Valves and valve manifolds

Abstract

This improves the accuracy and robustness of sensor-based detection of the position of valve components within a valve, which are located on a valve manifold. [Solution] A valve 100 for a valve manifold, comprising a valve housing 110 and a fluid passage 120 formed within the valve housing and extending between an inlet connection and an outlet connection, wherein a valve member 140 is housed within the fluid passage so as to be able to move linearly between a first functional position and a second functional position along a motion axis, and the valve member is coupled in a motion-transmission manner to a drive device provided with a permanent magnet 144 and arranged corresponding to the valve housing, and a magnetic field sensor for detecting the position of the valve member is arranged within the valve housing, wherein a shielding metal plate 150 is arranged on the side surface 112 of the valve housing at the height of the permanent magnet, thereby reducing the magnetic flux density provided by the permanent magnet in the space region adjacent to the side surface outside the valve housing.

Description

Technical Field

[0001] The present invention relates to valves and valve manifolds.

Background Art

[0002] Valves are used to control the flow of a working fluid, such as compressed air. Each valve has one fluid passage and a valve member movably disposed within the fluid passage, and this valve member can locally affect the cross-section of the fluid passage to be opened. Thus, when the cross-section of the fluid passage is largely opened, a large amount of the working fluid can pass through the fluid passage; when the cross-section of the fluid passage is slightly opened, a small amount of the working fluid can pass through the fluid passage; and when the cross-section of the fluid passage is not opened, the working fluid cannot pass through the fluid passage. The position of the valve member within the fluid passage provides information regarding the cross-section of the fluid passage to be adjusted and opened, and can be detected by a position sensor. For this purpose, for example, a magnetic field sensor is provided, and this magnetic field sensor includes a permanent magnet assigned to the magnetic field sensor. A plurality of valves may be grouped together on a valve manifold, whereby the supply of the working fluid to the plurality of valves and / or the control of the plurality of valves can be centralized.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The problem of the present invention is to improve the accuracy and robustness of the detection of the position of the valve member within the valve to be arranged on the valve manifold by a sensor.

Means for Solving the Problems

[0004] This problem is solved by a valve having the features described below.

[0005] The valve according to the present invention for a valve manifold has a valve housing and a fluid passage formed within the valve housing, extending between an inlet connection and an outlet connection, in which a valve member is housed within the fluid passage so as to be able to move linearly between a first functional position and a second functional position along a motion axis, the valve member having a permanent magnet and being coupled in a motion-transmission manner to a drive device arranged corresponding to the valve housing, a magnetic field sensor for detecting the position of the valve member is arranged within the valve housing, and a thin metal shield is placed on the side of the valve member at the height of the permanent magnet so as to reduce the magnetic flux density provided by the permanent magnet in the space region adjacent to the side outside the valve housing.

[0006] The valve housing may be made of plastic and define the external shape of the valve. A fluid passage extends within the valve housing. Within this fluid passage, the working fluid is guided through the valve housing. The working fluid, in particular compressed air, flows into the fluid passage through an inlet connection and flows out of the fluid passage through an outlet connection. There may be more than one inlet connection and more than one outlet connection. In particular, a working fluid source may be connected to the inlet connection, and a fluid consumer, such as a pneumatic drive device like a pneumatic cylinder, may be connected to the outlet connection.

[0007] Within the fluid passage, the valve member is housed so as to be able to move linearly along the axis of motion. The valve member can influence the fluid passage cross-section that is open within the fluid passage, that is, it can expand and / or contract the fluid passage cross-section depending on the starting position. The open fluid passage cross-section correlates with the amount of working fluid that can be pumped through the fluid passage per unit of time. The smaller the open fluid passage cross-section, the smaller the amount of working fluid that can be pumped through the fluid passage per unit time. When the fluid passage is closed, no working fluid can be pumped through the fluid passage anymore.

