JPH074726B2 - Table transfer device with linear motor - Google Patents

Description

The present invention relates to a table transfer device with a linear motor used in, for example, industrial robots, various machine tools, and the like.

(Prior Art) Conventionally, as a table transfer device of this type, a movable table is movably supported by a base through a linear bearing, and a linear pulse motor as a drive unit is interposed between the base and the movable table. What is dressed is known. By using a linear motor in this way, it is possible to simplify the device by eliminating the need for a feed mechanism such as a ball screw and to accurately hold the movable table at a predetermined stop position by the magnetic attraction force of the motor itself. It is designed for highly accurate positioning. The linear pulse motor is composed of a mover and a stator having fixed teeth provided at a constant pitch in the moving direction of the movable table, and enables fine-precision driving with high precision based on the pitch of the fixed teeth. .

(Problems to be Solved by the Invention) However, in the case of such a conventional example, the mover is moved by the length of the stator, and the portion of the stator not facing the mover is Since it is exposed to the outside, if a tool or the like falls onto the upper surface of the stator at the time of inspection, for example, the fixed teeth may be damaged. Further, as it is used for a long period of time, dust easily enters the groove between the fixed teeth of the stator. On the other hand, the gap between the mover and the stator is very small, and the dust accumulated in the groove interferes with the mover, and in the case of metal powder, the magnetic flux leaks, hindering the smooth operation of the movable table. There is a problem that the positioning accuracy also deteriorates.

In order to remove such dust accumulated on the stator, it is conceivable to attach a wiper to the movable table and scrape off the dust adhering to the surface of the stator as the movable table moves. However, even if the wiper is attached, it is not possible to remove even the dust in the groove between the fixed teeth, and the tip of the wiper bumps against the fixed tooth, which damages the wiper and also damages the edge of the fixed tooth. Bring problems.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to protect the fixed teeth of the stator and to move them into the groove without changing the drive characteristics of the linear motor. It is an object of the present invention to provide a table transfer device with a linear motor capable of preventing the intrusion of dust.

(Means for Solving Problems) In order to achieve the above object, in the present invention, a movable table is movably supported on a base through a linear bearing, and movable between the base and the movable table. In a table transfer device with a linear motor in which a linear motor consisting of a child and a stator having fixed teeth provided at a constant pitch in the moving direction of the movable table, the magnetic attraction force between the stator and the mover is A dustproof cover made of a non-magnetic material having a thickness that is not obstructed is provided in a fixed state in a range covering at least the fixed teeth on the stator, and a scraping member for scraping dust on the dustproof cover is provided on the movable table side. It is characterized by being provided.

(Operation) Therefore, even if an impact is applied to the stator, the fixed teeth are protected by the dustproof cover. Further, the dust cover prevents dust from entering the groove between the fixed teeth of the stator. Further, as the movable table moves, the scraping member slides on the surface of the dustproof cover, and the dust adhering to the dustproof cover is scraped off to remove the dust.

Further, since the dustproof cover is made of a non-magnetic material and has a thickness that does not impede the magnetic attraction force, the drive characteristics of the linear motor do not change.

(Example) Below, this invention is demonstrated based on the Example shown in figure. 1 to 8 showing a table transfer device with a linear motor according to a first embodiment of the present invention, 1 is a long base, on which a movable table 2 and a linear bearing 3 are attached.
It is movably supported in the longitudinal direction of the base 1 via. That is, a pair of raceways 4, 4 extending in the longitudinal direction over the entire length are arranged in parallel with each other on both side edges of the base 1, and these raceways 4, 4 are attached to the movable table 2. It is held by a pair of linear bearings 3,3, and the movable table 2 is slidable along the rails 4,4. The upper surfaces of the rails 4, 4 are assembled so as to be flush with the upper surface of the base 1 in the same plane.

As shown in FIG. 6, the linear bearings 3, ... Have a bearing block 3c having two ball rolling grooves 3a, 3a on one side and ball escape holes 3b, 3b provided therein,
It consists of a cage 3d that holds two rows of loaded balls, and side lids 3e and 3e that connect the ball rolling grooves 3a and 3a to the ball escape holes 3b and 3b. Ball rolling groove 3
It circulates between a and 3a and ball escape holes 3b and 3b. The contact angle α between the ball rolling grooves 3a, 3a and the loaded ball 3f is approximately 45 degrees, but is not limited to 45 degrees and may be in the range of 30 to 60 degrees.

