Method for manufacturing a nozzle piston, production method for a damper, nozzle piston, damper, production plant for producing a damper

Abstract

Provided is a method for the production of a nozzle piston for arrangement in a damping space of a damper, which contains a damping fluid, wherein the piston divides the damping space into a first fluid chamber and a second fluid chamber. Also provided is a production method with the method according to the invention for a damper. Also provided is a nozzle piston for arrangement in a damping space of a damper, which contains a damping fluid, wherein the nozzle piston can be obtained by means of ultra-short pulse lasering of the recess from a piston blank. Also provided is a damper having a nozzle piston according to the invention. Also provided is a production plant for the production of a damper having at least one ultra-short pulse laser station for machining a piston blank for the damper by ultra-short pulse lasering.

Claims

1. A method for producing a damper, the method comprising at least the following steps: a. producing a piston blank, b. introducing at least one recess into the piston blank by ultrashort pulse lasering, wherein the at least one recess, upon arrangement of a nozzle piston in a damper chamber, defines a nozzle for a damping fluid for adapting the flow impedance for the damping fluid between a first fluid chamber and a second fluid chamber, c. installing the nozzle piston in the damper chamber of the damper, wherein the nozzle piston is guided along a longitudinal axis of the damper chamber and divides the damper chamber into the first fluid chamber and the second fluid chamber, d. testing the nozzle piston, with respect to a force-velocity characteristic of the damper containing the nozzle piston, and e. controlling the step of introducing the at least one recess into a subsequently produced piston blank based on a result of the step of testing of the nozzle piston.

2. The method according to claim 1, wherein the introduction by ultrashort pulse lasering: a. is performed at a local piston temperature in a removal region of the nozzle piston, which piston temperature is above a sublimation temperature of a piston base material; and/or b. is performed at a regional piston temperature in a piston region adjoining a removal region of the nozzle piston, which is below a deformation temperature of a piston base material and corresponds to an ambient temperature of an environment of the nozzle piston; and/or c. is performed using a laser wavelength in the near infrared spectral range between 0.8 μm and 3.0 μm; and/or d. is performed using a pulse frequency between 200 kHz and 2000 kHz; and/or e. is performed using a pulse duration of less than 100 picoseconds; and/or f. is performed using a pulse energy of less than 500 mJ; and/or g. is performed using a laser spot diameter of between 25 μm and 500 μm, and/or h. is performed in a controlled atmosphere.

3. The method according to claim 1, wherein at least one of the following steps is performed: a. collecting thermal properties of the nozzle piston and/or thermal coupling of the nozzle piston to an environment of the nozzle piston; and/or b. selecting laser parameters based on thermal characteristics of the nozzle piston and/or thermal coupling of the nozzle piston to an environment of the nozzle piston; and/or c. attaching at least one cover element adjacent to the recess; and/or d. documenting a result of a testing of the nozzle piston on the nozzle piston; and/or e. labeling of the nozzle piston and/or the damper by ultrashort pulse lasering; and/or f. hardening a surface of the nozzle piston by ultrashort pulse lasering, and/or g. coating a surface of the nozzle piston.

4. A production plant for producing a damper, with a production method according to claim 1, including a. at least one ultrashort pulse laser station for treatment of a piston blank for the damper by ultrashort pulse lasering, b. at least one control unit for controlling the ultrashort pulse laser station, c. at least one testing station downstream of the ultrashort pulse laser station in the course of production for testing the nozzle piston and/or the damper, wherein the at least one testing station comprises a transmitting unit, for transmitting results of the testing to the at least one control unit, and d. at least one installation station downstream in the course of production of the ultrashort pulse laser station for installation of the nozzle piston in the damper.

5. The production plant according to claim 4, wherein the ultrashort pulse laser station: a. is assigned to a plurality of production lines of the production plant, wherein the ultrashort pulse laser station is formed mobile and/or the production plant comprises a transport system for supplying piston blanks from a plurality of production lines to the ultrashort pulse laser station; and/or b. is integrated into a transport system for transporting piston blanks; and/or c. comprises a laser scanner.

