In another embodiment, the system includes a third hydraulic power supply and a second connection line, wherein the first end of the second connection line is the first hydraulic power supply. Connected to the first hydraulic supply line at a position between the source and the first connection line, and the second end of the second connection line is connected to the third hydraulic power supply source, The second connection line and the third connection line, wherein the first end of the third connection line is located between the second hydraulic power supply source and the first connection line; The second connection line is further connected to the second hydraulic pressure supply line, and the second end of the second connection line is further connected to the third hydraulic pressure power supply source. May be.

  In order to better control the flow supplied by the power supply, the hydraulic system comprises a normally closed valve provided in the second connection line and a normally open valve provided in the third connection line. Or a normally open valve provided in the second connection line and a normally closed valve provided in the third connection line.

  In one example of use of the hydraulic system according to the present invention, the at least two hydraulic consumption sources are at least two hydraulic cylinder units. Such an engine can be used to propel a ship.

  As used herein, the term “comprising / comprising” is employed to identify the presence of the described feature, gross, process or component, but one or more other features, It should be emphasized that it does not exclude the presence or addition of collectives, processes, components or groups thereof.

  Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. It should be emphasized that the examples shown are used for illustrative purposes only and should not be used to limit the scope of the present invention.

  The drawing is shown schematically and thus is not a drawing of a complete hydraulic system. Many details such as return lines, additional actuators, control systems, sensors, etc. have been omitted. However, one skilled in the art of hydraulic systems can use his or her common general knowledge to supplement the omitted details.

  The hydraulic system 1 shown in FIGS. 1 and 2 is a simple schematic drawing of a portion of the hydraulic system of a large electronically controlled diesel engine. In particular, the hydraulic system 1 handles the power supply for the hydraulic cylinder unit (HCU). 1 and 2 show two HCUs 2a, 2b, but in most practical systems there are more than two HCUs. Typically, an engine has one HCU per cylinder, so that 12 cylinder engines have 12 HCUs, 6 cylinder engines have 6 HCUs, etc. become. An engine can also share one HCU among multiple cylinders, for example, two cylinders can share one HCU. In this case, 12 cylinder engines have 6 HCUs, 6 cylinder engines have 3 HCUs, and so on. However, to simplify the drawing, only two HCUs are shown. However, it will be apparent to those skilled in the art that the present invention is applicable to systems with any number of hydraulic consumption sources.

  As described above, the HCU typically controls the movement of the exhaust valve and the operation of the fuel injector. Since the function of the HCU is known to those skilled in the art, the internal details of the HCU are not further described herein.

  The hydraulic system 1 includes a first variable position pump 3a and a second variable position pump 3b. The first pump 3a is connected to the first common hydraulic pressure supply line 4a, and the second pump 3b is connected to the second common hydraulic pressure supply line 4b. As shown in the drawing, the two HCUs are both connected to both supply lines 4a, 4b. In other words, each supply line connects one pump to both hydraulic consumption sources. Both ends of the supply line are shielded by stoppers 5a and 5b. If additional HCUs are added to the system, they are connected to both supply lines 4a, 4b in the same manner as the two HCUs 2a, 2b shown in the drawing.

  A check valve 7 is provided in each of the two connections 6a and 6b between the HCUs 2a and 2b and the supply lines 4a and 4b. Check valve 7 allows fluid to flow only in the direction towards the HCU.

  The hydraulic system 1 further comprises valves 8a, 8b that are normally open on both supply lines 4a, 4b. Normally opened valves 8a and 8b are disposed between the pumps 3a and 3b and the HCUs 2a and 2b. The hydraulic system 1 further comprises a connection line 9, the first end of which is a first supply line 4a at a position between the first normally open valve 8a and the first pump 3a. And the second end of the connection line is attached to the first supply line 4b at a position between the second normally open valve 8b and the second pump 3b. A normally closed valve 10 is arranged in the connection line 9.

  The check valve 11 is further arranged in both supply lines downstream of the two pumps 3a, 3b. Check valve 11 prevents fluid from being pushed into the pump if the pump fails.

During normal operation of the hydraulic system 1, both normally open valves 8a, 8b are open and the normally closed valve 10 is closed. In this way, the fluid from the first pump 3a becomes the first
The fluid from the second pump 3b is supplied to the second supply line 4b. Since the HCU is connected to both the first and second supply lines 4a, 4b, the fluid is supplied to the HCU via both the first supply line 4a and the second supply line 4b.

  If any one of the supply lines ruptures and loses pressure, the HCU is still provided with hydraulic pressure from the other supply line. However, the amount of flow available to the HCU is reduced because one of the supply lines has stopped distributing the flow. The result is that the engine continues to drive even at lower power output levels.