[0008] The valve member is movable between a first functional position and a second functional position. The first and second functional positions differ from each other in the open fluid passage cross-section assigned to each functional position. For example, the first functional position may have the largest open fluid passage cross-section, while the second functional position may have the fluid passage closed. Furthermore, the valve may be configured to allow the valve member to be shifted to another functional position located between the first and second functional positions. Such a valve is called a proportional valve.

[0009] The axis of motion of the valve member may extend parallel to the longitudinal axis of the fluid passage, or it may be inclined with respect to the longitudinal axis of the fluid passage, and in particular may extend perpendicular to the longitudinal axis of the fluid passage. A valve seat may be located within the fluid passage, and the valve member has a seal section. This seal section either tightly abuts against the valve seat or rests on the valve seat in a first functional position. The valve may be formed such that the outer circumferential surface of the seal section abuts against the valve seat in a second functional position. Such a valve is called a slide valve. Alternatively, the valve may be formed such that the end face of the seal section rests on the valve seat in the second functional position. Such a valve is called a poppet valve. A rubber-elastic seal may be fixed to the seal section. In particular, the seal section may have a groove in which a rubber-elastic seal ring is housed.

[0010] To detect the position of the valve member within the fluid passage, the valve member is equipped with a permanent magnet, and a magnetic field sensor is located within the valve housing. The magnetic field sensor is configured to output a specific sensor signal in response to the magnetic field formed around it. The permanent magnet influences the magnetic field formed around the magnetic field sensor, such that the smaller the distance between the permanent magnet and the magnetic field sensor, the stronger the magnetic field, and conversely, the larger the distance, the weaker the magnetic field. Since the permanent magnet is coupled to the valve member, the movement or position of the valve member within the fluid passage affects the strength of the permanent magnet formed around the magnetic field sensor. To that extent, the position of the valve member within the fluid passage can be inferred based on the strength of the magnetic field formed around the magnetic field sensor, as detected by the magnetic field sensor.

[0011] A recess may be formed at the first head end of the valve member, which is located outward with respect to the axis of motion, and which protrudes into the valve member. A permanent magnet is housed within this recess. Alternatively, the permanent magnet may be formed as a ring positioned on the outer circumferential surface of the valve member.

[0012] The valve member is kinetically coupled to a drive unit positioned in the valve housing. Therefore, the valve member can be moved by the drive unit, or it can be displaced to various positions within the fluid passage by the drive unit. The drive unit may have an electric drive unit, an electromagnetic drive unit, or a pneumatic drive unit. In particular, the drive unit has a pneumatically functioning pilot valve. The pilot valve is connected to a pressure chamber, within which the first head end of the valve member is sealed. This pressure chamber will be referred to as the first pressure chamber below. When the pilot valve is operated so that the pressure chamber is filled with a working fluid, particularly compressed air, the volume within the pressure chamber increases, causing the valve member to move outward along a first direction of motion parallel to the axis of motion, i.e., away from the pressure chamber.

[0013] A second pressure chamber may be provided to allow the valve member to move in a second direction of motion opposite to the first axis of motion, which may be fluidly connected to another pilot valve, and a second head end located opposite the first head end is sealed within this second pressure chamber. When the valve member moves in the second direction of motion, pressure is applied to the second pressure chamber by supplying a working fluid, and the pressure in the first pressure chamber may be reduced, for example, by degassing the first pressure chamber. Instead of providing two pilot valves, one assigned to each pressure chamber, a single pilot valve may be provided that is assigned to both pressure chambers. This single pilot valve allows the first pressure chamber to be supplied with air while the second pressure chamber is degassed, and vice versa. Such a single pilot valve may be formed as a 3-port 2-position valve. Furthermore, instead of the second pressure chamber, or supplementing it to the second pressure chamber, a preloaded spring may be provided, coupled to the second head end. This spring moves the valve member in the second direction of motion when no pressure is applied to the first pressure chamber. Furthermore, the valve may be formed as a 5-port 3-position valve, in which a preloaded spring is provided, particularly supplementing the first pressure chamber and supplementing the second pressure chamber, preferably both preloaded springs, which, when no pressure is applied to either of the pressure chambers, shift the valve member to another intermediate position formed as an intermediate position, located between the first and second functional positions.

