JPH1182564A - Brake device for linear motor table - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a brake device which can stop a linear motor table in fixed condition even in case the current feed is shut off. SOLUTION: A brake device 1 for a linear motor table is composed of a shaft member 2 attached to the table upon being stretched in the moving direction, an outer cylinder 6 furnished at the inside surface with a taper 6a, a chuck member 4 to lock the shaft member 2 through the wedge effect of the taper surface 6a with the shaft member 2, a coil spring 8 to energize the chuck member 4 in the direction of being drawn to the taper surface 6a, and a linear solenoid 7 to separate the chuck member 4 from the taper surface 6a, wherein the chuck member 4 locks the shaft member 2 by means of wedge action when the current feed is shut off, and the table stops in the fixed condition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-axis positioning table device which is mounted on, for example, a machine tool or an industrial robot and guides an object (driven body) with high precision.
In particular, the present invention relates to a braking device for a linear motor positioning table device (hereinafter, simply referred to as a linear motor table) having a linear electromagnetic actuator as a drive source.

[0002]

2. Description of the Related Art FIG. 11 shows a conventional linear motor table.

[0003] As shown in the figure, this linear motor table has a rectangular bed 101 and a table 102 that moves on the bed 101 in the longitudinal direction.
The table 102 is guided along the bed 101 by rolling a plurality of rollers arranged on the bed 101 along a track (not shown) formed in the longitudinal direction of the bed 101.

An overhang 101a is formed on one side of the bed 101, and a linear scale 104 is provided on the overhang 101a. Also, this overhang portion 101a
The light-emitting element 105a and the light-receiving element 105b are attached to the side of the table 102 corresponding to, via a bracket 102a. Note that these linear scales 104,
The light emitting element 105a and the light receiving element 105b
It serves as a detecting means for detecting the position of the table 102 with respect to the position 1.

This linear motor table uses a linear DC motor.

This linear DC motor has a plurality of armature coils 10 arranged on a bed 101 along a longitudinal direction.
7 and a secondary side including a field magnet (not shown) mounted on the lower surface of the table 102 so as to face the armature coil 107.

The field magnet is provided such that a plurality of N and S magnetic poles are alternately arranged in the direction in which the table 102 moves.

The linear motor table supplies power to each of the armature coils 107 at a predetermined timing, so that the table 102 moves along the longitudinal direction of the bed 101, and moves to a desired position based on a detection signal of the detection means. Perform the positioning operation.

[0009]

In the conventional linear motor table, the moving parts such as the table 102 and the load on the table 102 are stopped and positioned only by the magnetic force, so that the power supply is interrupted due to a power failure or the like. There is a problem in that when the vehicle is hit, no braking force is applied and the movable part cannot move and stop and move. In particular, when the linear motor table is used in a state where the linear motor table is used in a vertical axis (the operation direction is vertical) or close to the vertical axis, and the power supply is cut off, there is a problem that the movable portion falls.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a braking device for a linear motor table capable of stopping and positioning the table by reliably applying a braking force even when power is cut off. .

[0011] The present invention provides a bed having a rectangular plate shape, a slidable table guided by a linear motion rolling guide unit along the longitudinal direction of the bed, and sliding and positioning the table with respect to the bed. A brake device disposed on a linear motor table having a linear electromagnetic actuator that can be driven freely, wherein the brake device extends in the longitudinal direction of one of the bed and the table via a bracket fastened to both ends and is fixed. Shaft member, and an outer cylinder attached to the other bed or table corresponding to the shaft member, the taper surface being formed in the inner periphery and being inclined in the axial direction. And a claw portion between the shaft member and the outer cylinder, which is fitted into a wedge portion formed by the tapered surface of the outer cylinder and the shaft member to lock the shaft member at an inner peripheral portion. A chuck member having a connecting member connected to an end of the chuck member on the side opposite to the claw portion side; and a plunger connected to the connecting member, wherein the chuck portion is detached from the tapered surface by energization. A linear electromagnetic solenoid fixed to the bed or the table together with the outer cylinder for moving the plunger; and biasing means for biasing the connecting member in a direction opposite to the direction in which the linear electromagnetic solenoid moves. When the power is cut off, the claw portion is fitted into the wedge portion, the shaft member is locked, and the movement of the table with respect to the bed is stopped.

The shaft member is attached to a side surface of the table.

Further, the connecting member is connected to the plunger parallel to the chuck member and the shaft member at right angles.

