TWI603353B - Elektromagnetische stellvorrichtung und kombination von elektromagnetischer stellvorrichtung und motorspindel - Google Patents

Description

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

The present invention relates to an electromagnetic adjustment apparatus 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 using a relative The axis radially 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 disk is arranged between two counteracting 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 motion 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 consisting of an armature, two inner pole pieces, two outer pole pieces, two permanent magnets and a coil, wherein the armature and the inner pole piece and the outer pole piece An air gap system is formed which is formed by four axially variable magnetic air gaps which are of equal size 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 an electromagnetic solenoid for achieving a large holding force at a stable end position. 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 device of the type described in the opening paragraph which is relatively stable in the case of no current excitation at both ends and which absorbs 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 to achieve the above object of the present invention is an electromagnetic adjustment device having the features listed in claim 1 of the patent application. An advantageous design of the adjusting device can be found in items 2 to 9 of the patent application.

According to the present invention, the electromagnetic adjustment apparatus includes: a housing including an armature movable between two end positions in the housing along an axis, the armature having two spaced apart from each other and electrically connected An armature disk to which the pivot rod is fixedly coupled; at least one magnetic system including an annular mechanism of a plurality of permanent magnets radially polarized with respect to the axis, the magnetic system being disposed in a manner fixed to the housing Between the armature disks and the armature disks, there are a plurality of axially variable gases 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 of the two end positions only by the permanent magnet flux without the coil being excited. And the coil can be moved from any end position to the opposite end position when the coil is energized.

An advantage of the adjustment device of the present invention is that the armature can be made of a simple element, which can be constructed of a magnetically conductive material, such as a soft magnetic material, and the armature rod can be constructed of a non-magnetic material or a non-soft magnetic material. The armature impact load constructed in this way extends the service life of the adjustment device.

One or more permanent magnets are arranged in the housing in such a way as to be embedded between several pole bodies, so as to be protected from 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. The permanent magnet is arranged between the plurality of pole bodies and adjacent to the armature disk, so that the holding force when the coil is not excited by the current can be increased. 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 coil adopt 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 coil are disposed between an inner pole body and an outer pole body which are formed of a soft magnetic material and have a closed loop shape. The axial thicknesses of the armature disks are preferably equal, but may also be unequal to achieve different holding forces in the two end positions.

According to another aspect of the present invention, at least one armature disk may be cylindrical and disposed in a single-sided closed cylindrical chamber of the housing, wherein the periphery of the armature disk is sealed by the The wall of the chamber is isolated. In this way, the chamber forms a closed space with the armature disk, in which case the medium (preferably air) contained in the space enters the armature disk. 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 oriented coaxially with the spindle, and wherein the armature is engagable with a longitudinal bore of the spindle The axially movable tappet is engaged, and the clamping device is movable toward the release position against the elastic 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‧‧‧Electrical rod

7‧‧‧ armature disk

8‧‧‧ armature disk

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 housing 1 is provided with an armature 5 arranged in a movable manner along this axis, which consists of an armature rod 6 and armature discs 7, 8 fixedly connected thereto and arranged at a distance from each other. 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 by a radial distance are provided in an intermediate space between the armature disks 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, 11 and the armature disks 7 and 8 form two. Magnetic system. 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 coil 12. Alternatively, the permanent magnets may be arranged side by side at one end of the coil 12 and preferably at one end adjacent to the armature disk 7, and the permanent magnets may also be separated by a single one. A permanent magnet having a corresponding strength, such as a ring magnet.

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

The diodes 10, 11 and the armature disks 7, 8 are all 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.

An armature disk 7 adjacent to the bottom 3 of the housing is disposed in a chamber 16 formed by the housing 1 and a sliding bushing 9 surrounding the armature disk, the armature disk being sealed by a sealing ring 17 and a sliding bushing 9 isolated. With this solution, when the armature disk 7 moves toward the bottom 3 of the casing, the air between the casing bottom 3 and the armature disk 7 is compressed. Thereby, the end position which restricts the movement of the pair of armatures 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 steered 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 disk 7 and holds the armature 5 at the end position by the 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.

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 disk 8, so that the armature 5 Move to the left. 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 rod 6 snaps into the longitudinal bore 27 in the mandrel 25, and in the retracted position of the armature 5 back to the housing 1, the end face of the end is at a very small distance The heads 35 of the rods 32 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 to be rotated by the mandrel 25 during machining and together with the mandrel The rotating 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 disk 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 fixed, 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 moves toward the position further protruding from the casing 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 is pinned. 33 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 inserting a new tool 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‧‧‧Electrical rod

7‧‧‧ armature disk

8‧‧‧ armature disk

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 (9)

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 from each other and An armature disk (7, 8) fixedly coupled to the armature rod (6); there are two magnetic systems including one or more rings of permanent magnets (13, 14) radially polarized with respect to the axis a magnetic mechanism disposed between the armature disks (7, 8) in a manner fixed to the housing and having a plurality of axially variable air gaps (L1, L2) with the armature disks An air gap system; and a toroidal coil (12) that is coupled to the magnetic system and connectable to the power source, wherein the magnetic system and the air gap system are designed such that the armature (5) is at the coil (12) Clamping in either of the two end positions without being energized, and moving from any of the end positions to the opposite end position when the coil (12) is energized, wherein The two magnetic systems each have an annular mechanism of permanent magnets that are radially polarized and disposed on opposite sides of the coil (12). 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. The adjusting device according to claim 1 or 2, wherein the magnet system or the magnet system has a radially inner pole body and a radially outer pole body (10, 11) made of a magnetic flux conductive material. An adjusting device according to claim 3, 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. An adjusting device according to claim 3, characterized in that a radial outer pole body (11) surrounds the permanent magnet or the permanent magnets (13, 14) and the coil (12) in a ring shape. The adjusting device according to claim 1 or 2, characterized in that the axial thicknesses of the armature disks (7, 8) are different. An adjusting device according to claim 1 or 2, characterized in that an armature disk (7) Cylindrical and disposed in a single-sided closed cylindrical chamber (16) of the housing, and the periphery of the armature disc (7) is sealed by the seal (17) and the chamber (16) The wall is isolated. The adjusting device according to claim 1 or 2, wherein the casing (1) is made of a non-magnetic material. A combination of an adjustment device (20) according to claim 1 or 2 and a motor spindle (21), the motor spindle including an electric motor and a heart that can be rotationally driven by the electric motor in the spindle housing (22) 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 elastic force.