JPH0669285B2 - Linear motor propulsion device - Google Patents

Description

The present invention relates to a so-called linear motor that moves a slider along a predetermined movement path, and more particularly to a plurality of linear motors arranged along the movement path. The present invention relates to a linear motor propulsion device that controls the excitation state of a coil.

(Prior Art) A linear motor uses a magnetic force between a slider to which a fixed magnetic pole is attached and a plurality of coils arranged along a moving path of the slider as a driving force. A propulsion device for a linear motor is installed for the purpose of controlling the excitation state of the plurality of coils and smoothly moving the slider to a desired position.

Therefore, the propulsion device of the linear motor, as a basic configuration,
A detection unit for detecting the relative position between the fixed magnetic pole attached to the slider and the coil and a current control unit for controlling the exciting current flowing through the coil according to the detection result of the detection unit are provided.

Hereinafter, a configuration of a conventional linear motor propulsion device will be briefly described with reference to the drawings.

FIG. 3 is a schematic explanatory view schematically showing a configuration of a conventional linear motor propulsion device. As shown in the figure, a plurality of coils 52 are regularly arranged along the movement path 50 at regular intervals. A Hall element 58 is attached to each end of each coil 52 in order to detect the relative positional relationship with the fixed magnetic pole 56 attached to the slider 54.

Since the Hall element 58 has a characteristic of generating an electromotive force proportional to the strength of the magnetic field, when the slider 54 enters from the direction of the arrow, the fixed magnetic pole 56 attached to the slider 54 attaches the Hall element 58. An electromotive force is generated when the position is reached. Therefore, the controller 60, which receives the detection signal of the Hall element 58, easily amplifies the electromotive force and passes the exciting current to the corresponding coil 52 to easily generate a magnetic flux that repels or attracts the fixed magnetic pole 56. be able to.

With the linear motor propulsion device configured in this manner, the slider 54 can smoothly move along the movement path 50.

(Problems to be Solved by the Invention) However, as shown in FIG. 3, the conventional linear motor propulsion apparatus is provided with the hall element 58 for each coil 52 arranged in the movement path 50, and for each coil 52. Hall element 58 is provided,
Moreover, the exciting current can be controlled for each coil 52.

Therefore, the wiring between the controller 60 of the propulsion device of the linear motor and the coil 52 and the hall element 58 arranged in the movement path 50 is complicated. This relationship is also clear from FIG.

In addition, since the excitation current is controlled independently for each coil 52, the number of driver circuits required for current control is the same as that of the coil 52, which makes the device large, complicated, and expensive. I am letting you. This becomes a big problem with the extension of the moving path 50, and is also a factor that refuses the introduction of the linear motor.

Further, as shown in FIG. 3, when the Hall element 58 is arranged at the end portion of the coil 52 and the slider 54 moves in the arrow direction of FIG. 3, the fixed magnetic pole 56 of the slider 54 causes the fixed magnetic pole 56 of the coil 54 to move. Before reaching the top, the Hall element 58 will detect the approach of the fixed magnetic pole 56. As a result, the coil 52
Before the induced electromotive force is generated by the fixed magnetic pole 56, the controller 60 supplies the exciting current to the coil 52, an excessive current (short-circuit current) flows to the controller 60, and a large electrical load is applied to the device. It will be.

Therefore, in the conventional linear motor propulsion device, the electric capacity of the driver circuit in the controller 60, the coil 52, and the like must be set to a large value, which causes a problem that the device becomes large.

On the other hand, in order to solve this problem, for example, as shown by the dotted line in FIG. 3, when Hall elements 58 are provided at both ends of the coil 52 and both Hall elements 58 detect the approach of the fixed magnetic pole 56, That is, when the fixed magnetic pole 56 reaches the coil 52, it is conceivable to supply an exciting current from the controller 60 to the coil 52. In this case,
Wiring becomes more complicated, and the price of the device is to be increased.

The present invention has been made to solve the above problems left in a propulsion device for a linear motor, and reduces the number of necessary components such as current drivers and Hall elements, simplifies the configuration, and reduces wiring. It is an object of the present invention to provide a propulsion device for a linear motor that can achieve the simplification and cost reduction of the slider, and can smoothly move the slider as in the conventional case.

