JPH0923679A - Robot-driving mechanism using linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a robot-driving mechanism having a high reliability and a low cost, by improving its structure using a linear motor. SOLUTION: A robot-machine 50 traveling drive mechanism 10 using a linear motor and having a traveling rail 20 and traveling table 40, wherein the two elements of the traveling rail 20 and traveling table 40 whereinto permanent magnet pieces 31 and excitation coils 32 of the linear motor, a guide block, a guide path, a mechanical stopping means 33 and the like are integrated in a body are formed previously, and by assembling only the two elements, the robot-driving mechanism 10 can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving mechanism for a robot using a linear motor, and more particularly, it is configured to linearly move a robot body using a traveling table and a traveling rail as basic structural elements. The present invention relates to a robot drive mechanism using a linear motor having a mechanical stopping means for surely and accurately stopping a robot body at a desired stop position while reducing the number of rail constituent parts as much as possible.

[0002]

2. Description of the Related Art A traveling device for traveling a robot body in a linear direction has been widely used, and has a linear feed drive mechanism including a servomotor, a rack and pinion mechanism, and a ball screw mechanism as a traveling drive means. Was widely used. However, in the linear drive mechanism using the rack and pinion mechanism and the ball screw mechanism as a transmission mechanism, a rack, a pinion, a ball screw, a ball nut, between the servo motor that constitutes the drive source and the traveling table that is the traveling body, Since many kinds of structural parts such as bearings are interposed, not only is manufacturing and assembling troublesome, but further improvement in running accuracy is required. For this reason, in recent years, a linear drive mechanism has been proposed in which a linear motor is used as a drive source and the interposition of a transmission mechanism between the driven body and the body is reduced, and a robot body is driven by this linear motor along a linear guide path. It constitutes a drive mechanism that drives the vehicle.

[0003]

However, even with the linear traveling drive mechanism of a robot using a linear motor as a drive source, which has already been proposed, smooth guiding performance in the linear traveling guide mechanism and an exciting coil portion constituting the linear motor are provided. Accurate setting of an appropriate working gap with the permanent magnet section over the entire traveling distance of the linear traveling drive mechanism still requires a complicated task, and similarly, a position detector on the linear traveling path is also required. Setting an appropriate amount of the detection gap between the linear scale and the detection head, which constitutes the above, also requires a troublesome work.

Further, since the linear motor of the linear traveling drive mechanism, the traveling table, the traveling rail, the traveling guide block, the guide path, the position detector and the like have a structure in which individual parts are gathered together, There is also a problem in that adjustments between the parts also impose a considerable burden on the robot manufacturing process and maintenance process. Furthermore, in the conventional linear travel drive mechanism that uses a linear motor as a drive source, the well-known dynamic braking method is used at the time of emergency stop or when the drive power supply of the linear motor is turned off. There was also the disadvantage that an inevitable coasting run would occur until the running table, which is the body, would stop, and a sudden stop would not be possible.

Accordingly, an object of the present invention is to provide a robot drive mechanism using a linear motor having a novel structure that solves the above-mentioned problems, satisfies the demands for improvement, and overcomes the disadvantages. It is something to do.

[0006]

In view of the above object, the present invention provides a robot drive using a linear motor that controls and travels a traveling table on which a robot body is mounted along a linear traveling rail. In the mechanism, the traveling table includes an excitation coil for the linear motor, a position detector for detecting a traveling position, a guide block for linear traveling, and mechanical braking for the traveling rail in response to a command signal. And a mechanical stop means for operating between them, and the traveling rail is extended in the traveling direction together with the magnet portion of the linear motor to give a traveling position signal to the position detector. A position detecting scale, a guide path that cooperates with the linear guide block, and a braking surface that cooperates with the mechanical stopping means to generate mechanical braking are integrally provided. Robot driving mechanism using linear motors have is provided.

