A piezo-actuator with an insulation layer against moisture.

Abstract

The present invention relates to a piezoelectric actuator (100) for use in fuel injectors in internal combustion engines, comprising a housing (1) extending along a length (L) between a first end (11) and a second end (12) far from the first end (11) and supplied with a piezoelectric material (10); a first outer electrode (21) located on a first side of the piezoelectric material (10); a second outer electrode (22) located on a second side of the piezoelectric material (10) opposite the first side; one or more first inner electrodes (31) extending through the piezoelectric material (10) from the first outer electrode (21) to the second outer electrode (22); and one or more second inner electrodes (32) extending parallel through the piezoelectric material (10) from the second outer electrode (22) to the first outer electrode (21) to the first inner electrodes (31).The actuator (100) comprises a first insulation layer (41) located on the first outer electrode (21) and a second insulation layer (42) located on the second outer electrode (22); the first insulation layer (41) and the second insulation layer (42) extend from the first end (11) to the second end (12), thus completely covering the first outer electrode (21) and the second outer electrode (22) respectively. Figure 1

Description

1 TARIFF A piezo-actuator with an insulation layer against moisture. TECHNICAL ASPECT OF THE INVENTION 5 The present application relates to an improvement in the technical field of piezoelectric actuators. Specifically, The present invention is based on a piezoelectric actuator, according to the prior part of the attached independent claim. It is related. BACKGROUND OF THE INVENTION Piezoelectric actuators, or piezo actuators for short, convert electrical energy into mechanical energy. Piezo actuators are devices for converting fuel in internal combustion engines. injectors, microfluidic applications, MEMS sensors, and many other technical fields - 15 They are used extensively. For example, some fuel injectors are a type of injection. To initiate the process, a length extension is created to lift the relevant valve needle. It incorporates a multi-layer piezo actuator for this purpose. For optimal energy transfer, copper (Cu) and silver (Ag) are commonly used as electrode materials. It is used in this way. Ag has the minimum resistance among metals. It is known that Ag can therefore provide maximum electrical conductivity. However, the use of Ag also brings with it several problems that need to be solved. The surfaces of the Ag electrodes can be considered to be in the form of silver oxide (Ag2O). When brought into contact with water, Ag ionizes from its oxide form according to the following reaction. is: Ag2O + H2O  2Ag+ + 2OH- 30 Ag+ ions move from the anode to the corresponding cathode through the piezoelectric material. It is migrating; thus, it is degrading the performance of the relevant piezo actuator. In addition, Ag+ The arrival of ions at the cathode causes branching growth from the cathode to the anode; the result A short circuit occurs, rendering the piezo actuator inoperable. 35 2 On the other hand, some piezo actuators use silver / palladium (Ag / Pd) in the internal electrodes. alloys are used; in such cases, the migration of Ag+ is due to the migration of Pd in ​​the alloy. It can be assumed that this is inversely proportional to the percentage. This information suggests that the migration of Ag+ ions... It appears to be beneficial in minimizing it; however, Pd is expensive. The material used causes an increase in the production cost for such piezo actuators. 5 is happening. EP 2 529 422 A1 refers to a material with one or more protective layers against moisture. The actuator is being disclosed. However, it has a longer service life and Providing a piezoelectric actuator that can be obtained at a low cost is still 10 It is requested. A BRIEF DESCRIPTION OF THE INVENTION The primary aim of the present invention is to overcome the aforementioned disadvantages of the previous technique. 15 Another aim of the present invention is to achieve a longer service life, more The goal is to develop a piezoelectric actuator with low complexity and low cost. The present application concerns the development of a piezoelectric actuator, as described in the attached independent claim. By implementing this, these objectives are achieved. In the context of the current application, piezoelectric 20 an actuator, piezo actuator, or simply actuator can be used as such. According to the current invention, the piezoelectric actuator can be used with fuel-based internal combustion engines. It is considered suitable for use in injectors. The actuator is a piezoelectric It includes a fuselage provided with the material; the fuselage has a primary end and a 25-inch section far from the primary end. It extends along a length between the two ends. The actuator, additionally, uses piezoelectric technology. The material includes a primary external electrode located on one side. The actuator, additionally... Specifically, a second outer layer of piezoelectric material located on a second side opposite the first side. It includes the electrode. The