DE102021002670B3 - Saddle lift lowering brake system - Google Patents

Abstract

The present invention relates to a system for a hydraulic saddle lift with a master/slave cylinder principle driven by an electromechanical linear drive. This master/receiver system has the advantage that no complex control technology is required due to the fact that the hydraulic system is filled with liquid once. A cyclist should be lifted slowly after starting off (e.g. in 10 seconds) so that no irritation occurs. A cyclist must be lowered quickly (e.g. in 1 second) so that the rider is lowered in any situation when stationary and can support himself with both feet safely on the ground. Due to the constant motor speed, the forward and reverse speeds of linear drives are the same . The saddle lift lowering brake system presented here enables a rapid lowering phase with a subsequent braking phase in which the acceleration energy is destroyed, so that the driver lands gently within a second, even in the event of an emergency or full stop. The deep mounting and dismounting position dynamically created by the saddle lift is comparable to the seating position on motorcycles.

Description

The present invention relates to a hydraulic system for lowering a cyclist's saddle with a rider, consisting of a rapid lowering phase and a braking phase.

The patent is from the state of the art DE 10 2019 006 320 B3 known, where the saddle height adjustment is realized by a hydraulic master/slave cylinder system. The master cylinder is driven by an electromechanical linear drive. The forward and reverse speeds of the linear drive are the same due to a constant motor speed. The advance speed is selected so that the bicycle saddle with the rider is raised relatively slowly so that the cyclist can be lifted very slowly into the “up” saddle position without being irritated after starting from a standstill. The disadvantage is that the lowering of the bicycle saddle also takes place slowly.

A slow lifting of e.g. B. 10 seconds and a rapid lowering of e.g. 1-2 seconds, so that the saddle has reached the "down" position in every situation, whether normal stop or emergency stop, so that the driver can safely stand with both feet, similar to motorcycles, can be supported on the ground. In addition, the published disclosure document DE 10 2020 004 649 A1 called, which also shows a height-adjustable seat post.

Against this background, the object of the present invention is to provide a system that solves the aforementioned problem and allows a driver to raise the vehicle slowly and lower it quickly.

The object of the present invention is a system which does not affect the lifting phase, but only the lowering phase. The lowering phase consists of a rapid lowering phase and a braking phase. The rapid lowering phase is realized at high speed up to free fall for the majority of the lowering section. During the last part of the lowering phase, just before the "down" position, the braking phase is initiated, in which the kinetic energy caused by gravity in connection with gravity is destroyed.

Such a solution according to the invention offers the advantage that a hydraulic master/slave cylinder system, driven by an electric motor, realizes a slow lifting speed and a fast lowering speed with a slow, constant advance and return speed.

This object is achieved according to the invention by the features of claim 1. Advantageous detailed solutions of the invention are specified in the dependent claims.

The solution is characterized in the fast lowering phase in that the oil pressure generated by the driver's body weight via a piston increases at the beginning of the lowering phase (corresponds to the simultaneous start of the linear drive "back" and opening of a solenoid valve to a buffer container which is advantageously under slight excess air pressure). relaxed and the saddle with the driver can mostly drop within e.g. 0.5 seconds. Another solution is that after the 0.5 seconds mentioned, the braking phase, during which hydraulic damping is activated in the slave cylinder, is initiated. This braking phase, during which the acceleration forces are destroyed, lasts e.g. 1.5 seconds, so that lowering to the lowest point takes around 2 seconds in total. After the 2 seconds, the linear drive moves “backwards” for about 8 seconds until it reaches its end stop and, in the meantime, sucks the buffered oil, supported by the slight overpressure, through the open solenoid valve from the buffer tank into its vacant cylinder space. The lowering braking process is complete after a total of 10 seconds.

Such an inventive solution is characterized in that in normal situations but also in emergency situations, the driver can be lowered as quickly as possible, so that the driver is lowered within a very short time from his raised driving position to a position in which he can safely stand with both feet can support on the ground.

According to a preferred embodiment, the lowering brake system consists of a rapid lowering phase in which a buffer container receives and temporarily stores relatively large amounts of oil that the linear drive cannot simultaneously absorb with its vacated cylinder space. The lowering brake system also consists of a braking phase in which hydraulic damping destroys the mass acceleration forces shortly before the "down" saddle position is reached, so that the driver is prevented from hitting the body when the "down" saddle position is reached. Based on the patent specification DE 10 2019 006 320 improves the safety of cyclists when dismounting, the buffer tank with solenoid valve in conjunction with the damping of mandrel and bore in a hydraulic master/slave system.

