DE60304569T2 - Assembly of an injector - Google Patents

Description

The The present invention relates to a piezoelectric injector unit, in particular for injecting fuel into a vehicle engine, with a housing with a valve needle in it for opening and closing a valve opening or an orifice, and a piezoelectrically actuated Actuator element for actuating the valve needle according to a electrical control voltage.

Of Furthermore, the present invention relates to a process for the preparation a piezoelectric injector unit.

piezoelectric Injection valve units with a piezoelectric arrangement for Actuate a valve assembly become ordinary in modern motor vehicles for controlling the injection of fuel used in the vehicle engine. The injection of the fuel in the vehicle engine can be fast and with high precision with Help a piezoelectric element take place, which is a piston element moves, which actuates a valve needle, which again an orifice accordingly opens and closes.

So far injection valve assemblies were considered as individual elements, which are constructed for a specific purpose and in accordance with certain Parameters are configured.

In EP 95 912 885 A1 a typical injection valve unit according to the prior art is disclosed. To form the overall unit, various and highly individualized sections of outer and inner, movable and fixed elements must be assembled and sealed.

Of the The main disadvantage of this prior art is that only the entire Device, i. the injection valve unit as such, on their function quality can be tested. If their overall performance is unsatisfactory, either the entire unit must be singled out, or each one each of its elements must be replaced individually to the Finding mistakes, for which each time the entire unit is completely dismantled and put together again must be added, with further error sources added.

In EP 1 046 809 A2 discloses an injection valve unit with a one-piece housing, in which the individual elements such as the valve needle, various springs, gaskets, stop elements, etc., must be positioned and fastened. The assembly is therefore very laborious and expensive. Likewise, the housing containing a separate fuel supply passage in the housing is difficult to machine. Furthermore, the orifice, which is a high-precision element, is configured as an opening in the housing. As a result, the entire housing must be machined with high precision, which increases costs. Finally, the disadvantages mentioned above regarding the testing of the unit also apply here.

In US 2003/0042325 A1 is a piezoelectric injection valve unit for injecting fuel into a vehicle engine with a casing with a valve needle in it for opening and closing an orifice and a piezoelectrically actuated Actuator element for actuating the valve needle according to a electrical control voltage disclosed. The valve needle and a valve body, the comprises a recess for receiving the needle, form a functional independent Valve module. The injection valve unit further includes a piezoelectric actuator module. The valve module and piezoelectric Steller are both housed in a housing.

In EP 245 828 A1 discloses a method of making and testing a modular injector unit having an electromagnetic actuator. A fuel module includes a valve body, a seat, and a guide having a needle, a pole piece, a spring, a filter, and an inlet tube. The fuel module is tested before an overmolded power group, which simultaneously forms the housing, is slid over the fuel module. The over-molded power group has the function of the housing and also includes a part of the actuator, and in particular comprises the coils for the electromagnetic actuator.

Of the present invention is based on the object, a piezoelectric Injection valve unit and a method for producing a piezoelectric To provide injection valve unit with which the disadvantages of Prior art are eliminated, and in particular a device to create that tested effectively and easily and at a lower cost together and to create a procedure for their execution.

The Task is satisfied with the features of the main claims.

preferred embodiments The present invention is defined in the subclaims.

With the injection valve assembly according to the present invention, an injection valve assembly according to the prior art is improved in that the valve needle and the orifice part of a functionally independent Ventilmo make up; the actuator element forming part of a functionally independent piezoelectric actuator module; and both modules - preferably reversible - are inserted into the rigid housing.

The is called, that the injection valve unit no more than a single device for one Overall performance but according to their various side functions is divided. Each secondary function is represented by its own module, which as a functionally independent Arrangement is configured. Any independent arrangement may be before Insert into the housing individually manufactured and tested. Consequently, mistakes can be made in an early Detect stage. The rejection of an unsatisfactory module is relatively cheap, the entire unit need not be disassembled and reassembled. The rigid housing can be edited in a fairly simple and straightforward way which significantly reduces overall costs.

The Valve module includes a connection opening to a fuel supply pipe. This works in such a way that the fuel is not through the entire housing, but only flooded through the valve module. Thus, only the valve module needs to be sealed, thereby further processing the housing is relieved.

The casing comprises a longitudinal slot, in which the fuel supply pipe connected to the valve module shifts, while the valve module in the housing is used. Due to this feature can in the housing Valve module can be used that on its function and its Sealing on changes its configuration has been tested, which could lead to further errors.

at a preferred embodiment is a heat balance agent to compensate for the thermal expansion the piezoelectric actuator module, wherein the heat balance means as a functionally independent Thermal compensation module is configured and together with the piezoelectric actuator module and the valve module inserted into the housing becomes. Piezoelectric modulators are known and include integrated heat balance means, however, it is a logical continuation of the basic idea of the present invention, this combination unit in various Divide units with special tasks, namely in an actuator unit and a compensation unit, which has similar advantages according to the above explanation he brings.