[0014] The urging means comprises a coil spring, and is located between the outer cylinder and the chuck member, and urges the connecting member to the outer cylinder.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a linear motor table braking device according to an embodiment of the present invention;

FIG. 1 is a perspective view showing a main part of a braking device for a linear motor table according to a first embodiment. FIG.
It is a top view of the braking device shown in FIG. FIG. 3 is a side view including a partial cross section of the braking device shown in FIGS. 1 and 2. FIG. 4 is a cross-sectional view taken along line BB ′ shown in FIG.

As shown in FIG. 1 to FIG.
Is composed of a shaft member 2, a chuck member 4, an outer cylinder 6, a linear electromagnetic solenoid (hereinafter, simply referred to as a solenoid) 7, a connecting member 17, and a coil spring 8. The chuck member 4, the outer cylinder 6, the solenoid 7, the connecting member 17, and the coil spring 8 are referred to as a braking device body.

The shaft member 2 is an elongated columnar member,
As shown in FIG. 2, the bed 31 on the fixed side and the table 32 on the movable side extend in the longitudinal direction, which is the sliding direction, and are attached and fixed.

In the following description, an embodiment in which the shaft member 2 is fixedly mounted on the movable table 32 will be described.

As shown in FIG. 1, the end of the shaft member 2 is fitted into a holding hole of the bracket 3 and fastened to the bracket 3 by bolts 3b. And this bracket 3
The bracket 3 is fixed to the side surface of the table 32 in parallel with the sliding direction by fastening the bracket 3 to both end surfaces of the table 32 with bolts 3a.

The outer cylinder 6 is, as shown in FIGS.
The inner circumference formed by inserting the shaft member 2 has a cylindrical shape from one end to a substantially central portion, includes the coil spring 8, and has a diameter from the cylindrical portion to the other end. Is a conical tapered surface 6a that gradually changes in the axial direction. Further, the outer shape is a quadrangular prism shape, and is attached to the bed 31 via the attachment plate 12 and the bracket 9 with screws 11, 14, and 10 corresponding to the shaft member.

As shown in FIGS. 2 to 4, the chuck member 4 is provided between the shaft member 2 and the outer cylinder 4 and has a cut into three parts in a circumferential direction from a central portion to an end portion. It is a claw portion 4b. The claw part 4b
Can be opened and closed. In addition, the inner periphery of the central portion is thin 4a, and the opening and closing force of the claw portion 4b is adjusted to be sharp. The other end is screwed and connected to the connecting member 17 by a screw 4d formed on the outer periphery, and the shaft member 2 is fitted on the inner periphery with a gap therebetween.
The chuck member 4 is made of steel.

The claw portion 4b has a tapered shape in which the outer peripheral portion is engaged with a conical tapered surface 6a formed on the inner periphery of the outer cylinder 6, and the outer diameter gradually changes and becomes larger toward the end portion. The inner peripheral portion 4c of the claw portion 4b is fitted into a wedge portion formed by the tapered surface 6a of the outer cylinder 6 and the shaft member 2.
Are reduced in diameter to chuck the shaft member 2 and lock the movement of the outer cylinder 6 and the shaft member 2 in one direction.

The coil spring 8, which is a biasing means, is located between the cylindrical inner peripheral portion of the outer cylinder 6 and the outer peripheral portion of the chuck member, one end of which engages the outer cylinder 6 and the other end thereof. The portion is engaged with the connecting member 17 to urge the connecting member 17 in a direction away from the outer cylinder 6. That is, the claw portion 4b of the chuck member 4 is pulled into the tapered surface 6a, and the shaft member 2 is chucked.

The solenoid 7 is fastened to the bracket 9 together with the outer cylinder 6 by screws 11 (see FIG. 2), and is fixed to the side surface of the bed 31 by screws 10 in parallel with the shaft member 2 via the bracket 9. I have. Also, the solenoid 7
A substantially L-shaped mounting plate 12 is fastened to the outer surface of the bracket by screws 13 and is fastened together with the outer cylinder 6 by being interposed between the mounting plate 12 and the bracket 9.

The solenoid 7 includes a plunger 7a of a movable core, which is a movable member, and an exciting coil (not shown) for moving the plunger 7a in one direction by supplying an AC or DC current. In this embodiment, the plunger 7a is made of a DC solenoid, and is moved in the direction of arrow P shown in FIGS.
Further, the connecting member 17 is perpendicular to the tip of the plunger 7a.
And move together with the plunger 7a.

The connecting member 17 has a vertically long and relatively thick oval plate shape. The screw 4d at the other end of the chuck member 4 is screwed into the upper screw hole 17a, and the lower hole is formed in the lower hole. The plunger 7a is fitted with the stopper pin 18a so that it cannot be removed.

Next, referring to FIG. 3, FIG. 5, and FIG.
The operation of the braking device according to the present invention will be described.

