EP1776526A1

EP1776526A1 - Hydraulic system for opening and closing wings of a truck

Info

Publication number: EP1776526A1
Application number: EP05750504A
Authority: EP
Inventors: Gisela Weber
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-28
Filing date: 2005-05-19
Publication date: 2007-04-25
Also published as: AU2005256348A1; JP4068660B2; JP2007533931A; WO2006000277A1; DE102004031202B4; CN1946941A; DE102004031202A1; US20070130937A1

Abstract

The invention relates to a hydraulic system for pivoting the lateral structural parts of a motor lorry upwards and downwards. Said hydraulic system comprises at least one hydraulic control unit (14) provided with a hydraulic pump (22) and hydraulic valves; a first hydraulic cylinder and a second hydraulic cylinder (7a, 8a) for pivoting a first component; and a third hydraulic cylinder and a fourth hydraulic cylinder (8b) for pivoting a second component. The hydraulic cylinders (7a, 7b, 8a, 8b) are embodied in a single-acting manner with an oil chamber (32) and a spring counteraction. A check valve (18) is provided between the at least one external hydraulic line and the oil chambers (32), said check valve blocking or enabling a reflux of the hydraulic liquid from the oil chamber (32) into an external hydraulic line (12, 12a, 12b, 13). In regulated positions of the lateral structural parts and when the hydraulic pump (22) is not actuated, the check valve (18) blocks the reflux of the hydraulic liquid from the oil chamber (32) and the external hydraulic line is depressurised.

Description

Hydraulic system for swiveling up and lowering the wing parts of a truck

The invention relates to a hydraulic system for swiveling up and lowering of wing-mounted parts of a truck according to the preamble of claim 1.

Such wing construction parts of a truck, also called wing bodies, are pivotally hinged to the top of the truck body and can be folded up to open the side of the truck bed.

Wing bodies or wing body parts of a truck are traditionally folded up and down by double-acting hydraulic pistons. For this purpose, the truck is e.g. On the underside of its construction a control aggregate with a hydraulic pump driven by a motor is provided, which via two parallel-connected 4/3-way valves and mutually controlling non-return valves eight external hydraulic lines, namely one hydraulic line to each of the both chambers of each of the four hydraulic cylinder controls. After pivoting of the respective wing assembly part, a blocking position of the check valves is subsequently set, so that the pressure set in the external hydraulic lines is blocked and the wing attachment part remains in its respective position.

However, this can cause significant security problems. If the truck is parked at a low temperature-for example, early in the morning after a first drive-with pressure set in the cylinders and the external hydraulic lines, and subsequently, for example, by solar radiation, a general heating of the vehicle body and the hydraulic lines occurs , This leads in the completed hydraulic volume of the external hydraulic lines to a significant pressure increase, z. B. at a temperature difference of 1 ⁰ C to 10 bar pressure difference, so that at temperature differences of 10 ⁰ C pressure increases of 100 bar and more can be achieved. In addition, an uneven increase in pressure occurs in the hydraulic lines, since the respective piston rod is guided by one of the two oil chambers of each double-acting hydraulic cylinder and thus the respective oil chamber pressurizes the piston in a smaller cross-sectional area than the other oil chamber. A general pressure increase in the hydraulic system thus leads to an un¬ uniform force on the piston, so that via a force balance over the piston, the pressure in the one oil chamber and the ange¬ closed hydraulic line can be further increased.

Thus, hydraulic lines can burst, which can lead to a considerable damage and in addition to an immediate fall of the relevant wing assembly part and thus the endangerment of persons and objects. Furthermore, oil can escape from the bursting hydraulic lines, which can lead to contamination of the goods located in the loading space.

The invention has for its object to provide a hydraulic system that is inexpensive to implement and high security sicher¬ makes.

This object is achieved by a hydraulic system according to claim 1. The dependent claims describe preferred developments.

