JPH0416634Y2 - - Google Patents

Description

[Detailed description of the invention] "Field of industrial application" This invention relates to a moving coil type linear motor that is used for various purposes in addition to driving various accessories of automobile bodies. The present invention relates to a linear motor equipped with brushes.

``Prior Art'' Conventionally, in linear motors that have a current collector brush on the moving coil, the current collector brush on the moving coil is fixed in order to maintain the moving coil at the stopped position without moving even if the moving coil receives a certain amount of external force when the moving coil is stopped. The movable coil was held in the stopped position by increasing the spring force and ensuring the sliding resistance of the movable coil. However, since the sliding resistance is increased, there is a problem in that the load increases accordingly during operation, and the thrust that can be extracted from the moving coil becomes small. Additionally, there was a problem in that the amount of mechanical wear due to sliding of the current collecting brush increased, resulting in decreased durability.

The brake device for a linear motor described in Japanese Utility Model Publication No. 61-10469 has a support frame 3 fixed to the side surface of a linear motor body 1 that generates a moving magnetic field, and a plurality of fixed iron cores arranged along the inner circumference of the support frame. 5 are provided at appropriate intervals, facing these fixed iron cores 5,
A movable iron core 6 that can move in the radial direction of the linear motor rod 2 is provided, and the linear motor rod 2 is connected to the movable iron core 6 via a friction plate 7 provided on the surface of the movable iron core 6 facing the linear motor rod 2. This is nothing more than a braking device for a linear motor, in which a spring 8 that exerts pressure on the movable core 6 and an excitation coil 9 that exerts an attractive force greater than the above spring force on the movable core 6 are provided between the movable cores. The spring force of the spring 8 pressing against the motor rod 2 is nullified by the attraction force of the excitation coil 9, and the braking action by the friction plate 7 and the spring 8 is canceled when the linear motor is energized and moved. Since a specially provided excitation coil 9 is required in addition to the coil that generates the magnetic field, there are serious drawbacks in that the structure is complicated and expensive due to the large number of components.

The idea described in the previous Utility Model Application Publication No. 13582/1982 is
By energizing the electromagnetic solenoid 33, the first lever 1
The motor is simply a linear motor equipped with a mechanical fixing device that allows the friction plate 21 provided at the side plate 5 to be released from contact with the side plate 27. In the conventional device described above, in order to move the movable part 3, in addition to supplying three-phase alternating current to the winding of the movable element 9, the electromagnetic solenoid 33 is energized to separate the friction plate 21 from the side plate 27. Then, the movable element 3 moves along the fixed part 1. Therefore, the conventional design requires a specially provided electromagnetic solenoid 33 in addition to the winding of the movable element 9, which has serious disadvantages in that it requires many components and is complex and expensive in structure.

Further, the conventional device disclosed in Japanese Utility Model Application Publication No. 61-65878 has a braking body 11 provided on the stator 3 side in parallel to the running direction of the movable element 1, and a braking body 11 provided on the movable element 1 side. This is nothing more than a fixing device for a movable element of a linear pulse motor, which consists of binding devices 15 and 21 that can be tightened and released freely. At the same time, since it is necessary to cut off the power to the solenoid 21 of the specially provided tightening device and stop the excitation, there are serious disadvantages in that the structure is complicated and expensive due to the large number of components.

