WO2007012402A1

WO2007012402A1 - Valve arrangement and cooling device

Info

Publication number: WO2007012402A1
Application number: PCT/EP2006/006805
Authority: WO
Inventors: Albert KÖCKEMANN; Gerold Liebler; Joachim Neumann
Original assignee: Bosch Rexroth Ag
Priority date: 2005-07-26
Filing date: 2006-07-12
Publication date: 2007-02-01
Also published as: DE102005042784A1

Abstract

The invention discloses an electrohydraulic valve arrangement (1) having a valve housing (6) and at least one electronics housing (4) for accommodating electronic components for controlling the valve (on-board electronics), and a cooling device for a valve arrangement of said type. According to the invention, the valve arrangement has a cooling element (28) which is traversed by coolant or acts thermoelectrically and is in thermal contact with the electronics housing.

Description

description

Valve arrangement and cooling device

The invention relates to a valve assembly according to the preamble of patent claim 1 and a Kuhlvorrichtung according to the preamble of claim 18th

Such a valve arrangement is known for example from DE 195 30 935 C2. In this conventional electrohydraulic valve arrangement, the actuation of a control piston takes place via one or two actuation magnets, which are actuated via control electronics as a function of control signals of a control unit. The control electronics and an inductive position transducer for detecting the position of the control piston are integrated with such valves in an electronics housing made of plastic (on-board electronics), which rests on two mutually perpendicular abutment surfaces on the valve housing and is fixed thereto. In the Elektronikgehause a bestuckte with electronic components of the control circuit board is arranged, which is attached to improve the heat dissipation to a base of a good heat-conducting material existing cover of the Elektronikgehauses. Further electronic power components of the control electronics, such as power transistors, are mounted directly on the base of the end cover for improved heat dissipation. The end cover is equipped in sections with cooling ribs, which improve the cooling effect of the end cover by passive thermal convection with the ambient air.

A disadvantage of such valve arrangements is that the heat dissipation via the end cover, in particular at high ambient temperatures, for example in warm Countries or in the warm area of working machines, as well as a reduced cooling air supply, for example, due to noise protection housings is insufficient to cool the electronic components of the control electronics sufficient and it due to the high operating temperatures to a faulty work and a shortened life of the electronic components to failure of the Control electronics can come.

In contrast, the present invention seeks to provide an electro-hydraulic valve assembly, in which an improved cooling of the electronic components is possible.

This object is achieved by a valve arrangement with the feature combination of claim 1 and by a cooling device for such valve arrangements with the features of claim 18.

The electrohydraulic valve arrangement according to the invention has a valve housing and at least one electronics housing for accommodating electronic components for controlling the valve (on-board electronics). According to the invention, an active, i. provided by a coolant flowing through or thermoelectrically acting cooling element for cooling the electronic components, which is in thermal contact with the electronics housing.

A cooling device according to the invention for an electrohydraulic valve arrangement has a cooling element and at least one retaining element for fastening the cooling element to an electronics housing of the valve. Inventive ^¬ according to the cooling device flowed through by a coolant or thermoelectrically acting Kühlele ^¬ has ment, which is in thermal contact with the Elektronikge- home stands. The cooling device can be attached as a retrofit kit to existing valves.

Due to the active cooling of the electronics housing via the coolant flowing through or thermoelectrically acting cooling element, the heat dissipation, compared to the prior art according to DE 195 30 935 C2 with passive convection cooling, significantly increased by the ambient air, so that even at high ambient temperatures and reduced cooling air flow sufficient cooling of the electronics housing and the electronic components is ensured. As a result, the operating temperature of the control electronics is lowered, so that a temperature-induced malfunction of the electronic components with increased service life of the control electronics is prevented.

In a preferred embodiment of the invention, the cooling element has at least one thermoelectric Peltier element. This consists for example of two thin ceramic plates between which alternately p- and n-doped semiconductor materials are arranged in a series circuit. By applying a DC voltage, one of the ceramic plates is cooled and the other heated by means of the series connection of two materials with different levels in the thermoelectric voltage series, so that a temperature gradient arises between the ceramic plates (Peltier effect). Such thermoelectric Peltier elements reach high temperature differences (up to 70 ⁰ C) with good efficiencies and are silent and maintenance-free due to the lack of moving components during operation. By thermal contact of the cooled ceramic plate with the electronics housing, the resulting amount of heat of the electronic components can be dissipated and thereby the temperature of the control electronics can be lowered. According to a further preferred embodiment of the invention, the cooling element is a fluid-cooled cooling plate. Due to the thermal convection of the fluid, for example, water, oil or air, a large amount of heat is dissipated from the electronics housing via the cooling plate depending on the type of coolant and its flow rate and thus cooled the control electronics defined.