As shown in FIGS. 5 and 6, the solenoid 7
When the solenoid 7 is energized, the plunger 7a is pulled by the arrow P against the urging force of the coil spring 8 due to the suction operation of the solenoid 7.
And the claw portion 4b of the chuck member 4 is
The claw 4b is released from the wedge portion formed by the tapered surface 6a of the outer cylinder 6 and the shaft member 2 by moving in the direction (the direction of the arrow P) separating from the tapered surface 6a. Is opened, the movement of the shaft member 2 becomes free.

Here, when the power supply to the solenoid 7 is cut off, the suction force of the solenoid 7 is lost, and as shown in FIG. To move in the direction of arrow A,
The claw portion 4b of the chuck member 4 is fitted into a wedge portion formed by the tapered surface 6a and the shaft member 2, and the inner peripheral portion 4c of the claw portion 4b is reduced in diameter to chuck the outer periphery of the shaft member 2. That is, the outer cylinder 6 and the shaft member 2 are fixed to each other, and the movement of the shaft member 2 in one direction (indicated by the arrow A) is locked.

In addition to the above-described structure, the solenoid 7 provided in the braking device 1 of the present invention draws the chuck member 4 from the tapered surface 6a of the outer cylinder 6 by pulling the plunger 7a (in the direction of arrow P). Alternatively, a solenoid having the same action by projecting the plunger may be used.

Although the shaft member 2 is cylindrical and the inner circumferences of the chuck member 4 and the outer cylinder 6 are correspondingly cylindrical, the cross-sectional shape is not limited to a circle but may be, for example, a square.

Although the coil spring 8 is used as the urging means for urging the connecting member 17, other types of springs or synthetic rubber having a high resilience may be used.

[0034]

Next, a first embodiment of a linear motor table having a braking device according to the present invention will be described with reference to FIGS. However, portions having the same structure and function as those of the braking device shown in FIGS. 1 to 6 will not be described again and will be omitted, and only the main portions will be described. In the following drawings, parts having the same structure and function as those of the braking device shown in FIGS. 1 to 6 are denoted by the same reference numerals.

FIG. 7 is a perspective view of a linear motor table provided with the braking device 1. FIG. 8 is a plan view of the linear motor table shown in FIG. FIG. 9 shows FIGS. 7 and 8
FIG. 4 is a side view showing a state where the linear motor table shown in FIG.

As shown in FIGS. 7 to 9, the linear motor table is mainly guided by a rectangular plate-shaped bed 31 which is a fixed side and a linear motion rolling guide unit along the longitudinal direction of the bed 31. It comprises a movable table 32 slidably movable, a linear electromagnetic actuator for driving the table 32 slidably and positionably with respect to the bed 31, and the braking device 1.

The bed 31 shown in FIG. 7 and FIG.
As shown in the figure, the bed 31 is placed on a worktable 33 such as a machine tool.
Are fastened by bolts 34 using a plurality of bolt insertion holes 31a formed along the longitudinal direction on both sides of the bolt. The table 32 is used by fixing a driven body, for example, a workpiece to a screw hole 32a on the upper surface side.

The guide means for the bed 31 of the table 32 is a linear motion rolling guide unit, and two track rails 35 provided with track grooves on the upper surface of the bed 31 are arranged in parallel on both sides. Unit 36 with rolling elements circulating endlessly along the raceway groove
Are spread over the track rail 35 two by two, and these slide units 36 are arranged in four corner recesses on the lower surface side of the table 32. The table 32 is smoothly guided by the guide means along the longitudinal direction of the bed 31.

Next, a linear electromagnetic actuator for slidingly driving the table 32 with respect to the bed 31 and driving the table 32 will be described.

In this embodiment, the linear electromagnetic actuator is constituted by a movable magnet type linear DC motor. In addition, various actuators such as a moving coil type linear DC motor, a linear pulse motor, and a voice coil motor may be used.

As shown in FIGS. 7 and 8, the movable magnet type linear DC motor of this embodiment is such that the primary side, which is the power supply side, is disposed in a recess provided on the upper surface of the bed 31 over the entire length in the longitudinal direction. The coil substrate 40 and, for example, eight armature coils 4 adhered in a line on the lower surface of the coil substrate 40 along the moving direction of the table 32.
And 1. Further, a Hall effect element 42 is mounted on the lower surface side of the coil substrate 40 so as to correspond to each of the armature coils 41.

On the primary side, these Hall effect elements 42 output an electric signal corresponding to the amount of magnetic lines of force generated by the field magnet 43, and based on this electric signal, power is supplied to the armature coil 41 and cut off. Control by an external control circuit (not shown) is performed.