6. The production plant according to claim 4, further comprising: a. at least one production station upstream of the ultrashort pulse laser station in the course of production for producing a piston blank from a piston base material; and/or b. at least one control unit for controlling a production station and/or a transport system and/or for documenting production parameters, of the ultrashort pulse laser station and/or a production station, and/or test results of a testing station.

7. The method according to claim 2, wherein the introduction by ultrashort pulse lasering: a. is performed using a laser wavelength in the IR-A range between 0.8 μm and 1.4 μm; and/or b. is performed using a pulse frequency between 500 kHz and 1000 kHz; and/or c. is performed using a pulse duration of less than 10 picoseconds; and/or d. is performed using a pulse energy of less than 200 mJ; and/or e. is performed using a laser spot diameter of between 50 μm and 150 μm.

8. The method according to claim 7, wherein the introduction by ultrashort pulse lasering: a. is performed using a laser wavelength in the IR-A range at 1.0 μm; and/or b. is performed using a pulse frequency at 800 kHz; and/or c. is performed using a pulse duration of 0.8 picoseconds; and/or d. is performed using a laser spot diameter at 75 μm.

Description

BRIEF DESCRIPTION

(1) Some of the embodiments will be described in detail, with references to the following Figures, wherein like designations denote like members, wherein:

(2) FIG. 1 a schematic representation of a method according to embodiments of the invention;

(3) FIG. 2 a schematic longitudinal section of a piston blank for producing a nozzle piston according to embodiments of the invention;

(4) FIG. 3 a schematic longitudinal section of a nozzle piston according to embodiments of the invention;

(5) FIG. 4 a schematic longitudinal section of a piston rod mounted on a nozzle piston according to embodiments of the invention; and

(6) FIG. 5 a schematic representation of a production plant according to embodiments of the invention.

DETAILED DESCRIPTION

(7) FIG. 1 shows a schematic representation of a method 200 according to embodiments of the invention. The illustrated method 200 comprises producing 210 a piston blank, for example, from a solid material and/or in a machining method. Thereafter, an introducing 220 of at least one recess takes place, which defines a nozzle, by ultrashort pulse lasering into the piston blank. For a given combination of piston material, piston geometry, and geometry and location of the recesses, a one-time collection 221 of thermal characteristics of the nozzle piston and/or thermal coupling of the nozzle piston to an environment of the nozzle piston and a selecting 222 of laser parameters based on the collected data can occur. As a result, suitable laser parameters for ultrashort pulse lasering can be obtained, which allow efficient removal of material without excessive thermal stress on the nozzle piston. Following the introduction 220 of the recess, the attachment 223 of a cover element limiting the recess at least on one side can take place so that the volume defined by the recess with the cover element constitutes a nozzle for the damping fluid. Subsequently, there may follow the testing 230 of the nozzle piston and/or a damper contained the nozzle piston, in particular with respect to a speed-dependent damping force. The method 200 can comprise controlling 240 the production 210 and/or the introduction 220, in particular using the results of the test 230 in a closed control loop. The method 200 can further comprise documenting 250 the results of the testing 230, process parameters, material parameters, and/or type data of a manufactured nozzle piston, for example, by labeling 260 the nozzle piston and/or the damper.

(8) FIG. 2 shows a schematic longitudinal section of a piston blank 18 for manufacturing a nozzle piston 19 according to embodiments of the invention. The piston blank 18 is formed rotation-symmetrical about a piston longitudinal axis KLA and for example, manufactured by turning from a solid material. The illustrated piston blank 18 has a peripheral web 22 in the form of a cylinder ring on an end face.

