DK142261B - HYDRAULIC DRIVER LIFTING EQUIPMENT - Google Patents

Description

(11) PRESENTATION OF PRESENTATION 1 ^ + 2261 DENMARK (51) Irrt. Cl.3 A 01 B 63/111 // A 01 D Section 41/12 (21) Note 1 882/73 (22) Filed on 6 Apr. 1973 (24) Live Day 6 Apr 1973 (44) The note submitted and _

the presentation reading published on 6 October. 19o <J

DIRECTORATE OF. .

PATENT AND TRADEMARKET F30 * Priority requested from tten

Apr 7 1972, 2216748, DE

(71) ROBERT BOSCH GMBH., 7 Stuttgart 1, Postfach 50, DE.

(72) Inventor: Friedrich-Wilhelm Hoefer, Weinbergstr. 35, 7251 Hoefin * gen, DE.

(74) The clerk under the oak processing:

The engineering company Budde, Sohou & Co._ (64) Hydraulically controlled lifting device for working vehicles.

The invention relates to a hydraulically operated lifting device for working vehicles, such as combine harvesters and tractors, whose pressure means supply is influenced by a control device electrically controlled by an adjustable nominal value generator and a work value sensor.

From German publication specification No. 1 582 166 a hydraulic lifting device is already known to a combine, in which the supply of pressure to the working cylinder is influenced by an electrically controllable control unit. Electrical switching means are used to transmit the control influence of the control unit. A pressure dependent and a position dependent element are associated with an electrical working value measuring element whose electrical properties change according to the influence of the two elements mentioned above. This electrical work value measurement element is coupled to a drop-down control connected to a handle with an electric nominal value setting element which affects said control unit.

In its working position, that is to say, the lifting device works completely satisfactorily. Only raising the dairy table at the field edge is cumbersome. To this end, the operator must bring the nominal value setting to the largest possible setting. The dairy table is thereby brought into its transport position in which the combine can be turned over. If the combine is then brought back to its working position, the operator must again bring the nominal value setting to the previous position. This procedure is cumbersome and time consuming.

It is therefore the object of the invention to provide a hydraulically operated lifting device by a working vehicle of the kind mentioned in the preamble, by which the working equipment, ie e.g. the dairy table, without adjustment of the nominal value, can easily be raised or brought into its transport position, and then, e.g. after reversing the working vehicle, is returned to the position corresponding to the previous nominal value.

This is achieved according to the invention by alternatively an extreme value simulator can be connected instead of one of the two signal generators, the nominal value generator or the working value sensor.

This has the advantage that e.g. a regulation effect corresponding to the maximum nominal value can be produced by e.g. operation of a simple tilt switch. Of course, it is also possible to simulate a work value corresponding to the maximum nominal value.

If the extreme value simulator, instead of the work value simulator, simulates the minimum work value, the lifting movement must be limited to the highest permissible position of the lifting device by means of an end switch.

It is particularly advantageous when comparing the nominal value and the working value of a comparator, and the signal generator that an extreme value simulator can replace instead of a diode is connected to the comparator. If this diode coupling 3 U2261 is controlled according to the maximum value, no switching shall take place, but only one switching on or off of the simulator.

The invention will now be explained in more detail with reference to the drawing, in which: FIG. 1 is a simplified view of a hydraulically controlled lifting device on a combine; FIG. 2 is a simplified embodiment of the embodiment of FIG. 1; FIG. 3 shows a third embodiment of the lifting device; and FIG. 4 shows a fourth embodiment of the lifting device.

The hydraulically controlled lifting device of a combine harvester has a pump 1 which, from a container 2, feeds pressure means into a pressure line 3 which leads to an electromagnetically operated 3-way valve 4. Between the pump 1 and the three-way valve 4 there is A pressure limiting valve 5 acting as a safety valve 3 is placed on the pressure line 3 · From the 3-way valve 4 the guide work lead 6 to a working cylinder 7 · The working cylinder 7 is · hinged pivotally on the combine's chassis and takes up a tight and sliding guide lifting piston 8. A piston rod 9 on the lifting piston 8 is pivotally attached to the combine table of the combine 10. A pressure accumulator 11 is connected to the work line 6 over a branch line.

