DE102012005486B4 - Modular pump arrangement - Google Patents

Abstract

Pump assembly comprising at least two supply blocks (203) which are joined together, wherein on each supply block (203) a pump (16) is arranged, wherein in each supply block (203) is provided an inlet bore (5) for a fluid, wherein the supply bores ( 5) in the supply blocks (203) are fluidically connected so that they represent a common inlet bore, wherein a suction side (17) of the pump (16) and the inlet bore (5) by means of at least one in the supply block (203) arranged Zufaufhilfsbohrung (4) fluidically connected, wherein at one of the at least two supply blocks (203) a connection block (209) is arranged at least indirectly, for supplying the fluid to the supply blocks (203), wherein at the connection block (209) at least one fluid connection (10) for the fluid is arranged and to the at least one fluid connection (10) at least one auxiliary connection hole (11) connects, which with a Ans The connection bore (12) is fluidically connected to the inlet bores (5) of the associated supply blocks (203) such that the connection bore (12) and the inlet bores (5) form a central inlet bore (6) of the Representing fluid to the pumps (16), wherein in the supply blocks (203) supply holes (208) for receiving a funded by the pump (16) supply flow are arranged and the supply holes (8, 208) via a supply connection (7) with customers ( 2) are in fluid communication, characterized in that the consumers (2) are injectors and each pump (16) is associated with an injector, wherein in the connection block (209) return bores (214) are arranged for excess fluid of the customers, wherein the return bores (214) at least one return port (13) and a return outlet, wherein a first valve (226) in a port Hilfsbohrung (11) is arranged so that it grants the feed stream of fluid from the fluid port (10) to the connection bore (12) in a first position and in a second position, the feed stream of the fluid from the fluid port (10) to the connection bore (12) prevents, and in the terminal block (209), a second valve (226) in a return bore (214) is arranged so that in a first position, the return flow of the fluid from the return port (13) granted to the return outlet (15) and in a second position prevents the return flow to the return outlet (15).

Description

The invention relates to a pump arrangement for supplying an exhaust aftertreatment device for internal combustion engines with a urea water solution having the features of the preamble of claim 1.

Exhaust after-treatment devices for internal combustion engines usually require a urea-water solution for purifying the exhaust gas. In this case, a pump conveys the urea water solution from a reservoir into the exhaust aftertreatment device, where it is usually injected through an injector into the exhaust gas.

From the DE 10 2008 012 780 A1 is a pump for supplying an exhaust aftertreatment device known. This pump is designed to deliver a given flow of urea water solution for purifying an exhaust gas of an internal combustion engine to a certain extent.

Other pump arrangements are in the WO 2012/119 251 A1 . EP 1 085 206 A1 . DE 103 45 106 A1 and the US 5 513 966 A shown.

The disadvantage of this is that appropriate for internal combustion engines for different performance pumps must be designed and provided, which are necessary for the required flow of urea water solution for the purification of the exhaust gas. This means different pumps for different internal combustion engines.

The object of the invention is to reduce the number of different pumps for the flow of urea water solution required for exhaust aftertreatment devices for internal combustion engines of different capacities.

The solution is carried out with a pump assembly having the features of claim 1. Advantageous embodiments of the invention are illustrated in the subclaims.

According to the invention, a pump arrangement is provided which comprises at least two supply blocks, wherein a pump is arranged on each supply block, wherein an inlet bore for a fluid is provided in each supply block. The inlet bores in the supply blocks are fluidically connected so that they represent a common inlet bore. Next, a suction side of the pump and the supply line are fluidly connected. At one of the at least two supply blocks, a connection block is arranged at least indirectly, for supplying the fluid to the supply blocks. At least one fluid connection for the fluid is arranged on the connection block. To the at least one fluid connection connects at least one auxiliary connection hole, which is fluidically connected to a connection bore. The connection bore is fluidically connected to the inlet bores of the associated supply blocks so that the connection bore and the inlet bores constitute a central inlet bore of the fluid to the pumps. Supply lines for receiving a supply current required by the pumps are arranged in the supply blocks. The supply bores are in fluid communication with consumers via a supply connection. The customers are injectors and each pump is assigned an injector. In the connection block return bores for excess fluid of the customers are arranged. The return bores have at least one return connection and one return exit. In this case, a first valve in a connection auxiliary bore is arranged so that it allows the inlet flow of the fluid from the fluid port to the connection bore in a first position and in a second position prevents the flow of fluid from the fluid port to the connection bore. In the connection block, a second valve in a return line is arranged so that in a first position it allows the return flow of the fluid from the return connection to the return outlet and in a second position prevents the return flow to the return outlet.