actuator, additionally, transmits signals from the first outer electrode to the second outer electrode. One or more primary inner electrodes extending through a piezoelectric material 30 It includes an actuator, additionally, from the second outer electrode to the first outer electrode. One or more electrodes extend parallel to the first inner electrode through the piezoelectric material. It includes a second internal electrode. The first and second outer electrodes extend from the first end to the second end, thus, the body 35 It closes the first side and then the second side completely, respectively. Additionally, the actuator... a primary insulation layer located on the first outer electrode and on the second outer electrode 3 It includes a second insulation layer; the first insulation layer and the second insulation layer. The layer extends from the first end to the second end, thus, respectively, the first outer electrode and the second It completely covers the outer electrode. Thus, water or moisture protection is made fully possible; this allows for a high 5 The service life is extended without requiring production costs. In a possible configuration, the first and second insulation layers are conical, so that, thicknesses, with a relatively high value at the first end and a relatively low value at the second end It has. Thus, an even higher degree of water protection is achieved around the first end, 10. It can be provided. One possible configuration of the actuator, when in use, would be along the gravity vector. It can be arranged to extend so that, when in use, the first end is the second. It is located above the tip. Thus, the top, at the first tip, provides even higher water protection. 15 It is at that level. One possible configuration of the actuator would be the first outer electrode around the first end and the second outer electrode around the first end. one or more anode wires connected sequentially to the electrode and one or more It can contain a large number of cathode wires. Thus, the insulation must cover the first end 20 thanks to the water along the cables mentioned, against moisture or gravity. Protection is provided against its approach. In a possible configuration, the first insulation layer and / or the second insulation layer could be semi-crystalline. thermoplastics, polyether ketones, polyether etherketones, polybenzimidazoles, 25 polyphenylenesulfides, polyamidymides, polysulfones, polyethersulfones; liquid crystal polymers and polymer variants, polyamides (Kapton) / polyimides, polymethylacrylates, parylenes; latex variants, one or more of which are selected from a list consisting of acrylate latex and fluoroethylene propylene. It includes a large number of building materials. These materials have excellent electrical and It exhibits mechanical behavior. 30 In a possible configuration, the first insulation layer and / or the second insulation layer could be a strip, It can be in the form of tape, paste, or sheet metal. These forms are easy to install and... The forms are applied in increasing numbers of layers towards the first end, allowing for incremental thickness. It gives. 35 4 A piezoelectric material may include a dielectric material. A piezoelectric material is a or it may contain more dielectric ceramics. The first inner electrodes and / or the second inner electrodes may contain silver. Similarly, The first outer electrode and / or the second inner electrode may contain silver. 5 In the present invention, additionally, any of the actuator configurations as described herein A fuel injector for internal combustion engines, which includes one of these components, is also presented. BRIEF DESCRIPTION OF THE FIGURES 10 The sole purpose of the figures, the brief descriptions of which are given here, is to facilitate a better understanding of the present invention. to provide and, where a specification is not available, to define the scope of protection. It is not intended to define the context in which the aforementioned scope will be interpreted. Figure 1 shows a schematic cross-sectional view of the piezoelectric actuator according to the present invention. is provided. DETAILED DESCRIPTION OF THE INVENTION Referring to the figure mentioned above, the present application includes a piezoelectric device containing the following: The actuator (100) is presented: - a length (L) between a first end (11) and a second end (12) far from the first end (11) a body (1) that extends along and contains a piezoelectric material (10), 25 - a first outer electrode (21) located on one side of the piezoelectric material (10); - a second side of piezoelectric material (10) located opposite the first side outer electrode (22); 30 - piezoelectric material (10) from the first outer electrode (21) to the second outer electrode (22) one or more first inner electrodes (31) extending from within and - piezoelectric material (10) 35 from the second outer electrode (22) to the first outer electrode (21) one or more second electrodes extending parallel to the first inner electrode (31) inner electrode (32). Both the first outer electrode (21) and the second outer electrode (22) are connected from the first end (11) to the second end (12) It is extended so that the first side and the second side of the trunk (1) are completely covered respectively. It is closing. The actuator (100) has, in addition, a first insulation 5 located on the first outer electrode (21). layer (41) and a second insulation layer (42) located on the second outer electrode (22) It includes the first insulation layer (41) and the second insulation layer (42), from the first end (11) extending to the second end (12), thus connecting the first outer electrode (21) and the second outer electrode respectively. (22) completely closes. Thus, the first outer electrode (21) and the second outer electrode (22) and In addition, the body (1) is protected from contact with moisture or water. 