JPH07203667A - Dc linear motor and driving unit - Google Patents

Abstract

PURPOSE:To increase thrust while decreasing the thickness by coupling the armature coils integrally through resin. CONSTITUTION:Armature coils (EC) are molded of an epoxy based synthetic resin 45, for example, and coupled integrally into a substantially rectangular plate. In other words, the molding is effected using a metal mold having a rectangular planar space. The ECs are arranged in a row within the space of the mold and then molten synthetic resin 45 is injected and eventually cooled to obtain a coupled body. The thickness of the couple body is set equal to the thickness (t) of the EC. Consequently, the EC is not coated at all, on the opposite sides thereof, with the synthetic resin 45 or coated with a thin film of 0 thickness. The width B1 of the coupling body is set wider than the width B2 of the EC. Consequently, a DC linear motor can be made thin and the thrust can be increased by disposing the field magnet and the EC closely each other thereby increasing the density of flux reaching the EC.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear DC motor, which is frequently used for moving an object to be moved with high precision in a motion mechanism section such as a machine tool or an industrial robot, and to the linear DC motor. And a drive unit to which guide means for guiding an object is added.

[0002]

2. Description of the Related Art FIG. 7 shows a drive unit including a conventional linear DC motor. The drive unit is a linear DC motor to which a guide unit for guiding an object is added.

As shown in the figure, the guide unit includes an elongated base member 101 acting as a track rail,
It has a movable body 102 that moves along the base member 101 as a slide base. Specifically, the movable body 102 is provided with a plurality of rollers (not shown), and these rollers roll on a track (not shown) formed along the longitudinal direction of the base member 101.

On the other hand, the linear DC motor, which constitutes the drive unit together with the above-mentioned guide unit, is constructed as follows.

As shown, the linear DC motor is
The primary side having a large number of armature coils 107 arranged side by side on the base member 101 in the longitudinal direction of the base member 101 and the lower surface side of the movable body 102 so as to face the armature coils 107 are attached. And a secondary side having a field magnet (not shown). Each armature coil 10
7 is wound in a rectangular ring shape and adhered to the coil substrate 108, and is further fastened to the base member 101 together with the coil substrate 108 by machine screws 109. Further, the field magnet has a direction in which the movable body 102 should move,
That is, N and S along the longitudinal direction of the base member 101.
Are magnetized so that a plurality of magnetic poles are alternately arranged.

As is apparent from FIG. 8, each armature coil 107 and coil substrate 108 is composed of the armature coil 107.
With the machine screw 109 as a fastening member inserted in the base member 101, the coil substrate 108 is placed outside.
Have been tightened against. Then, each of the countersunk screws 1
A spacer 112 is inserted through 09. These zakka 1
Reference numeral 12 is for preventing the coil substrate 108 from warping or the like due to the tightening of the countersunk screw 109, and is formed in a cylindrical shape as is clear from FIG.

In the drive unit having the above structure,
By supplying a predetermined current to each armature coil 107, a thrust force based on Fleming's left-hand rule is generated between both the primary side and the secondary side. For example, if the base member 101 to which the primary side is coupled is fixed, Movable body 10 integrated with the secondary side
2 is moved by this thrust.

[0008]

In the above-described conventional linear DC motor and drive unit, the coil substrate 108 is interposed between the field magnet (not shown) and the armature coil 107. Therefore, the distance between the field magnet and the armature coil 107 is relatively large, the density of the magnetic flux reaching the armature coil 107 is reduced, and the existence of the coil substrate 108 itself also lowers the magnetic flux density to a considerable extent. This is a drawback in increasing

On the other hand, in recent years, with respect to the linear DC motor and drive unit as described above, there is a case where it is desired to reduce the size, particularly to reduce the size, in order to reduce the size of a machine tool or the like to be equipped with the same. Further, in the above-described configuration, when the armature coil 107 is fastened together with the coil board 108, the spacer 112 is fitted into each of the countersunk screws 109 to prevent the coil board 108 from being deformed by the tightening force. To do. In such a configuration, each spacer 112
Since a large number of parts have to be manufactured and handled, the number of man-hours is large, which is a problem to be solved in order to reduce the manufacturing cost.