Starting from a pump with a certain delivery rate, an arrangement of a plurality of identical pumps advantageously makes it possible to provide any desired flow of a fluid, for example a urea-water solution for exhaust aftertreatment devices for internal combustion engines of different capacities. In addition, it is advantageous that the expense of piping the supply blocks with one another is eliminated by assembling the supply blocks with the inlet bores arranged therein. Thus, the individual inlet bores form a common inlet bore from which the pumps suck in the fluid.

The inlet of the fluid into the common inlet bore takes place at one point for all supply blocks.

From the fact that at one of the at least two supply blocks, a connection block is arranged at least indirectly for supplying the fluid to the supply blocks, advantageously results in a central supply of fluid, from which the fluid flows into the supply blocks. Thus, a supply to a special supply block, which is different from the other different from manufacturing technology. In the sense of a cost-effective equal part production so all supply blocks can be made the same. Between the supply block on which the connection block is arranged and the connection block, an additional component, for example a sealing element, can be arranged, which means that the connection block is arranged at least indirectly on the supply block.

By supplying the fluid to the connection block, it is easily possible to expand the pump arrangement by one or more distributor blocks without conversions at the inlet.

By providing supply holes in the supply blocks, a simple exchange of a pump is ensured without, for example, having to disassemble supply lines from the pump to the consumer.

Advantageously, it results from the first valve and the second valve in the connection block that the valves for a flow of the fluid are open during operation of the internal combustion engine and the exhaust gas aftertreatment device. At standstill of the internal combustion engine and exhaust aftertreatment device, the valves are closed. The closed valves have the advantage that the fluid remains trapped downstream of the first valve up to the second valve in the flow-through volumes. Thus, for example, the inlet, supply and return bores, as well as the pumps and injectors always remain filled with the fluid. When the fluid is discharged from the bores when the internal combustion engine is at a standstill, there is a risk that the fluid will come into contact with air and, consequently, may lead to undesirable reactions, such as crystallization of constituents, and therefore obstruction of the bores in some fluids.

According to a preferred embodiment of the invention, the supply blocks are substantially cuboid and lie on flange directly or indirectly to each other. Cuboid components are easy to manufacture and the side surfaces simultaneously yield flange surfaces. The flange surfaces of the supply blocks can lie directly against each other, d. H. the supply blocks are touching each other directly. However, it is also possible to arrange an additional component, for example a sealing element, between the flange surfaces, so they then lie indirectly against one another.

According to a further preferred embodiment of the invention, the terminal block is substantially parallelepiped-shaped and has at least one flange surface and on one of the flange faces at least one of the two supply blocks. Since the supply blocks are preferably also cuboid and have flat flange surfaces, a simple modular arrangement of the supply blocks on the terminal block is possible.

According to a further preferred embodiment of the invention, at least one further supply block is at least indirectly arranged on at least one further flange surface of the terminal block. By a plurality of flange surfaces on the terminal block, for example, a linear or star-shaped arrangement of the supply blocks on the terminal block is possible. In this case, an additional component, for example a sealing element, can be arranged between the connection block and a supply block.

According to a further preferred embodiment of the invention, the pickup is an injector and this is connected via a return line for excess fluid with at least one arranged in the connection block return port in connection and this is connected via arranged in the terminal block return bores with a return outlet fluidly connected.

