Internal combustion engine with a water injection device

Abstract

The invention relates to an internal combustion engine (1) with a water injection device (2), wherein the water injection device (2) has a distributor bar (4) which is connected to at least one injector (6) in a way that allows water to pass through it, wherein the injector (6) is designed to inject water (29) into the internal combustion engine (1), and wherein the distributor bar (4) has a pipe section (5) for receiving the injector (6), wherein the pipe section (5) is designed to allow water to pass through it with the distributor bar (4). According to the invention, the injector (6) is connected to the distributor bar (4) by means of a holding element (8), wherein the holding element (8) is designed in the form of a holding clip.

Description

[0001] The invention relates to an internal combustion engine with a water injection device according to the preamble of patent claim 1.

[0002] To achieve legally prescribed current and future emission levels, measures are required during the operation of the internal combustion engine that can be achieved with water injection, such as reduced exhaust temperatures for the efficient operation of the internal combustion engine's exhaust aftertreatment systems. For example, water can be injected into the combustion chamber, with the water and fuel only being mixed in the combustion chamber. The fuel and water are supplied to the combustion chamber using different injection systems.

[0003] Patent DE 10 2020 134 014 B3 discloses a distributor rail for a fuel injection system of an internal combustion engine, wherein the distributor rail is made of stainless steel. The distributor rail is used to inject a fuel-water emulsion into a cylinder of the internal combustion engine.

[0004] From the patent specification CN 108060992 B a water injection device for an internal combustion engine is known, wherein a distributor bar of the water injection system is made of stainless steel.

[0005] Patent document DE 10 2019 113 497 B4 describes a water injection system for an internal combustion engine with a stainless steel manifold. The water is injected into the intake ports of a cylinder head of the internal combustion engine.

[0006] From the document DE 10 2017 216 643 A1 a water injection device for an internal combustion engine is known, wherein an injector of the water injection device is held on the injector line by means of a holding clip with an injector line formed coaxially with the injector.

[0007] The document DE 10 2019 210 142 A1 discloses a water injection device for an internal combustion engine, wherein an injector of the water injection device is held on the body by means of a holding element with a body formed coaxially with the injector, which is provided for reducing a volume available to water in an inlet nozzle of the injector.

[0008] The document DE 10 2019 103 209 A1 discloses a water injection device for an internal combustion engine with a water distribution pipe which is designed to allow injection injectors to flow through and which is assembled from several parts, wherein a T-shaped connecting piece is formed between each of the injection injectors and the water distribution pipe, and the individual connecting pieces are connected by means of hose pieces which comprise a flexible material.

[0009] The document DE 39 18 410 A1 discloses a fuel distributor made of a plastic for an internal combustion engine.

[0010] From the document DE 10 2006 061 563 A1 a fuel distributor for an internal combustion engine is known, which has a double-shell housing for holding injection devices.

[0011] The document DE 10 2009 001 866 A1 shows a fuel distributor for an internal combustion engine, in which injection injectors assigned to each cylinder are arranged on different distributor rails.

[0012] The object of the present invention is to provide an improved internal combustion engine with a water injection device.

[0013] The object is achieved according to the invention by an internal combustion engine with a water injection device having the features of patent claim 1. Advantageous embodiments with expedient and non-trivial further developments of the invention are specified in the respective subclaims.

[0014] An internal combustion engine according to the invention with a water injection device has the water injection device comprising a distributor rail. The distributor rail is connected to at least one injector in a way that allows water to pass through it, wherein the injector is designed to inject water into the internal combustion engine. The distributor rail has a pipe section for receiving the injector, wherein the pipe section is designed to allow water to pass through it with the distributor rail. According to the invention, the injector is connected to the distributor rail by means of a holding element, wherein the holding element is in the form of a holding clip, and wherein the pipe section is connected to the distributor rail in a way that allows water to pass through it by means of a pipe section opening which is designed opposite a rail opening of the distributor rail, wherein the pipe section opening is designed at a distance from a longitudinal axis of the injector.The advantage of the invention is that the injector can be easily mounted and dismounted on the distribution bar, since the holding element is manufactured as independent, or in other words, separate from the distribution bar and separate from the injector, and is thus a stand-alone component which serves to connect the injector to the distribution bar.

[0015] A secure mounting of the injector on the distribution bar is achieved if the holding element is designed to connect the injector to the pipe section, since the injector is designed to protrude into the pipe section and is supplied with water directly via the pipe section.