The present invention has been made in view of the above points, and provides a linear DC motor and a drive unit which are thin and have a large thrust, and also achieve cost reduction by reducing the number of parts. It is intended to be provided.

[0011]

According to the linear DC motor of the present invention, a primary side including an armature coil group and different magnetic poles are alternately arranged and magnetized along a relative movement direction with respect to the primary side. A secondary side having a field magnet arranged so as to face the child coil, and the armature coils are integrally coupled to each other by a resin. Further, in the drive unit according to the present invention, different magnetic poles are alternately arranged along the primary side including the armature coil group and along the relative movement direction with respect to the primary side, and are arranged to face the armature coil. Linear DC motor having a secondary side having a field magnet,
And a guide means for guiding the primary side and the secondary side to each other, and the armature coils are integrally coupled to each other by a resin.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a drive unit including a linear DC motor according to the present invention will be described with reference to the accompanying drawings.
The linear DC motor is a movable magnet type.

The drive unit includes a guide unit for carrying an object to be moved and guiding it with high accuracy, and a linear DC motor as a drive means for driving the guide unit.

First, the guide unit will be described below.

As shown in FIGS. 1 to 3, this guide unit has a bed 1 formed as a whole in a substantially rectangular plate shape, and a table 2 to be moved along the longitudinal direction of the bed 1. is doing. As shown in FIGS. 1 and 3, the bed 1 is formed in a substantially rectangular plate shape on the upper surface thereof.
A coil yoke 3 having substantially the same length as the coil yoke 3 is arranged, and is fastened to the bed 1 by a plurality of bolts (with hexagonal holes: see FIG. 3) 5.

On both sides of the upper surface of the coil yoke 3, two track rails 7 are arranged along the longitudinal direction of the coil yoke 3, and a plurality of flat head screws 8 (see FIG. 3).
It is fastened to the coil yoke 3 by the reference.

As shown in FIG. 4, the track rail 7 is provided.
As a track, one track groove 7a having a substantially semicircular cross section is formed along the longitudinal direction on the outer side of the track. As is apparent from FIGS. 1 and 3, a slide member 10 as a slide base that is freely movable relative to the track rail 7 is arranged outside the track rail 7, and, for example, a plurality of slide members are provided. Bolt (with hexagon socket) 12
It is fastened to the lower surface side of the table 2 by (shown only in FIG. 3). As shown in FIG. 3, the table 2 is formed with a counterbore 2a and an insertion hole 2b through which the head and the screw of the bolt 12 are respectively inserted, and the bolt 12 has the counterbore 2a. , Is buried in the insertion hole 2b and does not project to the upper surface of the table 2.

A rolling element circulation path (not shown) is formed in the slide member 10, and a large number of balls 13 as rolling elements are arranged and accommodated in the rolling element circulation path. These balls 13 move along with the movement of the slide member 10 relative to the track rail 7.
Circulates while rolling on the track groove 7a of the track rail 7
And a load is applied between the slide members 10.

As shown in FIG. 4, the slide member 10 includes a casing 14, a pair of end caps 16a and 16b connected to both ends of the casing 14 with pan head screws 15, and the end caps 16a and 16b. 16
Two seals 17a and 17b fastened together on the outer surface of b
And have. The rolling element circulation path includes the casing 14
The load track groove and the return path formed so as to linearly penetrate in the longitudinal direction of the casing and parallel to each other, and both end portions of the load track groove and the return path formed on both end caps 16a and 16b. It is composed of a pair of substantially arcuate direction change paths that communicate with each other. The load track groove faces the track groove 7a of the track rail 7.