The piston of the master cylinder is attached to the push rod of a linear drive. This master cylinder pushes oil to the slave cylinder during lift travel. At the start of the lowering phase the piston of the master cylinder moves back and a solenoid valve opens and releases the oil pressure to the buffer tank. Within a very short time, the oil, which is under 16 bar, expands into the buffer tank, which is under slight overpressure, and the saddle with the rider's weight falls down very quickly. Shortly before the "down" position, a mandrel in the form of a tube with, for example, an outside diameter of 4 mm and an inside diameter of 2 mm, which forms the end of the supply line to the working piston, plunges into the bore (for example 4.1 mm) of the spring piston. The oil can no longer drain off without resistance and abruptly presses in the spring, which is preloaded according to the rider’s weight, and then relaxes again more slowly and pushes the residual oil through the narrow annular gap between the mandrel and the borehole in the direction of the master cylinder until the saddle lift position is “down”.

In the example, the buffer tank is located directly next to the linear drive. The buffer tank can also be any cavity on the bicycle, such as the tubular construction of the luggage rack, but it must always be ensured that the oil line ends in the oil level and has no contact with the gas filling. For this reason, the tank must always have a basic filling of e.g. 10% of the tank volume. The remaining 90% of the container volume is available for buffering and is under a slight gas overpressure of e.g. 0.2 bar. The amount of oil flowing in should not be greater than 45% of the total volume, so that at 45% the 0.2 bar is compressed to 0.4 bar.

• 1: Sattellift, bestehend aus einem Nehmerzylinder mit Arbeits- und Federkolben und einer Antriebseinheit bestehend aus dem Geberzylinder, Linearantrieb, Pufferbehälter und Magnetventil. 1 zeigt den Sattellift in Position „oben“.
• 2: Ein Diagramm mit Angaben zu Weg, Volumen, Kraft und Druck in der y-Achse und Zeit in Sekunden in der x-Achse.

Further advantages of the invention emerge from the following, non-restricted description of a preferred exemplary embodiment of the invention based on a sketch 1 and a diagram = 2 out.

• 1 : Saddle lift consisting of a slave cylinder with working and spring pistons and a drive unit consisting of the master cylinder, linear drive, buffer tank and solenoid valve. 1 shows the saddle lift in the “up” position.
• 2 : A diagram with displacement, volume, force and pressure information on the y-axis and time in seconds on the x-axis.

1 shows the drive unit with linear drive 6 with connecting rod 7, on which the master piston 9 of the master cylinder, which consists of the cylinder tube 8 fastened to the housing of the linear drive 6, and the piston 9, is fastened. A supply line 12 leads from the cylinder base 16 to the saddle lift or to the slave cylinder, which mainly consists of the working piston 21, spring piston 22 and slave cylinder tube 23. The end of the supply line 11 is the mandrel with an outer diameter of 4 mm and an inner diameter of 2 mm. In the spring piston 22 there is a bore 18 with a diameter of 4.1 mm, into which the mandrel 17 moves just before the "down" saddle position and throttles the oil flow. The spring 19 is biased by means of bias 20 to the driver's weight. The distance of the fully extended saddle lift stroke 24 is 82 mm in this example, resulting from the displaced volume of the master piston 9 from the cylinder chamber 10. A buffer line 11 leads from the cylinder base 16 through the solenoid valve 13 to the buffer tank 15 with the tensioning valve 25. The solenoid valve 13 blocks the line 11 to the buffer tank 15 in the de-energized state. The cylinder space 10 is larger in the “bottom” saddle position and in the completely retracted position of the linear drive 6 by the volume of the product of the working piston area times the saddle lift stroke 24 . The basic quantity levels 26 and the maximum filling quantity level 27 are shown in the buffer container 15 .

