WO2018007074A1

WO2018007074A1 - Electromagnetic actuating device, solenoid valve and pump

Info

Publication number: WO2018007074A1
Application number: PCT/EP2017/063293
Authority: WO
Inventors: Michael NADERER; Nikolaus SCHWEINERT
Original assignee: Dynamic E Flow Gmbh
Priority date: 2016-07-05
Filing date: 2017-06-01
Publication date: 2018-01-11
Also published as: DE102016112246B4; DE102016112246A1; EP3482403A1

Abstract

The invention relates to an electromagnetic actuating device (1), comprising a drive unit (28) with an electric coil (13) for generating a magnetic field and an armature (10), which is activated by the magnetic field generated by the coil (13), a chamber (27, 52) through which a fluid flows, and an actuating element (29), which can control or regulate the fluid flowing through the chamber (27, 52) and which is driven by the drive unit (28). According to the invention, the coil (13) is produced from a hollow conductor and a coolant line (15) is provided, which is connected to the coil and through which part of the fluid flowing through the chamber (27, 52) can be fed to the coil (13), in order to cool same.

Description

Electromagnetic actuator, solenoid valve and pump

FIELD OF THE INVENTION The invention relates to an electromagnetic actuator for a hydraulic system having an electromagnetic drive unit comprising an electric coil for generating a magnetic field and an armature which is moved by the magnetic field generated by the coil. Moreover, the invention relates to a solenoid valve and a pump with such a drive unit.

Electromagnetic actuators referred to herein include an electromagnetic drive unit having an electrical coil and an armature which is moved by the magnetic field generated by the coil. The movement of the armature is doing on a connected to the anchor component or actuator such. B. a piston, transmitted, which performs a specific control function. More particularly, the present invention relates to electromagnetic actuators for hydraulic systems that control or regulate fluid flow. Typical applications are z. As solenoid valves or hydraulic pumps. During operation of such an adjusting device, depending on the load, a relatively high current can flow through the coil of the drive unit. This can cause the coil to overheat and the actuator fail. Cooling the coil with the help of a

Coolant can help here. From DE 1 183 175 A, for example, a hydraulic distributor with a

Fluid-cooled coil known which has a drive unit with an electric coil and an armature which is actuated by the magnetic field generated by the coil. In normal operation, a first port (A) of the distributor communicates with another port (B) of the distributor. The first port (A) is used in this mode as a fluid inlet and the port (B) as a fluid outlet. Now, when the coil is energized, the connection between the terminal (A) and the terminal (B) is interrupted and a new connection between the terminal (B) and another terminal (D) is established. The connection (B) becomes the fluid inlet and the connection (D) the fluid outlet. The fluid in this case flows through port (B) into the distributor, is through various passages in the interior of the distributor to

Led outside of the coil and flows from there back to the output (D). Although this has the advantage that the coil is cooled in the excited state by the fluid, but cooling takes place only in a specific mode of operation of the distributor. DE 25 44 275 A1 and DE 409 796 A further disclose liquid-cooled, tubular induction coils, in which a cooling fluid through the interior of the

Induction coils can be passed.

OBJECT OF THE INVENTION

It is therefore an object of the present invention to realize an alternative actuator with a simple and effective cooling to avoid overheating of the coil. This object is achieved according to the invention by in the independent

Claims specified characteristics. Further embodiments of the invention will become apparent from the dependent claims.

According to the invention, an electromagnetic actuator with a

Propulsion unit proposed, which essentially comprises an electrical coil for generating a magnetic field and an armature, which is actuated by the magnetic field generated by the coil. The actuator further includes a chamber having an inlet and an outlet through which a fluid flows. The armature drives an actuator that serves to control or regulate the fluid flowing through the chamber. According to the invention, the coil is made of a waveguide, in particular a hollow wire, which is formed from a tubular body through which a coolant can flow. The adjusting device according to the invention further comprises a coolant line, which opens at an input side of the chamber and is also in communication with the waveguide of the coil. Thus, during operation of the actuator, a portion of the fluid flowing through the chamber may be diverted from the main fluid stream and passed through the coil to cool the coil. The coil of the

Electromagnet is thus cooled by a part of the fluid, which in any case flows through the actuator. As long as there is a sufficiently high pressure difference between the input and the output of the cooling system, a part of the flows in the Chamber guided fluid through a kind of bypass circuit through the coil, whereby the coil is cooled. As a result, in particular, it is no longer necessary to provide a cooling circuit separate from the main fluid flow with an additional coolant pump.