The guide unit having the above construction is fastened by a plurality of bolts (with hexagonal holes: not shown) to a flat mounting surface of a machine tool (not shown), for example. Therefore, as shown in FIG. 3, the bed 1 has a flat mounting bottom surface 1a for fixing the bed 1 to the mounting surface. As shown in FIGS. 1 to 3, on both sides of the bed 1, a counterbore 1b and an insertion hole 1c are formed, through which the head portion and the screw portion of the bolt for fastening the bed are respectively inserted. The bolt is buried in the counterbore 1b and the insertion hole 1c and does not project to the upper surface of the bed 1. Further, as shown in FIGS.
On the upper surface side of the movable table 2, for example, four screw holes 2c are formed at four corners, and a table (not shown) included in a device equipped with the drive unit is provided in these screw holes 2c. It is fastened to the table 2 by bolts (not shown) that are screwed together.

Next, the primary side and the secondary side of the linear DC motor mutually added with the guide unit having the above-mentioned structure will be described in detail.

First, as shown in FIGS. 1 to 3 and 5, on the primary side, the above-mentioned coil yoke 3 mounted on the bed 1 and the table 2 on the upper surface side of the coil yoke 3 are arranged. It has, for example, 14 armature coils 22 arranged in a line along the direction in which it should move.
Each armature coil 22 is wound in a substantially rectangular ring shape. Further, as shown in FIGS. 3 and 5, Hall effect elements 43 are provided corresponding to each armature coil 22.

As shown in FIGS. 1 to 3 and FIG.
Each of the armature coils 22 is made of synthetic resin 4 such as epoxy resin.
It is molded together with 5 and the like and is integrally connected to each other. As is particularly clear from FIG. 5, the combined body of the armature coil 22 and the synthetic resin 45 is formed into a substantially rectangular plate shape as a whole. That is, the molding is performed using the mold having the rectangular plate-shaped mold space, and the armature coils 22 are arranged in a line in the mold space,
After injecting the synthetic resin 45 in a heated and molten state, the synthetic resin is cooled and solidified to obtain the above-mentioned combined body.

As is apparent from FIG. 3, the thickness of the above-mentioned combined body is set to be equal to the thickness t of the armature coil 22. Therefore, the synthetic resin 45 is not coated on the upper and lower surfaces of the armature coil 22 at all, or is coated as a thin film having almost zero thickness. Also,
As shown in the figure, the width B ₁ of the above-mentioned combination is set to be considerably larger than the width B ₂ of the armature coil 22. One of the left and right side surfaces of the armature coil 22 is not covered with the synthetic resin 45 at all, or is covered with a thin film having a thickness of almost zero, and the other side surface is covered with a relatively large dimension C. It is designed to be put out.

As shown in FIG. 3, the synthetic resin 45 is also filled in the hollow portion of the armature coil 22, and this filled portion is indicated by reference numeral 45a. As shown also in FIG. 5, for example, two insertion holes 45b are formed in the filling portion 45a, and the combined body including each armature coil 22 is
It is fastened to the coil yoke 3 by a countersunk machine screw 46 as a fastening member which is inserted through these insertion holes 45b.

As described above, in the drive unit, the armature coils 22 are integrally coupled to each other by the synthetic resin 45, and therefore, the armature coils 22 are conventionally provided to hold the armature coils in line. The coil board that was used is no longer required. Therefore, the linear DC motor and the drive unit can be made thinner, and the field magnet and the armature coil 22 described later are brought close to each other to increase the density of the magnetic flux reaching the armature coil 22 and increase the thrust. It is possible to do.

Further, conventionally, a spacer provided for preventing the deformation of the coil substrate due to the fastening force when fastening the coil substrate is not required, and the man-hours for manufacturing and assembling the parts are small and the manufacturing cost is low. The effect of becoming

Next, a circuit board for supplying power to each of the above armature coils 22 will be described.

As shown in FIGS. 1, 3 and 5, the circuit board 48 is arranged on the lower surface side of the bed 1 and is attached to the bed 1 by a plurality of bolts (with hexagonal holes) 5. Have been concluded. The bolts 5 also fasten the coil yoke 3 to the bed 1.