2 shows a diagram where the approximate reactions during the lowering phase are shown as a function of time.
The working piston travel in curve 1 (solid line) shows the travel of the caliper in millimeters during the quick lowering phase and the braking phase. In the rapid lowering phase, the saddle with the rider dropped 70 mm after 0.5 seconds. From a fall stroke of 70 mm, the mandrel 17 is inserted into the hole 18, slowing down the fall speed until after 2 seconds the entire lowering phase has ended and the driver's weight has pushed the saddle into the "down" position.
The buffer quantity 2 (long dashed lines) shows the approximate course of the oil quantity in cubic centimeters, which is pressed at the beginning of the lowering process in < 1 second via the line 11 through the open solenoid valve 13 into the buffer container 15 up to the filling quantity level 27 and then during the reverse movement of the Linear drive 6 sucked back out of the buffer tank 15 through the open solenoid valve 13 to the basic quantity level 26 from the buffer tank 15 into the cylinder chamber 10, supported by the gas pressure, is pressed.
The master piston path 3 (short-long dashed lines) shows the path of the linear drive 6 with the push rod 7 and master piston 8 in millimeters. With a constant speed of the linear drive 6, the end point is reached after 10 seconds.
The gas pressure 4 (dotted) shows the compression of the stringing pressure from 0.2 bar to 0.4 bar. In about one second, oil flows into the buffer tank 15, the gas filling volume in the buffer tank 15 is reduced by around half and the gas pressure doubles to 0.4 bar. In the remaining 9 seconds, while the linear drive pulls back the complete master cylinder stroke 14, the gas pressure 4 falls back to the pressure of 0.2 bar. In this phase, the gas pressure of 0.2-0.4 bar supports the suction effect of the master piston 9.
The spring force 5 (short dashed lines) starts at one Preload of 80 kg. After 0.5 seconds, when the mandrel 17 has moved into the bore 18, the oil does not escape without resistance and the working piston 21 presses the spring piston 22 against the spring 19 with the amount of oil between the pistons and presses the spring 19 to open in a very short time 100 kg together. The spring 19 then relaxes somewhat more slowly to 80 kg and pushes oil into the supply line 12 with the spring piston 22 through the annular gap between the mandrel 17 and the bore 18. After 2 seconds from the beginning of the lowering phase, the saddle lift and thus the working piston 21 are in position "below" reached. Approximately 1.5 seconds were needed to dissipate the energy of the mass acceleration.

• - Durchmesser Geberkolben 9 = 32 mm
• - Hub Geberkolben 9 = 50 mm
• - Durchmesser Arbeitskolben 21 = 25 mm
• - Sattellifthub 24 = 82 mm
• - Geschwindigkeit Linearantrieb 6 = 5 mm/Sek.
• - Überdruck Pufferbehälter = 0,2 bar
• - Dorn 17 = 4,0 mm
• - Bohrung 18 = 4,1 mm
• - Pufferbehälter 15 Volumen gesamt 100%, davon 10 % Grundfüllung bis Grundmengenniveau 26,45 % Pendelvolumen bis Füllmengenniveau 27, 90 % Gasvolumen bei 0,2 bar und 45 % Gasvolumen bei 0,4 bar.
• - Federvorspannung auf 80 kg

Technical data for example 1 and 2 :

• - Diameter master piston 9 = 32 mm
• - Stroke master piston 9 = 50 mm
• - Diameter of working piston 21 = 25 mm
• - Saddle lift stroke 24 = 82 mm
• - Speed linear drive 6 = 5 mm/sec.
• - Buffer tank overpressure = 0.2 bar
• - Mandrel 17 = 4.0mm
• - Bore 18 = 4.1mm
• - Buffer tank 15 volume total 100%, of which 10% basic filling up to basic quantity level 26.45% pendulum volume up to filling quantity level 27, 90% gas volume at 0.2 bar and 45% gas volume at 0.4 bar.
• - Spring preload to 80 kg

This in 1 illustrated embodiment with the curves in 2 and the technical data listed only serves to explain the invention and is not limited.

• Startvoraussetzung:
  • Die Feder 19 ist auf das Fahrergewicht vorgespannt, in diesem Fall auf 80 kg. Der Sattellifthub 24 ist bis Stellung „oben“ ausgefahren und 80 kg Fahrergewicht 28 erzeugen zwischen Arbeitskolben 21 und Federkolben 22 einen Druck von zirka 16 bar. Der Linearantrieb 6 hat seine 50 mm Hub voll ausgefahren. Der Pufferbehälter 15 ist zirka zu 10 % mit Öl bis zum Grundmengenniveau 26 gefüllt und mittels Bespannungsventil 25 mit 0,2 bar Gasdruck bespannt.

Function description:

• Starting requirement:
  • The spring 19 is preloaded to the driver's weight, in this case 80 kg. The saddle lift lift 24 is extended to the “up” position and a driver's weight of 80 kg 28 generates a pressure of approximately 16 bar between the working piston 21 and the spring piston 22 . The linear drive 6 has fully extended its 50 mm stroke. The buffer container 15 is approximately 10% filled with oil up to the base quantity level 26 and is pressurized with a gas pressure of 0.2 bar by means of a pressurizing valve 25 .