According to the above construction, the traveling table is formed in a state where the exciting coil, the position detector, the guide block, the mechanical stopping means, etc. are integrally incorporated in advance, and the traveling rail is also the magnet portion of the linear motor. , Position detection scale,
Since the guideway, the braking surface, and the like are formed in advance, the linear traveling drive mechanism of the robot body can be configured with two parts, the traveling table and the traveling rail, and the assembly of the robot drive mechanism can be simplified. . In addition, by managing the manufacturing processing accuracy of both these elements,
It is possible to set the gap between the running rails within a certain predetermined value,
Adjustment of a working gap between the exciting coil of the linear motor and the magnet portion and a detection gap between the position detector and the position detecting scale can be omitted, and a smooth and highly accurate linear traveling mechanism can be obtained. . Moreover, by having the mechanical stopping means, the mechanical braking force can be applied not only when an emergency stop is required during a straight traveling of the traveling table but also when the traveling table is accurately stopped at a predetermined stop position. Alternatively, the stopping function of the linear motor and the mechanical stopping means cooperate to stop the operation by a strong stopping action.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below in detail based on the embodiments shown in the accompanying drawings. FIG. 1 is a plan view of an essential part of a robot drive mechanism using a linear motor according to an embodiment of the present invention, and FIG.
2 is a side view as seen from FIG. 2, FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1, and is a diagram for explaining the configuration of the linear motor and the position detection means, and FIG. 4 is 4-4 of FIG. FIG. 6 is a cross-sectional view taken along the line, which is a view for explaining the configuration of a mechanical stop means between the traveling table and the traveling rail, and FIG. 5 shows in detail the operating mechanism and structure of the brake leg in the mechanical stop means. FIG. 6 is a partial perspective view, and FIG. 6 is a cross-sectional view taken along the line 6-6 in FIG. 5 showing the engagement structure between the traveling table and the brake legs in detail.

Referring to FIGS. 1 and 2, in the present embodiment, the robot drive mechanism 10 is constructed by using the traveling rail 20 as a stationary element and the traveling table 40 as a traveling element. The traveling rail 20 extends along a desired straight line on the horizontal floor surface, although not limited thereto.
It is fixed to the floor or the like with a screw bolt or the like through the bolt hole 20a. A plurality of permanent magnet pieces 31 which are stationary elements of a linear motor 30 which is a driving source for linear traveling are extended along a linear path in a substantially central region of the surface of the traveling rail 20. Each of the permanent magnet pieces 31 is formed of a magnet piece in which both ends of a rhombus piece are cut off, and N poles and S poles are provided so as to be embedded and arranged alternately in the straight traveling direction. The exciting coil 32, which cooperates with the permanent magnet piece 31 of the linear motor 30 by being provided apart from the working gap G to generate a linear driving force, is an inner surface of the traveling table 40, that is, the traveling rail 20. It is provided with a structure buried in the surface side facing the surface of the (see FIG. 3).

The permanent magnet piece 3 of the linear motor 30 described above
A linear scale 21 for position detection in a traveling position detecting means is attached to one side of both sides of the surface of the traveling rail 20 in which 1s are linearly arranged, and integrated with the surface of the traveling rail 20 by an appropriate method such as embedding. It is provided in the state where it was opened. A position detector 22 that cooperates with the position detecting linear scale 21 to detect a position on a straight traveling road and emits a detection signal is attached to the inner surface side of the traveling table 40 as described later (see FIG. 3). ).

Further, the traveling table 40 integrally incorporates, for example, mechanical stopping means 33, which operates in response to an electrical command signal, at both front and rear ends (or either end) as viewed in the traveling direction. It is provided in the form. The mechanical stopping means 33 is interposed between the left and right L-shaped brake legs 34, 34, and both brake legs 34, and both ends thereof are the brake legs 3.
4 is composed of a coil spring or the like locked to the leg ends 34a, 34a, and the both brake legs 34, 34 are constantly moved to the stop state side.
An urging spring 35, a pair of series-connected exciting coils 36 and 36 (which exert an electromagnet function) fixed to the traveling table 40, and a pair of L-shaped brake legs 34 and 34 facing the side surface of the traveling rail 20. The brake pads 37 and 37 attached to the leg ends 34b and 34b are provided.