As shown in FIG. 5, a drive circuit composed of electronic components 53, 54 and the like is provided on the circuit board 48. This drive circuit includes the armature coils 22 described above.
An exciting current is supplied to the. By the way, each of the Hall effect elements 43 (shown in FIGS. 3 and 5) described above acts as a magnetic pole discriminating element and responds to a magnetic field line emitted by each magnetic pole of the field magnet when a field magnet described later approaches. Emits a signal (as a potential difference). This signal is sent to the drive circuit, and based on this signal, the drive circuit supplies power to the armature coil 22 corresponding to the Hall effect element that has issued the signal, and the signal is not yet obtained or is obtained. Control is performed so as to cut off the power supply to the armature coil corresponding to the missing Hall effect element. Thus, by regularly supplying a predetermined exciting current to each armature coil 22, a thrust force based on Fleming's left-hand rule is generated between both the primary side and the secondary side, and, for example, a bed in which the primary side is coupled. If 1 is the fixed side, the table 2 integrated with the secondary side moves by this thrust.

As shown in FIGS. 3 and 5, the Hall effect elements 43 are provided in a state of being buried in the synthetic resin 45 described above. That is, when the synthetic resin 45 and the armature coils 22 are molded using a mold, the Hall effect elements 43 are also arranged in the mold space and simultaneously molded. In addition,
Since the synthetic resin 45 having a high magnetic permeability is used, it does not hinder the magnetic pole discriminating action of each Hall effect element 43.

On the other hand, as shown in FIG. 3 and FIG. 5, the armature coils 22 and the drive circuit on the circuit board 48, which are arranged apart from each other via the bed 1 and the coil yoke 3, are arranged such that they are mutually separated. Male and female connectors 6 provided on the opposite side
Connection is made by connecting 3 and 64 to each other. As shown in FIG. 3, these connectors 63 and 64 have openings 1e and 3 formed in the bed 1 and the coil yoke 3, respectively.
interconnected through e.

As shown in FIGS. 3 and 5, as with the Hall effect elements 43, the connector 63 also has
The upper half portion is embedded in the synthetic resin 45. Like each Hall effect element 43, this connector 63 is simultaneously molded when molding is performed. As described above, by integrally molding at least a part of the components such as the Hall effect element 43 and the connector 63 in the synthetic resin 45, the components are inevitably positioned at predetermined positions by the synthetic resin 45. It is fixed and does not require special parts for positioning and fixing, and the number of parts can be reduced.

On the other hand, the secondary side of the linear DC motor is constructed as follows.

As shown in FIGS. 1 and 3, the secondary side is
Magnet yoke 68 fixed to the lower surface side of the table 2
And a field magnet 69 fixed to the lower surface of the magnet yoke 68 to face each of the primary side armature coils 22. As shown in FIG. 6, the field magnet 69 is formed in a substantially rectangular plate shape as a whole, and N and N are provided along the direction Q in which the relative movement of the primary side and the secondary side is made, that is, the longitudinal direction of the bed 1. A plurality of magnetic poles of S, for example, four poles are arranged and magnetized so as to be alternately arranged.

The drive unit is provided with the following structure as position detecting means for detecting the relative position of the bed 1 and the table 2.

That is, the position detecting means comprises the linear magnetic scale 71 shown in FIGS. 1 to 3 and the magnetic sensor section 72 shown in FIG. The linear magnetic scale 71 is
The table 2 is extended in the moving direction, and N and S magnetic poles are alternately magnetized in multiple pitches along a longitudinal direction thereof, and an origin signal magnetized portion is formed at one end thereof.
In addition, the magnetic sensor unit 72 is provided with a Hall effect element for origin detection, and the other two Hall effect elements of A phase and B phase are arranged so as to be offset from each other by a half of the pitch. With this configuration, A-phase and B-phase signals can be obtained, and it is possible to detect the relative position and determine the moving direction.

As shown in FIGS. 1 and 3, a flexible board 74 as a cable for extracting a signal from the magnetic sensor section 72 and a cover 75 for covering the flexible board 74 are provided. .

In the above embodiment, the guide unit having a mechanical structure is shown as the guide means for guiding the primary side and the secondary side to each other. However, due to the pressure of fluid (air or oil) or the magnetic force of the magnet. It is also possible to use a guide means configured to relatively levitate the both.

