GB2244792A

GB2244792A - Directional control valve assembly

Info

Publication number: GB2244792A
Application number: GB9110887A
Authority: GB
Inventors: Herbert Beuermann
Original assignee: Mannesmann Rexroth AG
Current assignee: Bosch Rexroth AG
Priority date: 1990-05-21
Filing date: 1991-05-20
Publication date: 1991-12-11
Anticipated expiration: 2011-05-20
Also published as: GB2244792B; JPH0658444A; FR2662226A1; FR2662226B1; DE4016360A1; GB9110887D0

Abstract

A directional control valve assembly having a tank port T, a pump port P and at least one user port A, B and a spool 16 reciprocably mounted in a longitudinal bore is provided within the housing of the valve assembly with a chamber 46 which communicates with the longitudinal bore via a passage 30, with the user port A and with the tank port T. A valve cartridge inserted into the chamber 46 provides selected control of flow from the spool to the user port and from the user port to the tank port. <IMAGE>

Description

Control Valve For "Lhe Application In The Area Of Mol,--Hvdraulics

Technical Field

The invention relates to a directional control valve. Speci-Ci cally, the invention relates to a directional control valve used in the area of mobile hydraulics, i. e. in the field of excavators, cranes, constructional and agricultural machinery as well as in construction. Such a valve is sometimes called a mobile valve.

Background

Prior art is known from German Offenlegungsschrifts 21 19 763, 23 02 043, 27 45 155 (corresponding to US patent 4,078,574), 32 40 038, 23 02 042, 37 01 211 and 24 26 071. Further, Mannesmann-Rexroth prospectus RD 09 307/4.86 discloses a mobile valve of the type-the invention relates to.

The directional control valve, which can be considered to be a primary valve, frequently requires one or more so called secondary valves. This requirement can lead to valve designs requiring a large amount of space and having relatively high C21 -ageous in the field of weights. This is particularly disadvant mobile hydraulic. Moreover, the operability of the secondary valves is difficult.

For instance the mobile valve shown in the above mentioned prospectus uses a secondary valve for connecting the connection between a main spool and a user port to the tank port. Similarly, said Offenlegungschrift 39 13 460 shows an additional secondary valve for controlling the fluid flow between the main spool and the user port. Thus, two valves 1 together with the respective spaces in the housing o4. control valve are recu_i_-,._,_J.

The present -invention is directed to overcoming one or mere of' the problems set forth above.

Disclosure of the Invention

It is an object of the present invention 'to provide a directional control valve such that a compact valve design is possible and that the weight of the valve is reduced. It is - of the invent another object ion to provide a valve which provides more space for secondary valves which are used together with the directional control valve.

It is another object of the present invention to provide a J_ k, t. 1 directional control valve which is readily adaptable to the requirements fo a user of said valve.

- of a directional control valve of the A preferred embodiment invention is described in claim 1. Preferred embodiments of the invention are disclosed in the dependent claims.

The present invention provides for the integration of one of a large range of secondary valves into the directional c=lrol valve or "mobile valve".

The valve of the invention reduces the number of conduits which are necessary for hydraulic connections and also reduces the possibilities for leackage.

The mobile valves of the invention also acquire the functions of a connecting plate. This will also increase the possibilities for checking the valve without having the valve connected to the machine with which it is to be used eventually.

The directional control valve of the invention comprises secondary ports (for connection to the secondary valves) such thaL,',, the connecting channels of the user or working ports to the main spool of the directional control valve can be opened and closed in addition from the area of the secondary valves.

This additional possibility of control multiplies the possible uses and the possibility of usable secondary valves tremendously.

The following basic valve types can be used as secondary valves of the directional control valve of the invention:

Poppet valves can be used which provide for a complete leackage free blockage. Said poppet valves can be operated pneumatically, hydraulically, mechanically or electrically 2. Throttling of the oil flow from the user port to the main spool or, from the main spool to the user port via throttles, throttle cheek valves as well as two or three directional flow control valves.

3. Throttling of the oil flow in the by-pass via throttles or flow controllers.

4. Reduction of pressure from the main spool to the user port.

ter suction.

5. Pressure limitation with or without aL 6. Function of a directional control valve in the form of two or three way valves operated mechanically, pneumatically, hydraulically or electrically.

