TW201443942A - Electromagnetic actuating device and combination of electromagnetic actuating device and motor spindle - Google Patents

Abstract

The invention relates to an electromagnetic actuating device with a housing (1) and an armature (5) which can be moved in the housing (1) between two end positions and which has two mutually spaced armature disk (7, 8) and an armature shaft (6). Two annular arrangements of permanent magnets (13, 14) which are polarized radially in the same direction with respect to the axis are secured to the housing between the armature disks (7, 8) and together with the armature disks form two magnet systems and an air gap system with axially adjustable air gaps (L1, L2). An annular coil (12) which can be connected to a power source is arranged between the two permanent magnets (13, 14). The magnet systems and the air gap system are configured such that the armature (5) can be retained in each of the two end positions without exciting the coil (12) and can be moved from one respective assumed end position into the opposite end position by exciting the coil (12).

Description

Electromagnetic adjustment device and combination of electromagnetic adjustment device and motor spindle

The present invention relates to an electromagnetic adjustment device comprising an armature movable between two end positions in a housing along an axis, at least one magnetic system and a coil connectable to a power source, the at least one magnetic system being The axially polarized permanent magnets are connected and form an air gap system with the armature. The invention also relates to a combination of an electromagnetic adjustment device and a motor spindle.

DE 197 12 293 A1 discloses an electromagnetic adjustment device comprising two magnetic systems spaced apart from one another and each having an excitation coil, between which an armature disk fixedly connected to the adjustment rod is arranged. The armature disc is arranged between two counter-acting springs and is movable by these magnetic systems to two operating positions. One of the magnetic systems is assigned a permanent magnet that is polarized in the direction of movement of the armature, which stabilizes the armature in an uncharged state in an operating position. To maintain the armature in another operating position, it is permanently energized.

EP 0 568 028 A1 also discloses an electromagnetic linear motor comprising an armature, two inner pole pieces, two outer pole pieces, two permanent magnets and a coil, wherein the armature forms an integral with the inner pole piece and the outer pole piece An air gap system consisting of four axially variable magnetic air gaps having equal sizes in the intermediate position. These permanent magnets stabilize the armature in an intermediate position where the coil is not charged. These pole pieces are half-shell shaped and form two fixed polarization magnetic systems with these half-shell permanent magnets.

DE 200 00 397 U1 also discloses a magnet arrangement which has a magnetically conductive outer a casing in which an iron core and a coil surrounding the core are disposed in an axially movable manner. Permanent magnets arranged coaxially with the coil are arranged on both sides of the coil, which are arranged with their same magnetic poles facing each other. These permanent magnets form two magnetic circuits for holding the core in two working positions. By energizing the coil in one or more current directions, the core can be moved to another working position, and the core remains in this position when the coil is not energized. Based on the cylindrical shape of the core and the polarization of the permanent magnet, there is no large holding force in the working position.

DE 102 07 828 B4 discloses a method for achieving a large hold at a stable end position Force electromagnetic solenoid. Such a solenoid consists of a stator with two magnetic systems spaced axially apart, each having an excitation winding for generating an electromagnetic flux. An armature is disposed between the two magnetic systems that carries a permanent magnet mechanism that is polarized perpendicular to its direction of motion and that is used to permanently retain the armature when the excitation winding is uncharged. The permanent magnet mechanism is disposed between the two excitation windings, so its efficiency is adversely affected by the leakage flux. In addition, the generally porous material of the permanent magnet mechanism may be damaged by the impact movement of the armature.

It is an object of the present invention to provide an electromagnetic adjustment of the type described in the opening paragraph The device is relatively stable in both ends without current excitation and can absorb a large holding force at least in one end. Furthermore, the adjustment device is easy to manufacture and has a low manufacturing cost.

The solution of the present invention for achieving the above object is a patent application Electromagnetic adjustment device with the features listed in item 1. An advantageous design of the adjusting device can be found in items 2 to 9 of the patent application.

According to the invention, the electromagnetic adjustment device comprises: a housing comprising An armature that moves between two end positions in the housing, the armature having two armature discs spaced apart from each other and fixedly coupled to the armature rod; at least one magnetic system, the magnetic system including a plurality of axes An annular mechanism for a polarized permanent magnet, the magnetic system being disposed between the armature plates in a manner fixed to the housing and having a plurality of axially variable gases with the armature plates a gap air gap system; and an annular coil disposed between the two magnetic systems and connectable to a power source. The magnetic system and the air gap system adopt a design such that the armature can be clamped in either end position of the two end positions only by the permanent magnet flux without the coil being excited. The coil can be moved from either end position to the opposite end position if the coil is energized.