The cooling plate preferably has at least one cooling channel, which can be connected via coolant connections to a cooling circuit and can be supplied via this with the coolant, for example water.

To be particularly advantageous, it has been found that the cooling plate has two substantially parallel bores, which are interconnected via an approximately perpendicular to this transverse bore and form an approximately U-shaped cooling channel in the cooling plate, which is supplied via two coolant connections with coolant , The cooling channel formed by the bores is easy to manufacture compared to a cooling channel produced by casting.

According to a variant of the invention, two inclined, mutually connected, interconnected bores are introduced into the cooling plate, which form an approximately V-shaped cooling channel in the cooling plate. For this purpose, only two holes are required, so that the production of the cooling channel is further simplified.

Preferably, the cooling element via a contact surface at least in sections with a side surface of the electronics housing directly or via a heat guide medium, in particular a thermal compound brought into abutment. As a result, the heat transfer between the cooling element and the electronics housing is further improved.

According to a preferred embodiment, the cooling element is connected via at least one retaining element to the electronics housing and / or the valve housing.

According to the invention it is preferred if the holding element is a holding plate which overlaps the electronics housing and the cooling element.

The retaining plate is preferably on the one hand via at least one fastening element, in particular a screw, connected to a cover of the electronics housing and on the other hand with an end face of the Kühlele ^¬ management and carries this.

The holding plate has, in an advantageous embodiment of the invention, a bore system with mutually offset holes for the variable positioning of the cooling element on the electronics housing. ^¬ on the staggered mounting holes reason, the cooling element is mounted on both sides of the electronics housing and are thereby adapted to the particular installation conditions of the valve.

The cooling element is connected according to a preferred embodiment of an additional, designed as a retaining tab retaining element with the valve housing. The retaining tab preferably has at opposite end portions two holes arranged substantially perpendicular to each other for receiving fastening elements, in particular screws. This allows the retaining tab at a first end portion with the Ventilge ^¬ housing and at a second end portion with the Kühlele- ment to be connected, so that the mounting of the cooling element to the electronics housing, and thereby the heat transfer ^¬ are further improved between the electronics housing and the cooling element.

According to a preferred embodiment, the retaining plate is at least partially adapted to the contour of the end cover and / or the retaining tab at least partially adapted to the contour of the electronics housing. The retaining plate, which is adapted to the contour of the end cover, enlarges the heat exchange surface and thereby increases the heat conduction via the end cap to the cooling element, so that the cooling effect is further improved.

The bore pattern of the holding elements is adapted in accordance with an advantageous embodiment of the invention to the existing hole pattern of the valve housing and / or the end cover. Preferably, the fastening elements of the holding plate and / or the retaining tab engage in existing threaded bores of the end cover and the valve housing, so that the cooling device according to the invention can be fastened to conventional valves with minimal production outlay.

In a particularly compact variant of the valve arrangement according to the invention, the cooling element is arranged at least in sections within the electronics housing.

According to the invention, it is particularly preferred to form the cooling element and / or the retaining plate from a material with high thermal conductivity, for example aluminum. This will increase the thermal efficiency of the Increased cooling element and improves the heat dissipation of the electronic ^¬ nikgehäuse.

The invention is in principle applicable to a variety of electro-hydraulic valve assemblies with integrated electronic components for controlling the valve (on-board electronics), for example in control valves with control electronics or pilot valves of control pumps with integrated electronics. However, the main application of the valve assembly is likely to be in direct-controlled control valves with integrated control electronics.

Other advantageous developments of the invention are the subject of further subclaims.

In the following, a preferred embodiment of the invention is explained in more detail with reference to schematic drawings. Show it:

Figure 1 is a three-dimensional view of a preferred embodiment of a valve assembly according to the invention with a cooling element;

Figure 2 is a plan view of the valve assembly of Figure 1;

Figure 3 is a side view of the valve assembly of Figure 1;

Figure 4 is a detail view of the retaining tab of Figure 3;

Figure 5 is another view of the valve assembly of Figure 1 and FIG. 6 is a sectional view of the cooling plate of FIG. 1.

The invention will be explained below with reference to a direct-controlled 4/3-way directional control valve with inductive position feedback.