On the other hand, the secondary side is composed of a field magnet 43 attached to the lower surface of the table 32.

The field magnet 43 is formed in a rectangular plate shape, and has a plurality of N and S magnetic poles along the direction of reciprocation of the table 32, in this case, an armature coil such that five poles are alternately arranged. It is attached to the lower surface of the table 32 corresponding to 41.

With the above-described configuration of the primary side and the secondary side, a thrust based on Fleming's left hand rule is generated, and the movable table 32 is slidably driven with respect to the bed 31.

As shown in FIG. 8, as a detecting means for detecting the relative position of the table 32 with respect to the bed 31 and determining the moving direction, a linear scale 44 is disposed on the lower surface of the table 32 and is opposed to the linear scale 44. A sensor 45 is provided on the upper surface of the bed 31.

The linear scale 44 is made of a magnetic scale, and N and S magnetic poles are alternately multi-polarized at a fine pitch along the longitudinal direction of the table 32, and a magnetic pole for an origin signal is provided at one end. It is magnetized.

Therefore, the linear DC motor always detects the current position of the table 32 based on the signal from the detecting means, moves the table 32 to an arbitrary position, and drives the positioning.

The extraction of signals from the Hall effect element 42 and the sensor 45, the power supply to the armature coil 41, etc.
This is performed through a cable 46 and a socket 47 as shown in FIGS. Power is also supplied to the solenoid 7 of the braking device 1 from the cable 46 and the socket 47.

Next, the operation of the linear motor table will be described.

When the operator operates an operation switch or the like to issue an operation command from the control unit, the table 32 stopped at an arbitrary position is moved to one end of its operation stroke, that is, in FIG. 7 to FIG. Move toward the rightmost reference position.

When the table 32 reaches the reference position, the scale position data is reset by the reference position signal from the sensor 45.

Next, the table 32 moves to a predetermined position according to a predetermined program. The movement position and direction of the table 32 are controlled based on signals from the linear scale 44 and the sensor 45.

When the linear motor table is performing the above operation, that is, when the power is supplied, the solenoid 7 is also energized as shown in FIGS. 5 and 6, and the plunger 7a of the solenoid 7 The claw portion 4 b of the chuck member 4 is pulled in against the urging force of the spring 8.
Is pulled out from the tapered surface 6a of the outer cylinder 6 in the detaching direction (the direction of the arrow P), the chuck of the claw portion 4b is released, the shaft member 2 can freely move, and the table 32 can also move freely.

On the other hand, when the power supply to the linear motor table is cut off due to, for example, a power failure, the thrust and braking force of the linear DC motor and the attraction force of the solenoid 7 disappear.
At this time, as shown in FIG. 3, the chuck member 4 connected to the connecting member 17 is moved by the urging force of the coil spring 8, and a claw portion is formed on the wedge formed by the shaft member 2 and the tapered surface 6 a of the outer cylinder 6. The shaft member 2 is chucked by the fitting of 4b. Therefore, the movement of the shaft member 2 and the movement of the table 3
2 is locked in a fixed state in one direction (indicated by arrow A).

When the power is restored after returning from the power failure state, the plunger 7a of the solenoid 7 is sucked again, and the claw 4b of the chuck member 4 is disengaged from the tapered surface 6a of the outer cylinder 6 in the same manner as described above. (In the direction of arrow P)
The chuck of the claw portion 4b is released. For this reason, the shaft member 2
Becomes freely movable, the fixed state of the table 32 is released, and the operation of the table 32 by the linear DC motor becomes free.

When the energization is resumed, the data in the memory of the control circuit can be read out and repositioned from the stop position, so that the moving distance of the table 32 is shortened and the efficiency is improved.

As described above, in the braking device for the linear motor table, when the power is cut off due to a power failure or the like, the chuck member 4 reliably chucks the shaft member 2 on substantially the entire inner peripheral surface of the claw portion 4b. . For this reason, the table 32 is always fixed and locked in one direction, so that the movable part such as the table 32 does not move or fall when used in a state of being close to the vertical axis or the vertical axis, which is effective.

Further, the braking device for the linear motor table includes a table 3 on which the shaft member 2 of the braking device 1 is movable.
2 and a braking device main body including the solenoid 7 is mounted on a bed 31 which is a fixed side. Since the shaft member 2 is lighter than the braking device body, the table 3
The load on the movable portion composed of the second and the like is reduced, and high-speed driving and highly accurate positioning are possible.

Further, in the braking device for the linear motor table, since the shaft member 2 is provided on the side surface of the table 32, an empty space is secured on the upper surface of the table 32, and the load can be mounted without any trouble.

