JPH08275453A - Braking mechanism of cylindrical linear pulse motor - Google Patents

Abstract

PURPOSE: To surely effectuate the braking force to a shaft of a cylindrical linear pulse motor. CONSTITUTION: A shaft of a cylindrical linear pulse motor is provided through an annular solenoid. At the upper surface 4a of a coil case 4, one end of a clamp body 6 is rotatably provided to a shaft member 7. A recessed/projected area 2a is formed on the shaft 2 and a recessed/projected area engaging with the area 2a is also formed to the part in contact with the shaft of the clamp body 6. The free end of the claim body 6 is provided with a coil spring 8 under the pulled condition to always energize the free end of the clamp body 6 toward the shaft 2 to effectuate the braking to the shaft 2. At the bottom part of the clamp body 6, a guide groove 6c restricted by a hard ball 10 is formed. When a solenoid is energized, the clamp body 6 receives a force in the circumferential direction to rotate in the direction of arrow mark (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brake mechanism for a cylindrical linear pulse motor whose shaft linearly moves in the axial direction.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional brake mechanism for a cylindrical linear pulse motor. This brake mechanism
A plurality of hard balls 22 are pressed against the shaft 21 of the linear pulse motor using the solenoid 20, and the shaft 21 is braked by the frictional force between the shaft 21 and the hard balls 22.

That is, when the solenoid 20 disposed in the casing formed by the tubular member 23 and the lid member 24 is excited, the plunger 25 resists the spring force of the spring 26 as shown in the figure. Move down. Plunger 2
A hard ball 22 is arranged on the taper 23a in the lower part of 5, and the hard ball 22 is pressed by the plunger 25 and comes into pressure contact with the shaft 21 to generate friction, and the shaft 21 is braked.

FIG. 7 shows a brake mechanism of a cylindrical linear pulse motor according to another prior art. In this brake mechanism, a solenoid 31 is used to sandwich a shaft 31 of a linear pulse motor between collets 32, and the shaft 31 is braked by the frictional force between the shafts 31 and 32.

That is, when the solenoid 30 provided in the casing 33 is excited, the plunger 34 is guided by the guide member 35 and moves rightward against the spring force of the spring 36. At the right end of the plunger 34, a collet 32 having several slits in the axial direction is formed. The inner peripheral wall 33a of the opening of the casing 33 is formed to have a smaller diameter toward the right side, and when the tip end portion 32a of the collet 32 comes into contact with the inner peripheral wall, the tip end portion 32a is pressed toward the axial line side of the shaft 31 and the tip end portion 32a. The pressure contact of the shaft 31 with the shaft 31 causes friction, and the brake is applied.

[0006]

However, these brake mechanisms have the drawback that a stable holding force cannot be obtained because the above-mentioned frictional force is used to brake the shaft.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cylindrical linear pulse motor having a large shaft holding force and capable of obtaining a stable braking force.

[0008]

The above object is to form the first uneven portion on the shaft of the cylindrical linear pulse motor,
A second concavo-convex portion that meshes with the first concavo-convex portion is formed on the clamp body arranged on the peripheral portion of the shaft, one end of the clamp body is rotatably attached to the shaft member, and the free end of the clamp body is attached. By biasing the shaft with the elastic member toward the axis of the shaft, the second concave-convex portion is pressed against the first concave-convex portion to fix the shaft, and the solenoid provided in the clamp body is excited to clamp the clamp. Brake mechanism for a cylindrical linear pulse motor, wherein the free end of the body is rotated in the direction opposite to the axis of the shaft to release the engagement between the first uneven portion and the second uneven portion. Achieved by

In the present specification, the meaning of the meshing / engaging of the concave and convex portions includes the meshing / engaging of the concave portion and the convex portion including those having a single shape.

