EP2519750A1

EP2519750A1 - Valve assembly with adjustable spring preload and tool kit for adjusting the spring preload

Info

Publication number: EP2519750A1
Application number: EP10787277A
Authority: EP
Inventors: Christian Spielvogel; Martin Zug
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2009-12-30
Filing date: 2010-11-19
Publication date: 2012-11-07
Also published as: CN102770669A; WO2011079891A1; US20130092250A1; DE102009060755A1; DE102009060755A8

Abstract

The invention relates to a control valve assembly comprising a valve body which is prestressed in a direction by a control spring assembly. The spring preload of the control spring assembly (12, 62) can be adjusted by an adjusting device (5, 7) which is completely accommodated in the valve box (2) or a fitted housing part.

Description

description

VALVE ASSEMBLY WITH ADJUSTABLE SPRING PRELOAD AND TOOL SET FOR

ADJUSTING THE SPRING PRELOAD

The present invention relates to a valve arrangement, in particular a control valve of a variable displacement pump according to the preamble of claim 1 and a

Tool set for adjusting the spring preload of such a valve arrangement.

From DE 101 36 416 A1 a generic control valve assembly is known. This has a valve housing, in which a pressure control valve and a flow control valve are integrated. A control piston of the control valves is biased in each case by means of a control spring in one direction. In the known solution, a spring housing is attached to the front side of the valve housing, in which the respective control spring is arranged, which acts on a spring plate on the control piston. This control spring in turn is supported on a support disk, which is adjustable by means of an adjusting screw in the axial direction, so that the control spring preload can be adjusted via the adjusting screw.

Such control valves for variable displacement pumps are usually set to values desired by the customer. This setting is preferably made only once at the pump manufacturer before delivery of the variable. For this purpose, the variable displacement pumps are adjusted on test stands during pump production by a test person and secured against subsequent, accidental change of setting. This backup takes place, for example, in the generic control valves via a lock nut, via which the adjusting screw is clamped to the spring housing. To seal the spring chamber, O-rings are still required in the known solution, which seal the overlap area between the spring housing and the valve housing and the other between the adjusting screw and the spring housing, so that the spring spring receiving the spring chamber to the outside Reliably completed. After adjustment, the adjustment screws are protected by means of safety caps attached to the spring housing. A disadvantage of this solution is that a plurality of components for adjusting and supporting the control spring and a plurality of seals must be provided for sealing the spring chamber.

In contrast, the invention has for its object to provide a simply constructed valve assembly and a tool set for adjustment.

This object is achieved by a valve arrangement with the features of claim 1 and a tool set according to claim 9.

Advantageous embodiments of the invention are the subject of the dependent claims.

According to the invention, the hydraulic valve arrangement is designed with a valve housing in which a valve piston receiving a valve bore is formed. This valve piston is biased by one or more springs whose

Bias is adjustable via a setting device. This adjusting device has a screw which is adjustable to change the spring preload and its target position is fixed via a fuse. According to the invention

Screw element and the fuse in a common threaded hole

screwed in and thus covered to the outside and thus not easily accessible.

The inventive concept turns away from the conventional solutions in which an adjusting protrudes and is countered by means of a screwed onto the adjusting screw lock nut against the housing. These

Although adjusting screws are - as mentioned above - protected against accidental adjustment by means of safety caps - these can be easily removed or lost, so that then on the one hand a risk of damage to the cantilevered adjusting screws and on the other an unauthorized adjustment of the spring preload is possible. In the solution according to the invention, both the adjusting screw and the fuse are completely received in a common threaded hole and thus outwardly in a simple manner reliably coverable, so that even at loss of coverage at least no damage to these adjustment elements is to be feared.

In a particularly preferred embodiment, the threaded hole for the screw and the fuse is not - as in conventional solutions - formed in an attached to the valve housing spring housing, but directly in

Extension of the threaded bore provided in the valve housing, so that the construction of the valve over known solutions is considerably simplified, with some sealing points (outer circumference of the spring housing, inner circumference of the

Spring housing omitted) and thus both the production and the assembly is simplified.

In a particularly simple construction example, the screw is designed as a threaded pin and the fuse as a lock nut, which is designed with a passage for the screw. That About this penetration, the screw can be adjusted through the lock nut.

A simple adjustment is guaranteed if the grub screw with a

Internal polygon is executed and the lock nut has a through-hole with at least the outer diameter of the polygon, so that a

corresponding polygonal key through the lock nut on the

Grub screw can be applied.

To avoid unauthorized adjustment of the spring preload can

Safety cap are provided, which is placed after the adjustment on the lock nut.

The fuse is particularly effective when the fuse cap can only be solved by destruction or deformation.