An advantage of the adjustment device of the invention is that the armature can be made of simple elements. The two armature discs may be formed of a magnetic flux conductive material, such as a soft magnetic material, and the armature rod may be composed of a non-magnetic material or a non-soft magnetic material. The armature impact load constructed in this way prolongs the service life of the adjustment device.

One or more permanent magnets are disposed in the housing in a manner interposed between the plurality of pole bodies Medium, thus protecting against dynamic loads. With such an arrangement, the permanent magnet can be constructed from a plurality of annularly arranged single magnets or as a ring magnet. Magnets can also be made of sensitive magnet materials, such as composite materials, to increase polarization and field strength. Arranging the permanent magnet between several pole bodies and abutting the armature disc can increase the holding force when the coil is not energized by the current. In addition, using only a single coil reduces manufacturing costs and reduces volume.

According to a preferred embodiment of the present invention, the armature, the magnetic system, and the line The circle adopts a rotationally symmetric construction scheme. Other designs are also available. Two magnetic systems may be provided which include permanent magnets that are symmetrically arranged in the radial midline plane of the coil and that are radially polarized in the same direction.

According to another aspect proposed by the present invention, the magnet or the magnets and the line The ring is disposed between an inner pole body and an outer pole body which are composed of a soft magnetic material and have a closed loop shape. The axial thicknesses of the armature discs are preferably equal, but may also be unequal to achieve different retention forces in the two end positions.

According to another aspect proposed by the present invention, at least one armature disc may be cylindrical and Arranged in a single-sided closed cylindrical chamber of the housing, wherein the periphery of the armature disc is isolated from the wall of the chamber by a seal. In this way, the chamber forms a closed space with the armature disc, in which case the medium (preferably air) contained in the space enters the armature disc. The space is compressed such that the armature decelerates in a path that moves toward the end position along the direction of motion and suppresses reaching the end position. Experimental accidents have shown that the use of a relatively small air volume is sufficient to effectively suppress the impact of the armature.

According to the invention, the housing of the adjustment device which also forms the chamber is preferably constructed of a non-magnetic material to prevent leakage flux from occurring and to concentrate the flux to the armature.

According to claim 10, a particularly advantageous application of the adjustment device of the present invention includes a combination with a motor spindle that includes an electric motor and a spindle that can be rotationally driven by the electric motor in the spindle housing. The mandrel has a tool holder for a cutting workpiece machining tool, wherein the mandrel is constructed as a hollow shaft and has a spring force in its longitudinal bore in a closed position and is used to clamp the tool or tool holder a quick clamping device, wherein the housing of the adjusting device is fixed on the spindle housing having an axis coaxial with the spindle, and wherein the armature is engageable with a longitudinal bore in the spindle The axially moving tappets are engaged and the clamping device is movable towards the release position against the spring force.

With the combination of the present invention, it is not necessary to arrange an adjustment device that is expensive and has many drawbacks, which are pneumatically or hydraulically driven, and such adjustment devices are typically used to manipulate the tool clamping device in the motor spindle. With the adjustment device of the invention it is possible to achieve an adjustment force sufficient to squeeze the spring clamping element of such a tool clamping device and release the clamping device, while being suitable in volume and weight. With the device according to the invention, the holding force required to hold the tool clamping device in the release position can also be produced by means of permanent magnets, so that the coil can only be short-lived when the tool clamping device needs to be released and returned to the clamping position. Manipulation.

Thus, the combination of the present invention achieves a motor spindle that requires only drive energy, i.e., current to clamp and loosen the tool, and to drive the tool used to carry out the machining process.

As described in this embodiment, the adjustment device can be mounted directly to the motor spindle. However, the present invention does not exclude embodiments in which the adjustment or adjustment force is transmitted to the motor spindle by a mechanical transfer system such as a push-pull cable or a hydraulic transfer system. Hydraulic transfer system helps to reduce the motor core The weight of the shaft.