10 Moisture is transferred to the outer electrodes: to the first outer electrode (21) and the second outer electrode (22) and then to the inner It is thought that moisture can move toward the electrodes: the first end (11) of the body (1) the relevant electrical cables that can be connected around it (anode cable (61) and cathode cable (62)) It can advance through the first inner electrode (31) and the second inner electrode (32) 15 It is conceivable that the present invention thus provides complete protection against moisture for the actuator (100). This makes it possible. Thus, from the first inner electrode (31) and the second inner electrode (32) ionization, ion migration, performance degradation, and dendrite growth are all related. This is prevented. Consequently, the present invention offers low production costs along with... A longer service life is provided to the actuator (100). 20 In a possible configuration, the first insulation layer (41) and the second insulation layer (42) are conical, Thus, in a direction parallel to the first inner electrode (31) and the second inner electrode (32) The thicknesses of the layers (41, 42) have a relatively higher value at the first end (11) and at the second The end (12) has a relatively lower value. In other words, the first insulation is 25 a thickness of the first layer (41) and the second insulation layer (42) starting from the first end (11) it decreases and has a relatively low value at the second end (12). When the actuator (100) is in use, the first end (11) will be located above the second end (12). In the figure, the body (1) extends parallel to the gravity vector (g) along its length (L) 30 It is conceivable. Accordingly, when the actuator (100) is in use, the top, around the first end (11) It can be assumed that it is designed to have thick insulation. The first (1) of the body An anode cable (61) and a cathode cable (62) which can be connected around the end (11) respectively 35 via the first outer electrode (21) and the second outer electrode (22) and then the first inner Moisture can advance to the electrode (31) and the second inner electrode (32). Therefore, possible moisture 6 The attack is more concentrated around the first end (11). The current structure is with the second end (12) When compared, the presence of moisture is more prominent around the first end (11) It provides a greater degree of protection against the existing structure. According to the actuator (100), it offers an even longer service life without requiring high production costs. It has a lifespan of 5. The actuator (100) is thus connected to the first outer electrode (21) and the second outer electrode (11) around the first end. one or more anode cables (61) that can be connected to the electrode (22) respectively and one or may contain more than one cathode wire (62). A building material used for the first insulation layer (41) and the second insulation layer (42) It can be considered to be waterproof. First insulation layer (41) and / or second insulation layer (42), semi-crystalline thermoplastics, e.g. polyether ketones, polyether etherketones, polybenzimidazoles, polyphenylenesulfites, polyamidimides, polysulfones, polyethersulfones; liquid Crystalline polymers and polymer variants, e.g., polyamides (Kapton) / polyimides, 15 polymethylacrylates, parylenes; latex variants, such as acrylate latex and fluoroethylene One or more structures selected from a list consisting of propylene (FEP for short). It may include this material. These materials have high dimensional stability and good It exhibits mechanical and electrical properties. The first insulation layer (41) and the second insulation layer (42) are made of a strip, tape, paste or sheet metal. It can be in the form of a conical structure, which can be more numerous around the first end (11) and by creating a smaller number of layers around the second end (12) It can be provided. Piezoelectric material (10) is a dielectric material, for example one or more They can be considered as numerous dielectric ceramic materials. The first inner electrodes (31) and / or the second inner electrodes (32) may contain silver. Similarly In this way, the first outer electrode (21) and / or the second outer electrode (22) may contain silver. 30 7 REFERENCE NUMBERS 1 body piezoelectric material 11 first end 5 12 second flight 21 first outer electrode 22 second outer electrode 31 first inner electrode 32 second inner electrode 10 41 first insulation layers 42 second insulation layers 61 anode cable 62 cathode cable 100 actuators 15 g is the gravity vector L length