(9) FIG. 3 shows a schematic longitudinal section of a nozzle piston 19 according to embodiments of the invention. The nozzle piston 19 can be manufactured, for example, by introducing a recess 20 by ultrashort pulse lasering from the piston blank 18 shown in FIG. 2. In the illustrated example, the recess 20 is located in the circumferential web 22 and thereby defines a radial nozzle which can be flown through by a damping fluid in a radial direction orthogonal to the piston longitudinal axis KLA. A plurality of, for example, two, three, four or more recesses 20 is also conceivable on a nozzle piston 19 according to embodiments of the invention, which recesses can be distributed in particular uniformly around the piston longitudinal axis KLA to thereby ensure the most uniform loading of the nozzle piston 19 during operation and thus a high reliability.

(10) FIG. 4 shows a schematic longitudinal section of a nozzle piston 19 according to embodiments of the invention mounted to a piston rod 120. The illustrated nozzle piston 19 comprises a cover element 23, for example, in the form of a perforated disk, which bears against the recess 20 of the nozzle piston 19 such that the volume between the nozzle piston 19 and the cover element 23 defines a radial nozzle for a damping fluid in the region of the recess 20. In operation, the nozzle piston 19 is arranged in the damper chamber (not shown) of a damper such that the nozzle piston 19 divides the damper chamber into a first fluid chamber 111 and a second fluid chamber 112. In this case, the damping fluid contained in the damper chamber, for example, can flow from the first fluid chamber 111 through an opening 24 of the cover element 23 to an inner side of the circumferential web 22. From there, the damping fluid can flow through the recess 20 to an outer side of the circumferential web 22 and further past the nozzle piston 19 into the second fluid chamber 112. The damping fluid can also flow back in the same way. The nozzle piston 19 and the cover element 23 are fastened to the piston rod 120 with a number of fastening elements 130, for example, at least one screw and one washer. The fastening is designed in the illustrated example so that the damping fluid, when it flows from the second fluid chamber 112 to the first fluid chamber 111, can lift the cover element 23 off the nozzle piston 19. As a result, a flow cross-section of the nozzle defined by the recess 20 and the cover element 23 increases, so that possible contaminants can be flushed out of the nozzle.

(11) FIG. 5 shows a schematic representation of a production plant 300 according to embodiments of the invention. The production plant shown comprises two production lines 320, for example, for the production of dampers differing in their damping behavior. Each illustrated production line 320 comprises a production station 350 for producing a piston blank. Furthermore, the production plant comprises at least one transport system 330 (represented by arrows and labeled only by way of example) for transporting the piston blanks from both production lines 320 to a common ultrashort pulse laser station 310 at which the piston blanks are machined by ultrashort pulse lasering into nozzle pistons. The transport system 330 further serves to supply the nozzle pistons in their respective production lines 320 to a test station 340 and an installation station 370 for installation of the nozzle piston into a damper. The installation station 370 in this case can be upstream or downstream of the test station 340, depending on whether the test of the nozzle piston is to be performed installed in the damper or not. The illustrated production plant 300 comprises a central control unit 360 for controlling the production plant 300.

(12) Although the invention has been illustrated and described in greater detail with reference to the preferred exemplary embodiment, the invention is not limited to the examples disclosed, and further variations can be inferred by a person skilled in the art, without departing from the scope of protection of the invention.

(13) For the sake of clarity, it is to be understood that the use of “a” or “an” throughout this application does not exclude a plurality, and “comprising” does not exclude other steps or elements.

LIST OF REFERENCE CHARACTERS

(14) 18 piston blank

(15) 19 nozzle piston

(16) 20 recess

(17) 21 piston region

(18) 22 web

(19) 23 cover element

(20) 111 first fluid chamber

(21) 112 second fluid chamber

(22) 120 piston rod

(23) 130 fastening element

(24) 200 method

(25) 210 producing

(26) 220 introducing

(27) 221 collecting

(28) 222 selecting

(29) 223 attaching

(30) 230 testing

(31) 240 controlling

(32) 250 documenting

(33) 260 labeling

(34) 300 production plant

(35) 310 ultrashort pulse laser station

(36) 320 production line

(37) 330 transport system

(38) 340 testing station

(39) 350 production station

(40) 360 control unit

(41) 370 installation station

(42) KLA piston longitudinal axis