Numeral 5 is a clearance adjusting bolt that presses one of the linear bearings 3 toward one of the way 4 and causes the reaction of the pressing force to move the linear bearing 3 on the opposite side to the other way 4 through the movable table 2. Press to load ball 3f,…
Preload is applied to the.

On the other hand, a linear motor 6 is provided between the base 1 and the movable table 2.
Is intervening. As the linear motor 6, a linear pulse motor is used in this embodiment, and the mover 7 and the stator 8 are
It is configured to operate by inputting a pulse to the mover 7 from a pulse generation source (not shown). The stator 8 is mounted on the base 1 over its entire length, and fixed teeth 8a, ... Are engraved on the upper surface of the stator 8 at a predetermined pitch in the moving direction of the movable table 2. There is. As for the upper surface of the stator 8, the upper surface of the base 1 and the upper surfaces of the raceways 4, 4 are arranged on substantially the same plane, and the width thereof is substantially the same as the width of the mover 7, and both side edges of the base 1 are arranged. It is attached to the central part that leaves.

On the other hand, a mover 7 is attached to the lower surface of the movable table 2 so as to face the stator 8. Each mover 7 is a permanent magnet
7a is interposed in the center, and two magnetic cores are arranged to face each other on the left and right sides, and one magnetic core is a permanent magnet.
The first magnetic pole 7b and the second magnetic pole 7c magnetized to the N pole by 7a are formed, and the third magnetic pole 7d and the fourth magnetic pole 7e magnetized to the S pole by the permanent magnet 7a are formed on the other magnetic core. Are formed.

A dustproof cover 9 made of a nonmagnetic material is fixed to the stator 8 to cover the grooves 8b formed between the fixed teeth 8a. The dustproof cover 9 is a thin plate and is fixed to the upper surface of each fixed tooth 8a, ... Of the stator 8 by adhesion or the like to shield the grooves 8b ,. As the dustproof cover 9, a stainless plate, a plastic sheet, or the like is used. The dust cover 9 is formed to a thickness that does not hinder the magnetic attraction between the stator 8 and the mover 7, and its surface is attached so as not to interfere with the mover 7. However, if the dustproof cover 9 is made of a low friction member, it may come into contact with the mover 7. In this embodiment, the width of the dustproof cover 9 is formed to be equal to the width of the stator 8, and the dustproof cover 9 is assembled so that its upper surface is flush with the upper surface of the base 1.

On the other hand, the movable member 7 is provided with a scraping member 10 whose tip slides on the dustproof cover 9 to scrape off dust on the surface of the dustproof cover 9. The scraping member 10 is formed by baking a rubber plate 10b on a metal plate 10a such as an iron plate. In this embodiment, the scraping member 10 is attached to the front and rear end surfaces of the movable table 2 with bolts 10c. The width of the rubber 10b of the scraping member 10 is formed to be the same as the width of the dustproof cover 9 and scrapes dust by the movement of the movable table 2. The rubber 10b of the scraping member 10 is formed of a material having a small frictional resistance so as not to have a sliding resistance, excellent abrasion resistance, and excellent followability. The scraping member 10 may be attached to both ends of the movable table 7 in the moving direction in addition to the movable table 2, or may be double mounted to both the movable table 2 and the movable table 7. .

On the other hand, at both ends of the linear bearing 3 in the moving direction,
A wiper 11 that slides on the ball raceways 4a, 4a, ... Of the raceways 4, 4 to scrape off the dust on the ball raceways 4a ,. is doing.

In the table transfer device with the linear motor having the above-described configuration, by inputting a pulse to the mover 7 of the linear motor 6 from a pulse generation source (not shown), each magnetic pole 7b, 7c, ... A magnetic attraction force is generated between the movable tables 2 and 8a, and the magnetic attraction force causes the movable table 2 to move relative to the base 1 in the longitudinal direction by the thrust force generated between the mover 7 and the stator 8. Along with the movement of the movable table 2, the dust D adhering to the surface of the dust-proof cover 9 is scraped off and removed by the scraping member 10 attached to the end of the movable table 2 on the traveling direction side, as shown in FIG. . Further, in the present embodiment, since the scraping member 10 is formed of a low friction material, smooth movement of the movable table 2 is not hindered and thrust loss is small.