[0010]

Since the clamp body is urged toward the shaft center side by the urging force of the elastic member, when the solenoid is not excited, the clamp body is urged toward the shaft side to form the first uneven portion. The second concave-convex portion meshes. This allows
The movement of the shaft in the axial direction is restricted and the brake is applied.
On the other hand, when the solenoid is excited, the clamp body moves so as to rotate in the direction opposite to the axis of the shaft, and disengages the first uneven portion and the second uneven portion. This allows the shaft to move in the axial direction.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A brake mechanism for a cylindrical linear pulse motor according to an embodiment of the present invention will be described below with reference to the drawings.

1 and 2 show a brake mechanism 1 for a cylindrical linear pulse motor according to the present invention. The brake mechanism 1 applies a brake to a cylindrical linear pulse motor by fixing a shaft 2 of a cylindrical linear pulse motor (not shown) whose main body moves in the axial direction.

As shown in the figure, the brake mechanism 1 has an annular shape as a whole, and a shaft 2 penetrates the ring of the brake mechanism 1 with a slight gap. The brake mechanism 1
The casing 3 is attached to the main body of the cylindrical linear pulse motor or the like. The casing 3 houses therein a coil case 4 having the same outer diameter as the inner diameter of the casing 3, which is fixed to the inner wall of the casing 3. Further, the coil case 4 houses a solenoid 5 therein, and the solenoid 5 is connected to a power source (not shown).

FIG. 2 is a perspective view showing the appearance of the brake mechanism 1 with the casing 3 in FIG. 1 removed. As shown in the figure, the brake mechanism 1 is provided with a pair of clamp bodies 6, a shaft member 7, a coil spring 8, a leaf spring 9 and a hard ball 10 on an upper surface 4 a of a coil case 4.

Of these, the clamp body 6 is a thick plate made of iron and having a curved planar shape, and the curved inner surface 6 thereof.
a is arranged toward the shaft 2 side, and the through hole 6b (see FIG. 1) provided at one end is arranged to be parallel to the axis of the shaft 2. At the bottom of the clamp body 6, a guide groove 6c guided by the hard ball 10 is provided. The planar shape of the guide groove 6c is such that when the clamp body 6 moves so as to rotate about the shaft member 7 as a support shaft, the clamp body 6 has a hard ball 10a.
It is formed in the shape of a locus passing above.

The shaft member 7 has a shaft diameter slightly smaller than the inner diameter of the through hole 6b of the clamp body 6 so that the clamp body 6 is rotatable along the upper surface 4a with the shaft of the shaft member 7 as an axis. Install. A coil spring 8 is provided in a tensioned state between the free end of the clamp body 6 and the shaft of another pair of shaft members 7 so that the free end of the clamp body 6 is constantly urged toward the shaft 2 side. To Further, the shaft member 7 is provided with a plate spring 9 which penetrates the shaft member 7, and the plate spring 9 is used to clamp the plate member 6.
It is provided in a compressed state between the lower part of and the upper surface 4a, and the clamp body 6 is always biased toward the head side of the upper shaft member 7.

FIG. 3 shows the inner surface 6a of the clamp body 6 and the shaft 2. As shown in the figure, the shaft 2 is formed with a first uneven portion 2a having a rectangular cross-sectional shape on the outer peripheral portion. On the other hand, the clamp body 6 has a shaft 2 on the inner surface 6a.
A notch having a curved surface that is substantially the same as the curvature of the surface is formed, and a second uneven portion 6d that meshes with the first uneven portion 2a is formed on this notched surface. The entire length of the first uneven portion 2a is formed to be slightly larger than the stroke of the shaft 2 in the axial direction.

FIG. 4 is a sectional view taken along line XX in FIG. 2, showing a longitudinal section of the guide groove 6c of the clamp body 6 and the hard ball 10 for guiding the clamp body 6. The guide groove 6c is a groove inclined in a curved shape as shown in the figure,
In the figure, the deeper groove is on the shaft 2 side,
The groove on the opposite side of the shaft 2 is shallow. The hard sphere 10 is fixed so as to be partially embedded in the upper surface 4a of the coil case 4.