In addition, the Utility Model Application Publication No. 61 (1989) for applications filed before the filing date of the present invention
The linear motor described in No. 117590 includes a stator 1 having a large number of magnetic pole teeth 2 made of a magnetic material at a constant pitch in the longitudinal direction, a permanent magnet 4 having magnetic poles in the longitudinal direction, and a mover having magnetic pole teeth. A movable element 3 having magnetic pole groups 5 to 8, yokes 9 and 9, and phase windings 10 to 13, and a movable element 3 facing the stator 1 while maintaining a minute gap 19, are arranged along the longitudinal direction. In a linear motor equipped with guide means 14 and 15 for guiding so that it can step, a plate spring whose base is fixed to the movable element 3 and whose tip tongue piece 20b or central part faces the magnetic pole teeth 2 of the stator 1 is used. Alternatively, a braking member 20 made of a piezoelectric element is provided, and when each phase winding 10 to 13 is not energized, the magnetic pole teeth 2 of the stator 1 are
When the stator 1 is in pressure contact with the inner circumferential surface of the stator 1 and
This is a linear motor that is mechanically configured to be spaced apart from the inner circumferential surface of the magnetic pole teeth 2 to perform stop/holding and stepping. Therefore, mover 3
There is a problem that vertical grooves 21 must be provided in the windings 10 to 10, which requires complicated machining.
When any of the energizing coils 13 are energized, vertical grooves 22 to 24 for attracting and storing the braking member 20 must be provided in a part of the longitudinal direction of the outer circumference of the mover magnetic pole groups 5 to 8, which requires even more complicated machining. The problem is that it requires

``Problems that the invention attempts to solve'' This invention was made to solve the above problems, and it provides a frictional holding force when the moving coil is stopped, reduces the frictional load when the moving coil is in operation, and A moving coil in a linear motor that has a simple structure without requiring special excitation coils or other parts other than the coil required for moving the coil, and is easy to install without requiring complicated machining. The purpose of the present invention is to provide a holding device for

"Means for Solving the Problem" For the above purpose, according to the present invention, permanent magnets are magnetized in the thickness direction and arranged along the inside of the rail so that the polarity is sequentially reversed; a stator having a power feeding pattern arranged along the inside of the rail; and a movable coil movably supported by a permanent magnet with respect to the stator, the movable coil consisting of a pair of coils; The coil is a linear motor equipped with a current collector brush that is brought into contact with the power supply pattern, and a plate spring made of a magnetic material having bent flanges at both ends and a convex center is held in the direction of movement by the bent flanges. It is positioned and attached to both ends of the moving coil in the moving direction, and when the moving coil is energized and moved, the leaf spring is attracted to the moving coil by leakage magnetic flux passing through the leaf spring from both ends of the moving coil in the moving direction. The sliding resistance of the moving coil is reduced, and when the moving coil is de-energized, the leaf spring is clamped and press-contacted to the gap between the inner upper surface of the rail and the upper surface of the moving coil. A coil retention device is provided.

"Operation" According to the above configuration, when the moving coil is stopped, the elastic force of the leaf spring presses the top of the leaf spring against the stator to hold the moving coil at the stop position, and when the moving coil is moved, the moving coil Due to the electromagnetic action of the leakage magnetic flux, the magnetic plate spring is attracted to the moving coil and forms a gap with the inner surface of the stator, reducing the frictional load. Further, when attaching the leaf spring to the moving coil, the leaf spring having bent flange portions at both ends can be attached by simply hooking the leaf spring to both ends in the moving direction of the moving coil.

"Example" Next, an example of the present invention will be described with reference to the drawings.

As shown in Figures 1A and B and Figure 2,
A magnetic leaf spring 2 is attached to the upper side surface of the moving coil 1 and inserted into the rail 6 that forms the stator, so that the moving coil 1 is guided by the permanent magnet 8 via the magnet holding part 7. Install. As shown in FIG. 1A, the leaf spring 2 has bent portions at both ends in the vertical direction, and is formed in a convex shape toward the inner surface of the rail 6 facing the upper side surface of the moving coil 1. Free state 2' shown by the dashed line in Figure A
The leaf spring 2 has a curved shape higher than the inner surface of the rail 6, but when the leaf spring 2 is inserted into the rail 6, the leaf spring 2 fills the gap between the inner surface of the rail 6 and the upper side surface of the moving coil 1. The rail 6 is clamped and pressed against the rail 6 and bent, and is pressed against the inner surface of the rail 6.