[0014] According to the present invention, a shielding metal plate is provided on the side of the valve housing at the height of the permanent magnet. This reduces the magnetic flux density provided by the permanent magnet in the space adjacent to the side outside the valve housing. This reduction in magnetic flux density in the space adjacent to the side outside the valve housing reduces the influence of the permanent magnet on the magnetic field sensors of adjacent valves that should also be placed on the valve manifold. This improves the accuracy and robustness of sensor detection of the position of valve members in adjacent valves. This is particularly advantageous when valves are arranged very closely together on the valve manifold, for example, with a gap of just a few millimeters or even a fraction of a millimeter between them.

[0015] The reduction in magnetic flux density is achieved by deflecting the magnetic flux lines of the magnetic field provided or induced by the permanent magnets, so that these flux lines extend into the shielding metal sheet rather than penetrating it. In this way, the deflected magnetic flux lines do not enter the valve housing of the adjacent valve, and are prevented from affecting the magnetic field sensor of the adjacent valve within this valve housing. Furthermore, the shielding metal sheet acts to prevent magnetic fields formed outside the valve housing from penetrating into the valve housing and affecting the magnetic field sensor. Such magnetic fields formed outside the valve housing are particularly those formed by the permanent magnets of adjacent valves.

[0016] The sides of the valve housing where the shielding metal plates are positioned are, in particular, positioned perpendicular to the alignment direction of the valve manifold in which the valves are aligned in a row. It may be specified that one shielding metal plate is positioned at the height of the permanent magnet on each of the two sides of the valve housing that are opposite to each other. This makes it possible to achieve that the magnetic flux lines caused by the permanent magnets do not enter into the valves adjacent to one side or the valves adjacent to the other side, or that the magnetic flux lines do not enter into the valves via either side.

[0017] Advantageous improved forms of the present invention are the subject of the dependent claims.

[0018] Preferably, the shielding metal sheet protrudes beyond the permanent magnet along the axis of motion, from the direction of the inlet connection at the first functional position and from the direction of the outlet connection at the second functional position. Considering that the magnetic field is formed in all spatial directions, particularly spherically, the magnetic field exists not only around the permanent magnet in the form of a cylindrical section perpendicular to the axis of motion, but also at an angle to and along the axis of motion. The magnetic field that is inclined with respect to the axis of motion but not perpendicular, and that exists in the horizontal plane drawn by the axis of motion and a vertical axis extending perpendicular to the side, is at least partially shielded by the shielding metal sheet protruding beyond the permanent magnet as described above. In particular, the shielding metal sheet is formed such that at least a portion of the magnetic field that is inclined with respect to the axis of motion but not perpendicular, and that exists in the horizontal plane, is shielded by the shielding metal sheet; otherwise, a portion of this magnetic field would affect the magnetic field sensor of the adjacent valve.

[0019] Preferably, along the axis of motion, the extending length of the shielding metal sheet is at least 20%, preferably at least 50%, and particularly preferably at least 100%, greater than the distance division the permanent magnet travels between the first functional position and the second functional position. This distance division arises as the distance between the position of the first outer portion of the permanent magnet facing the first functional position at the first functional position and the position of the second outer portion of the permanent magnet facing the second functional position, opposite to the direction of the first outer portion at the second functional position. Thus, this distance division arises as the sum of all positions the permanent magnet can be located in. This distance division depends on the extending length of the permanent magnet along the axis of motion, which arises on the one hand as the distance between the first outer portion of the permanent magnet and the second outer portion of the permanent magnet, and on the other hand as the distance between the first functional position and the second functional position. In particular, this distance division arises as the sum of the extending length of the permanent magnet along the axis of motion and the distance between the first functional position and the second functional position.