According to the invention, the hydraulic cylinders are thus simply designed to be effective or with a spring return. The spring return stroke can advantageously be effected by a gas spring integrated in the cylinder; However, it can also z. B. may be provided a cylinder spring. In front of the hydraulic cylinders, blocking valves according to the invention are arranged, which lock the pressure set in the relevant oil chamber in relation to the external hydraulic lines. In particular, they can be integrated in the cylinders or their housings, so that no further lines are required between the shut-off valves and the oil chamber and thus cost-effective implementation with high safety is possible.

According to the invention, one, two or four external hydraulic lines can be provided, with one or two hydraulic lines in the vicinity of the hydraulic cylinders being provided with branches to their check valves. Thus, the total length of external hydraulic lines can be significantly reduced to about one quarter of the total length of the conventional systems. In particular, since the front hydraulic cylinders and the rear hydraulic cylinders are close to each other particularly in the wing body parts, the total length of the external hydraulic lines is determined by the hydraulic lines outgoing from the control unit and only slightly by the branched hydraulic lines.

To lower the wing body parts, the oil chambers of the hydraulic cylinders can be connected to the hydraulic system by means of change-over valves without actuating the engine and bypassing or bypassing the pump. In particular, 2/2-way valves with either a basic position blocking on both sides and a switched position releasing on both sides, or with a basic position blocking the oil drain as a check valve and a switched position releasing the oil drain, can be used as check valves , Depending on the configuration of the check valves, they can be controlled by the control signal, which is also used for motor control, of a reset signal which is different therefrom. - A -

The invention will be explained in more detail below with reference to the accompanying drawings nigen embodiments. Show it:

Figure 1 is a perspective view of a truck according to the invention with hydraulically adjustable wing body parts.

FIG. 2 shows a circuit diagram of a hydraulic system according to the invention for adjusting the wing mounting parts according to a first embodiment with an external hydraulic line provided by the control unit; FIG.

3 shows a hydraulic system according to the invention for controlling the wing attachment parts according to a further embodiment with two hydraulic lines and reversible pump starting from the control unit;

4 shows a circuit diagram of a hydraulic system according to the invention for adjusting the wing-mounted parts according to another embodiment with two of the control unit ausge¬ existing hydraulic lines.

Fig. 5a is a front view and Fig. 5b is a plan view of a wing assembly part of Figure 1 in I unfolded state and II. Folded state.

6a shows an axial section of an embodiment according to the invention of the single-acting hydraulic cylinder for adjusting the wing mounting part with integrated shut-off valve;

FIG. 6b shows the radial section AA from FIG. 6 a; FIG. Fig. 6c is the circuit diagram of the hydraulic cylinder of Fig. 6 a, b;

A truck (lorry) 1 has a body 2 and two wing body parts 3, which are mounted on the body 2 in two, in the vehicle longitudinal direction extending, parallel pivot axes A. The wing body parts 3 or wing bodies are designed with a rectangular cross-section, in the folded-in state close the cargo space of the truck 1 on three sides and give it in the unfolded or extended state shown in FIG. 1 towards the sides free. Accordingly, the two pivot axes A of the two wing attachment parts 3 lie relatively close to each other in the middle region of the truck 1 with bearings 4 in a front frame part 5 and a rear frame part 6 of the body 2.

The wing body parts 3 are pivoted by a respective rear hydraulic cylinder 7a or 7b and a front hydraulic cylinder 8a or 8b, which are articulated in body-side bearings 10 and wing-side bearings 11. The hydraulic cylinders 7a, b, 8a, b are single-acting and connected via a hydraulic line 12, two hydraulic lines 12a, b or hydraulic lines 13 branched off from the hydraulic line or branches in branches 92, 93, 97 to a hydraulic control unit 14, e.g. is arranged on an underside of the body 2 of the truck 1. In the respective hydraulic cylinders 7a, b and 8a, b blocking valves are used or integrated, as will be explained in the following hydraulic circuit diagrams or schematics.

