SE450516B - DISTRIBUTION VALVE FOR THE HYDRAULIC SYSTEM OF A AGRICULTURAL TRACTOR - Google Patents

Description

l5 20 25 30 35 40 450 516 2 valves. The distribution valve has an inlet port for hydraulic auxiliary pressure intended to be connected to an auxiliary pressure pump and comprises a hand-operated piston valve with at least a first and a second position, the piston valve in the first position establishing a first connection between the inlet from the tractor hydraulic pump and the inlet port the second position breaks the first connection and establishes a second connection between the inlet from the tractor's hydraulic pump and the inlet opening to the control valves and that channels are arranged in the distribution valve for connecting the hydraulic auxiliary inlet opening to the inlet opening to the control valves and connecting the return valves with the return opening for hydraulic fluid.

Preferably, a non-return valve is inserted in the inlet opening for hydraulic auxiliary pressure.

In a preferred embodiment of the invention, the piston valve has a third position in which both the first and the second connection are established simultaneously.

In a further preferred embodiment, the valve assembly is connected to the upper side of the gearbox cover on an agricultural tractor made by Massey Ferguson (registered trademark), the control valves placed next to each other being of the Vanpormatic series 80 type.

The invention is described below in the form of exemplary embodiments and with reference to the accompanying drawings.

Figure 1 is a side view of a valve assembly according to the invention. Figure 2 is an end view of the valve assembly of Figure 1. Figure 3 is a plan view of the valve assembly of Figures 1 and 2. Figure 4 is a sectional view taken along line A-A of Figure 3. Figure 5 is a hydraulic circuit diagram of the valve assembly of Figure 1-4. Figure 6 is a section corresponding to Figure 4 of a modified embodiment of the valve assembly. Figure 7 is a perspective view showing the valve assembly according to the invention with remote control of input control valves with directed control action. Figure 8 is a perspective view similar to Figure 7, with an additional connection from an auxiliary pressure pump on the tractor.

Figures 1 - 3 show the valve assembly according to the invention connected to the upper side of the cover of the gear unit 15 20 25 50 35 5 450 516 the box_of an agricultural tractor of the Massey Ferguson brand (registered trademark) with control valves of type Vapormatic series 80. These control valves are arranged to be placed next to each other in blocks and work with valve pistons for steering connected hydraulically operated equipment. The cover for the gearbox on the tractor is marked with 1 and the steering valve of type Vapormatic series 80 is marked with 2.

The valve unit is adapted to the gearbox cover. the gearbox is equipped with standard controls.

The valve assembly comprises a piston valve housing 4 with a control lever 5 and an inlet for supplying hydraulic auxiliary pressure. The control valve 2 can be included in a valve block_ consisting of one or more control valves placed next to each other between the gear control block 7 and an end plate 8. Only one control valve 2 is shown in the drawing. The unit is held together by three screws 9 with a length adapted to the number of control valves included. An outlet 10 is provided for connection to the receiving container in a hydraulic auxiliary system if one is used.

The tractor has a hydraulic system containing a receptacle for hydraulic oil and a pump driven by the engine.

The hydraulic system was used for maneuvering hydraulic equipment connected to the tractor. Figure 4 shows the opening 11 connected to the inlet of the equipment after the tractor.

The return opening for the tractor's hydraulic system is indicated by 12.

The inlet opening for pressure fluid from the tractor's hydraulic pump is not particularly shown but is connected to a chamber 13, the control lever 5 is connected to a valve piston 14 which in the position shown connects the chamber 13 to the opening 11. In this position the tractor pump is connected to the inlet to the trailer after the tractor and there is no connection between the chamber 15 and the openings 15 which constitute inlet openings to the control valve 2. When the lever 5 is moved forward to the position indicated by 5a in Figure 1, the valve piston is moved backwards and breaks the connection between the chamber 15 and the opening 11.

Chamber 15 connect; instead with the openings 15. Inlet pressure is thus supplied from the tractor pump to the control valves. 10 15 20 25 50 55 450 516 4 From the control valves, connecting lines run to the hydraulic equipment to be controlled in the form of auxiliary devices for the tractor. Since it is possible to use a number of Control Valve 2, a corresponding number of auxiliary devices can be operated simultaneously during drive from the tractor pump.

Hydraulic fluid from the auxiliary devices is returned via the control valves 2 to return channels 16 which are permanently connected to the return opening 12.

A particularly significant feature of the device described above is that an auxiliary hydraulic system independent of the tractor hydraulic system can be easily connected to feed or contribute to the supply of the auxiliary equipment via the control valves 2. This is made possible by the arrangement of the additional inlet port 6 and the return port 10 which are connected. to the supply and return lines for the auxiliary hydraulic system. Normally, the return opening 10 can be blocked, whereby the hydraulic fluid is returned via the channels 16 to the tractor receiving container, and the auxiliary pump sucks hydraulic fluid from said container. The opening 10 is arranged to connect a return line if necessary, in case the restriction of the return flow via the valve assembly is too large.