In addition, in Fig. 1 A, B and Fig. 2, 6
is an extruded rail made of a material that cannot be ferromagnetic, such as aluminum or resin, and has an inverted U-shaped cross section as a whole. Reference numeral 7 designates a magnet holding portion formed in the shape of a canopy on the inner surface of one side of the rail 6, and reference numeral 8 designates a permanent magnet held by this holding portion 7. A yoke 9 is inserted into both sides of the rail 6 from its end. A plurality of permanent magnets 8 disposed on one side of the opposing yokes 9, 9 have a flat plate shape, are magnetized in the thickness direction, and are arranged in a plurality so that their polarities are sequentially opposite to each other. 3 and 4 are a pair of coils forming the movable coil 1, and the coils 3 and 4 can move within the gap between the side surface of the magnet 8 and the side surface of the other yoke 9 in a direction perpendicular to the magnetic flux, and have an effective winding portion. The wire is wound flat so that it is perpendicular to the magnetic flux and its length is approximately half the magnetic pole of the magnet 8 (Figure 4).
Further, the coils 3 and 4 have a substantially U-shaped cross section, and the upper and lower bent portions form a sliding guide that engages with the magnet holding portion 7. Coils 3 and 4 each have a length 1.5 times the magnetic pole of magnet 8, and have a space (air core) in the center that is 0.5 times the length of the magnetic pole, so that the cross-sectional width of the linear motor is minimized. A current collecting brush 5 is attached to the space (FIG. 5). Reference numeral 10 denotes a power supply pattern arranged on the inner surface of one side of the rail 6, and has a shape as shown in FIG. 5C. That is, the power supply pattern 10 energizes the effective windings of the coils 3 and 4 when the effective windings are completely within the magnetic flux in the same direction of the magnet 8, and changes the polarity of the magnetic flux passing through the effective windings. When the polarity is reversed, the feeding pattern is formed so that the feeding polarity is reversed. Line B in Figure 5 C
indicates the trajectory of the brush 5.

The operation of the linear motor having the above configuration will be explained. As shown in FIG. 4, when the magnetic flux φ due to the N pole of the magnet 8 is directed toward you from the plane of the paper, and an upward current flows through one of the effective windings of the coil 4, the coil 4 follows Fleming's left-hand rule. As a result, it receives a force directed to the right and moves to the right as shown in FIG. Fifth
As shown in Figure A, while the effective windings of the pair of coils 4 and 3 are completely within the magnetic flux in the same direction, the current collecting brushes 5 of the coils 4 and 3 are connected to each other in the feeding pattern. 10, both coils 4 and 3 are energized. As shown in FIG. 5B, while the effective winding part of one coil 3 is passing through a region where the direction of magnetic flux changes at the joint between the magnets, the current collecting brush 5 of this coil 3 is Since the coil 3 does not contact the energized section E of the power supply pattern 10, the coil 3 is not energized. During this time, each effective winding portion of the other coil 4 is completely within the magnetic flux in the same direction.
Since the current collecting brush 5 is in contact with the energized section of the power feeding pattern 10, the coil 4 is energized. Note that in order to switch the moving direction of the coils 4 and 3, the polarity of the power source connected to the power supply pattern 10 may be reversed. The brush 5 is attached to the space in the center of the coils 4 and 3, and the tip of the brush 5 protrudes from a circular window. By moving the current collecting brushes 5 of the coils 4, 3 while contacting the surface of the power feeding pattern 10, the magnetic flux φ at the location where the coils 4, 3 are located
The direction of the current I is switched in accordance with the direction of the current I, allowing optimum energization. When the coils 4 and 3 are further moved to the right by a distance 0.5 times the magnetic pole of the magnet 8 from the position shown in FIG.
enters the energized section E, and the other brush 5 comes into contact with the energized section E, so that the energization of the coil 4 is stopped and the coil 3 is energized in the opposite direction to that shown in FIG. 5A. The two coils 4 and 3 in the movable coil 1 are alternately energized in this way, and at least one of the coils 4 and 3 is always energized.