FIGS. 2 to 4 and 7 to 10 show various embodiments of the hydraulic system 16 according to the invention, each of which incorporates a control unit, hydraulic lines 12, 12a, b, 13 and hydraulic cylinders 7a, b and 8a, b, 56 and 60 electrical check valves 18 has. In this case, the control unit 14 of the embodiment of FIG. 2 has a hydraulic tank 20, a hydraulic pump 22 driven by a motor 21, and a hydraulic control unit 23 connected to the hydraulic pump 22. The control unit 23 has a shuttle valve 24 connected to the pump 22, which, when pressurized by a pumping operation of the hydraulic pump 22, changes from the closed or locked basic position to an open position and releases a hydraulic line 26, which via a quantity control valve 28 the Aus¬ transition of the hydraulic control unit 23 leads, which is connected via a connection of the control unit 14 with the laid on the truck 1 an external Hydraulik¬ line 12, which is connected via branches 92, 93 with other Hyd¬ raulikleitungen 13. In the closed or locked position shown, a return flow from the flow control valve 28 via the shuttle valve 24 to the hydraulic reservoir 20 is released. A safety valve 30 is additionally connected between the quantity control valve 28 and the hydraulic container 20 and thus bridges the shuttle valve 24 and the hydraulic pump 22 in the event of overpressure in the hydraulic line 26 and switched shuttle valve 24.

The electric check valves 18 are designed as double-blocking 2/2-way valves which are locked in the basic position of the hydraulic system 16 shown in FIG. 2 on both sides and upon receipt of a corresponding electrical control signal S, which also the Motor 21 drives, are switched to their open position. In this embodiment, the hydraulic cylinders 7a, b and 8a, b are designed as single-acting, pneumatically sprung or gas-sprung hydraulic cylinders. Thus, in each case only one oil chamber 32 is actuated via the electric shut-off valves 18, which presses the piston 33 against a gas-filled, closed gas chamber 34, through which the piston rod 35 extends. The check valves 18 are advantageously also operated manually, eg lever-operated as shown in the figures. In the basic state or idle state of the hydraulic system 16 shown in FIG. 2, the engine 21 is switched off, with the electric shut-off valves 18 separating the oil chambers 32 of the hydraulic cylinders 7 a, b and 8 a, b from the hydraulic line 12. The internal hydraulic line 26 of the blocking unit 23 and the external hydraulic line 12, which run on the truck 1 or its body 2, are thus depressurized. If the pressure in the hydraulic lines 12 increases, for example due to an increase in temperature, if the truck 1 is turned off at cold temperature and is significantly heated, for example, strong sunlight, so this pressure increase is not on the locked check valves 18 to the hydraulic cylinder 7a, b and 8a , b, but via the shuttle valve 24 to the Hydraulik¬ tank 20 output.

In order to fold up the wing attachment parts 2, the driver or user places a switch which, directly or via a control device of the truck 1, receives control signals S both to the motor 21 and to the relevant electrical blocking valves 18, eg two or four electric check valves 18, outputs. As a result, the motor 21 drives the pump 22, so that the external hydraulic line 12 is pressurized and via the open shut-off valves 18, the respective oil chambers 32 are pressurized and adjust the piston 33. Once the wing assembly parts 3 are in the open position shown in Fig. 1, the motor 21 is turned off again and continue the check valves 18 are switched to their normal position, so that relative to the position shown in FIG. 2, only the piston 33 are moved , Even in the unfolded or extended state of the wing body parts 3 thus the external hydraulic line 12 and the internal hydraulic line 26 is depressurized. In order to fold down the wing building parts 3, a control signal S can again be output to the check valves 18, without actuation of the engine 21, which opens them so that the single-acting hydraulic cylinders 7a, b and 8a, b be reset due to the spring action of the gas spring 34 and supplement the weight of the wing assembly parts 3 and the hydraulic fluid from the Ölkammem 32 via the open check valves 18 and the external hydraulic line 12 and the shuttle valve 24 in the hydraulic reservoir 20 is output. Here, a gentle, damped closing of the wing-mounting parts 3 is achieved by the flow control valve 28.