In this way, since the dust is removed by the scraping member 10 in the moving area of the movable table 2 on the surface of the dustproof cover 9, the mover 7 interferes with the dust, or magnetic powder such as iron powder is mixed with the dust. In this case, the magnetic flux between the mover 7 and the stator 8 does not leak, and the movable table 2 operates smoothly.

Further, even when a tool or the like is dropped on the stator 8 at the time of inspection or the like, the fixed teeth 8a, ... Are protected by the dust cover 9 to prevent damage.

Further, as shown in FIG. 7, the rubber 10 of the scraping member 10 is
If the b'width is widened to remove even the dust adhering to the upper surfaces of the raceways 4, 4 on both sides of the base 1, it is possible to prevent the dust from wrapping around the rolling surface side of the linear bearing 3 and prevent the linear bearing 3 from moving. It can guarantee smooth operation.

FIGS. 9 and 10 show a table transfer device with a linear motor according to a second embodiment of the present invention. The same components as those in the first embodiment are designated by the same reference numerals and described below. In the second embodiment, the width of the scraping member 12 is expanded so that both side end portions 12a, 12a have the function of the wiper 11 of the linear bearing 3 of the first embodiment. That is, the scraping member 12 is in sliding contact with the entire upper surface of the base 1 including the ball rolling surfaces 4a, 4a of the raceways 4, 4 provided on the base 1 and the dustproof cover 9, and the movable table 2 moves. As a result, not only the surface of the dustproof cover 9 but also the ball rolling surface 4 of the raceways 4, 4
Dust adhering to a, 4a, ... Is scraped off for cleaning. Regarding other configurations and operations, the first
The description is omitted because it is similar to the embodiment.

Although the rolling bearings are used as the linear bearings in the above-mentioned embodiments, sliding bearings may be used. Although the stator 8 is covered with the dustproof cover 9 in the present invention, the same effect can be obtained by burying the grooves between the fixed teeth 8a with a non-magnetic material.

(Effects of the Invention) The present invention has the above-described configuration and operation, and the groove formed between the fixed teeth of the stator of the linear motor interposed between the movable table and the base is formed in the stator and the movable element. Since it is covered with a dust-proof cover having a thickness that does not impede the magnetic attraction force between them, it is possible to prevent dust from accumulating in the groove between the fixed teeth.

Further, since the dust adhering to the dustproof cover or the stator provided with the non-magnetic material is removed by the scraping member, stable driving characteristics can be maintained without being influenced by the dust.

[Brief description of drawings]

1 is a vertical sectional side view of a table transfer device with a linear motor according to a first embodiment of the present invention, FIG. 2 is a vertical sectional front view of the device of FIG. 1, and FIG. 3 is a schematic overall view of the device of FIG. FIG. 5 is a perspective view, FIG. 4 is a partially cutaway enlarged perspective view of an end portion of the base of FIG.
FIG. 6 is an enlarged cross-sectional view taken along the line VV of FIG. 4, FIG. 6 shows an assembled state of the linear bearing of the apparatus of FIG. 1 with a way, and FIG. 6 (a) is a plan view. FIG. 6 (b) is a front view showing a part of the way, and FIG. 6 (c) is a side view.
7D is a cross-sectional view, FIG. 7 is a perspective view showing another aspect of the scraping member of the apparatus of FIG. 1, FIG. 8 is an enlarged cross-sectional view of the vicinity of the scraping member of the apparatus of FIG. FIG. 9 shows the second of the present invention.
FIG. 10 is a vertical sectional front view of the table transfer device with a linear motor according to the embodiment, and FIG. 10 is a vertical sectional side view of the device of FIG. Explanation of symbols 1 ... Base, 2 ... Movable table 3 ... Linear bearing, 6 ... Linear motor 7 ... Mover, 8 ... Stator 8a ... Fixed tooth, 9 ... Dust cover 10,12 ... Scraping member

Claims (1)

[Claims] 1. A movable table is movably supported on a base through linear bearings, and a movable element and fixed teeth provided at a constant pitch in the moving direction of the movable table are provided between the base and the movable table. In the table transfer device with a linear motor having a linear motor interposed between the stator and the stator, a dustproof cover made of a non-magnetic material having a thickness that does not hinder the magnetic attraction between the stator and the mover is provided on the stator. A fixed table is provided in a range covering at least the fixed teeth, and a scraping member for scraping dust on the dust cover is provided on the movable table side.