JP2010276060A - Linear motor device with brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small and lightweight linear motor device with a brake, easy in assembling, an adjustment and maintenance. <P>SOLUTION: A brake mechanism 8 is installed on an under surface of a table 6 for constituting a movable part. This brake mechanism 8 is constituted of a cylinder 81, a piston rod 85 integrally molded with a piston, a compression spring 83 for energizing the piston rod 85 and a brake pad 82. This brake mechanism 8 releases braking of the movable part by pulling up the brake pad 82 from an unillustrated base while energizing by contracting the compression spring 83 by impressing compressed air on an air chamber 84, and brakes the movable part by pushing the brake pad against the base by resiliency of the compression spring 83 by releasing the compressed air of the air chamber 84. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear motor device in which a movable part having a slider is driven along a rail with a driving force of a linear motor, and in particular, when the power is lost due to loss of power supply, the moving part is braked. The present invention relates to a linear motor device provided with a brake mechanism that can be safely fixed.

A linear motor device refers to a fixed magnet attached to a fixed member (hereinafter referred to as a fixed portion) of the device and an excitation coil attached to a movable member (hereinafter referred to as a movable portion) with an air gap therebetween. It is an apparatus configured to generate a linear driving force in the movable direction during excitation by being arranged so as to face each other.
This linear motor device is used in various industrial fields such as machine tools and conveyance facilities, taking advantage of its high-speed and high-accuracy responsiveness. In such a linear motor device, unlike the ball screw drive and rack & pinion drive, the fixed part and the movable part are in contact with each other only via the guide part composed of rails and slides, and when the power is cut off, etc. Since there is a problem that when the linear motor loses driving force when the current is not energized, the movable part is free to move, so it is common to provide a brake means that operates when the current is not energized.
As a conventional brake means, when energized, the brake is released by separating the brake pad from the friction engagement part with an electromagnet against the urging force of the coil spring, and when the coil is not energized, the magnetic force of the electromagnet is lost. There has been proposed one in which a brake pad is frictionally engaged with a friction engagement portion by force to perform a brake operation. (For example, Patent Document 1)

JP 2003-301872 (paragraph 0015)

In such a brake mechanism of the linear motor device, the main purpose is to stop the movable portion when the power is cut off, and thus it is necessary to generate a large braking force.
To that end, it is only necessary to press the brake pad against the frictional engagement part with a strong spring when the power is cut off. However, since this is always separated by the electromagnet when energized, it is necessary to always supply a considerable amount of power to the electromagnet. There was a vicious circle in which the electromagnets became larger and the moving parts became heavier.
In addition, since friction sliding parts are used for the brake pads, it is necessary to machine the parts with high precision, and the brake mechanism assembly requires fine adjustment, making it difficult to manufacture and expensive to manufacture. was there.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a linear motor device including a brake mechanism that is small and lightweight and that is easy to manufacture and maintain.

The linear motor device according to the present invention is a linear motor device in which a movable part provided with an exciting coil freely travels on a fixed part provided with a magnet and a rail by a driving force of the linear motor.
On the surface where the movable part faces the fixed part,
A brake pad that presses against the fixed part to brake the movable part;
A piston rod connected to this brake pad;
A piston connected to this piston rod;
A spring for biasing the piston rod;
A brake mechanism including a cylinder with a built-in piston;
The piston rod is housed in the cylinder while the spring is biased by press-fitting the fluid into the cylinder or discharging the fluid from the cylinder to release the braking of the movable part,
By releasing the positive or negative pressure of the fluid in the cylinder, the urging force of the spring is released, and the piston rod is protruded to brake the movable part.

The linear motor device according to the present invention is
On the surface where the movable part faces the fixed part,
A brake pad that presses against the fixed part to brake the movable part;
A piston rod connected to this brake pad;
A piston connected to this piston rod;
A spring for biasing the piston rod;
A brake mechanism including a cylinder with a built-in piston;
The piston rod is housed in the cylinder while the spring is biased by press-fitting the fluid into the cylinder or discharging the fluid from the cylinder to release the braking of the movable part,
By releasing the positive or negative pressure of the fluid in the cylinder, the spring is released and the piston rod is protruded to brake the movable part. Easy maintenance.