The electromagnetic actuator may be implemented, for example, as a solenoid valve or as a pump.

A waveguide according to the invention is in particular a tubular body made of an electrically conductive material, such. B. copper having a hollow interior, through which a fluid or coolant is conductive. The waveguide is preferably designed as a hollow wire. Preferred hollow wires have an outer diameter of less than 5 mm and in particular an outer diameter in the range between 1, 0 mm and 3.2 mm. They also preferably have a round or rectangular shape

Cross section or outer circumference. The above-mentioned coolant line is preferably at the chamber

connected, through which the fluid flows. In operation, the actuator is thereby automatically diverted a portion of the fluid flowing in the chamber from the chamber and then flows through the supply line into the coil to cool the latter from the inside. The adjusting device according to the invention further comprises a second coolant line or a return line, which discharges the heated fluid flowing out of the coil again.

The coolant lines, or at least one of them, is preferably one

Hollow wire produced.

According to a preferred embodiment of the invention, the return line opens at an exit side of the chamber through which the main fluid flow flows, whereby the heated fluid flowing out of the coil is returned to the main fluid flow. Alternatively, however, the return line could also lead to a collecting container, in which the heated fluid is collected. Optionally, the return line could also open at another location to return the fluid back into the fluid circuit. If the adjusting device is realized as a fluid pump, the return line may, for example, open at a suction side of the fluid pump. The electrical connections for the coil of the electromagnet z. B. to the coolant lines, ie the supply and / or the return line may be provided.

In a specific embodiment of the invention is at least in one of

Coolant lines arranged an insulator, which serves to provide an electrical

Short circuit between the electrical coil terminals to avoid

or better to electrically disconnect both coil terminals from the body of the actuator. The adjusting device according to the invention can be realized for example as a solenoid valve. In this case, the solenoid valve comprises a chamber through which a fluid flows during operation and in which a valve opening is provided, which is controlled by an actuator,

in particular a valve lifter, can be closed. The solenoid valve further includes an electromagnetic drive unit as described above having a waveguide coil communicating with the chamber via a coolant line.

Thereby, it is possible to branch off a part of the main fluid flow flowing through the chamber and supply it to the waveguide coil in order to cool it.

To cool the coil even in a fully opened state

To ensure solenoid valve, the valve opening is preferably dimensioned so that the pressure drop across the valve, d. H. between a valve inlet side and a valve outlet side is sufficiently large, and thus a sufficient amount of fluid flows through the coil via the coolant line. According to a specific embodiment of the invention, the chamber of the

Solenoid valve output side, a first section with a larger fluid cross section and a second section with a much smaller fluid cross section. The branch line is in this case preferably connected to the second section with the much smaller fluid cross section. Due to the Bernoulli effect, the fluid in the second section has a much higher velocity than in the first section, but a lower pressure. This increases the pressure difference between the valve inlet and the valve outlet. It is therefore possible to cool the coil even when the solenoid valve is open. The adjusting device according to the invention may alternatively also be realized as a diaphragm pump. In this case, the diaphragm pump comprises a chamber through which a fluid flows during operation. In the chamber, a membrane is arranged, which is moved by means of a pump piston back and forth. The pump piston is in turn driven by an electromagnetic drive unit as described above. That is, the drive unit comprises a waveguide coil which communicates with the chamber via a coolant line. Thereby, it is possible to branch off a part of the main fluid flow flowing through the chamber and supply it to the waveguide coil in order to cool it. According to a preferred embodiment of the present invention, a valve can be provided on the supply and / or the return line to control the cooling of the coil or to regulate.

For electrical insulation of one or both coolant lines, for example, an insulating ring can be provided, the z. B. between two sections of

Coolant line is used.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example with reference to the accompanying drawings. 1 is a side cross-sectional view of a solenoid valve with a hollow wire coil according to a first embodiment of the invention;

Fig. 2 is a side cross-sectional view of a solenoid valve with a hollow wire coil according to a second embodiment of the invention;

3 is a side cross-sectional view of a solenoid valve with a hollow wire coil according to a third embodiment of the invention;

4 is a side cross-sectional view of a solenoid valve with a hollow wire coil according to a fourth embodiment of the invention; and 5 is a side cross-sectional view of a solenoid valve with a hollow wire coil according to a fifth embodiment of the invention;

Fig. 6 is a side cross-sectional view of a diaphragm pump with a

Hollow wire winding; and

Fig. 7 is a timing diagram for illustrating the control of various valves of

Diaphragm pump of FIG. 6.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Fig. 1 shows an embodiment of a solenoid valve 1 with a coil made of hollow wire 13. The solenoid valve comprises a main body 30 having a chamber 27 through which a fluid flows. Within the chamber 27 is a valve opening which can be opened and closed by a valve lifter 4 to open or close the solenoid valve 1. At the chamber end of the

Valve tappet 4 (pictured below) is a closing plate 5 with a sealing ring 6, which presses in the closed state of the solenoid valve 1 against the valve opening 24 and seals them.