In the embodiment shown in Fig. 3, two external hydraulic lines 12a, b are connected to the hydraulic control unit 14. The electric check valves 37 in front of each hydraulic cylinder 7a, b, 8a, b are also formed as 2/2-way valves, but - as an alternative to Fig. 2 - in the basic position shown or rest position one-sided blocking, so that they as a check valve Prevent reflux of the hydraulic fluid from the oil chamber 32 and allow in the switched position only a return flow from the oil chamber 32 into the hydraulic lines 12.

Furthermore, in the hydraulic control unit 14 of the motor 21, a reversible hydraulic pump 39 is driven, emanating from the two symmetrical branches, which are each secured via safety valves 43 and additional check valves 40 against the hydraulic tank 20, so that both the occurrence of too high Overpressure and a negative pressure at the outputs of the hydraulic pump 39 is avoided. In both branches, exchange valves 41 are connected to the hydraulic pump 39, which correspond to the above-described shuttle valves 24 from FIG. 2 and open to a common internal hydraulic line 42 during a pumping operation.

Two quantity control valves 44 are connected in parallel to the internal hydraulic line 42, to each flow control valve 44 via two external hydraulic lines 12a, b and optionally via a branch 97 and hydraulic line 13 on the one hand, the two right hydraulic Zy-. Linder 7a and 8a and on the other hand, the two left hydraulic cylinders 7b and 8b are connected via a respective hydraulic shut-off valve 37.

The switching situations of the embodiment of FIG. 3 are essentially the same as those of FIG. 2. In the basic position shown with closed wing components 3, the stop valves 37, the external hydraulic lines 12 are depressurized and via the shuttle valves 41 di ¬ connected directly to the hydraulic tank 20. In order to fold up the wing assembly parts 3, the motor 39 is in turn switched on by a control signal S; however, unlike Fig. 2, the check valves 37 are not switched. The adjustment operation is terminated by turning off the motor 39, the pressure in the oil chamber 32 being held by the check valves 37. The pressure stored in the external hydraulic lines 12a, 13b and the in-line hydraulic line 42 can in turn be discharged directly into the hydraulic tank 20 when the engine 29 is switched off. To release the wing assembly parts 3, reset signals R are input to the check valves 37, which open them and release the direct return flow into the hydraulic tank 20 via the quantity control valves 44 and the shuttle valves 41. Alternatively, the check valves 37 can also be operated manually.

In the embodiment of FIG. 4, the control unit 14 is basically constructed according to those of FIG. 2, wherein to the motor 21 and the pump 22, a hydraulic control unit 46 is connected, which - unlike in Fig. 2 - on the internal Hydraulic line 26 has two parallel-connected flow control valves 28 which are connected to the internal Hydrauliklei¬ device 26 each via an electrically or electromagnetically actuated, designed as a 2/2-way valve with a base position open on both sides and a double-sided blocking switched position control valve 48 sen , By the control valves 48 can thus optionally be applied to the left and / or right external hydraulic line 12 a, 12 b with pressure and Thus, the cylinder 7a, 8a or the cylinder 7b, 8b or all cylinders 7a, b, 8a, b are actuated during a pumping operation.

In principle, it is also possible, as an alternative to the embodiments shown, that a separate external hydraulic line extends from the control unit to each cylinder; However, this is more expensive, as this results in a significantly higher overall length of hydraulic lines.

5 shows the wing construction part 3 in the unfolded position I and the folded-in position II, wherein the arrangement applies to all single-acting hydraulic cylinders 7a, 7b and 8a, b in this or mirror-image arrangement. The check valves 18 can be integrated into the hydraulic cylinders 7a, b and 8a, b as well as the corresponding hydraulic cylinders of the further embodiments corresponding to 6.12.

