JPH04236161A - Dc linear motor - Google Patents

Abstract

PURPOSE:To obtain an inexpensive miniature DC linear motor which exhibits brake function even under unexpected conditions, e.g. power interruption, by disposing a brake unit on a line so that it is juxtaposed to a thrust generating exciting coil. CONSTITUTION:Brake exciting coils 10a, 10b are excited simultaneously under normal operation. Consequently, attraction force functioning between the exciting coils 10a, 10b and an iron plate 11 causes a brake pad 12 to be released from a field permanent magnet 3 thus ensuring an air gap. When the operation of DC linear motor is interrupted, the brake exciting coils 10a, 10b are brought into no-excited state and released from the iron plate 11. A spring 13 carried on the iron plate 11 causes the brake pad 12 to be pressed against the field permanent magnet 3 thus keeping the runner 9 of the DC linear motor at an original position.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear DC motor used in positioning devices and moving devices.

0002

2. Description of the Related Art FIG. 4 shows the principle of the construction of a conventional linear DC motor, which is called a moving coil type motor and is constructed as follows. A moving coil type linear DC motor has a magnetic plate 2, which is narrower than the width of the base 1, fixed to a base 1 on a long plate, and an N pole magnetized in the thickness direction. A long plate-shaped field permanent magnet 3 having a large number of field permanent magnets 3 of S poles alternately arranged in the longitudinal direction is fixed as shown in FIG.

A U-shaped running magnetic yoke 4 is provided opposite to the field permanent magnet 3.
A running roller 5 rotatably supported by a shaft on the side surface of the magnetic plate 2 is guided by the side surface of the magnetic plate 2 and smoothly runs in the running direction. On the inner surface of the traveling magnetic material yoke 4, rectangular armature coils 6 as shown in FIG. 6 are arranged adjacent to each other so as not to overlap each other, and a printed circuit board 7 is attached and fixed to the lower surface thereof. A position detection element 8 (for example, a Hall element, a Hall IC) is installed on the printed circuit board 7 at a position where the body part contributing to thrust and the body part not contributing to thrust cross.
A position detection mechanism is formed by installing a magnetoelectric transducer (e.g., magnetoelectric transducer) by soldering.

As shown in FIG. 5, the position detection element 8 faces the side surface of the driving magnetic pole 3a of the field permanent magnet 3, and detects the leakage magnetic flux of the driving magnetic pole 3a of the north or south pole. and outputs an appropriate signal to a drive circuit (not shown). Therefore, when the driving power of the moving coil type linear DC motor is turned on, a current flows through the armature coil 6 constituting the armature, and a leftward or rightward thrust acts on the running element 9. Travels to a predetermined position to the left or right.

[0005]

A conventional linear DC motor is incorporated into a positioning device or a moving device, but depending on the arrangement of the device, the incorporated linear DC motor may be arranged at an angle. In such an installation situation, if the power of the linear DC motor that is the drive source is turned off, the linear motor itself does not have the function to maintain the current position, and the linear DC motor's running element will initially It has the disadvantage that it may deviate from the set position. Therefore, it is necessary to add a separate holding function to the positioning device or moving device in case an unexpected situation such as a power outage occurs.

[0006]An object of the present invention is to provide an excitation coil, which is arranged in parallel in the traveling direction of a stator core of a linear DC motor having field permanent magnets arranged in a straight line, in contrast to a conventional linear DC motor. It is equipped with a brake pad with an iron plate that is attracted by an attraction action, and a brake device that has a spring that acts to push the brake pad against the opposing permanent magnet when the excitation coil is not energized.During normal operation when a driving power source is present, The brake pad is released from the opposing permanent magnet by the iron plate attraction force generated by the excitation of the brake excitation coil, and when the linear DC motor stops operating, the brake pad is pressed against the field permanent magnet by the action of the spring, thereby disabling the brake action. It is an object of the present invention to provide a small and inexpensive linear DC motor having a braking function. [Structure of the invention]

[0007]

[Means for Solving the Problems] In order to solve the above problems, in the present invention, permanent magnets for field are arranged in the traveling direction of the stator core of a running element of a linear DC motor having field permanent magnets arranged in a straight line. The brake device is arranged in a straight line so as to be juxtaposed with the excitation coil for thrust generation.