In order to prevent accidental unscrewing of the adjustment of the threaded hole, in the rear end portion of the threaded hole a

Circlip or the like can be used. The hydraulic valve assembly according to the invention with the described special adjustment device can preferably be used in a control valve for a variable displacement pump, wherein the adjusting device each one

Can be associated flow control valve and / or a pressure control valve.

Part of the invention is also a tool set for adjusting the spring preload, with a tool on which at one end portion a polygon is formed and which is designed with a through-hole, through which another tool can be attached.

By such a tool set, the screw element and the fuse can be adjusted simultaneously without tool change in the valve assembly described above.

A preferred embodiment of the invention will be explained in more detail below with reference to schematic drawings. Show it:

1 shows a longitudinal section through a control valve arrangement of a pump controller;

Figure 2 shows the longitudinal section of Figure 1 with attached tool set and

FIG. 3 shows a 3D exploded view of the arrangement from FIG. 2.

The basic structure of this control valve assembly 1 is detailed in the beginning

described prior art according to DE 101 36 416 A1. The schematic structure of the pump controller is further explained in the out of the Bosch Rexroth AG out data sheet RD 92 711 / 10.07, so that in the following only the essential components for understanding the invention are described and incidentally for the sake of simplicity to the aforementioned state of Technology is referenced. The control valve assembly 1 shown in Figure 1 has a valve housing 2, in which a flow control valve 4 and a pressure control valve 6 are added. The

Pressure control valve 6 causes a constant pressure in a hydraulic system within the control range of the pump. By means of the flow control valve 4, the flow rate of the pump can be adjusted via a differential pressure at the consumer, so that the pump only the actually required by the consumer

Promotes pressure medium amount.

On the valve housing a pump pressure leading pressure port P, a working port A, a tank port T and in the figure only indicated LS port X are provided. The said working port A is in pressure medium connection. with a pressure chamber of an actuating cylinder, via which, as explained in the data sheet RE 92 711, a swivel angle of an adjustable axial piston pump is adjustable. A swash plate of this axial piston pump is swung out via a spring mechanism and can be pivoted back by the pressure in the pressure chamber of the actuating cylinder. At the LS port X is the highest load pressure of all consumers of the supplied via the pump with pressure medium system, which is tapped for example via a shuttle valve cascade from the consumer.

The pressure control valve 6 has a pressure control piston 8 which is guided in a valve bore 10 and is biased via a pressure control spring assembly 12 with two coaxially arranged springs in the illustrated basic position in which it rests against a valve 10 inserted into the valve plug 10. In the valve bore 10 leads to the pressure port P leading, designed as an inclined bore pressure channel 16, which extends beyond the valve bore 10 also up to a valve bore 18 of the flow control valve 4. The pressure regulating piston 8 is designed with a control collar 20, a guide collar 22 arranged adjacently thereto and two end collars 24 and 26. The left in the figure, end collar 26 is in the basic position of the screw 14 and limited with this one in the figure not visible control chamber, which runs over an angular bore

Control bore 28 is acted upon by the pressure in the annular space between the end collar 26 and the control collar 20. This control pressure corresponds to the pump pressure. In the hydraulically connected to the actuating cylinder working port A also runs as a blind hole working channel 30 which intersects the valve bore 10 and immersed in the illustrated basic position of the control collar 20 with its right end portion, so that the pressure medium connection between the pressure port P and the working port A is locked.

In Figure 1 below the valve bore 10 extends parallel to this a longitudinal channel 32, which opens to the right into a leading tank connection T tank channel 34. In this longitudinal channel 32, a nozzle body 36 with two radial nozzles 38, 40 is inserted in the transverse direction, via which the working channel 30 is connected to the tank channel 34. Between these two nozzles 38, 40 opens an intermediate channel 39, which is the two

Valve holes 10, 18 connects to each other and in the illustrated basic position a left end portion of the guide collar 22 so that in this basic position, the pressure medium connection between the working channel 30 and the connecting channel 39 is controlled by the cam between the two coils 20, 22.

The right in Figure 1 end collar 24 abuts against a spring plate 42 to which the pressure control spring assembly 12 engages. The spring plate 42 is arranged in a spring chamber 44, which is designed as a radially expanded portion of the valve bore 10. This spring chamber 44 is executed in contrast to the prior art described above exclusively in the valve housing 2 and not in a separate spring housing. The control pressure of the flow control valve 4 and the pressure control valve 6 can each be adjusted via an associated adjusting device 5 and 7 respectively. The structure of these adjusting devices 5, 7 will be discussed in more detail below.