In the above embodiment, the movable magnet type linear DC motor in which the armature coil 22 side is fixed and the field magnet 69 side moves is shown, but the present invention is also applicable to the moving coil type linear DC motor. Is.

Further, as another embodiment, the bed 1 and the like have a certain curvature, and can be similarly applied to the case of performing a curvilinear motion.

[0042]

As described above, according to the present invention, the armature coils are integrally connected to each other by the resin, and therefore, the armature coils are conventionally provided to hold the armature coils in line. The coil board is unnecessary. Therefore, it is possible to reduce the thickness, and by making the field magnet and the armature coil extremely close to each other, it is possible to increase the density of the magnetic flux reaching the armature coil and increase the thrust picture. In addition, conventionally, a spacer provided to prevent deformation of the coil board due to a fastening force when fastening the coil board is not necessary, and the number of steps for manufacturing and assembling parts is small, and the manufacturing cost is low. Is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view including a partial cross section of a drive unit including a linear DC motor as an embodiment of the present invention.

FIG. 2 is a plan view of the drive unit shown in FIG.

FIG. 3 is a view including a partial cross section taken along the line AA in FIG.

FIG. 4 is a perspective view including a partial cross section of a track rail and a slide member included in the drive unit shown in FIGS. 1 to 3.

5 is a diffusion exploded perspective view including a partial cross section of a main part of a linear DC motor included in the drive unit shown in FIGS. 1 to 3. FIG.

FIG. 6 is a perspective view of a field magnet that is a component on the secondary side of the linear DC motor included in the drive unit shown in FIGS.

FIG. 7 is a perspective view of a main part of a drive unit including a conventional linear DC motor.

8 is a vertical cross-sectional view of a main part of the drive unit shown in FIG.

FIG. 9 is a perspective view of a spacer included in the configuration shown in FIG.

[Explanation of symbols]

 1 bed 2 table 3 coil yoke 7 track rail 10 slide member (sliding table) 13 ball (rolling element) 22 armature coil 43 Hall effect element (pole discriminating element) 45 synthetic resin 46 further machine screw (fastening member) 48 circuit Substrate 53, 54 Electronic component 63, 64 Connector 68 Magnet yoke 69 Field magnet 71 Linear magnetic scale 72 Magnetic sensor section

Claims (8)

[Claims] 1. A field magnet in which a primary side including an armature coil group and magnetic poles which are different from each other along a direction of relative movement with respect to the primary side are alternately arranged and magnetized and are arranged to face the armature coil. And a secondary side having, and each of the armature coils is integrally coupled to each other by a resin. 2. The linear DC motor according to claim 1, wherein the resin is filled in the hollow portion of each of the armature coils. 3. An insertion hole is formed in a resin filled in a hollow portion of the armature coil, and the armature coil is fastened by a fastening member inserted in the insertion hole. 2. The linear DC motor described in 2. 4. The linear DC motor according to claim 1, wherein at least a part of the predetermined component is embedded in the resin. 5. The magnetic field discriminating element, which is provided corresponding to each of the armature coils and discriminates a magnetic pole of the field magnet, according to claim 4.
The described linear DC motor. 6. The primary side includes a circuit board that supplies power to the armature coil, and the predetermined component connects a drive circuit provided on the circuit board and the armature coil. It is a connector, The linear DC motor of Claim 4 or Claim 5 characterized by the above-mentioned. 7. A field magnet in which a primary side including an armature coil group and magnetic poles different from each other are alternately arranged along a direction of relative movement with respect to the primary side and are magnetized and arranged to face the armature coil. A linear direct current motor having a secondary side and a guide means for guiding the primary side and the secondary side to each other, and the armature coils are integrally coupled to each other by a resin. Drive unit characterized by. 8. The guide means has a track rail formed along a longitudinal direction and is coupled to one of the primary side and the secondary side, and is movable relative to the track rail. 8. The drive unit according to claim 7, further comprising: a slide base coupled to the one side with respect to the other side.