The three-way valve 4 has three coupling positions. When the three-way valve guide slides are in neutral position, the pressure line 3 above the return line 12 is connected to the container 2. The working line 6 leading to the cylinder 7 is closed in the neutral position of the control slider. The guide slides of the 3-way valve 4 can be guided by one or the other by a pair of electromagnets 13, 14 to one or the other of its end positions. Thus, the pressure line 3 in the raising position is connected to the working line 6, while the return line 12 is blocked. In the lowering position, both the pressure line 3 and the working line 6 are connected to the return line.

Above a branch line 15, a pressure dependent element 16 is connected to the working line 6. This has a measuring piston working against a spring 17 in the illustrated embodiment. that the longitudinal displacement of the measuring plunger 18 caused by the thrust force exerted in the pressure-dependent element 16 changes the position of the slider relative to the resistance of the potentiometer 19 in a region at its center. In addition, the work value encoder 19's cloud 142261 4 is also connected to a connecting arm 20 on the dairy table, which, by adjusting the height of the dairy table, is positioned to change the position of the slider relative to the upper area of the work value encoder 19. Finally, the work value encoder 19 is also affected by a sensing mechanism 21 which provides information on the position of the cutting table 10 relative to the ground. Thus, by sensor control of the height of the table height, the slider of the working value 19 is displaced in a lower area of the resistor.

Parallel to the work encoder is a nominal encoder 22, also designed as a potentiometer, which has a slider 22 '. The slider 22 * is connected to a handle 23 and can be displaced by this.

Inputs 24,25 to an operational amplifier coupled as a comparator 26 are connected above their input resistors to the slider 19 's slider 19' and the nominal slider 22 'slider. A diode 27 is connected in the line from the input 25 to the nominal encoder 22's slider 22 '. Above a switch 28, an extreme weather simulator 29 can be connected in parallel with the nominal encoder 22 as the diode 27 blocks the current path to the nominal encoder 22's slider 22 '. The extreme value simulator 29 is in the embodiment shown as an ohmic resistor. The resistance of the extreme value simulator 29 is determined to simulate the maximum nominal value that can be set on the nominal value sensor 22.

The output 50 of the comparator 26 is connected via power amplifiers 51, 52 to the electromagnets 13, 14 of the three-way valve 4. In addition, the power amplifier 32 is directly connected to the output 30 of the comparator 26, while the power amplifier 31 is connected to the output 30 of the comparator 26 over an inversion step 33.

The operation of the lifting device is as follows: If the runner selects with the handle 23 the desired height of the table height, he thereby places the nominal encoder 22's slider 22 'in e.g. FIG. 1 shows the center position of the sensor-dependent range of the potentiometer. Assuming that the cutting table 10 is held in the transport position, the slider 19 'of the working value 19' is also in its upper position such that in FIG. 1 of the nomine slider 22 'of the value potentiometer 22' is offset vertically relative to the slider 19 'of the working value 19. There is a differential voltage between the sliders 19 'and 22' of the two signal transducers, because the slider 19 'provides a different potential than the slider 22'. The output 30 of the comparator 26 then outputs a control voltage corresponding to this differential voltage, whereby the electromagnet 13 leads? 3-way - valve 4's guide slider in the lowering direction. Thereby, the cutting table 10 is lowered, the pressure means running from the working cylinder 7 into the container 2. At the same time, the working value 19 * s slider 19 ', which at the connecting arm 20 is connected to the cutting table 10, is adjusted until no difference voltage exists between The sliders 19 'and 22 *. At this moment, the control voltage on the comparator 26's output 30 drops to zero, so that the three-way valve 4's electromagnet 13 is no longer activated. In this way, the control slides of the 4-way valve 4 fall back into their neutral position, in which pressure line 6 is closed.

The same adjustment process begins when the slider 19's slider 19's is shifted either over the sensing mechanism 21 or the pressure dependent element 16. When the combine reaches the end of the field, the dodge table 10 from its working position must be swung into the transport position. In addition, the driver operates the switch 28, whereby the extreme value simulator 29 is switched on instead of the nominal value transducer 22. Since the resistance of the extreme value sensor 29 is of the same magnitude as that of the nominal value sensor at the upper position of the slider 22 ', the comparator 26 behaves as if the driver had brought the handle 23 into its top position.