The valve lifter 4 is driven by a drive unit 28 comprising a plurality of elements, including the hollow wire coil 13 for generating a magnetic field, an armature 10 which is moved by the magnetic field generated by the coil 13 and a spring arrangement with an opening spring 9 and a closing spring 8 for actuating the valve stem 4. Within the coil 13, a soft iron core or magnetic core 12 is arranged for guiding and amplifying the magnetic field. The armature 10 and the spring assembly 8, 9 are housed in a cap 11 which is placed on the valve body 30. The whole

Drive unit 28 is disposed within an overlying cover 14.

The valve main body 30 has two fluid ports 2, 3, which can be used optionally as an input or output. The valve shown here is a "normally open" valve, so it is open in the de-energized state and closed in the energized state. In the de-energized state of the solenoid valve 1, the fluid flow unhindered in both directions through the valve body 30.

Depending on the choice of the fluid input either at the fluid port 2 or at the fluid port 3 different functions of the solenoid valve 1 can be used: Is the

Fluid connection 2 as an input and the fluid port 3 selected as the output, the differential pressure building up between the valve inlet and the valve outlet presses the valve stem 4 additionally against the valve seat. If, on the other hand, the fluid connection 3 is selected as the fluid inlet and the fluid connection 2 as the fluid outlet, this can

Solenoid valve 1 also act as an overpressure relief valve. As soon as the differential pressure in the closed state of the solenoid valve 1 a certain threshold

exceeds, by the spring force of the closing spring 8 and the magnetic force of

Electromagnet 10, 12, 13 is predetermined, the valve 1 opens slightly, so that the fluid can flow through the valve opening 24 and thus reduces the pressure.

The function of the drive unit 28 for the valve stem 4 is briefly explained again below: In the de-energized state, the opening spring 9 presses on an am

Valve tappet 4 provided plunger plate 7 in an opening direction (in the illustrated embodiment, down) against the valve stem 4. As a result, the arranged on the other side of the plunger plate 7 closing spring is slightly compressed and the armature 10 is moved to an open position. If a sufficiently high voltage or a sufficiently high current is then applied to the electrical connections 16, 18, the electrical coil 13 builds up a magnetic field which pulls the armature 10 upwards in the image. With proper spring design of the valve stem 4 is first by means of the harder

Closing spring 8 pushed upwards, the softer opening spring. 9

is compressed until the closing plate 5 with the sealing ring 6, the valve opening 24 closes. As the armature 10 continues to move upwards, so does the stronger one

Closing spring 9 compresses and thereby builds up a closing pressure. The drive unit 28 is preferably designed so that the solenoid valve 1 is closed, even before the armature 10 abuts against the cap 1 1 at its upper end. The purpose of the cap is essentially the hydraulic sealing of the mechanism located therein. It can for example be pressed or screwed onto the valve body 30.

Solenoid valves 1 with high electrical power can overheat on prolonged operation. The solenoid valve 1 shown in Figure 1 therefore has one of a waveguide produced coil 13, the coolant lines 15, 17 in a cooling system

connected. In the illustrated embodiment, the coolant line 15 opens at a first side of the chamber 27 and the coolant line 17 at a second side of the chamber 27. When the fluid port 3 is used as a valve inlet and the fluid port 2 as a fluid outlet, a portion of the flowing through the chamber 27 flows Fluid through the coolant line 15 through the coil 13. A portion of the fluid flowing through the chamber 27 is thus branched off for cooling purposes. The fluid then flows after flowing through the coil 13 via the coolant line 17 back into the main fluid flow and opens at the output side in the chamber 27. In this type of valve connection, the coolant line 15 as supply or branch line and the coolant line 17th be referred to as return line. In reverse

Flow through the solenoid valve 1, the coolant line 17, the branch line and the coolant line 15, the return line.