The mechanical traveling means 33 is normally operated by the urging force of the spring 35 as described above, so that the pair of brake legs 3 is normally provided.
4, 34 are attracted toward the braking surfaces 20b, 20b provided on the two side surfaces of the traveling rail 20, and therefore the brake pads 37, 37 are brought into pressure contact with the braking surfaces 20b, 20b to generate a friction braking force and travel. The table 40 is mechanically stopped. At this time, the exciting coils 36, 36 inserted and arranged inside the brake legs 34, 34 are maintained in a non-excited state. On the other hand, when both exciting coils 36, 36 are excited, the magnetic attraction force resists the urging force of the spring 35 and causes the brake legs 34, 34 to move to the braking surface 20 of the traveling rail 20.
The frictional braking force is released by separating them from b and 20b so that the traveling table 40 can travel.

Referring to FIGS. 5 and 6, one brake leg 34, the spring 35, and the inner hole 34c of the brake leg 34 in the mechanical traveling means 33 are inserted and arranged and an appropriate holder is provided. The exciting coil 36 fixed integrally with the traveling table 40 by 36c, the magnetic attraction plate 36a attached to one end wall of the inner hole 34c of the brake leg 34, and the brake leg 34 are attached to the traveling table 40. A slide mechanism 38 is shown in detail, which makes it possible to slidably move between the braking position and the braking release position and at the same time holds the brake leg 34 integrally with the traveling table 40. That is, when the exciting coil 36 is not excited, the brake leg 34 is moved toward the braking position with respect to the traveling table 40 by the biasing force of the spring 35, for example, via the dovetail groove-engaging slide mechanism 38 shown in FIG. In the Pa direction. Therefore, the brake pad 37 is pressed against the braking surface 20b of the traveling table 20 to mechanically stop the traveling table 40 with respect to the traveling rail 20. When the exciting coil 36 is excited,
The brake leg 34 slides in the braking release direction indicated by the arrow Pb by the magnetic attraction force acting between the excitation coil 36 and the attraction plate 36a of the brake leg 34. Therefore, since the brake pad 37 of the brake leg 34 is separated from the braking surface 20b of the traveling rail 20 and the mechanical stop is released, the traveling table 40 can travel straight along the traveling rail 20.

In the sliding mechanism 38, the sliding groove 38a formed on the brake leg 34 and the sliding rail 38b formed on the end surface of the traveling table 40 are slidably engaged in a dovetail groove engagement type. The dovetail groove engaging type is used for the brake legs 34 and the traveling table 4 by the structure.
It is also possible to obtain a structure in which 0 is held integrally.

In place of the representatively illustrated slide mechanism 38 described above, both brake legs 34, 34 are attached to the traveling table 40 via a pivoting pin, and are pivoted around the pivoting pin. It is also possible to adopt a configuration in which the mechanical stop means 33 is movably configured and integrally incorporated in the traveling table 40. In that case, the brake pads 37, 37 of the brake legs 34, 34 are always kept on both braking surfaces 20 b, 20 of the traveling rail 20 by the urging force of the spring 35.
It is pressed against b and exerts frictional braking force, and the exciting coil 3
The brake pads 37, 37 are separated from the braking surfaces 20b, 20b in response to the pivotal movement of the brake legs 34, 34 when the magnets 6, 36 are excited, and the braking force is released.

Further, as shown in detail in FIGS. 3 and 4, the traveling table 40 further includes left and right guide block portions 23, 23 integrally formed on the jaw-like portions on both side surfaces, and the guide blocks 23, 23 are provided. Is the braking surface 2 on both sides of the traveling table 20.
0b, 20b above the straight guide path 24
The ball is smoothly slidably engaged to guide the straight traveling of the traveling table 40 in a stable manner.