[0016] An improved, secure mounting is achieved if the holding element is designed to at least partially accommodate the pipe section and the injector. In other words, this means that the pipe section extends at least partially into or through the holding element, as does the injector, so that, for example, a positive connection could be created, which serves to securely position the injector, particularly if the holding element is designed to at least partially engage the injector.

[0017] In order to supply the individual cylinders of the internal combustion engine evenly, the water injection device has a number of injectors which corresponds at least to a number of cylinders of the internal combustion engine.

[0018] To prevent corrosion, especially of the manifold and the pipe section, these are made of stainless steel. Preferably, all water-carrying pipe sections of the water injection device are made of stainless steel.

[0019] To ensure a secure connection of the distributor bar to the internal combustion engine, it is attached to the internal combustion engine using a fastening device.

[0020] The injector must be aligned depending on the desired injection point. Injection into the intake port, which is located in the cylinder head of an internal combustion engine, has the advantage that the water can mix with the intake air or air-fuel mixture before reaching the combustion chamber, essentially forming a mixture. The distributor rail is then advantageously attached to the cylinder head.

[0021] To prevent the water from freezing, especially while driving, the distribution bar is at least partially enclosed by a shielding element for thermal insulation. This shielding eliminates the need for complex and expensive heating for the water injection system, especially for the distribution bar.

[0022] Further advantages, features, and details of the invention will become apparent from the following description of preferred embodiments and from the drawings. The features and feature combinations mentioned above in the description, as well as the features and feature combinations mentioned below in the description of the figures and / or shown alone in the figures, can be used not only in the respective combinations specified, but also in other combinations or on their own, without departing from the scope of the invention. Identical or functionally equivalent elements are assigned identical reference numerals. They show: Fig. 1 shows a perspective top view of an internal combustion engine according to the invention with a water injection device, Fig. 2 shows a perspective view of a distributor bar with injectors of the water injection device of the internal combustion engine according to the invention, Fig. 3 shows a perspective view of an injector of the water injection device of the internal combustion engine according to the invention, Fig. 4 in a perspective schematic representation of a holding element of the water injection device, Fig. 5 shows a section through a cylinder head of the internal combustion engine according to the invention, Fig. 6 in a further section of the cylinder head of the internal combustion engine according to the invention, and Fig. 7 shows a plan view of a section of the cylinder head of the internal combustion engine according to the invention.

[0023] A according to Fig. The internal combustion engine 1 according to the invention, designed as shown in FIG. 1, has a water injection device 2, which is configured for injecting water into the internal combustion engine 1. In the present exemplary embodiment, the internal combustion engine 1 has four cylinders (not shown in detail) in a crankcase (not shown in detail), to which a cylinder head 3 of the internal combustion engine 1 is assigned.

[0024] The water injection device 2 comprises a distributor bar 4, which is connected to pipe sections 5 in a flow-through manner, wherein the pipe sections 5 are each designed to receive an injector 6. The pipe sections 5 are fixedly received on the distributor bar 4. In each pipe section 5, an injector 6 is received for injecting water 29 into the internal combustion engine 1, as shown in particular in Fig. 5 is clearly illustrated. Each injector 6 is accommodated in pipe section 5 so that the fluid can flow through it.

[0025] The distributor rail 4 has pipe sections 5 and injectors 6 corresponding to the number of cylinders in the crankcase. Thus, in this exemplary embodiment, the distributor rail 4 has four pipe sections 5 and four injectors 6. Of course, the crankcase could also have a different number of cylinders.

[0026] The distribution bar 4 is supplied with water 29 via a guide line 7 of the water injection device 2. A conveying means (not shown in detail) provided for conveying the water 29 is preferably designed in the form of a pump. The guide line 7, as the central hydraulic component, connects the conveying means (not shown in detail) and the injectors 6 to one another.

[0027] The water 29 to be injected is made available to the corresponding injector 6 at a specified time. The water 29 reaches a combustion chamber 9 of the internal combustion engine 1 via the injector. With the help of the injector 6, the water 29 is injected into an inlet channel 10 formed in the cylinder head 3, upstream of an inlet opening 11 of the combustion chamber 9 formed in the cylinder head 3, which in Fig. 5, is illustrated closed by means of an intake valve 12. The guide line 7 is fixed to the cylinder head 3.

[0028] In Fig. Figure 2 shows a perspective view of the distributor bar 4 with the injectors 6 of the water injection device 2 of the internal combustion engine 1 according to the invention. According to the invention, each injector 6 is connected to the distributor bar 4 by means of a retaining element 8, wherein the retaining element 8 is designed in the form of a retaining clamp. The retaining clamp could also be referred to as a retaining clip.

