DE3429218A1 - ELECTROMAGNETIC HYDROVALVE - Google Patents

Description

Y 76

Electromagnetic hydro valve

The invention relates to an electromagnetically operated hydraulic valve in slide design according to the preamble of claim 1.

Such a hydraulic valve is described in patent application P 33 43 827.7. There are electromagnetic in a hydraulic housing actuated pilot valve and a power valve arranged coaxially one behind the other. The pilot valve delivers a pilot pressure to the spool of the power valve, which counteracts the action of a helical spring a corresponding Executes travel and thereby a working connection located in the hydraulic housing to a hydraulic clutch, a Controls the return channel to the tank for hydraulic fluid and a pressure supply channel. This indirectly controlled valve unit has high leakage oil losses and requires a lot of effort for production and assembly.

The object of the invention is to create an electromagnetic hydraulic valve that can be manufactured with fewer components , can be installed more quickly and has lower leakage oil losses.

The characterizing features of claim 1 serve to solve this problem. When the power slide and the pilot slide are longitudinally guided in a sleeve, an almost play-free fit can be achieved by means of close-tolerance precision machining achieve, so that the leakage oil losses are reduced. There is a further reduction in the leakage power loss by a longer power slide overlap, which is made possible by the guide in the sleeve with long switching paths.

Y 76

Since the pilot control valve and the power valve are centered in a sleeve, the pilot control connecting lines, which in the known design are the valve housing contains, be housed in a pilot guide bushing within the sleeve, thereby reducing the overall volume of the valve is reduced and larger working channel cross-sections are made possible.

By combining the pilot valve and the power valve the total assembly time becomes a machine preassembled insert that can be plugged into the valve housing significantly reduced. Such a hydraulic valve can be used as a 3/2-way valve with a pump connection, a working connection and two tank return connections or as a pressure control valve.

Both exemplary embodiments of the invention are shown in the drawing and are explained below.

It shows

Fig. 1 3/2-way valve,

Fig. 2 pressure control valve.

In a valve housing 1 channels for a working connection A for forwarding the hydraulic pressure to a consumer, z. B. incorporated the actuating piston of a hydraulic coupling and for a pump connection P for pressure supply. At the end, the valve housing 1 contains a channel for a tank return connection T1 or T2 , via which the hydraulic fluid flows back to the reservoir.

A sleeve 2 is pressed into a bore connecting all the channels of the valve housing 1 with one another. In ring grooves on On the outer circumference of the sleeve 2, three O-rings 3 are inserted, one of which is between two connections of the valve housing 1 is arranged and these seal against each other. From one side, a pilot valve 4 is free of play in the sleeve

34292-13

Y 76

inserted into a guide bushing 5 which is centered in the sleeve is and contains a radial pressure supply channel 6 and a connecting channel 7, the pressure supply channel 6 is congruent Pressure feed ducts 6 'installed in the sleeve 2, into which fine filters 11 are inserted, are connected to the pump connection P

The cylindrical power slide is on the guide bush 5 9 centered, which is guided lengthways with a clearance fit in the sleeve 2 and with its end faces the in ,, the sleeve attached duct connections controls.

In the pressure control valve shown in FIG. 2, ntil contains a Valve housing 21 has a working connection A on one side, the end of which is pressed into valve housing 21 Sleeve 22 is arranged. Furthermore, a pump connection P and between it and the working connection A are in the valve housing 21 Tank return connection T2 incorporated; adjacent to the electromagnet 8 there is another tank return connection T1. Three 0-rings 23 between the outer surface of the sleeve 22 and the valve housing 21, the connections A, P and T1, T2 seal against one another and outwards.

When the electromagnet 7 is energized, the pilot valve is shifted against spring force in the direction of the power slide 9 and connects the pilot pressure supply channel 6 with the formed in the guide bushing 5 pilot connection channel 7. Thus, via the pilot control connection channel 7 is the Power slide 9 applied at the front so that it is under Compression of the spring 13 executes a switching movement to the left. It connects the pump connection P of the valve housing 1 with the working connection A of the valve housing. From the hydraulic pressure of the working port A, a Working piston, e.g. B. a hydraulic piston of an automatic gear shift can be operated.

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If the electromagnet 8 is de-energized by switching off the power supply, the pilot valve is in pushed back its starting position and establishes a connection between the pilot control connection channel.7 and the tank connection T1. After the pressure on the power slide 9 has been reduced in this way, the spring 13 can move it into its right starting position push back. The pressure supply channel 6 is closed; the working connection A is connected to the tank connection T2, so that the hydraulic oil runs back to the tank.

In the case of the pressure regulator according to FIG. 2, the pilot valve 24 is actuated by the electromagnet 8 in accordance with the size of the pressure supplied to it Stream shifted continuously. The front-side oil pressure at the pilot valve 24 acts as a counterforce in the guide bushing 25 mounted pilot pressure supply channel 26 and the pilot control connection channel 27 is established. The same oil pressure is on the front of the power slide 29 and creates the possibility that the power slide 29, if necessary, the pump connection P to the working connection A. connects.

For example, if a higher pressure is required on a working piston, in this way, the power supply to the electromagnet 8 and the pilot valve 24 are increased via a sensor is shifted to the left by a corresponding amount, so that a higher pressure builds up on the power slide 29 can, which generates a higher pressure at the working connection by the displacement of the power slide 29.

Claims (5)

Y 76 claims 1. Electromagnetically operated hydraulic valve, which consists of an electromagnetically switchable pilot valve and one of formed him with hydraulic pressure can be pressurized power valve is, the valve body of the pilot and Power valve are arranged coaxially in a valve housing and designed as a slide that moves longitudinally Control channel connections of the valve housing, characterized in that that the pilot valve (4, 24) and the power valve (9, 29) are guided within a sleeve (2, 22), which is tightly fitted into the valve housing (1, 21) and is provided with radial openings to which the connections (P, A, T) of the valve housing (1, 21) are in communication. 2. Hydro valve according to claim 1, characterized in that the power slide (9, 29) directly in the sleeve (2, 22) is performed, whereas the pre-control slide (4, 24) in one Guide bushing (5, 25) is guided longitudinally, which is centered and fastened in the sleeve (2, 22), the power slide (9, 29) is held in its initial position by a spring (13) on the face of the guide bushing (5, 25) in contact. 3. Hydraulic valve according to claim 1 or 2, characterized in that the connections (P, A, T) of the valve housing (1, 21) through O-rings (3, 23) are sealed against each other, which are inserted between the sleeve (2, 22) and the valve housing (1, 21). 4. Hydraulic valve according to claim 2, characterized in that the sleeve (2, 22) in the region of the guide bushing (5, 25) is radial Contains pressure supply channels (6 ', 26') into the fine filter (11) are used. Y 76 5. Hydro valve according to one of claims 1 to 4, characterized in that that the pilot control slide (4, 24) together with the electromagnet (8) with the guide bushing (5, 25), the power slide (9, 29) and the sleeve (2, 22) to one in the Valve housing (1, 21) combined with a plug-in unit is.