1 is a perspective view of a linear motor device according to Embodiment 1 of the present invention. It is a front view of the linear motor apparatus by Embodiment 1 of this invention. It is sectional drawing which cut | disconnected the slider and rail of the linear motor apparatus by Embodiment 1 of this invention perpendicularly | vertically with respect to the running direction of a movable part. It is a figure which shows the structure of the slider, rail, and ball | bowl of the linear motor apparatus by Embodiment 1 of this invention. 1 is a front view (during braking) of a linear motor device according to a first embodiment of the present invention. It is sectional drawing of the brake mechanism in the braking state in Embodiment 1 of this invention. It is a figure which shows the effect | action of the braking force of a brake mechanism in Embodiment 1 of this invention. It is a figure which shows the modification of the brake mechanism in Embodiment 1 of this invention. It is a figure which shows the modification of the brake mechanism in Embodiment 1 of this invention. It is a figure which shows the modification of arrangement | positioning of the brake mechanism in Embodiment 1 of this invention. It is a side view of the brake mechanism in Embodiment 2 of this invention.

Embodiment 1 FIG.
A linear motor device 1 according to Embodiment 1 of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of a linear motor device 1 (hereinafter referred to as device 1), and FIG. 2 is a front view of the device 1 as viewed from the traveling direction of the device 1.

A fixed magnet 3 is provided on the base 2, and rails 4 are arranged on both sides of the fixed magnet 3.
At the four corners of the lower surface of the table 6, sliders 5 having a U-shaped section are provided.
By guiding the slider 5 to the rail 4, the table 6 can move along the rail 4.

FIG. 3 is a cross-sectional view of the slider 5 and the rail 4 cut perpendicular to the traveling direction of the movable part.
FIG. 4 is a view of the slider 5 and the rail 4 of FIG. 3 as viewed from the direction A, and the lower part of the slider 5 (portion indicated by a broken line) is not shown for explanation.
Each of the rail 4 and the slider 5 is provided with an opposing V-shaped groove.
The ball 11 is supported at a total of four points on the rail 4 side and the slider 5 side, respectively, and a restriction is provided at both ends of the groove portion of the slider 5 so that the ball does not jump out of the slider 5. As the ball 11 rolls, the slider 5 can move smoothly along the rail 4.

Returning to FIG.
An excitation coil 7 is disposed at a position facing the lower surface of the table 6 and the fixed magnet 3.
An air gap is provided between the fixed magnet 3 and the excitation coil 7 so that the fixed magnet 3 and the excitation coil 7 do not come into contact with each other.
As shown in the figure, a brake mechanism 8 is attached to the lower surface of the table 6 between the left and right ends of the exciting coil 7 and the slider 5.
The illustrated brake mechanism 8 shows a state in which braking is released.

A position indicator 9 is arranged on the base 2 in parallel with the moving direction of the table 6, and a sensor head 10 for reading the current position information from the position indicator 9 is attached to the table 6.
Here, the base 2, the fixed magnet 3 fixed to the base 2, the rail 4 and the position indicator 9 are fixed members, and are hereinafter referred to as a fixed portion.
On the other hand, the table 6, the excitation coil 7, the brake mechanism 8 and the slider 5, and the sensor head 10 attached to the table 6 are movable members, and are hereinafter referred to as movable parts.

Next, a mechanism for driving the device 1 will be described.
The controller shown in FIG. 2 obtains the current position information of the movable part from the sensor head 10.
A controller that receives target position information to move the movable part from a control device (not shown) controls the magnetic pole of the exciting coil 7 and generates a linear driving force in the movable direction between the exciting coil 7 and the fixed magnet 3. . Due to this driving force, the movable portion moves along the rail 4.
The controller can drive the movable portion to an arbitrary position at an arbitrary speed by adjusting the amount of electric power output to the exciting coil 7 based on the position information from the sensor head 10.