1 shows a three-dimensional representation of a directly controlled 4/3-way directional control valve arrangement 1, which essentially consists of a 4/3-way directional control valve 2, an integrated in an electronics housing 4 of electrically insulating or conductive plastic or metal control electronics for controlling the Directional valve 2 and also arranged in the electronics housing 4 inductive displacement sensor (not shown). On an end face 8 of a substantially rectangular valve housing 6 of the directional control valve 2, an electrical actuating magnet 12 is arranged for direct actuation of the control piston, via which the control piston is moved in response to the electrical control signals of the control electronics in its working positions. For supplying energy and supplying the electrical control signals, an electrical line connection coupling 18 and a connection cable 20 are provided on a narrow side 16 of the electronics housing 4. The electronics housing 4 is fastened via fastening elements, not shown, on the actuating magnet 12 and the end face closed by a cover 22 made of aluminum, which is bolted to the electronics housing 4 via mounting screws 24. In the electronics housing 4 electronic components of the control electronics are arranged on a thermally conductively connected to the end cover 22 circuit board (not shown). Other electronic power components, such as power transistors, are used for good heat dissipation directly on a non-illustrated attached end cap 22 sockets. The end cover 22 is provided in sections with cooling fins 26 to increase the heat exchange surface, wherein the heat is dissipated by convection.

According to the invention, a cooling element 28 through which a coolant flows is provided for cooling the electronic components, which is in thermal contact with the electronics housing 4 of the valve arrangement 1. In the illustrated embodiment of the invention, the cooling element 28 is a fluid-cooled cooling plate 30 having a substantially rectangular cross-section, which is brought into abutment via a contact surface 32 with a side surface 34 of the electronics housing 4. The cooling plate 30, described in more detail below with reference to FIG. 6, has a cooling channel 36, which can be connected to a cooling circuit via two coolant connections 38, 40 and can be supplied with coolant via it. In the embodiment shown, water is used as the coolant. Depending on the flow rate of the water in the cooling channel 36, the heat is dissipated via the cooling medium via the cooling plate 30, whereby the heat transfer surface is relatively large due to contact of the cooling plate 30 with the electronics housing 4, so that the electronic components be sufficiently cooled.

In a non-illustrated variant of the valve arrangement 1 according to the invention, a thermoelectrically acting Peltier cooling element is provided for cooling the electronic components, which is in thermal contact with the electronics housing 4. By thermal contact of the cooled ceramic plate with the electronics housing 4, the resulting amount of heat of the electronic components of the control electronics can be removed and thereby lowering the temperature in the electronics housing.

Due to the active cooling of the electronics housing 4 via the cooling element through which flows coolant or thermoelectric cooling element 28, the heat removal rate, compared to the prior art according to DE 195 30 935 C2 with only passive convection cooling by the ambient air substantially increased, so that also sufficient cooling of the electronic components of the control electronics is ensured at high ambient temperatures and reduced cooling air flow. As a result, the operating temperature of the control electronics is lowered and a temperature-induced malfunction of the electronics and a lifetime shortening of the electronic components effectively prevented. To improve the heat conduction and thereby the heat dissipation between the electronics housing 4 and the cooling element 28, a heat transfer medium, such as a thermal paste, be introduced.

The cooling plate 30 is screwed via a retaining element 42 with the end cover 22 of the electronics housing 4. In the embodiment shown, the holding member 42 as a electronics housing 4 and the cooling plate 30 cross-holding plate 44 is formed with a substantially rectangular cross section, on the one hand via a screw 46 with the end cover 22 of the electronics housing 4 and on the other hand via two mounting screws 48, 50 with a Side surface 52 of the cooling plate 30 is screwed and thereby fixes the cooling plate 30 to the electronics housing 4. For fastening the cooling plate 30 to the holding plate 44 six threaded holes 54 are in the side surface 52 of the cooling plate 30 is introduced (in Figure 1, four of the threaded holes 54 are covered by the holding plate 44), of each of which two are brought into engagement with the two fastening screws 48, 50 of the retaining plate 44. By this bore pattern, the cooling plate 30 can be mounted on both sides of the valve assembly 1 and the axial positioning of the cooling plate 30 relative to the electronics housing 4 can be varied. In the exemplary embodiment shown, a threaded hole (tank thread) already present for a screw plug of a potentiometer used for zero point adjustment of the displacement transducer is used to fasten the retaining plate 44 on the end cover 22 as a fastening bore. To improve the heat dissipation from the electronics housing 4, the cooling plate and the retaining plate are formed of aluminum.