7. Directional control valve and throttle function actuated proportionally by electric or hydraulicc means.

8. Pressure compensators.

9. Valve functions of a lowering brake.

All the above possibilities can be assigned selectively and independently to each of said user ports witIrcut having to change the conception of the valve housing.

For instance, the use of a spool having four positions is no longer required. Such a spool is a complicated and expensive component. Due to the integration of directional cont-rol valves into the secondary ports the -Eloating posi,.iicn can be actively selected and secured both for a depressed as well as a pulled main spool.

The directional control valve of the invention provides for the use of a single secondary valve in a single space or chamber in the housing of the control valve such that said secondary valve -ween the main spooll and the 1. controls the fluid flow bet user port, and 2. is in a position to connect fluid path between said main spool and the user port to the tank port, i.e. a conduit leading to said tank port.

Brief Description of the Drawings

Fig. 1 is a longitudinal sectional view of a directional control valve of the prior art; f a detail of the

Fig. 2 is a schematic representation o. control valve of Fig. 1; Fig. 3 is a detail of a directional control valve of the Fig. 4 Ficy. 5 W Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 invention as shown in Fig. 4 through 9, with the detail being taken from the area of a connecting channel between the main spool and a user port; is a longitudinal sectional view along line 4-4 in Fig. 6 of a directional control valve of the invention; is a side elevational view of the valve of Fig. 4 from the right hand side; f Fig. 4; is a plan view onto the valve o. is a perspective view of the control valve of the invention as shown in Fig. 4 through 6; -ail of the invention in the area is schematicallv a de.111 of a connecting channel to the main spool; different control or valve systems for the directional control valve of the invention; - 13 a longitudinal view of the directional control valve of the invention with different types of secondary valves being connected to the secondary port; Fig. 14 a view similar to Fig. 1 together with a control lever; Fig. 15 three control valves of the invention connected together.

Fig. 1 discloses a directional control valve 1 known from the prior art. In fact, details of said known directional control valve may be gathered from the prior art. The control valve 1 comprises a housing 2 having a longitudinal bore within which a control spool 16 is reciprocally mounted. The control spool 16 (in its different posj4tions) provides for any desired connection via connecting channels provided in the housing; said connections can be established between user ports A, B as well as tank and pump ports T and P, respectively. It can be recognized, that a first connection can be provided between a first connecting channel 30 of a first user port bore 31 to the control spool 16, and from there to a first tank or the user o,rt B connecting channel 136. There is provided 1L in a mirror like fashion a second connec+,.,-ion which need nGt- be explained in any detail. A pressure supply valve car--r-4dge 5 is adapted to open or to close the connection between the connecting channel 30 and the tank connecting channel 36. Moreover, a check valve not referred to by a reference nu,-, ieral is shown.

Fig. 2 is a schematic representation showing a detail of the control valve 1 of Fig. 1 just described. Fig. 2 discloses a connection 21 which provides a fluid path between the connecting channel 30 and the tank connecting channel 36.

Referring now to Fig. 4 through 7 and also to Fig. 3 and 9 the C> control or mobile valve 100 of the invention will be described, which is basically a valve of the type shown in Fig. 1.

The directional control valve 100 comprises a housing 20 forming a surface 3 (Fig. 6, 7), a bottom surface 4 (Fig. 6), a right hand seat surface 6, a left hand seat surface 7, an upper seat surface 8, a lower seat surface 9 as well as right, and left inclined surfaces 10 and 11. The control or main spool 16 is shown in Fig. 4. Also, the longitudinal bore 14 adapted to receive said control spool 16 is shown. The control spool axis is referred to by reference numeral 13.

Reference numbers 18 and 19, respectively, refer to right and left secondary planes, respectively. As mentioned initially, the term "secondary" is used, because the directional control valve as such can be called a main or primary valve. In said secondary planes 18 and 19 the socalled secondary valves can be located, which will cooperate with hydraulic apparatus connected to said secondary valves.

Specifically Fig. 4 discloses - as is well known - annular recesses 23 to 29 in said housing 20 in the area of the longitudinal bore 1,d. Said annular recesses 2,35 through 29 are connected to ports and the like. For instance, a correc-.n,.z channel 30 (also called secondary port) provides a fluid path or connection from a first user port A, i. e. the port bore 31 to the control spool 16 (or the longitudinal bore receiving said main spool).