A further preferred embodiment is characterized in that the housing is a partially cylindrical molded interior, the modules a partially cylindrical shaped outdoor space have and the inner cylinder diameter of the housing to the outer cylinder diameter the module corresponds. This makes the case universally different Types of modules applicable, i. with different engines, which may require different fuel injection rates one or can several of the modules are exchanged for modules that are different according to Functional parameters are constructed, however, the same external shape exhibit. These different modules can be easily inserted into the universal housing or can be combined with other suitable modules.

Preferably is the injection valve unit according to the present invention with a housing provided with an adjustable cap, with the help of which in the casing used modules can be compressed with an adjustable force. The corresponds to a simple method for calibrating the injection valve unit, by which a biasing force is imposed on the piezoelectric element becomes.

Preferably is the case with an opening provided by which a terminal connector with the piezoelectric Stellermodul can be connected after this inserted into the housing is. There must be at least one electrical supply line through the housing be guided through to supply the piezoelectric module with the control voltage. Since an electrical connection is not difficult to install and no contains serious sources of error, This compound can after mechanical assembly of the Injection valve unit can be provided. So it can be easy a hole through the housing wall be useful.

• – Bereitstellen eines funktionell unabhängigen Ventilmoduls;
• – Bereitstellen eines funktionell unabhängigen piezoelektrischen Stellermoduls;
• – Bereitstellen eines starren Gehäuses, welches zwangsläufig der äußeren Form zumindest von Teilen der Module entspricht,
• – Einsetzen der Module in das Gehäuse; und
• – Zusammendrücken der Module mit einer definierten Kraft durch Befestigen und Einstellen des Einstellmittels – vorzugsweise einer einstellbaren Kappe – an dem Gehäuse.

The manufacturing method according to the present invention comprises the following steps:

• - Providing a functionally independent valve module;
• - Providing a functionally independent piezoelectric actuator module;
• Providing a rigid housing, which necessarily corresponds to the outer shape of at least parts of the modules,
• - Inserting the modules in the housing; and
• - Compression of the modules with a defined force by attaching and adjusting the adjusting means - preferably an adjustable cap - on the housing.

The main advantages of this method are explained above in connection with the injection valve unit according to the present invention. With the method is an optimized production of the separate modules and easy assembly same even by unskilled workers or simple machines. The modules can be manufactured in high production numbers, which reduces the price of each module. The assembly and calibration of the entire unit are also not changed by changes in parameters necessary to meet the requirements of different engines.

In a further step is the valve module before it is inserted into the housing will, with a fuel supply pipe connected. Thus, the valve module on its real function be tested, and its configuration can remain unchanged, when the whole unit is put together.

If the valve module in the housing is used, shifts the fuel supply in a longitudinal slot. This is a surprisingly simple one and cost-effective Method for implementing the one explained in the previous section Thought.

A preferred embodiment The present invention comprises the further step of providing a functionally independent Thermal compensation module and inserting it into the housing. Consequently, in the above explained way the basic idea of the invention logically continued, and the function which the device produced by the method according to the invention executing, is further divided into its elementary functions.

Preferably each module is tested independently, before it gets into the case is used. If a failure of a module is detected, This module can therefore be repaired or replaced without that the whole unit has to be taken apart. But when the whole unit does not work satisfactorily, the reason must be in a broken case or a wrong step in joining.

in the Below, the present invention will be described in more detail with reference to the drawings described in which

1 three different views of a housing according to the invention;

2 represents three ready for assembly modules;

3 an exploded view of the injection valve unit according to the invention; and

4 an assembled injection valve unit according to the invention.

1 represents three different views of a housing 10 according to the invention. 1a represents a side view of the housing 10 group; 1b represents a longitudinal view of the housing 10 group; and 1c represents another side view of the housing 10 of the 1a opposite side. Off 1b it can be seen that the case 10 with a substantially cylindrical inner surface 11 is provided, which is a cavity open at both ends, in which correspondingly cylindrical elements easily and reversibly from one side (the left side in 1b ) can be used. At the other end of the case 10 (the right end in 1b ) is a shoulder 12 provided as a stop member for in the housing 10 used parts acts.

Out 1c it can be seen that the case 10 with a longitudinal slot 13 is provided in the wall of the housing 10 is cut. This slot is used in the manner explained below as a slideway for the valve module and the connected fuel pipe. At one end of the housing 10 (the left end in 1c ) is the slot 13 open, so that modules can be used.

Opposite the slot 13 is a hole 14 provided, through which an electrical terminal connector can be inserted. At the in 1a the embodiment shown is the hole 14 on all sides of the wall of the housing 10 surround. In other embodiments, however, the hole 14 also be configured as a slot.

2 Provides three modules ready for assembly 20 . 30 . 40 dar. The module 20 is a piezoelectric actuator module having a piezoelectric element which is used to move a piston element in response to an electrical control voltage conducted thereto (both elements not expressly incorporated herein by reference) 2 are shown).

When the piston element is assembled and actuated, it acts on a movable active element of the valve module 30 , The active element can be the valve needle 32 of the valve module 30 or another connecting element. The valve element 30 However, it is configured such that the valve needle 32 when actuated by the actuator module 20 is moved to the orifice 31 according to the to the actuator module 20 guided control voltage to open and close. As the valve module 30 with the help of the fuel pipe 33 and a pipe connector 34 can be connected to a fuel reservoir or a pump, results from the opening and closing of the orifice 31 a well-measured injection of fuel into a vehicle engine.