The 3-way valve 4fs control slider is thereby set in the raising position.

The time course takes place when the transport is switched back to the working position at the beginning of the field, with the driver opening the switch 28.

In the embodiment of the lifting device described and shown herein, both signal transducers, the work value encoder 19 and the nominal value encoder 22, are designed as potentiometers. However, it is natural for a person skilled in the art to substitute other potentiometers, e.g. inductive or capacitive signal generators.

The FIG. 2, the embodiment of the lifting device shown almost completely corresponds to that of FIG. 1. The difference is that the extreme value simulator cannot be switched on instead of the nominal value sensor. In this embodiment, the extreme value simulator 36 can be coupled by means of a switch 37 in parallel with the working encoder 19. The lead 19 of the slider 19 'of the slider 19' to the input 24 of the comparator 26 is passed through a diode 38 such that the wire is blocked by activating the switch 37 · The extreme value simulator 36 resistance has such a size that it simulates a minimal work value that responds? to approximately the lower position of the slider 19 'of the working encoder 19 in FIG. 2. The function of the lifting device according to this embodiment is the same as already described above. However, since the return of the regulating mechanism is interrupted, the magnet 14 · must be energized at maximum lift height over a 14-T end switch operated by the lifting station.

In FIG. 3 shows a further embodiment of the lifting device. Here, a polarized relay 4l is connected in front of two power amplifiers 42 and 43. The slider 19 'of the working value 19r 19 is connected over a line 44 to the parallel power amplifiers 42 and 43. The slider 22' of the nominal value 22 is connected to the amplifiers 42 and 43 through a line 45 From the amplifier 42 before? two wires 46,47 to a coil 48 of relay 4l, and from amplifier 43. two wires 49.50 to a coil 51 of relay 41. Relay 4l has an anchor 52 with a coupling bridge 53 which in its position shown in the drawing occupies the center position between two contact pairs 54.55 and 56.57. The contacts 54, .56 are blinded over a line 58 by the voltage source. From the switch 55, a line 59 leads to the electromagnet 13 which triggers the lowering pulse, and from the switch 57 a line 60 leads to the electromagnet 14 which triggers the raising pulse.

In the line 45 connecting the nominal encoder 22's slider 22 'to the power amplifiers 42, 43, a switching contact 6l is provided which in the shown position connects the amplifiers 42, 43 to the slider 22'. In its second switching position, the switch 6l connects the power amplifiers 42, 43 to an extreme value simulator 62. The resistance value of the extreme value simulator 62 designed as an ohmic resistor is determined such that the simulator nominal value corresponding to the upper position of the nominal value sensor 22's slides .221.

The mode of operation shown in FIG. 3 is similar to the operation of FIG. 1 and 2. The amplifiers 42, 43 and the relay 41 with the two coils 48, 51 are simply coupled so that the coil 51 produces only a magnetic field when the nominal encoder 22's slider 22 'is displaced in the raising direction relative to the slider 19's slider 19', and the coil 48 only builds a magnetic field when the slider 22 'is offset in the lowering direction relative to the slider 19'. Depending on whether the coil 48 or 51 is activated, the coupling bridge 53 connects contacts 54, 55 or 56, 57, thereby activating either the electromagnet 13 or the electromagnet 14.

142261 7

If, at the end of the field, the driver wants to drive the dairy table 10 in transport position, he operates the switch 6l from the one shown in FIG. 3 to its second coupling position. By means of the extreme value simulator 62, the lifting device then behaves as if the handle 23 was in its upper coupling position.

The FIG. 4, the fourth embodiment of the lifting device differs only from the embodiment of FIG. 3, in that the line 45 connecting the power amplifiers 42, 43 with the slider 22 'of the nominal value transducer 22 is provided with a switch 64. In the embodiment shown in FIG. 4, the switching contact 64 connects the power amplifiers 42, 43 to a fixed outlet 65 on the nominal transducer 22. The fixed outlet 65 is located at the location of the nominal transducer 22, where the slider 22 'is in its highest position.

In this embodiment, the nominal value transducer 22 itself assumes the function of a separately arranged extreme simulator. The function of the embodiment according to FIG. 4 completely to that of FIG. 3 function.