(Means for Solving the Problem) That is, according to the present invention made to solve the above-mentioned problem, a plurality of coils arranged along the moving path is appropriately used to move the slider along a predetermined moving path. A propulsion device for a linear motor that is excited to generate a magnetic field that attracts or repels a fixed magnetic pole fixed to the slider, in which two continuous coils are generated among the coils arranged along the movement path. And a relative position between the fixed magnetic pole of the slider and the coil pair is detected in the vicinity of the central portion of each coil pair on the moving path, in such a manner that the magnetic fields are connected in series so as to be in opposite directions. For each of the coil pairs, and controls the exciting current supplied to the coil pairs based on the detection result of the detecting means. Further comprising a current supply means, and the gist of the propulsion system for a linear motor according to claim.

(Operation) In the linear motor propulsion apparatus of the present invention configured as described above, the magnetic fields generated by two continuous coils of the coils arranged along the movement path are in opposite directions. When the exciting current is supplied to the coil pair, the coils forming the coil pair, that is, the two coils continuously arranged along the moving path have different magnetic poles. It becomes the electromagnet.

On the other hand, the detection means detects the relative position between the fixed magnetic pole of the slider and the coil pair. The detection means is arranged near the center of each coil pair on the movement path.
Therefore, no matter which direction the slider moves along the movement path, when the fixed magnetic pole of the slider reaches one of the two coils forming the coil pair, the approach of the fixed magnetic pole can be detected. Become.

Then, the exciting current control means provided for each coil pair controls the exciting current supplied to the coil pair based on the detection result of the detecting means.

Therefore, in the linear motor propulsion device of the present invention,
Whichever direction the slider moves along the movement path, the detection means detects the approach of the fixed magnetic pole when the fixed magnetic pole of the slider reaches one of the two coils forming the coil pair. Even if the exciting current control means supplies the exciting current to the coil pair at the detection timing, a short circuit current may flow in the exciting current supplying means because the induced electromotive force due to the fixed magnetic pole has already been generated in the coil pair. It is prevented.

Hereinafter, in order to more specifically describe the linear motor propulsion device of the present invention, a detailed description will be given with reference to examples.

(Embodiment) FIG. 1 is a schematic perspective view of a linear motor adopting the propulsion device of the embodiment. As shown in the figure, in the propulsion apparatus of this embodiment, a large number of coil pairs 4 configured as follows are arranged on the moving path 2.

Coil pair 4 means two coils 4 whose outer shape is substantially rectangular.
The long sides of a and 4b are joined together to form a substantially "8" shape. Also, electrically, the two coils 4a and 4b are
The coils are connected in series so that the magnetic fields generated by the coils 4a and 4b are in opposite directions. Therefore, physically there are two coils 4
Although it is composed of a and 4b, it is electrically configured to have only one connection terminal, and this connection terminal is connected to the controller 6.

A Hall element 8 is provided at the center of the movement path edge of each coil pair 4, that is, at the joint between the two coils 4a and 4b, and the output terminal of the Hall element 8 is connected to the controller 6.

The other components, the slider 10 and the slider 10
The structure of the fixed magnetic pole 12 attached to the same is the same as the conventional one (see FIG. 3).

As is clear from the above configuration and comparison between FIG. 1 and FIG. 3, the linear motor propulsion apparatus according to the present embodiment has the moving path 2
The wiring that connects the controller 6 and the movement path 2 is greatly simplified compared to the number of coils provided above. That is, the controller 6 has a function of executing the control of the exciting current for each coil pair 4, and the control is achieved by one wiring for each of the two coils 4a and 4b. Also,
Since the Hall element 8 is provided for each coil pair 4, it is sufficient to provide only one for the two coils 4a and 4b as in the above.

In other words, even if the same number of coils are arranged in a row on the moving path, the linear motor propulsion apparatus of this embodiment is more advantageous than the configuration of the conventional linear motor propulsion apparatus (FIG. 3). The target of which the controller 6 controls the exciting current and the Hall element 8 to which the detection signal is input are completely halved.

Next, the operation of the linear motor propulsion apparatus of the present embodiment configured as described above will be described.

FIG. 2A is an electromagnetic view of the linear motor of FIG. 1 in order to facilitate understanding of the magnetic induction action acting between the propulsion device of the linear motor of the embodiment and the fixed magnetic pole 12 attached to the slider 10. It is an explanatory view of an operation drawn from different viewpoints. Further, in order to facilitate comparison with a conventional linear motor propulsion device, FIG. 2 (B) shows an operation explanatory diagram electromagnetically depicting the conventional linear motor propulsion device (FIG. 3). There is. Note that u, v, and w in the figure are the phases of a three-phase power supply.