Further, in the braking device for the linear motor table, the braking device body is fixed to the side surface of the bed 31 together with the shaft member.
There is no hindrance to running.

Further, the braking device of the linear motor table is compact because the biasing means is formed of a coil spring and is housed in an outer cylinder.

Next, a second embodiment in which the braking device according to the present invention is applied to a linear motor table will be described with reference to FIG.

FIG. 10 is a perspective view showing the second embodiment.

The second embodiment is different from the first embodiment in that the shaft member 2 of the braking device 1 is mounted on a table 32 on the movable side, and the braking device main body 20 includes a solenoid 7 and the like.
Is mounted on the bed 31, whereas the shaft member 2 is disposed on the fixed bed 31 and the braking device body 2
The effect is the same, except that 0 is provided in the table 32.

In this embodiment, the shaft member 2 is attached to the bed 31. In this embodiment, since the length of the shaft member 2 extends over the entire length of the bed 31, the operating stroke of the table 32 can be increased as necessary. It has become.

In each of the above embodiments, the table 32 is fixed in one direction and is stopped. However, when stopping in both directions, the table 32 is
This can be easily implemented by providing a plurality of braking device main bodies 20 facing each other, or providing a plurality of opposed tapered surfaces 6a in the outer cylinder 6.

[0068]

As described above, according to the present invention,
When the power supply is cut off due to a power failure or the like, the table is securely fixed and stopped. Further, even when the linear motor table is used in a state where the linear motor table or the vertical shaft is used, the movable portion such as the table does not drop.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main part of a braking device according to the present invention.

FIG. 2 is a plan view of the braking device shown in FIG.

FIG. 3 is a side view including a partial cross section of the braking device shown in FIGS. 1 and 2;

FIG. 4 is a sectional view taken along the line B-B 'shown in FIG.

FIG. 5 is a view for explaining the operation of the braking device shown in FIG. 3;

FIG. 6 is an enlarged view of a portion of the chuck pawl 4 shown in FIG.

FIG. 7 is a perspective view showing a first embodiment including a partial cross section in which the braking device of the present invention is applied to a linear motor table.

FIG. 8 is a plan view of the linear motor table shown in FIG. 7;

FIG. 9 is a side view showing a state where the linear motor table shown in FIGS. 7 and 8 is installed on a workbench;

FIG. 10 is a perspective view showing a second embodiment in which the braking device of the present invention is applied to a linear motor table.

FIG. 11 is a perspective view of a main part of a conventional linear motor table.

[Explanation of symbols]

 Reference Signs List 1 braking device 2 shaft member 4 chuck member 6 outer cylinder 6a tapered surface (of outer cylinder 6) 7 linear electromagnetic solenoid 8 coil spring (biasing means) 20 main body (of braking device 1) 41 armature coil 43 field magnet 44 Linear scale 45 Sensor 46 Cable 47 Socket

Claims (4)

[Claims] 1. A bed having a rectangular plate shape, a slidable table guided by a linear motion rolling guide unit along a longitudinal direction of the bed, and a table slidably and positionably movable with respect to the bed. A brake device disposed on a linear motor table having a linear electromagnetic actuator to be driven, the brake device being extended and fixed in a longitudinal direction of one of the bed and the table via brackets fastened to both ends. A shaft member, an outer cylinder attached to the other bed or the table corresponding to the shaft member, wherein a tapered surface is formed on the inner periphery in which the shaft member is inserted and is inclined in the axial direction; A jaw, which is located between the shaft member and the outer cylinder and which is fitted into a wedge portion formed by the tapered surface of the outer cylinder and the shaft member to lock the shaft member at an inner peripheral portion; A locking member, a connecting member connected to an end of the chuck member opposite to the claw portion side, and a plunger connected to the connecting member, wherein the claw portion is detached from the tapered surface by energization. A linear electromagnetic solenoid fixed to the bed or the table together with the outer cylinder, wherein the plunger is movable, and biasing means for biasing the connecting member in a direction opposite to the direction of movement of the linear electromagnetic solenoid. The claw portion is fitted into the wedge portion when power is cut off, the shaft member is locked, and the movement of the table with respect to the bed is stopped. Braking device. 2. The braking device for a linear motor table according to claim 1, wherein the shaft member is attached to a side surface of the table. 3. The linear motor table according to claim 1, wherein the connecting member is connected at right angles to the plunger parallel to the chuck member and the shaft member. Braking device. 4. The urging means comprises a coil spring,
4. The linear motor table according to claim 1, wherein the connecting member is biased against the outer cylinder between the outer cylinder and the chuck member. 5. Braking device.