An impulse that initiates the lowering process starts the linear drive 6 and thus the master piston 9 is moved in the master cylinder tube 8 at a speed of 5 mm/sec. withdrawn. When the linear drive 6 starts, the solenoid valve 13 opens and the 16 bar oil pressure relaxes against the 0.2 bar in the buffer tank 15 and compresses the 0.2 bar down to 0.4 bar, the saddle with rider falls 70 mm within half a second down. The mandrel 17 dips the last 12 millimeters into the bore 18, reduces the rate of fall, thus destroying the mass acceleration and gently putting the rider's feet down on the ground. The rapid lowering phase with the braking phase together lasts 2 seconds. After this time, the linear drive 6 travels another 8 seconds to its end position. While reversing, the master piston 9, assisted by the gas pressure, sucks oil out of the buffer tank 15 through the open solenoid valve 13 and fills its cylinder chamber 10 completely. After 10 seconds, the driver could be lifted again 82 millimeters. If lifting is initiated before the end point is reached, i.e. before the 10 seconds have elapsed, the solenoid valve 13 is de-energized, closes and the linear drive moves forward and lifts the driver less than 82 millimeters.

Reference List

1

working piston travel

2

buffer amount

3

master piston travel

4

gas pressure

5

spring force

6

linear actuator

7

push rod

8th

master cylinder tube

9

master piston

10

cylinder space

11

buffer line

12

supply line

13

magnetic valve

14

master cylinder stroke

15

buffer tank

16

cylinder bottom

17

mandrel

18

drilling

19

Feather

20

preload

21

working piston

22

spring plunger

23

slave cylinder

24

saddle lift lift

25

string valve

26

base quantity level

27

filling level

28

rider weight

Claims (7)

Saddle lift lowering brake system comprehensive a) a bicycle saddle connected to a working piston (21) which can be moved relative to a slave cylinder tube (23), b) a spring piston (22) which is arranged inside the slave cylinder tube (23) and which is preloaded onto the driver's weight (28) by means of a spring (19), c) a hydraulic fluid located between the working piston (21) and the spring piston (22), d) a supply line (12), which is routed through the working piston (21) and creates a connection between the hydraulic fluid and a cylinder chamber (10), which is formed by means of a cylinder tube (8) and a master piston (9), e) a mandrel (17), which extends the supply line (12) at the lower end of the working piston (21), and the mandrel (17) moves into a bore (18) of the spring piston (22) when the seat post is lowered, f) a linear drive (6) by which the master piston (9) is moved, g) a buffer line (11) which connects the cylinder chamber (10) via a solenoid valve (13) to a buffer container (15) which is under a slight excess gas pressure, h) when lowering, the driver's weight (28) acting on the working piston (21) generates an oil pressure which, by opening the solenoid valve (13), presses its quantity of oil almost without resistance into the buffer tank (15), which is under a slight excess gas pressure, and quickly pushes the saddle with the driver , almost free fall, so that before the "down" saddle position is reached, the mandrel (17) dips into the bore (18) of the spring piston (22) and throttles the oil flow into the supply line (12) and at the same time the spring (19 ) is pressed in and thus absorbs and destroys the fall acceleration force of the driver's weight (28), so that the spring (19) then relaxes again and the amount of oil corresponding to the compression stroke flows via the spring piston (22) through the annular gap between the mandrel (17) and bore (18) in the supply line (12) pushes that after reaching the "down" saddle position, the linear drive (6) continues to move back to its end point and meanwhile through the open solenoid valve (13) of the Geberko lben (9) sucks oil from the buffer tank (15) and completely fills its cylinder chamber (10) with oil. Saddle lift lowering brake system claim 1 , characterized in that in the buffer tank (15) there is always oil up to the basic quantity level (26) and this prevents the gas pressure from entering the cylinder chamber (10) via the buffer line (11). Saddle lift lowering brake system claim 1 or 2 , characterized in that the excess gas pressure can be introduced into the buffer tank (15) via the pressurizing valve (25). Saddle lift lowering brake system according to one of the preceding claims, characterized in that the mandrel (17) is the end of the supply line (12), with its outer surface ensuring the throttling via the annular gap with the bore (18) and that via its inner bore oil enters the space between Spring piston (22) and working piston (21) flows in to raise the saddle lift and oil flows out to lower the saddle lift. Saddle lift lowering brake system according to one of the preceding claims, characterized in that the spring (19) is pretensioned by means of the pretension (20) on the driver's weight (28), that the resting driver's weight (28) does not press in the spring (19), but larger forces, caused by the acceleration forces of the driver's weight (28), the spring (19) depresses. Saddle lift lowering brake system according to one of the preceding claims, characterized in that the buffer container (15) still has sufficient free volume when the filling quantity level (27) is reached in order to keep the resistance low in the rapid lowering phase. Saddle lift lowering brake system according to one of the preceding claims, characterized in that the buffer container (15) is not designed as a separate container, but from any cavity on the bicycle, in particular. the tubular construction of the luggage carrier.

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