The structure of the brake mechanism 8 will be described.
FIG. 5 is a front view when the brake mechanism 8 of the device 1 is in a braking state. FIG. 6 is a cross-sectional view of the brake mechanism 8 in a braking state.
The brake mechanism 8 includes a cylinder 81, a brake pad 82, a compression spring 83, and a piston rod 85.
A compression spring 83 is passed through a piston rod 85 protruding downward from the inside of the cylinder 81, and a brake pad 82 is attached to the lower end thereof. In the present embodiment, the piston rod 85 is integrated with a piston that slides in the cylinder.

Next, the operation of the brake mechanism 8 will be described.
As a power source of the piston rod 85, a commonly used compressed air source 15 may be used, or cooling water (not shown) of the exciting coil 7 may be used.
During energization, the brake pad 82 can be lifted with the compression spring 83 biased by applying compressed air from the compressed air source 15 to the air chamber 84 of the cylinder 81 by the operation of the electromagnetic valve 14.
By turning off the solenoid valve 14, the compressed air applied to the inside of the cylinder 81 is released, and the piston rod 85 is pushed down by the restoring force of the compression spring 83.

FIG. 7 is a diagram showing the action of the braking force when the brake mechanism 8 is in the braking state.
The brake pad 82 is strongly pressed against the base 2 by the repulsive force of the compression spring 83. The frictional force 33 acting between the brake pad 82 and the base 2 at this time becomes the main braking force of the brake mechanism 8.

When the brake pad 82 is pressed against the base 2, a reaction force 32 is applied to the entire movable part.
Since the relationship between the slider 5 and the rail 4 is the structure as described above with reference to FIG. 3, the reaction force 32 becomes a frictional force 34 between the rail 4 and the slider 5 via the ball 11.
Thus, in the present embodiment, the braking force can be distributed to the two brake pads 82 and the four sliders 5.

  In order to release the brake, the solenoid valve 14 is operated by energizing as described above, the compressed air is again applied to the air chamber 84 to raise the piston rod 85, and the brake pad 82 is pulled away from the base 2.

With the above configuration, since the braking is released during energization when the device 1 is in operation, the movable part can move, and when the linear motor loses the driving force due to power interruption or the like, the brake is activated and the movable part is moved. Can be fixed.
Further, as another example of the piston rod 85 that expands when not energized, a configuration of a brake mechanism 108 in which a compression spring 83 is embedded in the cylinder 81 as shown in FIG. Even in this configuration, the same operation as that of the brake mechanism 8 described above is possible.
Further, the compression spring 83 may be replaced with a disc spring 86 as shown in FIG. According to this configuration, a spring having a larger spring constant can be selected even if the size is the same as that of the compression spring 83.
Since the pressing force of the brake pad 82 to the base 2 can be increased, a strong braking force can be obtained.

As for the position where the brake mechanism 8 is disposed, FIG. 2 shows that the brake mechanism 8 is disposed between the exciting coil 7 and the slider 5, but the brake mechanism 8 is disposed outside the slider 5 as shown in FIG. You may arrange in.
In this embodiment, the compressed air is applied to the air chamber 84. However, the air may be evacuated from the air chamber 87 side shown in FIG. .
Furthermore, the spring that biases the piston rod 85 may be configured to use a tension spring.