Finally, a heat balance module 40 to compensate for the thermal expansion of the piezoelectric element in the actuator module 20 intended. However, if an actuator module is chosen such that the internal piezoelectric element is balanced, there is no compensation module 40 necessary.

3 FIG. 10 is an exploded view of the injector unit according to the invention, shown by the elements of FIG 3 is marked, together with the housing 10 according to 1 When assembling the injector, the valve assembly is first inserted into the housing, while the fuel pipe in the slot 13 shifts. The outer shape of the valve module 30 is chosen such that a cylindrical part with a diameter that corresponds to the inner diameter of the housing 10 corresponds, in light contact with the walls of the housing 10 is held and to the shoulder 12 abuts. The front section of the valve module 30 However, it is through the opening of the housing 10 fed through and represents the top of the entire injection valve unit. Furthermore, the actuator module 20 and the heat balance module 40 in a similar way in the housing 10 used.

So that the modules 20 . 30 . 40 not out of the case again 10 slip out, is the insertion end of the housing 10 (the left end according to 3 ) closed by an adjustable cap, in particular with a threaded ring 15 , The threaded ring 15 It can also be used to calibrate the injector unit by adjusting the force with which the modules are operated 20 . 30 . 40 are compressed in the housing, and thus on the piezoelectric element of the modulator module 10 applied biasing force is set.

So that a suitable control voltage to the actuator module 20 can be applied, an electrical terminal connector 21 through the hole 14 in the wall of the housing 10 through with the module 20 get connected.

4 illustrates an assembled injection valve unit according to the invention.

The Although this invention has been related to a preferred embodiment described, however, is for the skilled artisan recognizable that the present invention in numerous Ways can be modified and many other embodiments than the one specifically set forth and described above. Accordingly, with the attached claims All modifications of the invention will be made within the the scope of the invention.

Claims (8)

Piezoelectric injection valve unit, in particular for injecting fuel into a vehicle engine, having a housing ( 10 ) with a valve needle ( 32 ) therein for opening and closing an orifice (US Pat. 31 ), and a piezoelectrically actuated actuator element for actuating the valve needle ( 32 ) according to an electrical control voltage, characterized in that - the valve needle ( 32 ) and the orifice ( 31 ) a part of a functionally independent valve module ( 30 ) form; The actuator element is a part of a functionally independent piezoelectric actuator module ( 20 ) forms; - both modules in the rigid housing ( 10 ) are used; - the valve module ( 30 ) a connection opening to a fuel supply pipe ( 33 ); - the housing ( 10 ) a longitudinal slot ( 13 ), in which the with the valve module ( 30 ) connected fuel supply pipe ( 33 ) while the valve module ( 30 ) in the housing ( 10 ) is used. Injection-valve unit according to claim 1, characterized by a heat balance means for equalizing the thermal expansion of the piezoelectric actuator module ( 20 ), wherein the heat balance agent as a functionally independent heat balance module ( 40 ) and together with the piezoelectric actuator module ( 20 ) and the valve module ( 30 ) in the housing ( 10 ) is used. Injection valve unit according to one of the preceding claims, characterized in that the housing ( 10 ) has a partly cylindrically shaped interior, the modules ( 20 . 30 . 40 ) have a cylindrically shaped outer space and the inner cylinder diameter of the housing ( 10 ) to the outer cylinder diameter of the modules ( 20 . 30 . 40 ) corresponds. Injection valve unit according to one of the preceding claims, characterized in that the housing ( 10 ) an adjustable cap ( 15 ), with the help of which in the housing ( 10 ) used modules ( 20 . 30 . 40 ) can be compressed with an adjustable force. Injection valve unit according to one of the preceding claims, characterized by an opening ( 14 ) in the housing, through which an electrical terminal connector ( 21 ) with the piezoelectric actuator module ( 20 ), after this in the housing ( 10 ) is used. Method for producing a piezoelectric injector unit, in particular for injecting fuel into a vehicle engine, comprising the following steps: - providing a functionally independent valve module ( 30 ); Providing a functionally independent piezoelectric actuator module ( 20 ); Providing a rigid housing ( 20 ), which inevitably the outer shape of at least parts of the modules ( 20 . 30 ), - connect the valve module ( 30 ) with a fuel supply pipe ( 33 ), wherein the fuel supply pipe ( 33 ) in a longitudinal slot when the valve module ( 30 ) in the housing ( 10 ) is used; - Inserting the modules ( 20 . 30 ) in the housing ( 10 ); and - compressing the modules ( 20 . 30 ) with a defined force by attaching and adjusting the adjusting means ( 15 ) on the housing. An injection valve unit according to claim 6, characterized by the further steps of providing a functionally independent heat balance module ( 40 ) and inserting it into the housing ( 10 ). Injector valve unit according to claim 6 or 7, characterized by the further step of testing each module ( 20 . 30 . 40 ) independently before inserting it into the housing ( 10 ).