[0020] Purely illustrative, along the axis of motion, the extending length of the shielding metal plate is at least 150% greater than the distance division the permanent magnet travels between the first and second functional positions.

[0021] More preferably, along the axis of motion, the extending length of the shielding metal plate is up to 500%, preferably up to 300%, and particularly preferably up to 250%, greater than the distance divisions the permanent magnet travels between the first functional position and the second functional position.

[0022] Preferably, along the axis of motion, the extension length of the shielding metal sheet is at least 50%, preferably at least 100%, and particularly preferably at least 200% greater than the extension length of the permanent magnet along the axis of motion.

[0023] Preferably, the shielding metal plate protrudes beyond the permanent magnet along a lateral axis that is perpendicular to the axis of motion and parallel to the side surface, in the direction of the magnetic field sensor and in the direction away from the magnetic field sensor, respectively.

[0024] Preferably, along the transverse axis, the extending length of the shielding metal sheet is at least 50%, preferably at least 100%, and particularly preferably at least 250% greater than the extending length of the permanent magnet.

[0025] The magnetic field inclined with respect to the vertical axis, which exists in the vertical plane drawn by the lateral and vertical axes, is at least partially shielded because the shielding metal sheet is larger than the corresponding extending length of the permanent magnet along the lateral axis, as described above. In particular, the shielding metal sheet is formed such that at least a portion of the magnetic field inclined with respect to the vertical axis, which exists in the vertical plane, is shielded by the shielding metal sheet; otherwise, a portion of this magnetic field would affect the magnetic field sensor of the adjacent valve.

[0026] Preferably, along the transverse axis, the extension length of the shielding metal sheet is up to 1000%, more preferably up to 800%, and particularly preferably up to 600% greater than the extension length of the permanent magnet.

[0027] Preferably, the shielding metal thin plate has a magnetic permeability greater than that of the side surface. Magnetic permeability corresponds to the permeability of a material to a magnetic field. In this case, as the magnetic permeability increases, the permeability of the material to the magnetic field also increases, thereby reducing the resistance to obstructing the magnetic field. The passage of the magnetic field is affected by the resistance to obstructing the magnetic field so that the magnetic field passes through the place where the resistance is the smallest. Therefore, each time the magnetic field passes through the region having the highest magnetic permeability locally. Since the shielding metal thin plate has a higher magnetic permeability than the side surface where the shielding metal thin plate is disposed, the magnetic field caused by the permanent magnet mainly extends through the shielding metal thin plate in any case in the region of the side surface and does not extend through the side surface.

[0028] Preferably, the shielding metal thin plate is made of steel, particularly ferrite steel and / or martensitic steel. Steel has a high magnetic permeability. Ferrite steel has a higher magnetic permeability than martensitic steel. Martensitic steel has a higher magnetic permeability than austenitic steel. Preferably, the shielding metal thin plate is made of special steel. Thereby, a shielding metal thin plate having high corrosion resistance can be provided.

[0029] Preferably, the magnetic field sensor is a magnetoresistive sensor or a Hall sensor. Thereby, a magnetic field sensor having a small volume can be provided, and thereby, the valve housing can be dimensioned smaller.

[0030] Preferably, shielding metal thin plates are arranged at the height of the permanent magnet on two side surfaces located on opposite sides of the valve housing, whereby the magnetic flux density provided by the permanent magnet can be reduced in the space regions adjacent to the respective side surfaces outside the valve housing. The above description regarding the individual shielding metal thin plates is equally applicable to the individual shielding metal thin plates of the two shielding metal thin plates.

[0031] Furthermore, the problem of the present invention is solved by a valve manifold having the features described below.

[0032] The valve manifold according to the present invention has a base plate, the base plate has an air intake passage, an exhaust passage, and a plurality of interfaces, and at least two interfaces are coupled to the valve manifold, each valve being formed as described above, and the valves are aligned in a line such that their sides are substantially parallel to each other in an alignment direction extending perpendicular to the axis of motion.