Since the brake mechanism 8 includes a small number of parts such as the cylinder 81, the brake pad 82, the compression spring 83, and the piston rod 85, the linear motor device 1 that is simple and easy to assemble and maintain can be provided at low cost.
In contrast, the electromagnet used in the conventional brake mechanism operates by passing a current through a copper wire wound around the iron core, whereas the cylinder 81 used in the present invention has a hollow structure. Therefore, the brake mechanism 8 for the linear motor device 1 that is small and lightweight can be realized.
In addition, once the braking of the brake mechanism 8 is released, the brake can be operated simply by opening the solenoid valve 14, so that it is not always necessary to attract the brake with an electromagnet as in the conventional example, greatly reducing power consumption. it can.
In addition, since the brake operation is performed by pressing the brake pad 82 against the upper surface of the base 2, the brake pad portion does not require any parts that require high precision such as friction sliding parts, and fine adjustment is required during assembly. Therefore, it is easy to manufacture.
Furthermore, since the type of spring can be easily changed by removing the brake pad, the braking force can be adjusted flexibly according to the weight of the device attached to the table.

Embodiment 2. FIG.
The linear motor device according to the second embodiment of the present invention will be described focusing on the differences from the first embodiment.
FIG. 11 is a side view of the brake mechanism 308.
A plurality of spring guide shafts 88 are fixed to the upper surface of the large brake pad 182, and a compression spring 183 is passed through each of them. Although not shown, the table 6 is provided with a hole through which the spring guide shaft 88 can slide up and down. The method of applying compressed air in the cylinder 81 or evacuating the air from the cylinder 81 is the same as in the first embodiment.
According to this configuration, the number of compression springs can be increased and a larger brake pad 282 can be attached as compared with the first embodiment.
Thereby, the pressing force of the brake pad 282 to the base 2 can be easily increased, and a strong braking force can be obtained.

Further, by attaching the brake mechanism 308 to the table 6 so that the left-right direction in FIG.
That is, if a braking operation is performed during movement, the brake pad 182 slides in the left-right direction in the figure while pressing the base 2 until the movable part stops. At this time, the brake pad 182 receives a larger force at the front portion in the moving direction due to the frictional force acting between the brake pad 182 and the base 2.
That is, the piston rod 185 is applied with a force acting not only in the vertical direction in the figure but also in the horizontal direction during braking.
In this embodiment, the force applied to the piston rod 185 and the cylinder 81 can be received by the spring guide shaft 88 arranged at a position different from the cylinder 81 and the side surface of the hole formed in the table 6. It is possible to disperse and secure more stable braking force and rigidity.

1 Linear motor device, 2 bases, 3 fixed magnets, 4 rails, 5 sliders,
6 tables, 7 excitation coils, 8, 108, 208, 308 brake mechanism,
81 cylinder, 82, 182 brake pad, 83, 183 compression spring,
84,87 Air chamber, 85,185 Piston rod, 86 Belleville spring,
88 Guide shaft for spring, 9 Position indicator, 10 Sensor head, 11 Ball,
14 Solenoid valve, 15 Compressed air source, 32 reaction force, 33, 34 Friction force.

Claims (7)

In the linear motor device in which the movable part including the excitation coil travels freely on the fixed part including the magnet and the rail by the driving force of the linear motor,
On the surface where the movable part faces the fixed part,
A brake pad that presses against the fixed part to brake the movable part;
A piston rod connected to this brake pad;
A piston connected to this piston rod;
A spring for biasing the piston rod;
A brake mechanism including a cylinder containing the piston;
The piston rod is housed in the cylinder while urging a spring by press-fitting a fluid into the cylinder or discharging the fluid from the cylinder to release the braking of the movable part,
A linear motor device that releases the positive or negative pressure of the fluid in the cylinder, thereby releasing the bias of the spring and causing the piston rod to protrude to brake the movable portion. The linear motor device according to claim 1, wherein the spring is provided in the cylinder. The linear motor device according to claim 1, wherein the spring is provided between the brake pad and the cylinder. The linear motor device according to claim 1, wherein the spring is provided between a table constituting the movable portion and the brake pad. The linear motor device according to any one of claims 1 to 4, wherein the spring is a compression spring. The linear motor device according to any one of claims 1 to 4, wherein the spring is a disc spring. The linear motor device according to any one of claims 1 to 6, wherein the pressure in the cylinder is released by an electromagnetic valve.

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