Claims

claims

A hydraulic system for raising and lowering wing assemblies (3) of a truck (1) comprising at least: a hydraulic control unit (14) with a hydraulic pump (22, 39) and hydraulic valves (24, 30, 40, 41, 43, 44, 48), a first front hydraulic cylinder (8a, 8b) and a zwei¬ th rear hydraulic cylinder (7a, 7b) for pivoting a first wing-mounting part (3) of a truck (1), a third front hydraulic Cylinder (7b) and a fourth rear hydraulic cylinder (8b) for pivoting a second wing-mounting part (3) of a truck (1), wherein the hydraulic cylinders (7a, 7b, 8a, 8b) each with a single effective oil chamber ( 32) and a spring counteracting action and are adjustable by the control unit (14) via an external hydraulic line (12, 12a, b, 13), wherein between the at least one external hydraulic line (12, 12a, b, 13) and the oil chambers (32) of the hydraulic cylinders (7a, 7 b, 8a, 8b) a check valve (18, 37) is provided, which blocks and releases a return flow of the hydraulic fluid from the oil chamber (32) to the external hydraulic line (12, 12a, b, 13), and wherein in one steady state at set positions of the wing assembly parts (3) and unconfirmed hydraulic pump (22, 39) the check valve (18, 37) blocks the return flow of the hydraulic fluid from the oil chamber (32) and the at least one external hydraulic line (12, 12a , a, 13) is depressurized.

2. Hydraulic system according to claim 1, characterized in that the check valves (18, 37) in the hydraulic cylinders (7a, b, 8a, b) are integrated.

3. Hydraulic system according to claim 1 or 2, characterized in that the check valves (18, 37) are 2/2-way valves, each with at least one electromagnetic actuation.

4. Hydraulic system according to one of the preceding claims, characterized ge indicates that the check valves (18, 37) in both Richtun¬ conditions blocking state and a release in both directions state or the return flow from the oil chamber (32) on one side blocking and having a backflow from the oil chamber (32) releasing state.

5. Hydraulic system according to one of the preceding claims, characterized ge indicates that in a stationary state, the at least ei¬ ne external hydraulic line (12, 12a, b, 13), bypassing the hydraulic laulikpumpe (22, 39) with a hydraulic container ( 20) of the hydraulic system is connected.

6. Hydraulic system according to claim 5, characterized in that between the hydraulic pump (22, 39) and the external hydraulic line (12, 12a, b) a change-over valve (24, 41) is provided, which opens at ei¬ nem pumping and In this case, a connection from the hydraulic pump (22, 39 to the external hydraulic line (12, 12a, b) releases and, in the locked state, releases a return flow from the external hydraulic line (12, 12a, b) to a hydraulic container (20) ,

7. Hydraulic system according to claim 6, characterized in that the hydraulic pump (22, 39) and the shuttle valve (24, 41) by means of a safety valve (30) are bridged.

8. Hydraulic system according to one of claims 1 to 7, characterized ge indicates that emanates from the control unit to each hydraulic cylinder own hydraulic line.

9. Hydraulic system according to one of claims 1 to 7, characterized ge indicates that of the control unit exactly two hy cal lines (12, 12a, b) go out, each with a direct and the other via a branch (97) the two Sperr¬ valves (18, 37) of the hydraulic cylinder of one of the two components is connected.

10. Hydraulic system according to one of claims 1 to 7 characterized ge indicates that from the control unit exactly one Hydrauliki¬ cal line (12) emanating in two consecutively arranged branches (92, 93) each with the check valves (18, 37) connected by two hydraulic cylinders.

11. Hydraulic system according to one of the preceding claims, characterized ge indicates that the springs in the single-acting hydraulic cylinders see gas springs (34) or cylinder springs.

12. Hydraulic system according to one of the preceding claims, characterized ge indicates that the check valves (18, 37) are actuated electromagnetically and manually.