JPH0520222B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a brake device for a linear guide table having a brake device capable of holding a table on a track base.

(Prior Art) Conventionally, a linear pulse motor 12 as described in Japanese Utility Model Publication No. 58-32477 as a first conventional example has been used.
0 is proposed. The linear pulse motor 1
20, 121 is a scale, 122 is a slider movable on the scale 121 in the X-axis direction, and 123 is a table movable on the slider 122 in the Y-axis direction orthogonal to the X-axis. The lower surface of the table 123 has a large number of teeth 12 extending in the X-axis direction and provided at equal pitches P along the Y-axis direction.
It has 3a.

On the upper surface of the slider 122, magnetic pole portions of a plurality of phases A to E are provided. By alternately exciting the magnetic pole portions of the plural phases, the table 123 moves stepwise in the Y-axis direction.

With a similar configuration, the slider 122 also moves stepwise on the scale 121 in the X-axis direction.

Here, a brake device 129 using a magnet for holding the slider 122 is attached to the slider 122.
attached to one side of the Brake device 12
9 is a support metal fitting 13 fixed to the slider 122
1, a plate spring 133 fixed to the support fitting 131 with a bolt 132, and a magnet 135 fixed to the plate spring 133 with a bolt 134. When the magnet 135 is de-energized,
The end face of the magnetic pole part of the magnet 135 is scale 1.
21 with a predetermined gap in between.

When holding the slider 122 on the scale 121 at a stable point, the coil 13 of the magnet 135
When power is applied to 6, magnet 135 and scale 1
A magnetic flux flows through the scale 21, and the magnet 135 is attracted to the scale 121. Therefore, slider 12
2 is held on the scale 121 by the frictional resistance between the scale 121 and the magnet 135.
Then, when the coil 136 is prevented from being energized,
The magnet 135 is configured to return to the initial position shown in FIG. 9 by the restoring force of the leaf spring 133, and the slider 132 is separated from the scale 121 and becomes free. A second conventional example (Japanese Patent Application Laid-Open No. 61-293741) describes a device in which electromagnetic brakes are provided separately on both sides of the first and second movable bases.

(Problems to be Solved by the Invention) However, according to the brake device 129 of the linear pulse motor 120 of the first conventional example, since the scale 121 is held on one side, sufficient holding force cannot be obtained, and the slider 122 There is a problem in that when an external force is applied to the workpiece, the side opposite to the side held down by the brake device 129 shifts, that is, so-called one-sided shift occurs, and the workpiece cannot be accurately held at the stopped position.

By applying the technical concept of the second conventional example to the first conventional example and separately providing brake devices 129 on both sides of the scale 121, the problem of one-sided displacement can be solved.
However, since the coil 136 of the magnet 135 is placed on the side of the scale 121, the number of turns N of the coil 136 is limited due to space constraints, and as a result, the excitation current must be increased in order to obtain a large magnetic attraction force. There is a problem in that increasing the excitation current increases the amount of heat generated. Also, scale 12
If the brake devices 129 are separately provided on both sides of the coil 1, the magnetic attraction forces of the magnetic circuits formed by the respective coils 136 may be different. As a result, the operating characteristics of the pair of brake devices do not match, resulting in poor stopping accuracy of the slider 122.

Additionally, the current applied to the separate coils 136 must be precisely controlled to match the operating characteristics of the pair of brake devices.

The present invention was made in view of the above-mentioned problems, and its purpose is to provide a wide coil winding space and a straight line that can apply an even magnetic attraction force to a pair of shoes. It is to provide a brake device for the guide table.

(Means for Solving the Problems) The present invention having the above objects includes a track having a ball rolling groove in the longitudinal direction, a table movably attached to the track, and a table movable in the ball rolling groove. A linear guide table having a bearing installed between the track and the table and having a large number of balls for moving the table, and a table driving device provided in the table and on the track to move the table along the track, A magnetic body provided on the table in an arch shape spanning the track in the width direction, a current-carrying coil wound around the magnetic body, and a coil that passes through the magnetic body and the track at both ends of the magnetic body. A brake device is provided with a pair of shoes provided so as to be attracted to both sides of the track base by the magnetic attraction force of the magnetic circuit formed as described above.

(Function) According to the linear guide table brake device of the present invention, when the coil is not energized, no magnetic circuit is formed and the shoe does not contact the track base. Therefore, no braking force is generated and the table is movable along the axial direction of the track. When the coil is energized, a magnetic circuit passing through the magnetic body and the track is formed. Then, the pair of shoes are attracted to both sides of the track base by the magnetic attraction force of the magnetic circuit, and the frictional resistance between the shoes and both sides of the track base acts as a braking force to stop and fix the table.

Here, since the magnetic body has an arch shape, a large space for winding the coil can be secured, and the number of turns of the coil can be increased.

In addition, since a pair of shoes are provided at both ends of the arch-shaped magnetic body, a single magnetic circuit can be formed.
A pair of shoes can be actuated by the single magnetic circuit.