The upper surface of the traveling table 40 is formed as a mounting surface of the robot body 50, and the robot body 50 is fixed and erected on the traveling table 40 by appropriate fixing means such as a bolt screw and a positioning pin. 3 and 4 show the traveling rail 20 and traveling table 4 described above.
0 is a cross-sectional view showing in more detail various elements that are integrally provided in advance in FIG. 0. FIG. 3 shows a state in which the exciting coil 32 and the permanent magnet piece 31 in the linear motor 30 are arranged to face each other with a working gap G therebetween. And in this state, the exciting coil 32
It is the same as the well-known principle of operation of a linear motor that a linear driving force is exerted on the basis of a magnetic attraction action with the permanent magnet piece 31 when excited by the supply of electric current.

Further, when the traveling table 40 is traveling, the linear scale 21 integrally embedded and installed on the upper surface of the traveling rail 20 is read and detected by the traveling position detector 22 provided on the lower surface side of the traveling table 40. A position detection signal is transmitted from the position detector 22. Furthermore, the brake legs 34, 3 of the mechanical stop 33
4, the overall structure of the spring 35, the exciting coils 36 and 36, the brake pads 37 and 37, and the rail braking surfaces 20b and 20b is shown in detail in FIG.

According to the linear drive mechanism of the robot body 50 using the linear motor 30 having the above-described structure, the permanent magnet piece 31 of the linear motor 30 is previously incorporated and arranged integrally with the traveling rail 20, and the traveling position is also provided. The linear scale 21 for detection is also embedded in advance in advance. And
The braking surfaces 20b, 20b of the mechanical stopping means 33 and the guideway 2
4, 24 are also preformed integrally with the traveling rail.

On the other hand, the traveling table 40 is equipped with the exciting coil 32 of the linear motor 30, the position detector 22, the guide block portion 23, etc., which are integrally incorporated. Therefore,
Since the traveling rail 20 and the traveling table 40 are formed in advance as respective unitized elements, the robot drive mechanism itself assembles the traveling table 40 with respect to the traveling rail 20 using only these two elements. Can be formed by. From this, the number of parts constituting the drive mechanism 10 of the robot can be reduced.

Moreover, in assembling the robot drive mechanism 10, the operating air gap value and the position detection between the permanent magnet piece 31 of the linear motor 30 and the exciting coil 32 are detected in the state of each single element of the traveling rail 20 and the traveling table 40. Since the air gap values between the linear scale 21 and the position detector 22 of the means are designed and managed respectively, focus on the dimension management of the gap G between the traveling rail 20 and the traveling table 40. It is possible to form the robot drive mechanism 10 capable of exhibiting proper straight line traveling performance and also exhibiting highly accurate position detection performance.

Further, according to the robot driving mechanism using the linear motor of the present invention, the mechanical stopping means 33 is provided, and in response to the supply of the exciting current to the exciting coils 36, 36 as a command signal, Is a brake leg 34, 34 that is urged toward the braking position by a spring urging force.
Can be released from the braking surfaces 20b, 20b of the traveling rail 20 and the traveling table 40 can be freely traveled. On the other hand, when the excitation of the exciting coils 36, 36 is not released, the spring biasing force is immediately released. Thus, the brake pads 37, 37 of the brake legs 34, 34 are urged to the braking position, so that the traveling table 40 can be mechanically stopped. From this fact, the excitation coils 36, 36 are de-excited in an emergency such as when an abnormality occurs in the robot body traveling with the traveling table 40 or when an emergency stop is required due to an obstacle on the traveling path. It is also possible to prevent coasting of the robot body 50 together with the traveling table 40 and to make an emergency stop. As a result, the safety performance of the robot drive mechanism 10 is improved, and it is possible to contribute to the improvement of the reliability of the robot at the site where the robot is used.