The structure of the brake mechanism 1 for the cylindrical linear pulse motor according to the embodiment of the present invention has been described above. Next, the operation thereof will be described.

FIG. 1 shows a state in which the solenoid 5 is not excited when the brake mechanism 1 is operating. In this state, the pair of clamp bodies 6 are urged by the spring force of the coil spring 8 toward the shaft 2 side of the cylindrical linear pulse motor. Therefore, the first concavo-convex portion 2a of the shaft 2 and the second concavo-convex portion 6d of the clamp body 6 mesh with each other, and the shaft 2 of the cylindrical linear pulse motor is braked.

When the brake of the shaft 2 is released, the solenoid 5 is energized. As a result, when the solenoid 5 is excited, the clamp body 6 is pulled downward by the attraction force of the solenoid 5. As shown in FIG.
At this time, the inclined surface of the guide groove 6c of the clamp body 6 is the hard ball 1.
Abut 0. However, in the clamp body 6, due to the action of this inclined surface, the downward force is dispersed into the horizontal force,
It receives a force that moves it to the right in the drawing, ie in the direction opposite to the shaft 2.

This force resists the spring force of the coil spring 8,
The clamp body 6 is moved so as to rotate in the arrow a direction with the shaft member 7 as a spindle. Since the clamp body 6 has the guide groove 6c formed on the bottom surface, the edge of the guide groove 6c has a hard ball 1a.
Rotate until it contacts 0. Therefore, the engagement between the first concave-convex portion 2a of the shaft 2 and the second concave-convex portion 6d of the clamp body 6 is released, the brake of the shaft 2 is released, and the shaft 2 can move linearly in the axial direction b.

Although the clamp body 6 is also attracted to the lower side by the solenoid 5, it is not completely in contact with the upper surface 4a due to the spring force of the hard ball 10 and the leaf spring 9. Therefore, when the current of the solenoid 5 is cut off, the shaft 2 is immediately braked without being affected by the remaining exciting force.

Next, when the shaft 2 is braked, the current flowing through the solenoid 5 is cut off so that the magnetic force acting on the clamp body 6 is not received. As a result, the clamp body 6 is biased toward the shaft 2 side by the spring force of the coil spring 8, the first uneven portion 2a and the second uneven portion 6d mesh with each other, and the shaft 2 is braked.

At this time, when the first uneven portion 2a and the second uneven portion 6d do not mesh with each other, if the load on the shaft 2 is small, the convex and concave portions are in pressure contact with each other.
The brake is applied. Further, when the load on the shaft 2 is large, the first concave and convex portion 2a and the second concave and convex portion 6d are engaged with each other with a shift of a half pitch, and the brake is reliably applied. In addition,
This deviation can be improved by reducing the pitch between the first uneven portion 2a and the second uneven portion 6d.

As described above, the clamp body 6 is used in this embodiment.
As a result, the shaft can be reliably braked on the shaft 2 of the cylindrical linear pulse motor, and the brake holding force can be increased and stabilized. Further, since the shaft 2 is braked when the solenoid 5 is not energized, the brake is automatically operated in the event of a power failure, and safety is guaranteed. Further, the structure of the brake mechanism is simple and the assembly can be facilitated.

Next, a modified example of the brake mechanism of the cylindrical linear pulse motor of the present invention will be described. The same components as those in the embodiment will be described with the same reference numerals.

FIG. 5 shows a shaft 11 of a cylindrical linear pulse motor and a clamp body 12 of a brake mechanism. The shaft 11 has a concave portion 11 which is a semi-spherical first concave and convex portion.
A large number of a are aligned in the axial direction and the circumferential direction. On the other hand, in the clamp body 12, convex portions 12a, which are second semi-spherical concave and convex portions that mesh with the concave portions 11a of the shaft 11, are formed at the same pitch. Other configurations are the same as those in the above embodiment.