Figure 5 shows a wiring diagram for the hydraulic system.

Hydraulic fluid is supplied from the tractor pump via the opening 13 and is led via the valve piston 14 either to the opening 11 or to the openings 15, depending on the position of the valve piston. the inlet opening 6 for hydraulic fluid from the auxiliary system is permanently connected to the openings 15 and the outlet openings 16 from the control valve are permanently connected to the return opening 12 for the tractor's hydraulic system. The two positions of the valve piston 14 are determined by means of a ball lock 18.

Figure 6 shows a modified embodiment of the piston valve.

The same reference numerals are used to an appropriate extent in Figure 6 and Figure 5. The essential difference of the embodiment according to Figure 6 is that three positions of the valve piston are possible here. In Figure 6, the valve piston is 10 15 20 25 50 55. 34, 5 45Ü 516 shown in the middle position, the inlet chamber being connected both to the inlet opening 11 and to the inlet openings 15 to the control valves. In this way, both the equipment after the tractor and each additional auxiliary device connected to the control valves can be operated simultaneously.

In this embodiment, the valve piston has a non-return valve consisting of a ball 20 in an inner bore 21. The ball cooperates with a seat 22 to prevent backflow of liquid from the inlet 11 to the chamber 15 when the piston is in the position shown.

When the valve piston is moved to the left from the position shown in Figure 6, the bore 24 is closed by means of the portion 25 of the piston and the connection between the chamber 15 and the inlet openings 15 is broken. At the same time, the portion 26 of the valve piston exposes the bore 27 and the connection between the chamber 15 and the inlet 11 is established past the ball valve.

When the valve piston is moved to the right from the position shown in Figure 6, the portion 28 of the piston enters the bore 27 and thereby breaks the connection between the chamber 15 and the opening 11. The connection between the chamber 15 and the openings 15 remains.

The control valve comprises a shell-shaped cast and machined housing containing a hardened and ground valve piston.

The valve piston is sealed with an O-ring at each end.

Figure 7 is a perspective view of a device comprising a valve assembly 43 for connecting two auxiliary devices to the tractor's hydraulic system. As shown in the drawing, the connecting lines end in four quick couplings 50. The valve assembly is provided with two control valves Za, 2b of type Vapormatic series 80 connected to it. The control valves are in this case not provided with control levers 35 mounted on the valves via flexible cables. In Figure 7, the inlet 6 for auxiliary pressure is blocked.

Figure B shows a device similar to Figure 7, where, however, auxiliary pressure is supplied by hydraulic fluid via an inlet line 51 from an auxiliary pressure pump (not shown) which is connected to the tractor engine. The line 51 contains a non-return valve 52 and is connected to the inlet 6. A return line 55 is connected to the outlet opening 10 and returns to the auxiliary pressure pump. Normally, the tractor's hydraulic pump supplies hydraulic fluid in the range of 27 liters per minute, but with the auxiliary pressure pump connected to the hydraulic system via the inlet to the control valves, hydraulic fluid can be supplied in the range of 59 liters per minute. The available hydraulic power is thus significantly increased.

It will be appreciated that when using a valve assembly as above, a block of control valves may be mounted directly on the tractor gearbox without the use of external piping.

The valve assembly constitutes a combined shut-off valve and connection flange. The unit enables simultaneous hydraulic operation of a number of auxiliary devices.

Claims (3)

10 15 20 25 30 35 v 450 516 PATENT CLAIMS 1. Distribution valve for the hydraulic system on an agricultural tractor, the tractor having a connection surface with (a) an inlet opening from the tractor's hydraulic pump, (b) a return opening for hydraulic fluid and (c) an inlet opening for hydraulic fluid for auxiliary devices, characterized that the distribution valve (4a) is arranged to be connected directly to the connection surface and has openings (13, 12, 11) in connection with the respective said openings (a), (b) and (c), that the distribution valve is arranged to be connected is taken directly to a valve block consisting of one or more adjacent control valves (2) with directed control action, that the distribution valve has an inlet opening (13) in connection with an inlet opening (15) of the control valve or control valves (2) and a return opening (16) in connection with a return opening from the control valve or control valves, that the distribution valve has an inlet opening (6) for hydraulic auxiliary pressure intended to be connected to an auxiliary pressure and comprises a hand-operated piston valve (4,14) with at least one first and a second position, the piston valve in the first position establishing a first connection between the opening (13) and the opening (11) and in the second position breaking the first the connection and establishes a second connection between the opening (13) and the inlet opening (15) and that channels are arranged in the distribution valve for connecting the inlet opening (6) for hydraulic auxiliary pressure to the inlet opening (15) and connecting the return opening (16) to the return opening (12). Distribution valve according to claim 1, characterized in that a non-return valve (20) is inserted in the inlet duct for auxiliary pressure. Distribution valve according to Claim 1 or 2, characterized in that the valve piston (14) has a third position in which both the first and the second connection are simultaneously established.