FI74333B - VAELJARVENTILENHET FOER HYDRAULSYSTEMET I EN LANTBRUKSTRAKTOR. - Google Patents

Description

1 74333

Selector valve unit for the hydraulic system of an agricultural tractor

The invention relates to a selector valve unit for the hydraulic system of an agricultural tractor, wherein the pointer comprises an additional connector piece with a supply connection from the hydraulic pump of the tractor, a return connection for hydraulic fluid and an inlet connection for hydraulic fluid entering the accessories.

Most agricultural tractors have a closed hydraulic system with an oil tank and a pump driven by the tractor engine. In general, the pump can use a number of hydraulically operated implements that can be connected to the tractor's rear linkage. Hydraulic attachments can be connected via the connector system-15 piece of the tractor system, to which the inlet and return pipes can be connected. Generally, each attachment requires a control valve, and installing piping from the tractor connector to each control valve is cumbersome and time consuming. Also, if an optional hydraulic pump is added, the complexity of the put-20 system will increase.

The present invention seeks to provide an improvement by which hydraulic accessories and additional pressure sources traversed therefor can be easily connected to a torch hydraulic system.

The above object is achieved by a selector valve unit according to the invention, characterized in that the selector valve unit fits directly into the auxiliary connector body, that the selector valve unit has connections corresponding to the auxiliary connector pieces, that the selector valve unit fits directly into one or more control valves communicating with the inlet connection of the control valve or valves and a return connection communicating with the return connection of the control valve or valves, the selector valve unit having an additional pressure supply connection for connection to the auxiliary hydraulic pump and a manually operated second and second sliding valve, 2 74333 in which in the first position the slide valve connects the supply connection and the inlet connection with the first connection and in the second position disconnects the first connection and 5 connects the supply connection and the liquid channel with the second connection. and that the selector valve unit is provided with channels for connecting the auxiliary pressure supply connection to the fluid passage and for connecting the return connection to the return connection of the auxiliary connection piece.

10 Cheap! there is a non-return valve in connection with the additional pressure supply connection.

In a preferred embodiment of the invention, the slide valve has a third position in which both said first and second connections are operating simultaneously.

In particular, the selector valve unit according to the invention can be fitted to one or more hydraulic control-valve valves of a connection piece on the gearbox cover of a Massey Ferguson (registered trademark) agricultural tractor, known under the type name Vapormartic Serie 80.

The invention is further described with reference to the accompanying drawings, in which:

Figure 1 is a side view of a selector-25 valve unit according to the invention.

Figure 2 is an end view of the valve unit of Figure 1.

Figure 3 is a top view of the valve unit of Figures 1 and 2.

Fig. 4 is a section taken along line A-A of Fig. 3.

Fig. 5 is a hydraulic diagram of the selector valve unit of Figs. 1-4, and Fig. 6 is a sectional view of the modified selector valve unit corresponding to Fig. 4.

Fig. 7 is a perspective view of an arrangement according to the invention with remote control valves, and Fig. 3 74333 Fig. 8 is a perspective view of the arrangement of Fig. 7 also connected to the auxiliary pump of the pointer.

The unit shown in Figures 1-3 is intended to accommodate a Vapormatic Series 80 hydraulic control valve on the cover of a gearbox cover of a Massey Ferguson (registered trademark) ground-5 locomotive, which is a block-mounted slide valve to control the operation of hydraulic equipment connected thereto. The tractor gearbox cover is shown at reference number 1 and the position of the Series 80 control valve at reference number 2. The arrangement is suitable for the tractor gearbox cover in addition to the standard gearshift linkage (not shown).

The selector valve unit comprises a slide valve housing 4 with a hand lever 5 and an additional pressure supply opening.

15 The Series 80 control valve2 may be one of a series of block valves mounted in parallel between the gearbox control block 7 and the Series 80 outlet end plate 8. As shown in the drawings, only one control valve 2 belongs to the system. The apparatus is connected by three 20 bolts 9 of suitable length to connect the required number of control valves. The outlet 10 is arranged to be connected to the oil tank of the auxiliary hydraulic fluid system, if such auxiliary system is used.

The tractor's hydraulic system includes a hydraulic fluid-25 tank and a motor-driven pump. The hydraulic system is mainly intended to use a hydraulic attachment attached to the tractor's lifting gear. Referring to Fig. 4, reference numeral 11 shows a connection connected to the liquid inlet channel of the accessory 30 attached to the lifting devices. Reference number 12 shows the return connection to the tractor's hydraulic system. An inlet connecting pressure from the tractor's hydraulic system is not specifically shown, but is connected to chamber 13.

The control lever 5 is connected to a slide 14 which, in the position 35 shown, connects the chamber 13 to the connection 11. In this embodiment, the tractor pump is connected to the inlet of the lifting linkage 4 74333 and there is no connection between the chamber 13 and the ducts 15 which are Series 80 control valve pressure connections. When the lever 5 is pushed forward to the position 5a of Fig. 1, the slide moves backwards and closes the connection between the chamber 13 and the slider 5. Instead, the chamber 13 connects to the ducts 15. Thus, the incoming pressure is supplied from the tractor pump to the control valves. The control valves have a switch for any hydraulic device that is to be controlled as an auxiliary device for the tractor. As there are as many as 10 valves as possible, it is possible to use several similar auxiliaries at the same time with the tractor's own pump.