1‧‧‧shell

2‧‧‧Drilling

3‧‧‧Bottom of the casing

4‧‧‧ Cover

5‧‧‧ Armature

6‧‧‧Chapter

7‧‧‧ Armature plate

8‧‧‧ Armature plate

9‧‧‧Sliding bushing

10‧‧‧ polar body, inner body

11‧‧‧ polar body, outer body

12‧‧‧ coil

13‧‧‧ permanent magnet

14‧‧‧ permanent magnet

16‧‧‧ chamber

17‧‧‧Seal ring, seal

20‧‧‧Adjustment device

21‧‧‧Motor spindle

22‧‧‧ mandrel housing

23‧‧‧ stator winding

24‧‧‧ rolling bearings

25‧‧‧ mandrel

26‧‧‧Rotor

27‧‧‧ longitudinal drilling

28‧‧‧Conical drilling

29‧‧‧Tool cone

30‧‧‧tool holder

31‧‧‧Quick clamping device, clamping device

32‧‧‧Tungsten

33‧‧‧ pin

34‧‧ ‧ disc spring

35‧‧‧ head

36‧‧‧stop ring

F‧‧‧ arrows, force

L1‧‧‧ air gap

L2‧‧‧ air gap

1 is a cross-sectional view of the electromagnetic adjusting device of the present invention; FIG. 2 is a schematic view showing a field force line for generating an adjusting force in a first direction when the coil is charged; FIG. 3 is a diagram showing the coil being uncharged and in the case shown in FIG. Schematic diagram of the field force line when the magnetic holding position; FIG. 4 is a schematic diagram of the field force line generating the adjusting force in the second direction when the coil is reversely energized; and FIG. 5 is a motor spindle provided with the adjusting device of the present invention. Cross-sectional view.

The invention will now be described in detail in connection with a number of embodiments.

The electromagnetic adjustment device shown in Fig. 1 comprises a cylindrical casing 1 having a cylindrical bore 2 extending along an axis, one end of which is closed by the bottom 3 of the casing and the other end is fixed to the casing The cover 4 on 1 is closed. The armature 5, which is arranged in a movable manner along the axis, is provided in the housing 1 and consists of the armature rods 6 and the armature discs 7, 8 which are fixedly connected thereto and are arranged at a distance from one another. The armature rod 6 passes through the bore 2 in the cover 4 and is movable in the bore. The armature discs 7, 8 have parallel side and cylindrical side areas for supporting them in the sliding bushing 9, which are arranged in the bore 2 of the housing 1.

An annular inner pole body 10 and an annular outer pole body 11 spaced apart from each other are provided in an intermediate space between the armature plates 7, 8. A coil 12 having at least one winding is disposed in the annular space between the diodes 10, 11, and a permanent magnet 13, 14 is disposed at each end of the coil 12. The two permanent magnets 13 and 14 are radially polarized in the same direction, so they are polarized transversely to the direction of movement of the armature 5, and the two permanent magnets and the pole bodies 10 and 11 and the armature plates 7 and 8 constitute two magnetic systems. . The permanent magnets 13 , 14 are arranged annularly around the pole body 10 and can be constructed as a ring magnet or constructed as the same A mechanism for a single magnet that is polarized. The pole bodies 10, 11 are fixedly connected to the permanent magnets 13, 14, and the outer pole body 11 is axially fixed in the casing 1 by means of a sliding bushing 9 supported on the bottom 3 of the casing and the cover 4.

The permanent magnets 13, 14 are arranged symmetrically with respect to the coils 12. Alternatively, the permanent magnets may be arranged side by side at one end of the coil 12 and preferably adjacent to one end of the armature disc 7, and the permanent magnets may also be provided by a single one. A permanent magnet of corresponding strength, such as a ring magnet.

An axially variable air gap L1, L2 of an air gap system is respectively disposed between each armature disc 7, 8 and an adjacent side of the adjacent permanent magnets 13, 14 and the pole bodies 10, 11, wherein Each air gap L1, L2 is assigned a magnetic system.

The diodes 10, 11 and the armature discs 7, 8 are made of a material having good magnetic flux transmission properties, in particular, a soft magnetic material. The armature rod 6 can also be constructed of a magnetic flux conducting material, but is preferably constructed of a non-magnetic material to prevent leakage flux from occurring. The casing 1, the cover 4 and the sliding bushing 9 are also made of a non-magnetic material.

The armature disc 7 adjacent to the bottom 3 of the housing is arranged in a chamber 16 formed by a housing 1 and a sliding bushing 9 surrounding the armature disc, the armature disc being insulated from the sliding bushing 9 by a sealing ring 17. With this solution, when the armature disc 7 moves toward the bottom 3 of the housing, the air between the bottom 3 of the housing and the armature disc 7 is compressed. Thereby, the end position which reaches the limit of the movement of the armature 5 toward the bottom 3 of the casing can be effectively suppressed.