A brake pad with an iron plate is arranged between the brake coil and the permanent magnet for the field, and when the brake excitation coil is not energized, the iron plate of the brake pad with the iron plate has a
A spring is arranged that acts in the direction of pressing the brake pad with iron plate against the opposing permanent magnet for the field. therefore,
During normal operation when the power is on to drive the linear DC motor, the brake excitation coil is simultaneously excited, and the magnetic flux generated from the excitation coil passes through the iron plate, the paired brake excitation coil, and the running magnetic yoke. Return to the original brake excitation coil. In this way, the attractive force acting between the brake excitation coil and the iron plate releases the brake pad from the field permanent magnet so as to maintain an air gap.

When the operation of the linear DC motor is stopped, the excitation of the excitation coil for thrust generation is stopped, and at the same time, the excitation coil for the brake is also de-energized, and the excitation coil for the brake and the iron plate are released, and the iron plate is Due to the action of the attached spring, the brake pad is pressed against the field permanent magnet, and a brake is applied between the brake pad and the field permanent magnet to maintain the running element of the linear DC motor in its original position.

0010

[Operation] In the linear DC motor of the present invention configured as described above, the excitation coil for thrust generation is arranged in the direction of movement of the stator core of the linear DC motor, which has field permanent magnets arranged in a straight line. Brake devices including excitation coils for brakes are arranged in parallel so that they are juxtaposed to each other. A brake pad with an iron plate is arranged between the excitation coil for the brake and a permanent magnet for the field, and when the excitation coil for the brake is not energized, the brake pad with the iron plate is placed in a field that faces the brake pad with the iron plate. It has a spring that acts in the direction of pressing against the permanent magnet. Therefore, during normal operation excitation when the power is on to drive the linear DC motor, the brake excitation coil is also excited at the same time, and the magnetic flux generated from the excitation coil is transmitted to the iron plate, the paired brake excitation coil, and the running magnet. It passes through the body yoke and returns to the original brake excitation coil.

[0011] The brake pad is released from the field permanent magnet by the attractive force acting between the brake excitation coil and the iron plate so as to maintain an air gap. When the linear DC motor stops operating, the excitation of the excitation coil for thrust generation is stopped, and at the same time, the excitation coil for the brake is also de-energized, and the excitation coil for the brake and the iron plate are released and attached to the iron plate. Due to the action of the spring, the brake pad is pressed against the field permanent magnet, and a brake is applied between the brake pad and the field permanent magnet to maintain the original position of the running element of the linear DC motor.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 3.

As shown in FIGS. 1 to 3, the excitation coil 6 for thrust generation is placed in parallel with the excitation coil 6 for thrust generation, which is arranged in the advancing direction of the stem core of a linear DC motor having permanent magnets 3 for field arranged in a straight line. Brake excitation coil 1
0a and 10b are arranged in parallel. Between the brake excitation coils 10a, 10b and the field permanent magnet 3,
A brake pad 11 with an iron plate is arranged, and a brake excitation coil 10 is mounted on the iron plate 12 of the brake pad 11 with an iron plate.
When a and 10b are not energized, the brake pad with iron plate 1
It has a spring 13 that acts in a direction that presses the magnetic field permanent magnet 1 against the field permanent magnet facing the spring 13 to produce a braking action.

In the linear DC motor of this embodiment configured as described above, the excitation for thrust generation is arranged in the traveling direction of the stator core of the linear DC motor, which has field permanent magnets arranged in a straight line. Brake excitation coils 10a and 10b are arranged in parallel so as to be juxtaposed to the coil 6. The brake excitation coils 10a, 10b
Brake pad 1 with iron plate is placed between
1 is disposed on the iron plate 12 of the brake pad 11 with iron plate, and when the excitation coils 10a and 10b for brake are not energized, the brake pad 11 with iron plate 11 is pressed against the field permanent magnet 3 facing it, and the brake is applied. It has a spring 13 that acts in a direction that causes .