The coolant lines 15, 17 may, for. B. by brazing, possibly also by soldering, gluing, pressing or crimping hydraulically connected tightly to the valve body 30. In contrast to the illustration of FIG. 1, the

Coolant lines 15, 17 also run within the cover 14, whereby they would be better protected. To avoid an electrical short circuit between the electrical contacts 16, 18 via the valve body 30 here at least one insulator 20 is provided, which can be realized, for example, as a plastic ring, which is arranged between two adjacent sections of the coolant line 17. The insulator 20 is surrounded by a seal 19.

FIG. 2 shows an alternative embodiment of a solenoid valve 1, which is constructed substantially identically to the solenoid valve 1 of FIG. 1. In contrast to

Embodiment of Fig. 1, however, the branched off to cool the coil 13 fluid is no longer returned to the valve outlet, but for example to the suction side of a fluid feed pump (not shown) or in a collecting container. The coolant line 17 and return line is executed accordingly in this case.

Fig. 3 shows a solenoid valve 1, which is constructed similar to the solenoid valve of Fig. 1, although it is closed in the de-energized state. It is like that If the coil 13 is energized in this case, the valve stem 4 moves upward, causing the

Valve opening 24 is released. To be in the energized (open) state of

Solenoid valve 1 to ensure sufficient cooling of the coil 13, the pressure difference between the valve inlet and the valve outlet must be sufficiently large, so that a portion of the fluid through the coolant lines and the coil 13 flows. A sufficient pressure difference is here by a correspondingly small

Cross section of the valve opening 24 ensured.

In the de-energized, closed state of the solenoid valve 1 would be a small

Leakage flow through the coolant lines 15, 17 flow. To prevent this leakage, for example, a valve 23 may be provided, which is arranged in the illustrated embodiment in the coolant line 17. Instead of a return of the branched fluid into the chamber 27, the branched fluid could also be returned to another location.

Fig. 4 shows a further embodiment of a solenoid valve 1, which is constructed similarly to the solenoid valve of Fig. 3. It is again a normally closed valve. In this embodiment, the valve outlet is located on the side of the valve connection 3 (in the picture on the left), the valve inlet is on the side of the valve connection 2 (in the picture on the right). As can be seen in Fig. 4, the valve chamber 27 has on the output side two sections with different sized flow cross-section. In the present case, a thin outlet channel 25 is provided near the valve opening 24, which opens into a channel with a significantly larger cross-section. At the input side of the solenoid valve 1 thus builds up a comparatively higher pressure when the solenoid valve 1 is opened, so that the coil 13 in the open state of the

Solenoid valve 1 can be cooled. The coolant line 15 opens in this case at 26 in the second section with the larger diameter.

Fig. 5 shows a similar embodiment of a solenoid valve 1 as shown in FIG. 4, but in which the coolant line 15 opens into the thin output channel 25. In the outlet channel 25, the flow velocity of the fluid is significantly greater than, for example, on

Valve inlet (right in the picture) or in the second section (at 3) at the valve outlet; however, the pressure is much lower. This is where the Bernoulli effect comes into play, resulting in an additional pressure difference between the valve inlet (on the right in the picture) and the valve outlet (left in the picture). Thus, is also open

Solenoid valve 1 ensures sufficient pressure difference to ensure the cooling of the coil 13.

Fig. 6 shows a diaphragm pump with an electromagnetic pump drive. The diaphragm pump comprises a main body 51, in which a membrane 53 is arranged, which is moved by operation of a pump piston 71 up and down. The membrane 53 is attached to a head 58 of the pump piston. On one side of the membrane 53 (in the picture below) is the conveyed fluid 57, on the other side of the membrane 53 (in the picture above) is air. On the upper side of the main body 51 a plurality of openings 64 are provided through which air can flow in and out.

The pump piston 71 is driven by a drive unit 28, which essentially comprises an electric coil 13 for generating a magnetic field and a magnet or armature 10, which is moved back and forth by the magnetic field generated by the coil 13. The magnet and the coil 13 are housed in a housing of a plurality of plates and a pipe section 61 -63, which is mounted on the main body 51.