According to a further preferred embodiment of the invention a Absteuerbohrung is arranged in the connection block, which connects a connection auxiliary bore fluidly with a return bore downstream of the second valve, further in the Absteuerbohrung a check valve is arranged, the flow direction is directed so that it is a partial flow from the inlet flow of the fluid granted in the form of a Absteuerstroms in the direction of return outlet and prevents a flow in the opposite direction of flow. When using a prefeed pump, the line system can be filled up to the first valve with the fluid in this way before starting the internal combustion engine with the first valve closed. Another advantage is the operation of the internal combustion engine, the rapid Absteuern of excess fluid, if the flow rate of the pump is suddenly reduced and the feed pump is fed technically delayed.

According to a further preferred embodiment of the invention, bores for a flow of a medium for heat regulation of the fluid are arranged in the supply blocks and in the connection block. Advantageously, such a too hot fluid can be cooled, or in cold ambient conditions, a freezing of the fluid can be prevented by the flow through the supply blocks and the terminal block with a warm medium.

According to a further preferred embodiment of the invention, the free flange surfaces of the supply blocks, on which no other supply block or the terminal block is arranged, and on which at least one open bore is arranged, sealed fluid-tight with a closure means.

According to a further preferred embodiment of the invention, a filter is arranged on each supply block, which is flowed through downstream of the pump via the supply bore from the supply current before the supply current flows through the supply connection to the customer. As a result, impurities are retained in the filter and do not clog the customers.

According to a further preferred embodiment of the invention, a filter is arranged on the connection block, which is traversed downstream of the fluid connection via the auxiliary connection bore from the fluid before the fluid flows into the connection bore. As a result, impurities are already retained in the filter before they get into the pump.

According to a further preferred embodiment of the invention, the fluid is a urea-water solution.

According to a further preferred embodiment of the invention, the medium is engine cooling water. Warm engine cooling water is usually present in running internal combustion engines and can therefore be used for antifreeze of the urea water solution. Elaborate additional heaters are therefore not necessary.

Embodiments of the invention are illustrated in the drawings and will be described in more detail below.

Show it:

1 a cross section through the basic structure of the pump assembly according to the prior art.

2 a cross section through the basic structure of a pump assembly according to an embodiment of the invention.

1 shows a cross section through a basic structure of a pump assembly 1 for the supply of customers 2 with a fluid according to the prior art. Preferably, the customers 2 Injectors which are arranged in an exhaust gas aftertreatment device (not shown) and inject into a waste gas stream of an internal combustion engine (not shown) as fluid a urea water solution for purifying the exhaust gas flow. The pump arrangement 1 in a first embodiment comprises two supply blocks 3 and a terminal block 9 , which on flange surfaces 19 lie directly against each other. At the connection block 9 is a fluid connection 10 arranged to the one auxiliary connection hole 11 connects that into a connection hole 12 empties. In each supply block 3 is an inlet hole 5 arranged, the fluidically with each other and with the connection bore 12 are connected so that they have a central inlet bore 6 represent. At every supply block 3 is a pump 16 arranged with the suction side 17 via an auxiliary auxiliary drilling 4 with the inlet bore 5 of the respective supply block 3 fluidically connected. The print side 18 the pump 16 is fluidically with a in a supply connection 7 opening supply bore 8th in the supply block 3 connected. Free flange surfaces 19 the supply blocks 3 and the terminal block 9 with open holes are with closure means 20 sealed fluid-tight. In operation, all pumps suck 16 a total of a feed stream of urea water solution through the auxiliary auxiliary wells 4 , the central inlet hole 6 , the connection hole 11 and a connecting cable 22 at the fluid connection 10 is connected, from a storage container 21 , Every pump 16 promotes its sucked stream of urea water solution in the form of a supply current pressure side into the supply bore 8th , About one at the supply connection 7 connected pressure line 23 the supply current flows to each pump 16 associated injector. As described above, each injector injects the urea water solution into the exhaust stream in an exhaust aftertreatment device. In this case, not the entire supply stream of urea water solution is injected into the exhaust gas. The injector introduces a certain amount of leakage, which is used systematically as well as intentionally to cool the injector. This leakage represents an excess urea water solution, in the form of a return flow through a return line 24 to a return port 13 at the connection block 9 flows. From the return connection 13 the return flow flows through return bores 14 in the connection block 9 to a return outlet 15 and from there centrally through a leakage line 25 in the reservoir 21 ,