The mechanical stopping means 33 is provided,
Moreover, by sufficiently increasing the stop braking force, the present invention is not stopped when the robot drive mechanism is used on a horizontal floor installation, and is inclined or, if necessary, according to the present invention on the vertical axis of the robot. Even when the robot body 50 is moved up and down under the action of gravity as a configuration incorporating a drive mechanism, it can be reliably stopped at a desired stop position, and the usage of the robot drive mechanism 10 can be expanded. Becomes

On the other hand, the traveling rail 20 according to the present invention is formed into a rail unit whose length is previously designed and set to a predetermined length, and a plurality of rail units are mutually connected according to the actual required length at the site where the robot is used. It can also be configured to be combined and assembled. Therefore, the traveling rail 20 is formed into a rail unit having an economical length and a large number of them are used in combination without making the length of the traveling rail 20 unnecessarily long, so that the cost of the rail unit can be reduced.

The present invention can be embodied as follows. The mechanical stop means includes a pair of brake legs that are constantly urged by a spring force toward a braking surface formed on both side surfaces of the traveling rail, and a pair of brake legs attached to the ends of the brake legs. A pair of brake pads and a pair of the brake legs are attracted by a magnetic force against the spring force from the braking position to the braking release position in response to the application of the exciting current, and the brake pads are separated from the braking surface of the traveling rail. An exciting coil is provided, and the pair of exciting coils is integrally fixed to the traveling table.

The brake leg of the mechanical stopping means is slidably engaged with and held on the end face of the traveling table via a slide mechanism, for example, a dovetail groove type slide mechanism.

[0027]

As can be understood from the above description of the embodiments, according to the present invention, the robot drive mechanism is simplified by simplifying the assembly by reducing the number of parts of the robot drive mechanism using the linear motor. As a result, it is possible to reduce the cost as well as improve the linear traveling performance, the detection of the desired traveling position, and the stopping performance at the desired position.
In addition, since the robot can be mechanically stopped suddenly and coasting can be prevented, the reliability of the robot as a drive mechanism for linear traveling can be significantly improved.

Moreover, since the traveling rail can be combined with a plurality of rail units to obtain a traveling rail having a desired length, cost reduction can be realized by unitizing the traveling rail. Has the effect.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a robot drive mechanism using a linear motor according to an embodiment of the present invention.

FIG. 2 is a side view taken along the line 2-2 of FIG.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 1, illustrating the configuration of a linear motor and position detecting means.

FIG. 4 is a cross-sectional view taken along line 4-4 of FIG. 1 and is a diagram for explaining the configuration of a mechanical stop means between the traveling table and the traveling rail.

FIG. 5 is a partial perspective view showing in detail the operating mechanism and structure of the brake leg in the mechanical stopping means.

6 is a cross-sectional view taken along line 6-6 of FIG. 5 showing the engagement structure between the traveling table and the brake legs in detail.

[Explanation of symbols]

 10 ... Robot drive mechanism 20 ... Traveling rail 21 ... Linear scale 22 ... Position detector 23 ... Guide block part 24 ... Guide rail groove 30 ... Linear motor 31 ... Permanent magnet piece 32 ... Excitation coil 33 ... Mechanical stop means 34 ... Brake Leg 35 ... Spring 36 ... Excitation coil 36a ... Adsorption plate 37 ... Brake pad 38 ... Slide mechanism 40 ... Traveling table 50 ... Robot body

Claims (2)

[Claims] 1. A robot drive mechanism using a linear motor for controlling and traveling a traveling table on which a robot body is mounted along a linear traveling rail, wherein the traveling table comprises an exciting coil of the linear motor and a traveling coil. A position detector for detecting a position, a guide block for linear traveling, and a mechanical stopping means for actuating mechanical braking between the traveling rail and the traveling rail in response to a command signal are integrally incorporated and provided. Also, the traveling rail includes a magnet portion of the linear motor, a position detecting scale extending in the traveling direction to give a traveling position signal to the position detector, and a guide path that cooperates with the linear guide block. A robot drive using a linear motor, characterized in that it is integrally provided with a braking surface that cooperates with the mechanical stopping means to generate mechanical braking. Structure. 2. The robot driving mechanism using a linear motor according to claim 1, wherein the traveling rail is configured to connect a plurality of rail elements having a predetermined length in a separable manner.