Also in this modification, when the solenoid 5 is not excited, the clamp body 12 is biased toward the shaft 11 by the spring force of the coil spring 8, and the recess 1 of the shaft 11 is depressed.
1a and the convex portion 12a of the clamp body 12 mesh with each other to apply a brake. On the other hand, when the solenoid 5 is excited, the clamp body 12 receives a downward magnetic force and the shaft 1
It moves so as to rotate to the side opposite to 1, the engagement between the concave portion 11a and the convex portion 12a is released, and the brake is released.

As described above, also in this modification, the same effect as that of this embodiment is obtained. Further, since the uneven portion is spherical, it has an effect of smoothly engaging with each other. That is, in the present invention, various meshing shapes such as a bellows shape, a wavy shape, and a trapezoidal shape can be considered for the first uneven portion and the second uneven portion,
Further, the effect can be subtly changed by decreasing or increasing the pitch length and the groove depth.

The embodiments and modifications of the present invention have been described above. Of course, the present invention is not limited to these and various modifications can be made based on the technical idea of the present invention.

For example, although two clamp bodies 6 are used in the above embodiments, the number of clamp bodies may be one or three or more, and when four or more clamp bodies are provided, two clamp bodies are addressed. The first concavo-convex portion and the second concavo-convex portion may be arranged with the pitch shifted by a half pitch, or the brake mechanism 1 itself may be arranged in series with the shaft 2 and two or more thereof may be provided.

Although the clamp body 2 is provided above the solenoid 5 in the above-mentioned embodiments, the solenoid is provided perpendicularly to the axis of the shaft 2 (or a plane passing through the axis) and is provided behind the clamp body 2. However, it has the same effect as the embodiment.

Furthermore, although the inclined surface of the guide groove 6c of the clamp body 2 is a curved surface in the above embodiment, the inclined surface may be a flat surface.

[0035]

As described above, according to the present invention, the shaft of the cylindrical linear pulse motor can be reliably braked, and the brake holding force can be increased and stabilized. The structure is simple and the assembly is easy. Also, since the shaft is braked when the solenoid is not energized, the brake is automatically activated in the event of a power failure, ensuring safety.

[Brief description of drawings]

FIG. 1 is a front view showing a braked state of a brake mechanism of a cylindrical linear pulse motor according to an embodiment of the present invention.

[Fig. 2] Fig. 2 shows the same brake mechanism with the casing removed.
It is a perspective view showing a place where a brake is released.

FIG. 3 is a perspective view showing a first uneven portion of the shaft and a second uneven portion of the clamp body.

FIG. 4 is a sectional view taken along line XX in FIG.

FIG. 5 is a perspective view showing a first concavo-convex portion and a second concavo-convex portion of a brake mechanism of a cylindrical linear pulse motor according to a modification of the present invention.

FIG. 6 is a front view showing a conventional brake mechanism of a cylindrical linear pulse motor.

FIG. 7 is a front view showing a brake mechanism of a cylindrical linear pulse motor in another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Brake mechanism 2,11 Shaft 2a 1st uneven | corrugated part 5 Solenoid 6,12 Clamp body 6d 2nd uneven | corrugated part 8 Coil spring 11a Recess 12a Convex part

Claims (1)

[Claims] 1. A first concavo-convex portion is formed on a shaft of a cylindrical linear pulse motor, and a second concavo-convex portion that meshes with the first concavo-convex portion is formed on a clamp body disposed around the shaft. , One end of the clamp body is rotatably attached to the shaft member,
By urging the free end of the clamp body toward the axis of the shaft with an elastic member, the second concave-convex portion is brought into pressure contact with the first concave-convex portion to fix the shaft, and is attached to the clamp body. A cylinder formed by releasing the engagement between the first uneven portion and the second uneven portion by rotating the free end of the clamp body to the side opposite to the axis of the shaft by exciting the solenoid. Type linear pulse motor brake mechanism.