As can be seen in particular Figure 2, which shows a plan view of the valve assembly 1 of Figure 1, the support plate 44 has a bore system 56 with mutually offset through holes 58, 60 (the through hole 60 is hidden by the screw 46) for variable positioning of the cooling plate 30 on the electronics housing 4. Due to the staggered through holes 58, 60, the cooling plate 30 on both sides of the electronics housing 4, ie on the side surface 34 and a side surface 62 of the electronics housing 4 depending on the particular installation conditions of the valve assembly 1 to the existing holes the end cover are mounted. The retaining plate 44 is adapted to the contour of the end cover 22 of the electronics housing 4 via a groove 64 (see FIG. 1), in each of which a projection 66, 68 of the end cover 22 engages. By a flat contact surface 70 in this region of the end cover 22, the heat dissipation of the electronic components on the end cover 22 and the support plate 44 to the cooling plate 30 is further improved. The hole pattern 56 of the holding plate 44 is on adjusted the existing hole pattern of the electronics housing 4, so that the screw 46 engages for fastening the retaining plate 44 in an existing threaded bore of the end cover 22. As a result, the cooling plate 30 can be attached to the conventional directional control valve 2 with minimal manufacturing outlay.

According to FIG. 3, which shows a side view of the valve arrangement 1 from FIG. 1, the cooling plate 30 is connected to the actuating magnet 12 in addition to the holding plate 44 via a retaining element 74 designed as a retaining tab 72. For this purpose, the retaining tab 72, as shown in particular Figure 4, at opposite end portions 76, 78 two mutually perpendicular through holes 80, 82 for receiving fastening screws 83, 84. The retaining tab 72 is in the region of the valve-side mounting hole 82 via • a radius R adapted to the contour of the electronics housing 4. Due to the mutually perpendicular through holes 80, 82, the retaining tab 72 can be connected at the end portion 78 to the electronics housing 4 and at the end portion 76 with a side surface 86 of the cooling plate 30 so that the attachment of the cooling plate 30 and thereby the heat transfer between the electronics housing 4 and the cooling plate 30 are further improved. The hole pattern of the retaining tab 72 is adapted to the hole pattern of the actuating magnet 12, so that the fastening screw 83 of the retaining tab 72 engages through the actuating magnet 12 into the already existing threaded bore of the valve housing 6. As a result, the cooling plate 30 can be attached to the conventional directional control valve 2 with minimal production outlay.

As can be seen from Figure 5, which shows a bottom view of the valve assembly 1 of Figure 1, are for Fixing the cooling plate 30 via the retaining tab 72 on the actuating magnet 12 four threaded holes 98 (two threaded holes 98 are hidden in Figure 5 of the retaining tab 72) in the side surface 86 of the cooling plate 30 is provided. Thereby, the cooling plate 30 can be mounted on both sides of the valve assembly 1 and the axial positioning relative to the electronics housing 4 can be varied.

According to FIG. 6, which shows a sectional illustration of the cooling plate 30 from FIG. 1, two parallel blind bores 90, 92 are introduced into an end face 88 of the cooling plate 30, which are connected to one another via a transverse bore 94 which runs perpendicular to the latter and is also formed as a blind bore form approximately U-shaped cooling channel 36 in the cooling plate 30, which can be supplied with coolant via the two coolant connections 38, 40 serving as coolant inlet or coolant outlet. The transverse bore 94 is closed by a closure screw 96 (see FIG. 5). The formation of the cooling channel 36 from the blind holes 90, 92, 94 allows a simple component design, so that the cooling plate 30 manufacturing technology is easy to manufacture.

The valve assembly 1 according to the invention is not limited to the embodiment described above. For example, any known from the prior art coolant, in particular oil for cooling use, which ensures sufficient heat dissipation. It is essential to the invention that the electronic components of the valve arrangement 1 are actively cooled by means of a cooling element through which a coolant flows or thermoelectrically acting cooling element 28, which is in thermal contact with the electronics housing 4. Disclosed are an electro-hydraulic valve assembly 1 with a valve housing 6 and at least one electronics housing 4 for receiving electronic components for controlling the valve 2 (on-board electronics) and a cooling device for such a valve arrangement. According to the invention, the valve arrangement 1 has a cooling element through which a coolant flows or thermoelectrically acting cooling element 28, which is in thermal contact with the electronics housing 4.