As shown in FIG. 2, the fixed magnetic poles 12 attached to the slider 10 are alternately arranged N along the direction of the movement path 2 (50).
The poles and the S poles are arranged so that the attraction force and the repulsion force are alternately generated between the coil pair 4 (coil 52) arranged on the movement path 2 (50) to efficiently move. Has been done.
That is, the coil arranged on the moving path 2 (50) path is N when viewed magnetically along the path direction.
It will be excited so as to generate magnetic fields that are different from those of the poles and the S poles.

The propulsion device of the linear motor of this embodiment is constructed by paying attention to this regularity, so that the two coils 4a and 4b, which are continuous in advance along the moving path, generate magnetic fields in opposite directions. The coils are connected in series to form a coil pair 4.

Therefore, the controller 6 only controls the exciting current of one coil pair 4 to configure the coil pair 4.
Control of the excitation current of the two coils 4a, 4b is achieved. Therefore, for the number of wires between the controller 6 and the coil pair on the moving path 2 and the total number of drivers for controlling the exciting current that the controller 6 should have, it is sufficient to prepare only one for the coil pair 4, and the conventional controller Compared with the 60, the wiring has been greatly simplified, the size and weight have been reduced, and the cost has been reduced.

Further, since it is sufficient to provide the Hall element 8 for each coil pair 4 whose excitation current is to be controlled, the number of elements is halved as compared with the conventional case, and the simplification of wiring is achieved accordingly.

That is, in the linear motor propulsion apparatus of this embodiment,
As shown in FIG. 1, since the Hall element 8 is arranged at the joint portion of the coils 4a and 4b forming the coil pair 4, no matter which direction the slider 10 moves on the movement path 2, , The fixed magnetic pole 12 constitutes a coil pair 4, a coil 4a,
When any one of 4b is reached, the approach of the fixed magnetic pole 12 is detected by the Hall element 8.

Therefore, even if the controller 6 supplies the exciting current to the coil pair 4 at the timing when the approach of the fixed magnetic pole 12 is detected by the Hall element 8, the induced electromotive force by the fixed magnetic pole 12 has already occurred in the coil pair 4, This prevents the short-circuit current from flowing to the controller 6.

Therefore, according to the linear motor propulsion apparatus of the present embodiment,
Despite the configuration in which one Hall element 8 is provided for each coil pair 4, it is possible to prevent the occurrence of short-circuit current and downsize the configuration of the controller 6. The number can be greatly reduced and the wiring can be simplified.

EFFECTS OF THE INVENTION As described above in detail with reference to the embodiments, in the linear motor propulsion apparatus of the present invention, two continuous coils are generated from the plurality of coils arranged along the movement path. The magnetic poles are connected in series so that the magnetic fields are in opposite directions, and a detection means for detecting the relative position between the fixed magnetic pole of the slider and the coil pair is arranged near the center of each coil pair. The coil pair is one unit of control by the exciting current control means.

Therefore, according to the linear motor propulsion device of the present invention, the controlled object is halved, and the number of components such as the current driver and the Hall element, which are required by the number of the conventional coils, are reduced,
The configuration is simplified. Further, simplification of wiring, weight reduction of the device and cost reduction are achieved, and the propulsion device for a linear motor is excellent in operability and workability. Therefore, it is possible to easily extend the moving path of the linear motor as compared with the related art, and it is possible to construct a system having high versatility.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a linear motor that employs the linear motor propulsion device of the embodiment, FIG. 2 is an operation explanatory diagram of the linear motor drawn electromagnetically, and FIG. 1A is an operation explanatory diagram of the same embodiment. , (B) are operation explanatory views of a conventional example, and FIG. 3 is a schematic configuration diagram of a linear motor adopting a conventional linear motor propulsion device. 2,50 …… Movement path 4 …… Coil pair 4a, 4b, 52 …… Coil 6,60 …… Controller, 8,58 …… Hall element 10,54 …… Slider, 12,56 …… Fixed magnetic pole

Claims (1)

[Claims] 1. A magnetic field that attracts or repels a fixed magnetic pole fixed to the slider by appropriately exciting a plurality of coils arranged along the moving path to move the slider along a predetermined moving path. In the propulsion device for a linear motor, of the coils arranged along the moving path, two continuous coils are configured as a coil pair connected in series so that the magnetic fields generated by the coils are in opposite directions, and A detection means for detecting the relative position between the fixed magnetic pole of the slider and the coil pair is arranged near the center of each coil pair on the movement path, and the detection means is provided for each coil pair. A propulsion device for a linear motor, comprising: an exciting current supply means for controlling an exciting current supplied to the coil pair based on a detection result.