[0029] The holding element 8 is designed to establish an operative connection between the injector 6 and the holding bar 4, and is designed to hold the injector 6 on the distributor bar 4, in particular for connection to the pipe section 5. The holding element 8, which is designed in the form of a retaining clip, is designed to at least partially accommodate the pipe section 5 and the injector 6.

[0030] The holding element 8, which is shown in a perspective schematic diagram in Fig. 4, is manufactured separately from the distributor bar 4 and the injector 6. In the present embodiment, it is U-shaped, having two opposing holding arms 13 that are connected to each other by means of a connecting arm 14. Preferably, the two holding arms 13 are resiliently attached to the connecting arm 14.

[0031] The holding element 8 is designed to at least partially enclose the injector 6, with a space being formed between the holding arms 13 and the connecting arm 14, in which the injector 6 is received. The holding arm 13 is designed to at least partially engage the injector 6. For this purpose, it has a holding strip 15 on the holding arm 13 that extends in the direction of the injector 6.

[0032] In Fig. 3 illustrates the injector 6 in a perspective view. It has a holding section 18 and a nozzle section 19, with the nozzle section 19 facing the inlet channel 10, in particular projecting into it. The holding section 18 has a receiving element 20, which in this exemplary embodiment is designed in the form of a groove, into which the holding element 8 can engage, in the present exemplary embodiment with the aid of the holding strip 15 formed on the holding arm 13.

[0033] The holding section 18 further comprises a control element 21, with the aid of which a nozzle opening 22 formed on the nozzle section 19 can be opened or closed. The control element 21 is electronically connected to a control unit (not shown in detail) of the internal combustion engine 1, with the aid of which the injection timing and / or injection duration and / or injection quantity can be regulated. In the present exemplary embodiment, the nozzle opening 22 is designed as a two-hole opening. If two inlet openings 11 are formed, they can preferably be supplied with water 29 simultaneously.

[0034] To accommodate the pipe section 5, the holding arm 13 has a receiving opening 16 designed to receive the pipe section 5. Starting from a longitudinal axis L of the pipe section 5, the latter extends radially through the receiving opening 16. The receiving opening 16 can be designed to extend completely through the holding arm 13, but it could also be designed to extend only partially through the holding arm 13, essentially in a groove-like manner. This depends on the pipe section 5 and its section element 17 extending in the holding arm 13.

[0035] The distribution bar 4 and the guide bar 7 are flow-through, thus being hollow, whereby the water 29 is pumped into the distribution bar 4 under high pressure and can flow through it.

[0036] In Fig. 6 shows a further section of the cylinder head 3 of the internal combustion engine 1 according to the invention. The pipe section 5 is connected in a flow-through manner by means of a pipe section opening 23, which is formed opposite a bar opening 24 of the distributor bar 4. In other words, this means that the water 29 from the distributor bar 4 can flow into the pipe section 5 via the bar opening 24 and the pipe section opening 23. An injector opening 25 is accommodated in the pipe section 5, so that the water 29 can flow directly into the injector 6 via the injector opening 25. To seal the pipe section 5 against the water 29 escaping past the injector 6, a sealing element 26 is arranged between the holding section 18 and the pipe section 5. A further sealing element 31 is designed to seal the injector 6 from the cylinder head 3.

[0037] The manifold 4 and the pipe sections 6 are made of stainless steel to prevent corrosion. The manifold 4 has an integrated pressure sensor for determining the pressure within the manifold 4.

[0038] As particularly in Fig. As can be seen in Figure 5, the distributor bar 4 is fastened to the internal combustion engine 1, in particular to the cylinder head 3, by means of a fastening means 27, which is designed in the form of a screw. To simplify the attachment of the distributor bar 4 to the cylinder head 3, a support 28 is arranged on the cylinder head 3, receiving the distributor bar 4 and the fastening means 27. The distributor bar is held securely by means of the support 28.

[0039] As well as Fig. 5, the injector 6 is arranged for injection into the intake port 10 of the internal combustion engine 1, which is connected to an intake manifold 32 of the internal combustion engine 1 in a flow-through manner and is formed in the cylinder head 3 of the internal combustion engine 1.

[0040] In Fig.Figure 7 shows a plan view of a section of the cylinder head 3 of the internal combustion engine 1 according to the invention, wherein the distributor rail 4 is at least partially enclosed by a shielding element 30 for thermal insulation, and is thus protected by the shielding element 30. With the help of the shielding element 30, icing of the water 29 flowing in the distributor rail 4 can be prevented. The shielding element 30 is preferably made of foam and protects the distributor rail 4 and the injectors 6 against airflow, so that radiant heat from the cylinder head 3 is virtually encapsulated and the water injection device 2 is heated by the radiant heat. The distributor rail 4 is arranged between the cylinder head 3 and the shielding element 30. This represents an effective and cost-effective solution, allowing water injection to be implemented even at temperatures down to -10°C.