The control spring assembly 12 is supported on a threaded pin 46, the left end portion 48 located in Figure 1 dips into the spring chamber 44 and the right-most end portion is formed as a threaded piece 50 which is slightly widened relative to the end portion 48 in the radial direction and from this via a

Circumferential groove 51 is separated. The threaded piece 50 is in threaded engagement with a threaded bore 52 corresponding to the diameter of the

Spring housing 44 is expanded in the radial direction. In the threaded piece 50 is the front side Hexagon socket 53 designed for applying a tool described below. The axial position of the threaded piece 50 and thus the bias of the control spring assembly 12 is also in the threaded bore 52nd

screwed counter nut 54 fixed in position, after adjusting the

Federvorspannung is braced with the threaded pin 46. The lock nut 54 is also designed with a hexagon socket 55 whose diameter is substantially larger than that of the hexagon socket 53 of the threaded piece 50. According to Figure 1, this hexagon socket 55 passes through the entire lock nut 54 in the axial direction, so that the tool for adjusting the threaded pin 46 can be recognized by the lock nut 54 therethrough. On the outer circumference of the end portion 48, an annular groove for receiving a seal assembly 49 is provided.

After carried out adjustment and countering a lock cap 56 is placed on the lock nut 54. This is preferably carried out with a press fit, so that a release only when destruction of the fuse cap 56 is possible. Instead of the interference fit, a connection of the safety cap 56 with the lock nut 54 can also be done by gluing, welding or the like.

According to the invention it is provided to manufacture the safety cap 56 made of a plastic.

To unintentionally unscrewing the adjusting device 5 from the

To avoid threaded bore 52, a locking ring 57 is inserted at an axial distance from the safety cap 56 into the threaded bore 52, which engages, for example, in an annular groove 58.

The flow control valve 4 shown in the figure above has a control piston 60 which is displaceable in the valve bore 18 and is biased in the normal position according to the figure via a control spring assembly 62 against a further screw plug 64. The control piston 60 has a control collar 66, a guide collar 68 and two Endbunde 70, 72. The latter Endbund 72 immersed in a spring chamber 74 for the control spring assembly 62, the other end collar 70 is in the home position on the screw plug 64 and limited with her a control chamber which, via another control bore 76 designed as an angular bore, is pressurized into a ring Spaces between the control collar 66 and the end collar 70 is acted upon. In this annular space of the pressure channel 16 opens, so that in the left control chamber of the flow control valve 4, the pump pressure is applied.

In the region of the spring chamber 74 between the adjusting device 7 and the end collar 72, the highest load pressure of the controlled consumer acts, which is tapped off via the LS connection X. Accordingly, the control piston 60 of the

Flow control valve 4 on the one hand from the pump pressure and on the other hand from

Load pressure and acted upon by the force of the control spring assembly 62, so that in the control position, the pump pressure is adjusted to a value that is around the

Pressure equivalent of the control spring assembly 62 is above the highest load pressure. In this control position, the control collar 66 is in coincidence with the

Intermediate channel 39, so that depending on the pressure difference change to a Zumeßblende, not shown, the variable from-pivoted (connection with

Tank pressure) or swung back (connection with pump pressure) can be.

The control collar 66 is designed so that it shuts off the pressure medium connection of said control space and thus of the pressure channel 16 to the intermediate channel 39 in the basic position. In the illustrated basic position, the pressure medium connection between the intermediate channel 39 and the tank channel 34 is opened via the control groove between the control collar 66 and the guide collar 68, so that the working port A communicates via the working channel 30, the intermediate channel 39 and the tank channel 34 with the Tank connection T is connected and thus the pressure chamber of the adjusting cylinder for adjusting the pivot angle is acted upon with tank pressure (pump swung).

The control spring assembly 62 engages via a spring plate 76 on the end collar 72 of the control piston 60 and is supported on the adjusting device 7, via which in turn the spring bias of the control spring assembly 62 is adjustable. The basic structure of this adjusting device 7 corresponds to that of the above-described

Adjusting device 5. Accordingly, the control spring assembly 62 is supported on a threaded pin 78 which dips with an end portion 80 in the spring chamber 62 and with a threaded piece 82 in a relative to the spring chamber 74 radially extended threaded bore 84 is screwed. At the threaded piece 82 is a

Hexagon socket 86 is formed for applying a tool. The position fixing is also done via a lock nut 88 with hexagon socket 90, which passes through the lock nut 88 and through which the tool for adjusting the

Threaded piece 82 can be recognized. The seal is made via a

Seal assembly 81 which is inserted into a circumferential groove of the threaded piece 82.

In the delivery state, a lock cap 92 is placed on the lock nut 88. Another axial securing is formed by a locking ring 94 inserted into the threaded hole 84. As stated above, there is - apart from the dimensions - constructive and functional agreement between the adjusters 5, 7 - further explanations are therefore unnecessary.