In the above electromagnetic adjusting device, the armature 5 can be held by the magnetic force of the permanent magnets 13, 14 in its two end positions with a relatively large force. The intermediate position of the armatures 5 having equal sizes of air gaps L1, L2 is in an unstable state. In order to move the armature 5 toward one end or the other end, the coil 12 is excited with a short current, wherein the direction of the current determines the direction of movement of the armature.

2 to 4 show the field lines of the magnetic flux in different operating states of the adjusting device. The figure shows an axial half-section of the flux conducting component.

In the example shown in Figure 2, the coil 12 is energized with a current in a direction such that the current produces a coil field that is in the same direction as the magnetic field of the permanent magnet 14. The two games complement each other and trigger one A strong electromagnetic flux that is conducted via the armature disk 7 in a manner that is deflected by the permanent magnets 13. The field of the permanent magnets 13 is weakened during this process, but it still produces force. Therefore, the armature 5 is applied with a strong force in the direction of the arrow F, and the armature moves to the right end position under its action.

Figure 3 shows the right end of the armature 5 after the de-energization of the coil 12. The permanent magnet 13 which is no longer weakened by the coil field at this time generates a strong field which contains the armature disc 7 and holds the armature 5 at the end position with a force F. The field of the permanent magnets 13 is also enhanced by a portion of the field of the permanent magnets 14. The flux of the permanent magnet 14 conducted by the right armature disk 8 is thus significantly weakened by the larger air gap L2 and thus hardly acts.

Fig. 4 is a magnetic flux curve when the coil 12 is excited by a reverse current for the reverse movement of the armature 5. In this case, the coil field enhances the field of the permanent magnets 13, weakens the field of the permanent magnets 14, and the permanent magnets 14 direct the common flux of the coils 12 and the permanent magnets 13 to the armature disc 8, such that the armature 5 faces the left end. Bit movement. The suppression effect produced by the chamber 16 during this movement is particularly effective.

The electromagnetic adjustment device described above is particularly suitable for use with a tool clamping device that operates a motor spindle. Figure 5 is a mechanism in which an electromagnetic adjustment device 20 is combined with a motor spindle 21. The motor spindle 21 is composed of a multi-component spindle housing 22, a stator winding 23, and a spindle 25 supported by a plurality of rolling bearings 24 and having a rotor 26. The mandrel 25 is provided with a continuous longitudinal bore 27 which communicates with the tapered bore 28 for receiving the tool cone 29 at the lower end in the figure. The tool cone 29 can be mounted directly to the tooling tool or can be mounted to the tool holder 30 as shown. In the longitudinal bore 27, a quick-clamping device 31 and a tappet 32 fixedly connected thereto and axially movable are provided in an axially movable manner. The quick clamping device 31 cooperates with a pin 33 fixed to the tool cone 29. In the illustrated clamping position, the pin 33 is form-fitted by the quick-clamping device 31 and pulled into the mandrel 25 by the pre-tensioned disc spring 34, thereby clamping the tool cone 29 Conical borehole 28. The disc spring 34 is disposed on the tappet 32 with one side axially supported on the head 35 of the tappet 32 and the other side supported on a stop ring 36 that abuts the shoulder in the longitudinal bore 27.

The adjusting device 20 is substantially the same as the adjusting device shown in Fig. 1, and therefore the same component symbols are used. The adjustment device 20 is fixed to the end of the spindle housing 22 remote from the tool holder 30 by means of a cover 4 . The end of the extension cover 4 of the armature 6 snaps into the longitudinal bore 27 in the mandrel 25, and in the retracted position of the armature 5 returning to the housing 1, the end face of the end is at a very small distance from the tappet 32 The heads 35 are arranged opposite each other. Also in the radial direction, there is a gap between the end of the armature rod 6 and the wall of the longitudinal bore 27, so that the armature rod 6 is not rotated by the mandrel 25 which rotates during machining and rotates together with the mandrel. The head 35 is in contact. In this position of the adjustment device 20, the tool holder 30 is clamped by the quick clamping device 31 by the force of the disc spring 34. In the case where the coil 12 is not energized by the magnetic system constituted by the permanent magnet 14 and the armature disc 8, the armature 5 is held in the retracted position.