Therefore, during normal operation when the power is turned on to drive the linear DC motor, the brake excitation coils 10a and 10b are also excited at the same time. The magnetic flux generated from the excitation coil 10a passes through the iron plate 11, the paired brake excitation coil 10b, and the running magnetic yoke 7, and returns to the original brake excitation coil 10a. In this way, the brake pad 12 is released from the field permanent magnet 3 by the attraction force acting between the brake excitation coils 10a, 10b and the iron plate 11 so as to secure an air gap.

When the operation of the linear DC motor is stopped, the excitation of the excitation coil 6 for generating thrust is stopped, and at the same time,
The brake excitation coils 10a, 10b are also in a non-excited state, and the brake excitation coils 10a, 10b and the iron plate 11
is released, the brake pad 11 is pressed against the field permanent magnet 3 by the action of the spring 13 provided on the iron plate 11, and the brake pad 11 is applied with the field permanent magnet 3, causing the linear DC motor to run. It functions to maintain the child 9 in its original position.

In the linear DC motor of this embodiment described above, the linear DC linear DC motor has field permanent magnets arranged in a straight line, and is arranged in parallel with the excitation coil for thrust generation, which is arranged in the traveling direction of the stator core. It has a brake device to do so.

Therefore, during normal operation when the power is turned on to drive the linear DC motor, the brake excitation coils 10a, 10b are also excited at the same time, and the attraction acting between the brake excitation coils 10a, 10b and the iron plate 12 is The force releases the brake pad 11 from the field permanent magnet 3 so as to secure an air gap.

When the operation of the linear DC motor is stopped, the brake excitation coils 10a and 10b are also de-energized, the brake excitation coils 10a and 10b and the iron plate 12 are released, and the action of the spring 13 provided on the iron plate 12 is released. As a result, the brake pad 11 is pressed against the field permanent magnet 3 and acts as a brake between the field permanent magnet 3 and has the effect of maintaining the running element 9 of the linear DC motor in its original position.

Therefore, conventional linear DC motors do not have the power to hold the original position when the drive power is turned off, and when incorporated into a moving device, even if the moving device is used to position the motor, it is susceptible to unforeseen situations such as power outages. When this occurs, the position of the travel element would be displaced, but this can be prevented by the present invention.

[0021]

As described above, according to the present invention, when the operation of the linear DC motor is stopped, the excitation of the excitation coil for thrust generation is stopped, and at the same time, the excitation coil for the brake is also in a non-excited state. , the excitation coil for the brake and the iron plate are released, and the brake pad is pressed against the permanent magnet for the field by the action of the spring provided on the iron plate, and the brake is operated between the permanent magnet for the field. Since the linear DC motor's running element is held in its original position, there is no force to hold it in its original position when the drive power is turned off, and if it is incorporated into a moving device, even if the moving device is used for positioning, unexpected situations such as power outages may occur. Even when something like this occurs, it is possible to prevent the position of the travel element from shifting. Furthermore, there is also the effect that there is no need to separately provide a brake function in the positioning device or the like.

[Brief explanation of the drawing]

FIG. 1 is a top view of a linear DC motor of the present invention.

FIG. 2 is a side view of the linear DC motor of the present invention.

FIG. 3 is a sectional view of a brake device incorporated in the linear DC motor of the present invention.

FIG. 4 is a top view of a conventional linear DC motor.

FIG. 5 is a sectional view of a conventional linear DC motor.

FIG. 6 is a perspective view of the armature coil.

[Explanation of symbols]

3 Permanent magnet for field 10 Brake device 10a, 10b Excitation coil for brake, 11 Brake pad 12 Iron plate 13 Spring

Claims (1)

[Claims] Claim 1: In a linear DC motor having field permanent magnets arranged in a straight line, a brake excitation coil is placed side by side in the direction of movement of the stator core, and the brake is attracted to the coil side by the brake excitation coil. It is equipped with an elastic body that acts in a direction to push the pad and the brake pad against the opposing permanent magnet when the excitation coil is not energized, and during normal operation when a drive power source is present, the brake pad is pushed against the opposing permanent magnet by the ripple force caused by the excitation of the excitation coil for the brake. A linear DC motor is characterized in that it has a braking function in which the brake pad is released from a permanent magnet for a field, and when the operation is stopped, the brake pad is pressed against the permanent magnet for a field by the action of an elastic body, thereby acting as a brake.