  Once a rupture is detected, either by the person monitoring the system or by automatic monitoring equipment if installed, the normally open valve 8a in the ruptured supply line 4a can be closed. The normally closed valve 10 can be opened. Depending on the type of monitoring and the type of control used in the system, these two steps can be performed manually or automatically. Once these two steps are performed, the HCU will again have full pressure and full flow. This is because the two pumps provide the desired amount of fluid flow and pressure through the remaining supply line 4b. This situation is illustrated in FIG. Personnel can repair damaged supply lines 4a and reset valves 8a, 10 to their normal state. During the engine repair procedure, the engine can continue to run at full power. In order for the engine to continue to run at full power, each supply line, as well as the valves and connections in the supply line, must supply the overall required flow along one of the supply lines. Can do.

  FIG. 3 shows the second hydraulic system 20. The second hydraulic system 20 is very similar to the first hydraulic system 1. The only difference is that the second hydraulic system has three variable position pumps 3a, 3b, 3c instead of only two. The third variable position pump 3c is connected to the first supply line 4a at a position between the first pump 3a and the connection line 9. In addition, the 3rd pump 3c may be connected to the 2nd supply line 4b as an alternative example.

  In a hydraulic system that provides flow to the HCU of a diesel engine, the fact that there are three pumps 3a, 3b, 3c in the hydraulic system can be advantageous if any one of the pumps fails. This can be explained by examining the flow rate requirements of the HCU of a typical electronically controlled diesel engine. In a typical electronically controlled diesel engine, the HCU controls both the flow injection system and the exhaust valve movement of each cylinder. The flow rate required by the exhaust valve is almost independent of the engine power output. In other words, approximately the same amount of fluid flow is required by the exhaust valve actuator when the engine is driving at low power output, as required when the engine is driving at high power output. . However, the fluid flow required by the fuel injection system is highly dependent on the engine power output.

  For example, when the engine is running at full power output, about 50% of the available fluid flow is used by the exhaust valve actuator and about 50% of the available fluid flow is used by the fuel injection system. . However, when the engine is running at low power output, the exhaust valve assembly still uses about 50% of the available fluid flow rate, and the fuel injection system will probably only be about 5% of the available fluid flow rate. Is used.

  When considering an example where the hydraulic system comprises two pumps, each pump is sized to provide approximately 60% of the total fluid flow required at maximum power output. During normal operation, the two pumps can provide up to 120% of the required fluid flow, which means that the system is oversized. However, if one pump fails, the remaining pumps can supply only 60% of the total required fluid flow rate. Since the exhaust valve requires a certain amount of fluid flow independent of the power output, most of the fluid flow from the remaining pumps is used to power drive the exhaust valve, thereby allowing the fuel injection system Leave only a small amount of fluid left for. This means that when a single pump fails, the remaining power output of the engine is significantly reduced.

  However, if there are three pumps, each pump provides 40% of the requested fluid flow rate, and even if one pump fails, 80% of the requested fluid flow rate still remains. ing. This means that if one of the three pumps fails, the engine can continue to run at a much higher power output than if one of the two fails.

FIG. 4 shows a third hydraulic system 30. The system 30 is very similar to that shown in FIGS. 1 and 2 and is therefore not described in further detail herein.
As was the case with the second system 20 shown in FIG. 3, the third system 30 also has three pumps 3a, 3b, 3c. However, the way in which the third pump 3c is connected to the first and second supply lines is different from the way in which the third pump is connected to the supply line in the second system 20.

  In the system 30 shown in FIG. 3, the third pump 3 c is connected to the first supply line 4 a via the second connection line 31. The second connection line 31 is connected to the first supply line 4 a at a position between the first pump 3 a and the first connection line 9. The third pump 3c is also connected to the second supply line 4b via the third connection line 32. The third connection line 32 is connected to the second supply line 4 b at a position between the first pump 3 b and the first connection line 9. In this way, the third pump can direct fluid to either the first supply line 4a or the second supply line 4b. The system further comprises a normally open valve provided in the second connection line 31 and a normally closed valve 34 provided in the third connection line 32. Because of the valves 33 and 34 provided in the second and third connection lines 31 and 32, one of the first and second supply lines 4a and 4b can be easily controlled by controlling the fluid flow rate from the third pump 3c. It can be redirected to one or both. It should be noted that the second connection line 31 has a normally closed valve and the third connection line 32 is normally open instead of the configuration shown in FIG. 4 without any difference in the function of this system. Can have a valve.

  It can also be envisaged that the system 30 is arranged with valves normally open in both the second connection line 31 and the third connection line 32. In this way, the two supply lines 4a and 4b have the same fluid flow rate.

  It should be specified herein that the examples used in the description all relate to large, electrically controlled diesel engines. However, hydraulic systems using the teachings of the present invention can also be used for other applications. For example, the system can also be used as a common rail hydraulic supply system for multi-degree-of-freedom hydraulic mappers.