The second user port is referred to by reference sign B and the port bore of said user port B is referred to by reference numeral 33. The respective axes of said bores 31 and 33 are referred to by 32 and 34, respectively. A connecting channel 35 leads to the main spool 16 and corresponds to the connecting channel 30 which is provided for the user port A.

As in the valve of the prior art shown in Fig. 1, the control valve 100 of the invention comprises a tank connecting channel 36, which is connected via a tank port channel 37 to a tank channel 38, which is in turn connected to,a tank port; also, a tank connecting channel 40 is connected to the tank channel 38 via a tank port channel 39. Additional channels which are required for the proper function of the control valve 100 (as well as the control or mobile valve 1) are shown in Fig. 1 as well as in Fig. 4 and are referred to by reference numerals 47 and 54. In so far, a detailed description of the embodiment of the invenion can be deleted, because it is well-known from the prior art.

Turning now to Fig. 7, annular abutment surfaces 61 through 63 are shown together with a generally rectangular channel 64. Further, surfaces 66 and 67 can be seen which are connected with the tank channel.

-ures Fig. 8 in comparison with Fig. 3 discloses essential feat of the invention in a schematic representation of the connection between the connecting channel 3C and the connecting channel 36 (Fig. 4). When comparing Fig. 8 and 3 i: sh.oulld be - Fig. 8 was ---jrned abc.u-- the noted that the reoresentation o angle alpha referred to in Fig. 4. The preceding remarks as well as the following remarks are similarly true also for the - B, the tank connecting connection between the user port channel 40 and the connecting channel J35, as well as for the different control possibilities shown ir. Filg. 9.

^ the It is noted that the connection 21 allows by means o-E pressure relief valve 5 only the connection of the connecting channel 30 with the tank connecting channel 36 or else the blockage of the connecting channel 30 from the channel 36. In contrast thereto, in accordance tank connecting with the invention, a first connection 46 (see Fig. 3 and 8) is prov;.ded Cz such, that the connecting channel 30 of the user port A (and further, if desired, the connecting channel 35 of the user port B) can be opened or closed towards the main spool 16 by the secondary valve arranged in the so-called secondary plane. For this purpose said first connection 46 is provided in the valve housing 20 in such a manner that the valve means 22 (Fig. 3) adapted to be inserted into said connection A6 can not only provide a connection and/or a blockage between said (first) connecting channel 30 and the (first) tank connecting channel 36, but can also interrupt and/or control the (first) connecting channel from the (first) user port A to the main spool 16. Thus, the connecting channel 30 is separated into two connecting channel sections 301 and 30''.

Likewise, a second connection can be provided for the second user port B the respective channels. For reasons of simplicity, the description is, however, concentrated on the user port A with the understanding that similar comments are true for the user port B. t Continuing with the description of the connection 46 shown specifically in Fig. 3,.4 and 8, it can be seen in Fig. 4 that - ght inclined surface 10 said connection 46 extends from the r-i along the inclined secondary axis 18 cutting first the tank connecting channel 36, then the connecting channel section 3011 (see now Fig. 3 and 8 and note that the connecting channel section 30' leads to the user port A), and eventually the connecting channel section 301, the latter section 301 leading to the main spool 16. Connection 46 is provided in the form of an inclined opening or bore and forms control edges for a valve 70 shown for instance in Fig. 9. Indeed, Fig. 9 shows different types of socalled secondary valves 30, which can be used together with the "prima.-y" valve 100. It should it is possible to insert into the chamber or be noted that opening 46 (Fig. 3, 4 and 8) a valve cartridge so as to realize the secondary valves 70 shown in Fig. 9.

Referring now specifically to Fig. 8 it can be seen that the connection 46 comprises three sections 43, 44 and 45 with the section 45 again comprising two section portions 55 and 56.

Fig. 10 through 13 disclose different types of valves, which can be arranged in the opening 46. Fig. 14 is a view similar to Fig. 7, however, Fig. 14 shows the control lever. Fig. 15 is a plan-view of valves of the invention which are connected to each other.

Summarizing it can be said that the invention provides a chamber or opening 46 which in turn forms two control edges: one control edge is located in fig. 8 to the right of the bracket of 55; the other control edge is located to the left of the bracket of reference number 56. With these two edaes a W control of the flow path between the main spool and the user port, and the control of the flow path to the tank port can be controlled in an easy manner.