Claims

8 REQUESTS 1. A length (L) between a first end (11) and a second end (12) far from the first end (11) a body (1) that extends along and is provided with a piezoelectric material (10), a first outer electrode located on one side of the piezoelectric material (10) 5 (21); a piezoelectric material (10) located on a second side opposite the first side second outer electrode (22); from the first outer electrode (21) to the second outer electrode (22) One or more primary internals extending from within the piezoelectric material (10) piezoelectric electrode (31) and from the second outer electrode (22) to the first outer electrode (21) One or more of the materials (10) extending parallel to the first inner electrodes (31) fuel in internal combustion engines containing a large number of second internal electrodes (32) It is a piezoelectric actuator (100) for use in injectors; its feature is; first insulation layer (41) and second insulation layer (42), from the first end (11) to the second end (12) extending, thus, the first outer electrode (21) and the second outer electrode (22) respectively completely closing and actuator (100), in addition, the first outer electrode (21) 15 a first insulation layer (41) and a second outer electrode (22) on it including a second insulation layer (42); the first insulation layer (41) and The second insulation layer (42) extends from the first end (11) to the second end (12), so that, It is to completely cover the first outer electrode (21) and the second outer electrode (22) respectively.

2. An actuator (100) according to claim 1, whose characteristic is; the first insulation layer (41) and the second The insulation layer (42) is conical so that the thicknesses are one at the first end (11). It has a relatively high value at the second end and a relatively low value at the second end (12).

3. An actuator (100) according to claim 1 or 2, whose characteristic is that when in use, 25 It is arranged so that it lies along the gravity vector (g), so that, When in use, the first end (11) is positioned above the second end (12).

4. An actuator (100) according to any of the requirements 1 to 3. its feature; the first insulation layer (41) and / or the second insulation layer (42), semi-30 crystalline thermoplastics, polyether ketones, polyether etherketones, polybenzimidazoles, polyphenylenesulfides, polyamidymides, polysulfones, polyethersulfones; liquid crystal polymers and polymer variants, polyamides (Kapton) / polyimides, polymethylacrylates, parylenes; Latex variants are selected from a list consisting of acrylate latex and fluoroethylene propylene. or it contains more than one building material. 35 9 5. An actuator (100) according to any of the requirements 1 to 4. its feature is that the first insulation layer (41) and / or the second insulation layer (42), one It can be in the form of strips, tape, paste, or sheets.

6. An actuator (100) according to any of the requirements 1 to 4, 5 Its characteristic is that the piezoelectric material (10) contains a dielectric material.

7. An actuator (100) according to claim 6, whose characteristic is that a piezoelectric material (10) is either It also contains a larger number of dielectric ceramics.

8. An actuator (100) according to any of the requirements 1 to 7. its feature is that the first inner electrodes (31) and / or the second inner electrodes (32) are silver It includes.

9. An actuator (100) according to any of the requirements 1 to 8, 15 its feature is that the first outer electrode (21) and / or the second outer electrode (22) is silver It includes.

10. An actuator (100) according to any of the requirements 1 to 9. its feature is that the first end (11) is connected to the first outer electrode (21) and the second outer electrode (22) 20 one or more anode cables (61) connected in sequence and one or It contains a larger number of cathode wires (62).

11. Containing the actuator (100) according to any of the requirements 1 to 10, A fuel injector for internal combustion engines. 25

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