When it is necessary to replace the tool holder 30 to which the tool is attached, after the mandrel 25 is stopped, the coil 12 is excited by a current, and under the action of the current, the armature rod 6 is moved toward the position further protruding from the housing 1 (see figure 2). During this process, the armature rod 6 comes into contact with the head 35 of the tappet 32, and presses the tappet 32 and the quick-clamping device 31 downward in the direction opposite to the force of the disc spring 34 until the pin 33 It is released by the quick clamp 31 and the tool cone 29 is released. In this way, the tool holder 30 and the tool attached thereto can be manually or automatically removed.

After the quick clamping device 31 is released, the coil 12 is uncharged, and the release position of the quick clamping device 31 is only by the permanent magnets 13, 14 in the direction opposite to the force of the disc spring 34 when the coil is not energized. Hold it (see Figure 2).

After the new tool is inserted into the tapered bore 28 of the mandrel 25, the coil 12 is reversely energized to clamp the tool, as shown in Figure 3, the armature 5 is returned to the housing 1. Among them, the pin 33 of the new tool is caught by the clamping device 31 by the disc spring 34 and clamped in the tapered bore 28 of the mandrel 25.

1‧‧‧shell

2‧‧‧Drilling

3‧‧‧Bottom of the casing

4‧‧‧ Cover

5‧‧‧ Armature

6‧‧‧Chapter

7‧‧‧ Armature plate

8‧‧‧ Armature plate

9‧‧‧Sliding bushing

10‧‧‧ polar body, inner body

11‧‧‧ polar body, outer body

12‧‧‧ coil

13‧‧‧ permanent magnet

14‧‧‧ permanent magnet

16‧‧‧ chamber

17‧‧‧Seal ring, seal

L1‧‧‧ air gap

L2‧‧‧ air gap

Claims (10)

An electromagnetic adjustment device comprising: a housing (1); an armature (5) movable between two end positions in the housing (1) along an axis, the armature having two distances apart from each other Iron (6) fixedly coupled armature discs (7, 8); at least one magnetic system comprising one or more annular mechanisms of permanent magnets (13, 14) radially polarized relative to the axis, the magnetic system Arranging between the armature discs (7, 8) in a manner fixed to the housing and forming an air gap system having a plurality of axially variable air gaps (L1, L2) with the armature discs; a loop coil (12) for the magnetic system and connectable to a power source, wherein the magnetic system and the air gap system adopt a design such that the armature (5) can be unenergized in the coil (12) The lower portion is clamped in either of the two end positions and can be moved from either end position to the opposite end position if the coil (12) is energized. The adjusting device of claim 1 is characterized in that the armature (5), the magnetic system and the coil (12) adopt a rotationally symmetric construction scheme. An adjusting device according to any one of claims 1 to 2, characterized in that the two magnetic systems each have a ring mechanism composed of magnets of the same radial polarization and are arranged in the coil ( 12) on both sides. The adjusting device according to any one of the preceding claims, characterized in that the magnet system or the magnet systems have a radially inner pole body and a radially outer pole body (10, 11) composed of a magnetic flux conducting material. An adjusting device according to claim 4, characterized in that a radial inner pole body (10) is in the form of a closed loop in the permanent magnet or the permanent magnets (13, 14) and in the coil (12) ) extends inside. The adjusting device according to any one of claims 4 or 5, characterized in that a radial outer pole body (11) the permanent magnet or the permanent magnets (13, 14) and the coil (12) Surrounded by a ring. An adjusting device according to claim 1 or 2, characterized in that the axial thickness of the armature discs (7, 8) is different. An adjusting device according to any one of the preceding claims, characterized in that an armature disc (7) is cylindrical and arranged in a single-sided closed cylindrical chamber (16) of the housing, and The periphery of the armature disc (7) is isolated from the wall of the chamber (16) by a seal (17). An adjustment device according to any of the preceding claims, characterized in that the housing (1) consists of a non-magnetic material. A combination of an adjustment device (20) according to any one of the preceding claims and a motor spindle (21), the motor spindle comprising an electric motor in the spindle housing (22) and a heart that can be rotationally driven by the electric motor a shaft (25) having a tool holder for a workpiece machining tool, wherein the spindle (5) is constructed as a hollow shaft and has a spring force in its longitudinal bore (27) held in a closed position and a quick clamping device (31) for clamping a tool or a tool holder (30), wherein the housing (1) of the adjusting device (20) is directly or indirectly fixed to the spindle housing (22), And wherein the armature (5) is operatively coupled to a tappet (32) axially movable in a longitudinal bore (27) of the mandrel (25) for transmitting force or motion, and The quick clamping device (31) can be moved to the release position while overcoming the spring force.