The coil 13 is in turn made of a hollow wire, through which a coolant can be passed to cool the coil 13. The coil 13 is also over

Coolant lines 15, 17 integrated in a cooling system. The first coolant line 15 leads from the pump chamber 52 to the coil, the second coolant line 17 then leads from the coil to a fluid outlet of the diaphragm pump. One at the exit of the

Diaphragm pump 1 connected output line includes a T-piece 73, to which the coolant line 17 is connected. As a result of this design of the cooling system, a portion of the fluid conveyed by the membrane pump can in turn be branched off from the main flow and used to cool the coil 13. It is therefore not necessary to set up a separate cooling circuit with an additional coolant pump. To control the pumping process and the cooling of the coil 13, a valve 54 at the fluid inlet of the magnetic pump (bottom left), a valve 55 at the fluid outlet of the magnetic pump 1 (bottom right), and a valve at the coolant line 15 56 provided. It is clear to the person skilled in the art that the said valves could naturally also be arranged elsewhere with the same function. For controlling the magnetic pump 1 and the individual valves 54-56, a control unit 66 is provided. Further, a sensor 65 is provided which monitors the magnetic position. The individual valves 54-56 can be driven, for example, as shown in Fig. 7.

Fig. 7 shows the control signals for the individual valves 54-56 in a time chart. In a suction operation of the diaphragm pump 1 - the pump plunger 71 moves upward in this case - the input valve 54 is opened. The output valve 55 and the coolant valve 56 are closed in this phase. In the upper end position of the valve stem 71, the input valve 54 is then closed and initially only the

Coolant valve 56 is opened while the output valve 55 is still closed. In the initial phase of the following piston stroke, the fluid 57 present in the pump chamber is thus initially supplied via the coolant line 15 to the coil 13 in order to cool it. Shortly thereafter, the output valve 55 is opened so that the fluid 57 flows outside via the regular pump outlet. In the further course of the piston stroke, the coolant valve 56 can be closed again. It could also remain permanently open, so that further a part of the fluid 57 flows through the coil 13. The diaphragm pump illustrated in FIG. 6 has the significant advantage that the fluid 57 delivered by the pump can be used simultaneously as a coolant. A separate or completely separate coolant circuit with an additional coolant pump is not required.

Instead of an electrically controllable inlet valve 54 could also be a pure

mechanical valve can be used with an automatic inlet function. The inlet valve 54 need not be controlled in this case. Correspondingly, the coolant valve 56 can also be of a purely mechanical nature, since the waveguide lines 15, 17 and the magnet coil 13 in total have a significantly higher flow resistance than the outlet valve 55 activated for passage. In this case, it would be sufficient to correct only the outlet valve 55 in time drive.

Claims

claims

Electromagnetic actuator (1), comprising:

a drive unit (28) having an electrical coil (13) for generating a magnetic field and an armature (10) actuated by the magnetic field generated by the coil (13),

a chamber (27, 52) having an inlet and an outlet through which a fluid (57) flows

an actuating element (29) driven by the drive unit (28), by means of which the fluid (57) flowing through the chamber (27, 52) can be controlled,

characterized in that

• The coil (13) is made of a waveguide and

• A coolant line (15) is provided, which opens at an input side of the chamber (27, 52) and is also in communication with the waveguide of the coil (13), so that a part of the fluid flowing through the chamber (27, 52) (57) can be branched off from the chamber (27, 52) and passed through the coil (13) to cool the coil (13).

Electromagnetic actuator (1) according to claim 1, characterized in that a second coolant line (17) is provided, which discharges the heated fluid flowing out of the coil (13).

Electromagnetic actuator (1) according to claim 1, characterized in that in the coolant line (15, 17) at least one electrical insulator (20) is arranged.

Solenoid valve, characterized in that it has an electromagnetic

Actuating device (1) according to one of the preceding claims.

Solenoid valve according to claim 4, characterized in that it has a valve opening (24) which is dimensioned so that the pressure drop between a fluid inlet and a fluid outlet is sufficiently large to a fluid flow through the coolant line (15) and the To ensure coil (13) when the solenoid valve is fully open.

6. Solenoid valve according to claim 5, characterized in that it has at the fluid inlet of the chamber (27) has a first portion with a larger fluid cross section and a second portion (25) with a significantly smaller fluid cross section.

7. Solenoid valve according to claim 6, characterized in that the coolant line (15) opens at the first section.

8. Solenoid valve according to claim 6, characterized in that the coolant line (15) opens at the second section.

9. membrane pump with a chamber (52) arranged in the membrane (53),

characterized in that the diaphragm pump comprises an electromagnetic actuator (1) according to one of the preceding claims 1 to 3.

10. A diaphragm pump according to claim 9, characterized in that at the

Coolant line (15) a valve (56) is provided.