A directional control valve comprising: a housing, pump-, tank-, and user ports in said housing, a longitudinal bore in said housing, a main spool (16) reciprocally mounted in said longit,,idina"i. bore, a secondary port in the area of connection between said control spool and said user port (A), a chamber or opening in said housing providing a connection between said secondary port and a tank channel in said' housing and leading to said tank port, and valve means -- providing pressure-, suction-, bypass-, and throttle functions -- arranged in said chamber to provide the required valve functions between said control spool, said user port and said tank channel.

2. The control valve of claim 1 characterized in that the housing chamber forms control edges, one of which is located in the direction towards the control spool and the ctiher off which is located in the direction towards the tank channel.

3. The control valve of claim 2 comprising at least a first connection (46) between a first connecting channel (30) leading from said first user port (A) to said main spool (60) and a first tank connecting channel (36).

4. The control valve of claim 3 wherein a second connection is provided between a second connecting channel (35) leading from said second user port (B) to the main spool (16) and a second tank connecting channel (40), wherein first. valve means are provided in said first connection and second valve means are provided in said second connection, and wherein further said - 1 first and/or second connection (46) is provided in said valve housing (20) such that said valve means cannot only be used for connecting or blocking the connection between the first and second connecting channel and the first or second tank connecting channel, but can also interrupt, open or control the first and second connecting channel, respectively, leading from either said first or said second user port to said main spool.

5. The valve of claim 4 wherein said first and/or second connection (46) interrupts the connecting channel and forms a space or chamber adapted to receive a valve spool or a valve cartridge such that any type of valve function can be provided at this location.

6. The valve of claim 5 wherein the connection (46) extends in a direction inclined with respect to the main spool axis (13) so as to save space.

7. The valve of claim 6 wherein said connection (46) divides the connecting channel (30) into two sections (301 and 3011).

8. The valve of claim 7 wherein said two sections (301 and 3011) are located parallel offset to each other in said housing.

9. The valve of claim 8 wherein said sections (30' and 3WI) extend perpendicular to said inclined secondary axis (18, 19).

10. The valve of claim 9 wherein said connection (46) ends in an inclined surface (10) of said valve housing.

11. The valve of claim 10 wherein said valve comprisse's three control planes.

11 - 12. The valve of claim 1 wherein in said conrie,--+,.cr. ('a6) a pressure reducing valve or a directional con-cr,--.1 valve is arranged.

13. The valve of claim 1 arranged in a valve block having one or more spool axes.

14. The valve of claim 13 wherein the secondarv axis extend perpendicular to the axis of the user ports.

15. A directional control valve comprising:

housing; longitudinal bore extending through said housing; main spool (16) reciprocably mounted in said longitudinal bore; at least one tank port, at least one pump port and at least one user port (A); a connecting channel (30) connecting said longitudinal bore with said user port; a valve means located in said connecting channel (-0) such that either the fluid flow in said connecting channel between the longitudinal bore and the user port (A) can be controlled, or that said connecting channel can be connected to said tank port.

16. The valve of claim 15 wherein said valve means comorises at least two control edges, said one control edge being used for controlling the fluid flow between the longitudinal bore and the user port, the other control edge being used to control the connection of the user port to the tank port.

17. The valve of claim 15 wherein a single chamber or connection (46) is provided in said housing (20) providing a connection between a connecting channel (30) - which is connected to the longitudinal bore (14) - and a user port (A) 1 1 as well as a tank connecting channel (36) leading to the tank port, said connection (46) being adapted to receive a valve means adapted to control the fluid flow between the long-itudinal bore, the user port and the tank port.

18. The valve of claim 17 wherein two of said valve receiving channels (46) are provided in said housing (20) in a mirror-like fashion.

ng 19. The valve of claim 17 wherein one of said connect. channels (46) is closed towards the outside of said housing (20) if it is not to be used for receiving a valve means.

20. The valve of claim 1 used as a mobile valve.

21. A directional control valve according to claim 1 and as herein described.

22. Directional control valves as herein described and illustrated in the accompanying drawings.

- 13 Published 1991 at The Patent Office, Concept House, Cardiff Road. Newport. Gwent NP9 I RH. Further copies maybe obtained from Sales Branch, Unit 6. Nine Mile Point. Cwrnfelinfach. Cross Keys, Newport. NP I 7HZ. Printed by Multiplex techniques ltd, St Mary Cray, Kent.