LIST OF REFERENCES

valve assembly

way valve

electronics housing

valve housing

front

actuating magnet

narrow side

Line connection coupling

connection cable

End cover

fixing screw

cooling fins

cooling element

cooling plate

contact surface

side surface

cooling channel

Coolant connection

retaining element

Retaining plate

screw

fixing screw

side surface

threaded hole

drilling system

Through Hole

side surface

groove

head Start

contact surface 72 retaining tab

74 retaining element

76 end section

78 end section

80 through hole

82 Through hole

83 fixing screw

84 fixing screw

86 side surface

88 side surface

90 blind hole drilling

92 blind hole

94 cross bore

96 screw plug

98 threaded hole

Claims

claims

1. Electrohydraulic valve arrangement (1) with a valve housing (6) and at least one electronics housing

(4) for receiving electronic components for controlling the valve, characterized by a coolant flowing through or thermoelectrically acting cooling element (28), which is in thermal contact with the electronics housing (4).

2. Valve arrangement according to claim 1, wherein the cooling element (28) has at least one Peltier element.

3. Valve arrangement according to claim 1, wherein the cooling element (28) has a fluid-cooled cooling plate (30).

4. Valve arrangement according to claim 3, wherein the cooling plate (30) has at least one cooling channel (36) via coolant connections (38, 40) connected to a cooling circuit and can be supplied via this with the coolant, in particular water.

5. Valve arrangement according to claim 4, wherein the cooling plate (30) comprises two substantially parallel bores

(90, 92), which are connected to each other via an approximately perpendicular to this transverse bore (94) and the approximately U-shaped cooling channel (36) in the cooling plate

(30) train.

6. Valve arrangement according to claim 4, wherein the cooling plate (30) has two obliquely one another employed, interconnected holes which form an approximately V-shaped cooling channel in the cooling plate (30).

7. Valve arrangement according to one of the preceding claims, wherein the cooling element (28) at least is arranged in sections within the electronics housing (4).

8. Valve arrangement according to one of the claims 1 to 6, wherein the cooling element (28) with a contact surface

(32) directly or via a heat conducting medium, in particular a thermal paste, on a side surface (34) of the electronics housing (4).

9. Valve arrangement according to claim 8, wherein the cooling element (28) via at least one holding element (42, 74) with the electronics housing (4) and / or the valve housing

(6) is connected.

10. Valve arrangement according to claim 9, wherein the holding element (42) is an electronics housing (4) and the cooling element (28) cross-holding plate (44).

11. Valve arrangement according to claim 10, wherein the retaining plate (44) on the one hand via at least one fastening element (46), in particular a screw, with a cover (22) of the electronics housing (4) and on the other hand with an end face (52) of the cooling element (28). is connected and wearing this.

12. Valve arrangement according to claim 10 or 11, wherein the holding plate (44) has a bore system (56) with mutually offset through holes (58, 60) for the variable positioning of the cooling element (28) on the electronics housing (4).

13. Valve arrangement according to one of the preceding claims, wherein the cooling element (28) via a retaining lug (72) formed retaining element (74) with the valve housing (6) or an actuating magnet (12) is connected.

14. Valve arrangement according to one of the claims 9 to 12, wherein the retaining tab (72) at opposite end portions (76, 78) has two substantially mutually perpendicular holes (80, 82) for receiving fastening elements (83, 84), in particular screws ,

15. Valve arrangement according to one of the claims 10 to 14, wherein the holding plate (44) to the contour of the end cover (22) and / or the retaining tab (72) is adapted to the contour of the electronics housing (4).

16. Valve arrangement according to one of the claims 10 to 15, wherein the fastening elements (46, 83) of the holding plate (44) and / or the retaining tab (72) engage in existing threaded bores of the end cover (22) and / or the valve housing (6) ,

17. Valve arrangement according to one of the claims 10 to 16, wherein the cooling element (28) and / or the holding plate (44) are formed of a material having high thermal conductivity, in particular aluminum.

18. Valve arrangement according to one of the preceding claims, wherein the valve (2) is a direct-operated directional control valve, in particular a pilot valve for a multi-stage valve or a control pump.

19. Cooling device for an electrohydraulic valve arrangement (1), in particular according to one of the preceding claims, comprising a cooling element (28) and at least one retaining element (42, 74) for fastening the cooling element (28) to an electronics housing (4) of the valve arrangement (1 ), wherein the cooling device flows through a coolant or thermoelectric acting cooling element (28) which is in thermal contact with the electronics housing (4).