[0033] The present invention will be described in more detail below with reference to the accompanying drawings. [Brief explanation of the drawing]

[0034] [Figure 1] This diagram shows three valves aligned in a straight line. [Figure 2] This is a longitudinal cross-sectional view of the valve. [Figure 3] Figure 2 is a cross-sectional view of the valve. [Modes for carrying out the invention]

[0035] Figure 1 shows three valves 100 aligned in a line in the alignment direction 305. Each valve 100 extends along a motion axis 301 perpendicular to the alignment direction 305, a vertical axis 303 parallel to the alignment direction 305, and a lateral axis 302 perpendicular to both the motion axis 301 and the vertical axis 303.

[0036] Figure 2 shows a longitudinal cross-section of the valve 100, which was first illustrated in Figure 1. The longitudinal cross-section is derived from the cutting plane 401 shown in Figure 1. The cutting plane 401 is defined by the axis of motion 301 and the vertical axis 303.

[0037] Valve 100 has a valve housing 110. Within the valve housing 110, a fluid passage 120 extends along the motion axis 301 between an inlet connection (not shown) and an outlet connection (not shown). A valve member 140 is housed within the fluid passage 120. The valve member 140 is housed so as to be able to move linearly between a first functional position and a second functional position (not shown) along the motion axis 301. In Figure 2, the valve member 140 is in the first functional position.

[0038] For purely illustrative purposes, a stopper 114 is formed within the valve housing 110. In the first functional position, the second head end 149 of the valve member 140, which faces the stopper 114, is separated from the stopper 114. In the second functional position, the second head end 149 of the valve member 140 abuts against the stopper 114. Between the first and second functional positions, a stroke 180 is generated, during which the valve member 140 can move within the fluid passage 120.

[0039] For purely illustrative purposes, valve 100 has an actuation mechanism (not shown) equipped with a pilot valve 160. The pilot valve 160 is located at the first head end 148 of valve member 140, opposite to the stopper 114. In the first functional position shown in Figure 2, the pilot valve 160 controls valve member 140 so as not to act against a spring 162 located at the second head end 149 of the valve member 140. When valve member 140 acts against spring 162 and the pilot valve 160 is controlled to overcome the spring force caused by spring 162, valve member 140 is shifted to a second functional position.

[0040] A permanent magnet 144 is provided on the valve member 140. Purely illustrative, a recessed portion 142 is formed on the first head end 148 that protrudes into the valve member 140, and the permanent magnet 144 is housed within this recessed portion 142.

[0041] A shielding metal plate 150 is placed on the side surface 112 of the valve housing 110 at the height of the permanent magnet 144, thereby reducing the magnetic flux density provided by the permanent magnet 144 in the space region adjacent to the side surface 112 outside the valve housing 110.

[0042] Purely illustrative, a valve seat 124 is located within a fluid passage 120, in which case the valve member 140 has a sealing section 146 that seals tightly against the valve seat 124 in a first functional position. The valve 100 shown in Figure 2 is formed purely illustrativeally as a slide valve.

[0043] Purely illustrative, the valve member 140 has multiple seal sections 146, and multiple valve seats 124 are arranged in the fluid passage 120. For clarity, in Figure 2, only individual seal sections 146 and individual valve seats 124 are given reference numerals. Purely illustrative, in both the first and second functional positions, some seal sections 146 abut against the valve seats 124 assigned to those seal sections 146. In this case, some of the multiple seal sections 146 that abut against the assigned valve seat 142 in the first functional position do not abut against the assigned valve seat 124 in the second functional position, and conversely, some seal sections that do not abut against the assigned valve seat 124 in the first functional position abut against the assigned valve seat 124 in the second functional position.

[0044] Purely illustrative, the valve 110 is formed as a 5-port, 2-position valve and is provided with four seal sections 146 and four valve seats 124.

