Cilinder en werkwijze voor het bepalen van een positie van een zuiger in een cilinder

Abstract

De werkwijze betreft een cilinder (100; 200; 400; 500), in het bijzonder voor de toepassing in een hydraulisch systeem, met een cilinderhuis (102) met een cilindrische zijwand (103); een axiaal verschuifbaar in het cilinderhuis (102) ingerichte zuiger (101); ten minste een signaal-invoerinrichting (106; 201; 401), welke aan het cilinderhuis (103) ingericht en gevormd is, een ultrasoon signaal (108) zodanig uit te zenden, dat zich het ultrasoon-signaal (108) langs een binnenzijde (103a) van de zijwand (103) van het cilinderhuis (102) verplaatst; ten minste een ontvangstinrichting (107; 201; 401), welke aan het cilinderhuis (102) ingericht en gevormd is, het van de zuiger (101) gereflecteerde ultrasoon-signaal (108) te ontvangen; en een evaluatie-inrichting (112), welke gevormd is, aan de hand van een looptijd (at) van het ultrasoon-signaal (108) tussen een uitsturen van het ultrasoon-signaal (108) door de signaal-invoerinrichting (106; 201; 401) en een ontvangen van het ultrasoon-signaal (108) door de ontvangstinrichting (107; 201; 401) een positie (x) van de zuiger (101) te bepalen.

Claims

1. Cylinder (100; 200; 400; 500), in particular for use in a hydraulic system, with a cylinder housing (102) with a cylindrical side wall (103); a piston (101) arranged axially in the cylinder housing (102); at least one signal input device (106; 201; 401), which is arranged and formed on the cylinder housing (103) to transmit an ultrasonic signal (108) in such a way that the ultrasonic signal (108) travels along an inner surface (103a) of the side wall (103) of the cylinder housing (102); at least one receiving device (107; 201; 401), which is arranged and formed on the cylinder housing (102) to receive the ultrasonic signal (108) reflected from the piston (101); and an evaluation device (112), which is designed to, on the basis of a transit time (At) of the ultrasonic signal (108) between an output of the ultrasonic signal (108) by the signal input device (106; 201;401) and a reception of the ultrasonic signal (108) by the receiving device (107; 201; 401), to determine a position (x) of the piston (101).; 2. Cylinder (100; 200; 400; 500) according to claim 1, where the signal input device (106; 201; 401) comprises: an attachment (106a), which is fitted to the side wall (103) of the cylinder body (102), and a transmitter (106b) fitted to the attachment (106a), where the transmitter (106b) is designed to transmit the ultrasonic signal (108) through the attachment, such that the ultrasonic signal (108) strikes the cylinder body (102) at an angle of incidence (φA), the angle of incidence (φA) being chosen such that an ultrasonic wave carrying the ultrasonic signal (108) is refracted at an interface (110) of attachment (106a) and cylinder body (102) such that it ultrasonic signal (108) travels along an inner side (103a) of the side wall (103) of the cylinder housing (102).

3. Cylinder (100; 200; 400; 500) according to claim 1, where the signal input device (106; 201; 401) is arranged on the side wall (103) of the cylinder body (102) and comprises at least two electrodes (201a-l, 201a-2), which are comb-shaped and formed to transmit an ultrasonic signal (108).

4. Cylinder (100; 200; 400; 500) according to claim 1, where the signal input device (106; 201; 401) is arranged on an outer wall (104) in the axial direction of the cylinder housing (102) and has at least one sliding plate (403), which is movable in a direction (404) parallel to the outer wall (104) of the cylinder housing (102) and is coupled to the cylinder housing (102) by friction, whereby an ultrasonic signal (108) is transmitted to the cylinder housing (102) by periodic sliding of the sliding plate (403) on the outer wall (104) of the cylinder housing (102), which travels along an inner side (103a) of the side wall (103) of the cylinder housing (102).

5. Cylinder (500) in accordance with one of claims 1 to 4, where the signal input devices (502a to 502d) and the receiving devices (502a to 502d) are arranged axially spaced apart from one another, and where the cylinder (500) includes a control device (111) designed to control the transmission of an ultrasonic signal (108) by the signal input devices (502a to 502d) and the reception of the reflected ultrasonic signal (108) by the receiving devices (502a to 502d) in a multiplexing mode, in particular a time multiplexing mode or a frequency multiplexing mode.

6. Cylinder (500) according to claim 5, where the steering device (111) is designed to control the signal input devices (502a to 502d) in such a way that the signal input devices (502a to 502d) emit time-shifted ultrasonic signals (105), where the time difference between the emission of two ultrasonic signals (108) by different signal input devices (502a to 502d) is greater than the transit time (At) of the ultrasonic signals (108).

7. Method for determining the position (x) of a piston (101) in a cylinder (100; 200; 400; 500), in particular for use in a hydraulic system, with the following steps: sending (Sl) an ultrasonic signal (108) onto a cylinder housing (102) of the cylinder (100; 200; 400; 500) with a cylindrical sidewall (103), such that the ultrasonic signal (108) travels along an inner surface (103a) of the sidewall (103) of the cylinder housing (102), receiving (S2) the ultrasonic signal (108) reflected from the piston (101) arranged axially in the cylinder housing (102), calculating (S3) a position (x) of the piston (101) based on a running time (At) of the ultrasonic signal (108) between sending and receiving the ultrasonic signal (108).

8. Method according to claim 7, whereby the emission of the ultrasonic signal (108) takes place through an attachment (106a) fitted to the side wall (103) of the cylinder housing (102), whereby the ultrasonic signal (108) strikes the cylinder housing (102) at an angle of incidence (φA), and whereby the angle of incidence (φA) is chosen such that the ultrasonic signal (108) is refracted at the interface of the attachment (106a) and the cylinder housing (102) in such a way that the ultrasonic signal (108) travels along an inner side (103a) of the side wall (103) of the cylinder housing (102).

9. Method according to claim 7, whereby the emission of the ultrasonic signal (108) is carried out by means of at least two electrodes (201a-l, 201 a-2), which are arranged in a comb-like manner on the side wall (103) of the cylinder housing (102).

10. Method according to claim 7, whereby the emission of the ultrasonic signal (108) is achieved by sliding a sliding plate (401) on an outer wall (104) in a radial direction (403), whereby the sliding plate (401) is coupled to the outer wall (102) by friction.

11. Method according to one of claims 7 to 10, whereby the transmission of the ultrasonic signal (108) or the reception of the reflected ultrasonic signal (108) at different positions of the cylinder housing (102) is carried out in a multiplexing method, in particular a time multiplexing method or a frequency multiplexing method.

12. Method according to claim 11, where the ultrasonic signals (105) are transmitted in a time-shifted manner at different positions of the cylinder housing (102), and where the time difference between the transmission of two ultrasonic signals (108) at different positions of the cylinder housing is greater than the transit time (At) of the ultrasonic signals (108).

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