2 shows a cross section through the basic structure of the pump assembly 1 according to an embodiment of the invention. It is on another flange 19 of the terminal block 209 another supply block 203 arranged. In addition, in the connection block 209 in the connection auxiliary hole 11 and the return bore 214 one valve each 226 arranged. These valves 226 are preferably electromagnetically actuated and have a first ("open") and a second ("closed") position. During operation of the internal combustion engine and exhaust aftertreatment device are the valves 226 opened for a flow of urea water solution. At standstill of the internal combustion engine and exhaust aftertreatment device are the valves 226 closed. From the closed valves 226 there is the advantage that, for example, the feed 5 , Supply 208 and return bores 214 , as well as the pumps 16 and injectors remain at standstill of the internal combustion engine filled with the urea water solution. When the urea water solution is discharged, there is a risk that residues of the urea water solution remaining in the bores and lines come into contact with air, which can lead to the crystallization of solid urea, and therefore obstruction of the bores and lines. A diversion bore 227 in the connection block 209 branches upstream of the first valve 226 from the connection hole 11 and flows into the return bore 214 downstream of the second valve 226 , Additionally is in the diversion well 227 a check valve 228 arranged so that it flows from the feed stream of urea water solution a partial flow in the form of a Absteuerstroms in the direction of return 15 granted and locks in the opposite direction of flow. In some applications of the internal combustion engine is the reservoir 21 the urea water solution so deep that the pumps 16 can not overcome the suction height. For this reason, in the connecting cable 22 a prefeed pump 229 arranged, which the feed stream with a certain feed pressure to the pumps 16 promotes. At a fast load change of the internal combustion engine can short-term operating conditions occur, in which, for example, the pumps 16 quickly reduce the supply flow, the prefeed pump 229 but only delayed control technology is tracked. To avoid excessive pressure build-up, excess urea water solution flows through the spill port 227 in the return bore 214 and further into the storage container 21 , To prevent clogging of the injectors by dirt in the urea water solution is at each supply block 203 the pump 16 a filter 230 which filters the supply current before flowing to the injector. Not shown are the possibilities of a sole or additional arrangement of a filter 230 on the terminal block 209 , This is the filter 230 fluidically in the auxiliary connection bore 11 such that the fluid is downstream of the fluid port 10 first through the filter 230 flows and is cleaned before moving further into the connection hole 12 flows. At low outside temperatures, there is a risk of freezing with a urea-water solution, with the result that the exhaust-gas aftertreatment system is inoperative. That's why in the supply blocks 203 and in the terminal block 209 medium holes 231 arranged, through which a medium for heat regulation flows. In the present case, the medium is engine cooling water that enters through a medium 232 in the connection block 209 into the medium wells 231 enters, while the supply blocks 203 and so also heats the urea water solution before it passes through a medium 233 in the connection block 209 exit.

LIST OF REFERENCE NUMBERS

1

pump assembly

2

customer

3, 203

supply block

4

Feed auxiliary bore

5

inlet bore

6

central inlet bore

7

supply terminal

8, 208

supply hole

9, 209

terminal block

10

fluid port

11

Connecting auxiliary bore

12

connection bore

13

Return connection

14, 214

Return bore

15

Return outlet

16

pump

17

suction

18

pressure side

19

flange

20

closure means

21

reservoir

22

connecting cable

23

pressure line

24

Return line

25

leakage line

226

Valve

227

spill port

228

check valve

229

prefeed

230

filter

231

medium holes

232

medium inlet

233

medium outlet

Claims (11)