The liquid from the auxiliary devices is returned through the valves 2 to the return channels 16, which are permanently connected to the return connection 12.

15 A particularly important feature of the arrangement described with reference to the drawings is that an auxiliary hydraulic system independent of the tractor system can be easily connected to supply the auxiliaries via the control valves 2. This is made possible by the introduction of an additional pressure-20 supply connection 6 and an additional return connection 10, which are connected to the pressure source and the return lines of the additional pumping system, respectively. Normally, the outlet connection 10 can be closed when the liquid returns through the channels 16 to the tractor tank and the auxiliary pump is arranged to suck the liquid 25 from the tractor tank. The connection 10 is arranged to allow the return pipe to be fixed if necessary, in case the resistance of the return flow through the valve unit is too high.

Fig. 5 shows a diagram of the hydraulic circuit-30 of the system, in which the pressure connection 13 of the tractor can be connected by a slide 14 to either the connection 11 of the lifting linkage or to the control pressure channel 15 depending on the position of the slide. The auxiliary pressure connection 6 is permanently connected to the ducts 15 and the return ducts 16 of the control valves are permanently connected to the return connection 12 of the tractor hydraulic system 35. The two positions of the slider are positively adjusted by a spring-loaded ball retaining device 18.

5 74333

Referring now to Figure 6, a modification of a spool valve is shown. In Figure 6, the same reference numerals are used as in Figure 5, where it has only been possible. The main difference is that in the embodiment shown in Figure 6, the valve slide has three possible positions. Fig. 6 shows the slide in its central position, in which the incoming pressure chamber is connected to both the inlet 11 of the lifting linkage and the inlet ducts 15 of the directional valves.

In this embodiment, the slide includes a non-return valve formed by a ball 20 in the internal bore 21. The ball co-operates with the seat 22 to prevent the liquid from the inlet 11 11 from returning to the chamber 13 when the slide is in the position shown.

When the slide is moved to the left of the position of Fig. 6, the bore 24 closes with the slide part 25 and the connection between the chamber 13 and the inlet channels 15 is thus broken. At the same time, the slider part 26 opens the bore 27 and the connection between the chamber 13 and the inlet connection 11 comes directly past the ball valve.

When the slide is moved to the right of the position of Figure 6, the slide part 28 enters the bore 27, closing the connection between the chamber 13 and the connection 11. The connection between the chamber 13 and the chickens 15 is maintained.

The selector valve consists of a jacket cast and machined body containing a hardened and ground control slide. The slider is sealed at both ends with a 30 "0" ring.

Fig. 7 is a perspective view of an arrangement comprising a selector valve unit 4a which connects the tractor's hydraulic system to two possible accessories. In the drawings, the connections end at four quick connectors 35 30. Two Series 80 control valves 2a, 2b are included in the selector valve unit. Instead of the remote control levers being connected to the control valves as shown in Figure 1, the valves are controlled manually by flexible cables using the levers 34, 35. In Fig. 7, the additional pressure supply connection 6 is shown closed.

Fig. 8 shows an arrangement similar to Fig. 7, in which, however, the additional pressure is taken via the inlet connection 31 from an additional pump (not shown) connected to the tractor engine. Line 31 includes a non-return valve 32 and is connected to inlet port 6. Return line 33 is connected to return port 10 and an auxiliary pump. As usual, the output of a standard liquid pump is about 24 1 / min (6 gal / min), but with an additional pump connected to the system at the selector valve inlet, a liquid output of about 52 1 / min (13 gal / min) is possible. The available hydraulic power is thus considerably increased.

It will be seen that the selector valve arrangement described allows the user to easily install a series of control valves on the tractor gearbox deck without additional piping. The selector valve forms a combined isolator valve 20 and connection piece. The valve allows the tractor hydraulics to operate at the same time as numerous accessories.

Claims (3)

7 74333 A selector valve unit for a hydraulic system of an agricultural tractor, the tractor comprising an additional connection piece 5 with a supply connection (13) from the tractor hydraulic pump, a return connection (12) for hydraulic fluid and an inlet connection (11) for hydraulic fluid entering the accessories, characterized in that the selector valve unit , that the selector valve unit has connections (13, 12, 11) corresponding to the connections of the auxiliary connector piece, that the selector valve unit fits directly into one or more control valve blocks (2), that the selector valve has a fluid channel (15) connected to the control valve:. 15 with the inlet connection of the valves and the return connection (16) in communication with the return connection of the control valve or valves, that the selector valve unit has an additional pressure supply connection (6) for connection to the auxiliary hydraulic pump and a manually operated spool valve. . 20 (14) having at least a first and a second position, in the first position the slide valve connecting the supply connection (13) and the inlet connection (11) with the first connection and in the second position disconnecting the first connection and connecting the supply connection (13) and the fluid channel ( 15) and that the selector valve unit is provided with channels for connecting the additional pressure supply connection (6) to the fluid channel (15) and for connecting the pressure connection (16) to the return connection of the additional connection piece *; Selector valve unit according to Claim 1, characterized in that a check valve (32) is provided in connection with the additional pressure supply connection (6). Selector valve unit according to claims 1 and 2, characterized in that the spool valve (14) has a third position in which both said first and second connections are operated simultaneously.