  Furthermore, the term “line” as used in the context of the present application can be interpreted in a number of different ways. The “line” may be, for example, a hose or a pipe. However, it may be a perforation formed in a valve block or the like. Furthermore, the supply line need not be a single piece. The supply line can be composed of a number of different components connected together to form a supply line. However, the term supply line is to be understood in the context of the present specification as a unique path for fluid flow connecting a power supply and a hydraulic consumption source.

FIG. 1 shows a schematic diagram of a first hydraulic system according to the invention during normal operation. FIG. 2 shows a schematic diagram of the same system as that shown in FIG. 1, but showing one of the supply lines destroyed. FIG. 3 shows a schematic diagram of a second hydraulic system according to the invention during normal operation. FIG. 4 shows a schematic diagram of a third hydraulic system according to the invention during normal operation.

Claims (9)

At least two hydraulic consumption sources (2a, 2b);
A first hydraulic power supply source (3a);
A first common hydraulic supply line (4a), which is a unique path connecting the first hydraulic power supply source to the at least two hydraulic consumption sources (2a, 2b);
A hydraulic system (1; 20; 30) comprising:
The hydraulic system is
A second hydraulic power supply source (3b);
A second common hydraulic supply line (4b), which is a unique path connecting the second hydraulic power supply source to the at least two hydraulic consumption sources (2a, 2b);
A hydraulic system, comprising: The system
A first hydraulic pressure supply line (4a) disposed between the first hydraulic power supply source (3a) and the at least two hydraulic pressure consumption sources (2a, 2b); A normally open valve (8a),
A second hydraulic pressure supply line (4b) disposed between the second hydraulic power supply source (3b) and the at least two hydraulic consumption sources (2a, 2b); A normally open valve (8b),
A first connecting line (9), the first end of which is connected to the first hydraulic power supply (3a) and the first normally open valve (8a) Is connected to the first common hydraulic pressure supply line (4a), and the second end of the first connection line is connected to the second hydraulic power supply source (3b). The first connection line (9) connected to the second common hydraulic supply line (4b) at a position between the second normally open valve (8b);
A normally closed valve (10) arranged in the first connection line (9);
The hydraulic system (1; 20; 30) according to claim 1, further comprising: The system
The first hydraulic pressure supply line (4a) is disposed between the first hydraulic power supply source (3a) and the first connection line (9), and the first liquid is supplied. A first check valve (11) enabling flow in a direction away from the pressure power supply source (3a);
Between the second hydraulic power supply source (3b) and the first connection line (9), the second common hydraulic pressure supply line (4b) is disposed, and the second liquid A second check valve (11) enabling flow in a direction away from the pressure power supply source (3b);
The hydraulic system (1; 20; 30) according to claim 2, further comprising:   The hydraulic system includes a third hydraulic power supply source (3c) connected to the first common hydraulic supply line (4a) and / or the second common hydraulic supply line (4b). The hydraulic system (20; 30) according to claim 1, 2 or 3, further comprising:   The hydraulic system is connected to the first common hydraulic supply line (4a) at a position between the first hydraulic power supply source (3a) and the first connection line (9). Or connected to the second common hydraulic pressure supply line (4b) at a position between the second hydraulic power supply source (3b) and the first connection line (9). Hydraulic system (20; 30) according to any of claims 2 or 3, characterized in that it further comprises three hydraulic power supplies (3c). The hydraulic system is
A third hydraulic power supply source (3c);
A second connection line (31), wherein a first end of the second connection line is connected between the first hydraulic power supply source (3a) and the first connection line (9). Connected to the first hydraulic pressure supply line (4a) at a position between, the second end of the second connection line is connected to the third hydraulic power supply source (3c), The second connection line (31);
A third connecting line (32), the first end of the third connecting line being connected between the second hydraulic power supply source (3b) and the first connecting line (9); Connected to the second hydraulic pressure supply line (4b) at a position between, the second end of the second connection line is connected to the third hydraulic power supply source (3c), The third connection line (31);
The hydraulic system (30) according to any one of claims 2 or 3, characterized by comprising:   The hydraulic system includes a normally open valve (33) provided in the second connection line (31) and a normally closed valve (34) provided in the third connection line (32) or the 7. The valve according to claim 6, further comprising a normally closed valve provided in the second connection line (31) and a normally open valve provided in the third connection line (32). The hydraulic system as described (30).   8. The hydraulic system (1; 20; 30) according to any one of the preceding claims, wherein the at least two hydraulic consumption sources (2a, 2b) are at least two hydraulic cylinder units. diesel engine.   A ship comprising the diesel engine according to claim 8.

Images