Pump arrangement comprising at least two supply blocks ( 203 ), which are joined together, whereby at each supply block ( 203 ) a pump ( 16 ), wherein in each supply block ( 203 ) an inlet bore ( 5 ) is provided for a fluid, wherein the supply bores ( 5 ) in the supply blocks ( 203 ) are fluidically connected so that they form a common inlet bore, wherein a suction side ( 17 ) of the pump ( 16 ) and the inlet bore ( 5 ) by means of at least one in Supply block ( 203 ) arranged auxiliary auxiliary bore ( 4 ) are fluidically connected, wherein at one of the at least two supply blocks ( 203 ) a terminal block ( 209 ) is arranged at least indirectly, for supplying the fluid to the supply blocks ( 203 ), whereby at the connection block ( 209 ) at least one fluid connection ( 10 ) is arranged for the fluid and to the at least one fluid connection ( 10 ) at least one auxiliary connection hole ( 11 ) connected with a connection bore ( 12 ) is fluidically connected, and the connection bore ( 12 ) fluidically with the inlet bores ( 5 ) of the assigned supply blocks ( 203 ) is connected so that the connection bore ( 12 ) and the inlet bores ( 5 ) a central inlet bore ( 6 ) of the fluid to the pumps ( 16 ), where in the supply blocks ( 203 ) Supply bores ( 208 ) for receiving one of the pumps ( 16 ) are arranged and the supply bores ( 8th . 208 ) via a supply connection ( 7 ) with customers ( 2 ) fluidically, characterized in that the customers ( 2 ) Are injectors and each pump ( 16 ) is assigned to an injector, wherein in the terminal block ( 209 ) Return bores ( 214 ) are arranged for excess fluid of the customers, wherein the return bores ( 214 ) at least one return port ( 13 ) and a return outlet, wherein a first valve ( 226 ) in a connection auxiliary bore ( 11 ) is arranged so that it in a first position, the feed stream of the fluid from the fluid port ( 10 ) to the connection hole ( 12 ) and in a second position, the inflow stream of the fluid from the fluid connection ( 10 ) to the connection hole ( 12 ) and in the terminal block ( 209 ) a second valve ( 226 ) in a return bore ( 214 ) is arranged so that in a first position, the return flow of the fluid from the return port ( 13 ) to the return outlet ( 15 ) and in a second position, the return flow to the return outlet ( 15 ) stops. Pump arrangement according to claim 1, characterized in that the supply blocks ( 203 ) are substantially cuboidal and on Flanschflächen ( 19 ) abut each other directly or indirectly. Pump arrangement according to claim 2, characterized in that the connection block ( 209 ) is substantially cuboidal and at least one flange surface ( 19 ) and on one of the flange surfaces ( 19 ) one of the at least two supply blocks ( 203 ) is present. Pump arrangement according to claim 3, characterized in that on at least one further flange surface ( 19 ) of the terminal block ( 209 ) at least one further supply block ( 203 ) is arranged at least indirectly. Pump arrangement according to one of claims 1 to 4, characterized in that in the terminal block ( 209 ) a diversion bore ( 227 ) is arranged, which the auxiliary connection hole ( 11 ) fluidically with the return bore ( 214 ) downstream of the second valve ( 226 ) and in the diversion bore ( 227 ) a check valve ( 228 ) is arranged, the flow direction is directed so that it flows from the inlet flow of the fluid a partial flow in the form of a Absteuerstroms in the direction of return ( 15 ) and prevents a flow in the opposite direction of flow. Pump arrangement according to one of claims 1 to 5, characterized in that in the supply blocks ( 203 ) and in the connection block ( 209 ) Medium bores ( 231 ) are arranged for a flow of a medium for heat regulation of the fluid. Pump arrangement according to one of the preceding claims, characterized in that the free flange surfaces ( 19 ) of supply blocks ( 203 ), where no other supply block ( 203 ) or the connection block ( 209 ) is arranged, and at which at least one open bore is arranged, with a closure means ( 20 ) are completed fluid-tight. Pump arrangement according to one of claims 1 to 7, characterized in that at each supply block ( 203 ) a filter ( 230 ) located downstream of the pumps ( 16 ) via the supply bore ( 208 ) is flowed through by the supply current before the supply current via the supply terminal ( 8th ) to the customer ( 2 ) flows. Pump arrangement according to one of claims 1 to 7, characterized in that the connection block ( 209 ) a filter ( 230 ) located downstream of the fluid port ( 10 ) via the auxiliary connection hole ( 11 ) is traversed by the fluid before the fluid in the connection bore ( 12 ) flows. Pump arrangement according to one of the preceding claims, characterized in that the fluid is a urea water solution. Pump arrangement according to one of the preceding claims, characterized in that the medium is engine cooling water.

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