[0045] Purely illustrative, the shielding metal plate 150 protrudes along the motion axis 301, in the first functional position from the direction of the inlet connection, i.e., from the direction of the first head end 148, beyond the permanent magnet, and in the second functional position from the direction of the outlet connection, i.e., from the direction of the second head end 149, beyond the permanent magnet.

[0046] Purely illustrative, a rubber-elastic seal 147 is fixed to the seal section 146. Furthermore, also illustrative, the seal section 146 has a groove not denoted by a reference numeral, in which the seal 147, formed as a rubber-elastic seal ring, is housed.

[0047] Figure 3 shows a cross-section of the valve 100 shown in Figure 2. The cross-section is obtained from the cutting plane 402 shown in Figure 2. The cutting plane 402 is drawn by the transverse axis 302 and the vertical axis 303.

[0048] A magnetic field sensor 130 for detecting the position of the valve member 140 is located inside the valve housing 110.

[0049] Purely illustrative, the shielding metal plate 150 protrudes beyond the permanent magnet 144 along the transverse axis 302, in the direction of the magnetic field sensor 130 and away from the magnetic field sensor 130.

[0050] For purely illustrative purposes, the valve 100 has a coupling section 170, which allows the valve 100 to be coupled to the interface of a valve manifold (not shown).

Claims

1. A valve (100) for a valve manifold, comprising a valve housing (110) and a fluid passage (120) formed within the valve housing (110) and extending between an inlet connection and an outlet connection, wherein a valve member (140) is housed within the fluid passage (120) so as to be able to move linearly between a first functional position and a second functional position along a motion axis (301), the valve member (140) is equipped with a permanent magnet (144) and is coupled in a motion-transmission manner to a drive device arranged corresponding to the valve housing (110), and a magnetic field sensor (130) for detecting the position of the valve member (140) is disposed within the valve housing (110), A valve (100) is characterized in that a shielding metal plate (150) is placed on the side surface (112) of the valve housing (110) at the height of the permanent magnet (144), thereby reducing the magnetic flux density provided by the permanent magnet in the space region outside the valve housing (110) adjacent to the side surface (112).

2. The valve (100) according to claim 1, characterized in that the shielding metal plate (150) protrudes beyond the permanent magnet (144) along the axis of motion (301) from the direction of the inlet connection at the first functional position and from the direction of the outlet connection at the second functional position.

3. The valve (100) according to claim 2, characterized in that the extending length of the shielding metal plate (150) along the axis of motion (310) is at least 20%, preferably at least 50%, and particularly preferably at least 100%, greater than the distance divisions that the permanent magnet (144) travels between the first functional position and the second functional position.

4. The valve (100) according to any one of claims 1 to 3, characterized in that the extending length of the shielding metal plate (150) along a lateral axis that extends perpendicular to the axis of motion (310) and parallel to the side surface (112) is at least 50%, preferably at least 100%, and particularly preferably at least 250%, greater than the extending length of the permanent magnet (144).

5. The valve (100) according to any one of claims 1 to 4, characterized in that the shielding metal plate (150) has a magnetic permeability greater than that of the side wall (112).

6. The valve (100) according to any one of claims 1 to 5, characterized in that the shielding metal sheet (150) is made of steel, particularly ferritic steel and / or martensitic steel.

7. The valve (100) according to any one of claims 1 to 6, characterized in that the magnetic field sensor (130) is a magnetoresistive sensor or a Hall sensor.

8. A valve manifold comprising a base plate, wherein the base plate has an air intake passage, an exhaust passage and a plurality of interfaces, and at least two interfaces are fluidly connected to the valve manifold by a valve (100) according to any one of claims 1 to 7, wherein the valves (100) are aligned in a line such that their sides (112) are substantially parallel to each other, particularly in an alignment direction (305) that extends perpendicular to the axis of motion (301).

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