In the present invention, when the linear motor is energized and moves, one of the two coils 3 and 4 of the moving coil 1 is always energized, so if the coil 3 is energized now, the leaf spring 2 As shown in FIG. 3, the leakage magnetic flux generated around the center of the coil 3 is attracted toward the center of the coil 3 by the magnetic force, and as shown in FIG. There will be no contact with.
A gap is created between the bent flanges at both ends of the leaf spring 2 and both ends of the moving coil 1 in the moving direction. Since the movable coil 1 has no frictional force due to the spring force of the leaf spring 2, the only sliding resistance is the sliding resistance between the brush 5 of the movable coil 1 and the power supply pattern 10, and the sliding resistance between the movable coil 1 and the rail 6 is reduced. The resistance becomes extremely small compared to when it is stopped. Since the sliding resistance of the moving coil 1 is reduced, the effective thrust of the linear motor is increased.

In the present example, since there is no need to ensure the holding force by the spring force of the current collecting brush 5, the spring force can be reduced to the value necessary for current collection, and this makes the current collecting brush 5 durable. Sexuality also improves.

Since the holding force of the leaf spring 2 is a frictional force caused by the spring force, it can be set to any value by selecting the strength of the leaf spring 2, and the movable coil 1 will be held on the rail 6 under the assumed external force. However, it has the advantage of increasing the degree of freedom in design, such as being able to move it easily by hand.

"Other Embodiments" Also, as in the second embodiment shown in FIG. 6, a material 21 with a large friction coefficient is attached to the contact portion of the leaf spring 2 with the rail 6, or as shown in FIG. As in the third embodiment, if a groove 61 is provided on the side of the rail 6 and a protrusion 22 is provided so that the shape of the leaf spring 2 fits into the groove 61, the holding force can be further increased.

``Effects'' As mentioned above, the moving coil holding device in the linear motor of the present invention is installed by positioning the leaf spring in the moving direction by the bent flanges at both ends and hooking it to both ends of the moving coil in the moving direction. ,
When the movable coil is stopped, the holding force for holding the movable coil in the stopped position is increased, and when the movable coil is slid, the sliding resistance is decreased, so that the effective thrust can be increased. Another advantage is that the structure is simple, requiring no parts such as a special excitation coil other than the coil necessary for moving the moving coil, and it is easy to install without requiring complicated machining. It has a positive effect.

[Brief explanation of the drawing]

1 to 5 show a first embodiment of the present invention, FIG. 1A is a front view showing when the moving coil is stopped, FIG. 1B is a side view of the linear motor when the moving coil is stopped, Fig. 2 is a front view showing the moving coil when it is moving, Fig. 3 is a perspective view of the moving coil when it is moving, Fig. 4 is a perspective view showing the operating principle of a linear motor, and Fig. 5 A, B, and C are linear motors. Fig. 5A and B are cross-sectional views;
Figure C is a front view of the power feeding pattern. FIG. 6 is a front view showing the second embodiment, and FIG. 7 is a front view showing the third embodiment. 1... Moving coil, 2... Leaf spring, 3, 4...
Coil, 5... Current collection brush, 6... Rail forming a stator, 8... Permanent magnet, 10... Power feeding pattern.

Claims (1)

[Claims for Utility Model Registration] Permanent magnets magnetized in the thickness direction and arranged along the inside of the rail so that their polarities are sequentially opposite, and a power supply pattern arranged along the inside of the rail. and a movable coil movably supported by a permanent magnet with respect to the stator, the movable coil consisting of a pair of coils, the pair of coils having a current collecting brush in contact with the power feeding pattern. In the linear motor, a magnetic plate spring having bent flanges at both ends and a convex center is positioned in the moving direction by the bent flanges and hooked to both ends in the moving direction of the movable coil. Attachment: When the movable coil is energized and moved, the leaf spring is attracted to the movable coil by leakage magnetic flux passing through the leaf spring from both ends of the movable coil in the direction of movement, thereby reducing the sliding resistance of the movable coil; 1. A holding device for a moving coil in a linear motor, characterized in that when the moving coil is de-energized, the leaf spring is clamped and pressed into a gap between an inner upper surface of the rail and an upper surface of the moving coil.