Since the pair of shoes are actuated by the magnetic attraction force of a single magnetic circuit, it is easy to control the current flowing to the coils.

(Example) Hereinafter, the brake device for a linear guide table of the present invention will be specifically described based on an example.

1 to 7, a braking device for a linear guide table according to an embodiment of the invention is shown. This linear guide table includes a track 1 having a pair of ball rolling grooves 5 along the longitudinal direction, and a table 2 disposed above the track 1 at a predetermined distance from the top surface thereof. , a bearing 3 having a large number of balls 26 provided on both left and right sides of the table 2 and rolling in each ball rolling groove 5 of the track 1 while applying a load in the vertical and horizontal directions; and a brake drive device. The table drive device includes a stator 7 attached to the track 1 side, a movable element 11 attached to the table 2 side, and a linear motor mechanism 4 for driving the table 2. .

The track 1 has ball rolling grooves 5 on both sides thereof.
A stator 7 is provided along the longitudinal direction at the center of the upper surface of the rail 6, and the stator 7 has a large number of teeth 9 extending in the width direction.
is formed. Note that the track base 1 does not necessarily have to be formed of one rail 6, and may be formed as a split type consisting of a pair of rails 6 or a holster.

On the other hand, the movable element 11 of the linear motor mechanism 4 having a plurality of excitation parts 10 is attached to the lower surface of the table 2 while maintaining a predetermined clearance between it and the stator 7. The movable member 11 is driven by a magnetic action acting between the movable member 11 and the movable member 11.

In this embodiment, the linear motor mechanism 4 composed of the stator 7 and the movable element 11 is a composite type that uses both a variable reluctance and a permanent magnet.
It is equipped with Further, a plurality of inductor teeth 13 facing the teeth 9 of the stator 7 are formed on the lower surface of the tip of the excitation core 12a. Note that the excitation method for exciting the linear motor mechanism 4 employs a two-phase excitation method that can obtain thrust, has little damped vibration, and can respond to a wide frequency range.

In this embodiment, the relationship between the track 1 in which the linear motor mechanism 4 is incorporated and the table 2 is such that the thrust and holding force of the linear motor mechanism 4 can be adjusted by adjusting the clearance between the stator 7 and the movable element 11. Track base 1 and linear guide table 2 are provided for adjustment.
It is now possible to adjust the spacing between.

As shown in FIG. 2, the bearing 3 has a bearing block 24 attached to both left and right sides of the table 2 with bolts 22 while adjusting the clearance with an eccentric pin 23, and a bearing block 24 attached to both end surfaces of the bearing block 24. Attached side cover and track base 1
It is composed of a large number of balls 26 that roll in each ball rolling groove 5 while applying a load, and a retainer 27 that holds each of these balls 26. It is designed to be able to carry loads. Such a linear guide table moves on the track 1 at a predetermined pitch when the current flowing through the coil of the linear motor mechanism 4 is sequentially switched and energized.

On the other hand, a brake device 30 is attached to one end of the table 2 in the axial direction. Brake device 30
has an arch shape that straddles the track 1 in the width direction. That is, the coil 3 is attached to the table 2 via the plate 31 and is arranged so as to surround the iron core 32 which is parallel to the upper surface of the track base 1.
It has 3. The coil 33 and the iron core 32 are connected to the holder 3
4, the holder 34 is attached to the plate 31 by screws 35. The brake device 30 further includes leaf springs 36 on both sides of the iron core 32. A first clamp 37 is attached to the outside of the leaf spring 36 via a screw 38. 1st
A shoe 39 and a second clamp 40 are attached below the clamp 37 via a leaf spring 36, and the second clamp 40 and shoe 39 are fixed with screws 41. A pair of second clamps 40 are connected to the track base 1
located on both sides of the The iron core 32, the first clamp 37, and the second clamp 40 assembled in an arch shape in this manner constitute the magnetic body of the present invention. Here, a curved surface 42 having the same circular curvature is formed between the first clamp 37 and the second clamp 40 with a minute gap interposed therebetween. That is, the lower end of the first clamp 37 is a convex arcuate surface, and the upper end surface of the second clamp 40 is a concave arcuate surface. If necessary, a lining with a high friction coefficient is attached to the surface of the shoe 39 facing the track base 1. In addition, 43
is the cover. The brake device 30 configured in this manner operates as follows. First, when the coil 33 is energized, a magnetic circuit is generated between the first clamp 37, the second clamp 40, the leaf spring 36, and the track base 1 of the brake device 30, and the magnetic attraction force of this magnetic circuit causes the shoe 39 to move on the track. It is attracted to the side of the table 1 (see Fig. 6). As a result, the shoes 39 sandwich the track base 1 from both sides of the track base 1, and as a result, the linear guide table is firmly fixed onto the track base 1. Note that by controlling the amount of current flowing through the coil 33, the magnetic attraction force can be changed.