[0041] The water injection device 2 can be designed for an internal combustion engine 1 having multiple cylinder banks, wherein a connecting line (not shown in detail) is designed to connect the corresponding distributor rails 4 in a way that allows flow. This line is then routed along a corresponding end face of the cylinder banks.

[0042] In general, materials and a connection technology for individual line sections can also be used, which are also used in so-called low-pressure fuel injection systems.

[0043] The pressure in the distribution line 4 is approximately 10 bar, with the water 29 preferably being demineralized water. The water supply is realized by means of an unheated and movable connecting line to a motor vehicle body having the internal combustion engine 1 according to the invention.

[0044] The water injection device 2 can be controlled, for example, with the aid of the regulating and control device. Depending on a specific requirement, it is flooded with water 29, and the injectors 6 inject the water 29 into the intake port 10 for internal engine cooling. The evaporation of the water 29 extracts energy from the combustion chamber 9, thus cooling it. This can significantly increase engine power. After the internal combustion engine 1 is switched off, the water 29 is sucked out using the conveying medium to prevent the water injection device 2 from freezing. Thus, with the aid of the internal combustion engine 1 according to the invention with the water injection device 2, an air-fuel ratio λ in the exhaust gas with a value of 1 can be achieved in all operating states. List of reference symbols 1 internal combustion engine 2 water injection device 3 cylinder head 4 Distribution strip 5 Pipe section 6 Injector 7 Management 8 Holding element 9 Combustion chamber 10 Inlet channel 11 Entrance opening 12 Inlet valve 13 Holding arm 14 Connecting arm 15 retaining strip 16 Receiving opening 17 Section element 18 stopping section 19 Nozzle section 20 receiving element 21 Control element 22 Nozzle opening 23 Pipe section opening 24 groin opening 25 Injector opening 26 Sealing element 27 Fasteners 28 carriers 29 Water 30 Shielding element 31 Additional sealing element 32 intake manifold L Longitudinal axis

Claims

[1] Internal combustion engine (1) with a water injection device (2), wherein the water injection device (2) has a distributor bar (4) which is connected to at least one injector (6) in a flow-through manner, wherein the injector (6) is designed to inject water (29) into the internal combustion engine (1), and wherein the distributor bar (4) has a pipe section (5) for receiving the injector (6), wherein the pipe section (5) is designed to allow flow through the distributor bar (4), characterized byin that the injector (6) is connected to the distributor bar (4) by means of a holding element (8), wherein the holding element (8) is designed in the form of a holding clamp, and wherein the pipe section (5) is connected to the distributor bar (4) in a flow-through manner by means of a pipe section opening (23) which is designed opposite a bar opening (24) of the distributor bar (4), wherein the pipe section opening (23) is designed at a distance from a longitudinal axis (L) of the injector (6). [2] Internal combustion engine (1) according to claim 1, characterized by that the holding element (8) is designed to connect the injector (6) to the pipe section (5). [3] Internal combustion engine (1) according to claim 1 or 2, characterized by that the holding element (8) is designed to at least partially accommodate the pipe section (5) and the injector (6). [4] Internal combustion engine (1) according to one of the preceding claims, characterized bythat the holding element (8) is designed to engage at least partially into the injector (6). [5] Internal combustion engine (1) according to one of the preceding claims, characterized by that the water injection device (2) has a number of injectors (6) which corresponds at least to a number of cylinders of the internal combustion engine (1). [6] Internal combustion engine (1) according to one of the preceding claims, characterized by that the distribution bar (4) and the pipe section (5) are made of stainless steel. [7] Internal combustion engine (1) according to one of the preceding claims, characterized by that the distributor bar (4) is fastened to the internal combustion engine (1) by means of a fastening means (27). [8] Internal combustion engine (1) according to one of the preceding claims, characterized bythat the injector (6) is arranged for injection into an inlet channel (10) of the internal combustion engine (1), which is formed in a cylinder head (3) of the internal combustion engine (1). [9] Internal combustion engine (1) according to claim 8, characterized by that the distributor bar (4) is attached to the cylinder head (3). [10] Internal combustion engine (1) according to one of the preceding claims, characterized by that the distribution strip (4) is at least partially surrounded by a shielding element (30) for thermal insulation.

Images