Figure 2 shows the control valve assembly 1 in a figure 1 corresponding

Sectional view during the adjustment of the flow control valve, wherein the spring bias of the pressure control valve 6 is already adjusted and accidental adjustment is prevented by the safety cap 56. The spring bias of the flow control valve 4 is just adjusted in the view according to FIG. The threaded pin 78 is screwed into the threaded bore 84. The lock nut 88 is also used, but not yet clamped to the threaded pin 78. In the hexagon socket 90 of the lock nut 88 is a designed as a special tool Allen key 96 is used, which is designed with an axial passageway 98, through which another conventional Allen key 100 for adjusting the threaded pin 78 can be attached.

Adjusting the control spring preload is done by adjusting the set screw 78 by means of the Allen key 100. Once the target position is reached, the lock nut 88 is tightened with the Allen key 100 attached via the other Allen key 96 while the set screw 78 is held firmly so that the target position does not change can. That is, by simultaneous operation of the two keys 96, 100 a very simple fixation of the adjustment device 7 is possible. After this adjustment, the two a tool set 102 (see Figure 3) forming key 96, 100 are withdrawn and the fuse cap 92 for Preventing unauthorized adjustment. During the adjustment of a captive securing ring 94 is already inserted into the threaded hole 84.

Figure 3 shows the components described above again in one

Exploded view. It can be seen the valve housing 2 with the sections for the flow control valve 4 and the pressure control valve 6 with the terminals P, A and the right in Figure 3 arranged areas in which the control spring assembly 62 and the Druckregelfederanordnung 12 is received. The essential components of Einsteilvorrichtungen 5, 7 are shown in exploded view. The two threaded pins 46, 82 can be seen with the end section 48 dipping into the two respective spring chambers 44 and 74 and the respective threaded section 56, 82 inserted into the threaded bores 52 and 84. The two are also visible

Innensechskante 86 and 53, the two lock nuts 54, 88, the retaining rings 57, 94 and the safety cap 56 of the pressure control valve. 6

The set screw 78, the lock nut 88 and the locking ring 94 are inserted into the threaded hole 84, wherein the screwing takes place via the tool set 102 with the hex keys 96 and 100 in the manner described above.

An advantage of the described embodiment is that the individual

Adjusting elements of the adjusting devices 5, 7 completely in the valve housing. 2

recorded and thus covered to the outside.

The tool set 102 is for the intended by the manufacturer adjustment of

Control valve assembly 1 required .. Without this special accessory is a

Proper adjustment of the spring preload only with greater effort possible - accordingly contributes to the need for this special tool set 102 for reliability.

Disclosed is a control valve assembly having a valve body which has a

Control spring assembly is biased in one direction. The spring preload of the control spring arrangement can be adjusted via an adjusting device. This is completely included in the valve body or an attached housing part.

Claims

claims

1. Hydraulic valve arrangement, in particular control valve of a variable displacement pump, with a valve bore (10, 18) having valve housing (2) in which a valve body (8, 60) is guided, by means of at least one spring (12, 62) in one

Direction is biased, wherein the spring (12, 62) on an adjusting device (5, 7) with a screw member (46, 78) is supported, the desired position via a fuse (54, 88) is fixable, characterized in that the screw (46, 78) and the fuse (54, 88) are screwed into a common threaded bore (52, 84) and covered to the outside.

2. Valve arrangement according to claim 1, wherein the threaded bore (52, 84) in the valve housing (2) in extension of the valve bore (10, 18) is formed and the screw member (46, 78) completely in the associated threaded bore (52, 84) is immersed ,

3. Valve arrangement according to claim 1 or 2, wherein the screw is a threaded pin (46, 78) and the fuse is a lock nut (54, 88) which is formed with a passage to the threaded pin (46, 78).

4. Valve arrangement according to claim 3, wherein the threaded pin (46, 78) has a polygonal socket (53, 86) and the lock nut (54, 88) has a Durchgriffsausnehmung (98) with at least the outer diameter of the polygon.

5. Valve arrangement according to claim 3 or 4, with a safety cap (56, 92) which is placed on the lock nut (54, 88).

6. Valve arrangement according to claim 5, wherein the safety cap (56, 92) is solvable only by destruction or deformation.

7. Valve arrangement according to one of the claims 2 to 6, with a

Circlip (57, 94) of the rearward in the axial distance to the screw member (46, 78) and the securing element (54, 88) in the threaded bore (52, 84) is inserted.

8. Valve arrangement according to one of the preceding claims, wherein this with a flow control valve (4) and / or a pressure control valve (6) of a

Pump controller is executed, each having an adjusting device (5, 7) of the

have the type described above.

9. Tool set for adjusting the spring preload of a valve assembly according to one of the preceding claims, comprising a tool (96) having a polygonal edge at one end portion and which has an opening in the region of this polygon through-hole (98) for another tool (100).