Here, when the shoe 39 is attracted to the side surface of the track base 1, the second clamp 40 moves toward the track base 1. However, since the lower end of the first clamp 37 and the upper end of the second clamp 40 form an arcuate surface, the gap L remains constant even when the second clamp 40 moves. Therefore, unlike when the lower end of the first clamp 37 and the upper end of the second clamp 40 are straight, there is no gap, which increases magnetic resistance and reduces the number of transmitted magnetic fluxes. Since a substantially constant number of magnetic fluxes is always formed in the magnetic circuit 45, a stable and strong magnetic attraction force can be obtained.

Further, since the magnetic body has an arch shape, a wide winding space can be secured, and the number of turns of the coil 33 can be increased. As a result, a strong magnetic attraction force is generated, ensuring stable braking characteristics and accurate stopping accuracy.

Further, since the pair of shoes 39 are provided at both ends of the arch-shaped magnetic body, a single magnetic circuit 45 can be formed, and the pair of shoes 39 can be operated by the single magnetic circuit 45. Therefore, the magnetic attraction forces acting on the pair of shoes 39 are equal and the braking forces match, ensuring accurate stopping accuracy.

Furthermore, since the pair of shoes 39 are actuated by the magnetic attraction force of the single magnetic circuit 45, the current flowing to the coil 33 can be easily controlled.

(Effects of the Invention) According to the present invention, since the present invention has a brake device equipped with a pair of shoes that hold the table on the track base by sandwiching the track base from both sides, the linear guide table can be moved to a predetermined position when the linear guide table is stopped. Since the linear guide table can be firmly and reliably held, it can be used particularly in processes where an external force is applied to the linear guide table, improving the versatility of the linear guide table.

Furthermore, since the magnetic body has an arch shape, a wide winding space can be secured, and the number of turns of the coil can be increased. As a result, a strong magnetic attraction force is generated, ensuring stable braking characteristics and accurate stopping accuracy.

In addition, since a pair of shoes are provided at both ends of the arch-shaped magnetic body, a single magnetic circuit can be formed.
A pair of shoes can be actuated by the single magnetic circuit. Therefore, the magnetic attraction forces acting on the pair of shoes are equal, the braking forces match, and accurate stopping accuracy can be ensured.

Furthermore, since the pair of shoes are actuated by the magnetic attraction force of a single magnetic circuit, it is easy to control the current flowing to the coils. Furthermore, the linear guide table can be gradually stopped by changing the amount of current flowing through the coil so that it gradually decreases.

[Brief explanation of the drawing]

FIG. 1 is a plan view of a linear guide table according to an embodiment of the present invention, FIG. 2 is a cross-sectional view of FIG. 1, and FIG.
The figures are a vertical sectional view of FIG. 1, a is an overall longitudinal sectional view, b is an enlarged detailed view of section E in FIG. 3 a, and FIG. 4 is a front view of the brake device in FIG. Figure 5 is
Fig. 1 is a side view of the brake device, Fig. 6 is an explanatory diagram of the operation of the brake device, Fig. 7 is an explanatory diagram of the magnetic circuit formed in the linear guide table, and Fig. 8 is a linear diagram of the first prior art. A perspective view of the guide table, and FIG. 9 is a sectional view of a main part of the linear guide table of FIG. 8. Explanation of symbols, 1... Track base, 2... Linear guide table, 3... Bearing, 4... Linear motor mechanism, 5... Ball rolling groove, 6... Rail, 7...
...Stator, 9... Teeth, 11... Mover, 30...
Brake device, 31...plate, 32...iron core, 33...coil.

Claims (1)

[Claims] 1. A wayway having a ball rolling groove in the longitudinal direction;
A table movably attached to the track, a bearing having a large number of balls moving in ball rolling grooves and installed between the track and the table, and a table for moving the table along the track. A linear guide table having a table driving device provided inside and on a track base, the table having a magnetic body provided in an arch shape across the track base in the width direction, and a current-carrying member wound around the magnetic body. a pair of shoes provided at both ends of the magnetic body so as to be attracted to both sides of the way by the magnetic attraction force of a magnetic circuit formed to pass through the magnetic body and the way. A brake device for a linear guide table, characterized in that the brake device is equipped with the following. 2. The brake device has a leaf spring to which the shoe is attached, a first clamp that is attached to the side facing the shoe and fixes the leaf spring to the table, and a second clamp that fixes the shoe to the leaf spring. The lower end of the first clamp is a convex arc surface, and the second clamp has a convex arc surface.
2. The brake device for a linear guide table according to claim 1, wherein the upper end of the clamp has a concave arcuate surface. 3. The braking device for a linear guide table according to claim 1 or 2, wherein the shoe has a lining on a surface facing the track base. 4. Claims 1 to 3, characterized in that the table driving device comprises a stator attached to a track base, a movable element attached to the table, and a linear motor mechanism for driving the table. A brake device for a linear guide table according to any of paragraphs.