JP3433210B2 - Linear motor drive feeder for machine tools - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motor drive feed device for machine tools, for example, a feed device for a grinding wheel head of a grinder using a linear motor.

[0002]

2. Description of the Related Art A linear motor is used as a drive source in a feeder of a machine tool. For example, in the feeding device of the type shown in FIG. 4, the movable body 3 is slidably mounted on the guide portion 2 along the guide portion 2. Guide 2
Is formed with a guide groove having a convex cross-section with an open upper part, and as a result, the guide rail portions 22, 2 facing the upper part of the guide groove are formed.
2 is formed, and each guide rail portion 22
A counter guide surface that is restricted in the left-right direction and a vertical guide surface that is restricted in the up-down direction are formed on the.

The movable body 3 that slides along the guide portion 2 has an inverted E-shaped cross section, and is fitted in a guide groove having a convex cross-section of the guide portion 2, and slides on both sides where the guide rail portion 22 is fitted. The groove surface of the groove is a sliding surface that faces the facing guide surface and the upper and lower guide surfaces, respectively. The stator portion (armature) 61 of the pair of linear induction motors 6 is mounted on the bottom surface of the guide groove of the guide portion 2 in the feed direction, and the moving body facing the bottom surface of the guide groove of the guide portion 2 is moved. A mover portion 62 of the linear induction motor 6 facing the stator portion (armature) 61 with a minute gap is mounted on the lower surface of 3.

Similarly, in the feeder of the type shown in FIG.
The guide groove of the guide portion 2 in FIG. 4 has a cross-shaped cross-section with an open upper portion, and the hanging portion extending downward from the central portion of the lower surface of the moving body is fitted into the leg groove portion of the guide groove having a narrow width. is doing. In this type, the stator portions (armatures) 61 of the pair of linear induction motors 6 are mounted on the groove surfaces on both sides of the leg groove portion in the feed direction, and the stator portions (armatures) are mounted on both side surfaces of the hanging portion of the moving body. A mover portion 62 of the linear induction motor 6 facing the (armature) 61 via a minute gap is mounted.

Further, the structure shown in FIG. 6 has an upside-down structure of the structure shown in FIG. In all of the above-mentioned types, a static pressure pocket is formed on all the sliding surfaces of the moving body 3, and an oil passage communicating with and connected to a pressure oil supply source is opened in the static pressure pocket through a throttle. There is. In the above-mentioned feeder for machine tools, when the lubricating oil is pressure-supplied to all the static pressure pockets and the linear motor is driven, the moving body is statically supported by the guide body and moves along the guide groove. To do.

[0006]

When driving the linear motor in the machine tool feeder according to the above-mentioned conventional technique, in the linear motor, several times the thrust in the feed direction (the multiple depends on the type of linear motor). 4) acts toward the guide surface, so that in the form of FIG. 4, the upper and lower guide surfaces of the vertical direction regulation may be deformed, and the static pressure sliding of the sliding surface facing it is also burdened. The problem arises.

Therefore, in order to prevent this, in the type shown in FIG. 5 and FIG. 6, two linear motors are provided so as to be back-to-back (target arrangement) so as to cancel out the attraction force of each other. . However, when two linear motors are arranged back to back (target arrangement) as shown in FIGS. 5 and 6, since the upper part of the guide portion 2 is open, the suction force of the linear motor causes The left portion of the guide portion 2 is bent in the right direction, and the right portion of the guide portion 2 is bent in the left direction, which may deform the guide portion 2, and the static pressure sliding of the sliding surface facing the guide portion 2 may be burdened. There is a problem of joining.

Further, if there is a difference in the gap between the stator part and the mover part in the two linear motors due to a processing error or an assembly error, a difference in the suction force on both sides will occur, so that the moving body will be displaced in the rolling direction. Or, horizontal displacement will occur.
As a result, in addition to affecting the feeding accuracy in the feeding device, if the difference in the suction force is large, the moving body that slides under static pressure may be destroyed.

[0009]

In a linear motor drive feed device for a machine tool according to the present invention, a guide portion in the feed direction in which both side guide surfaces for horizontal direction regulation and upper and lower guide surfaces for vertical direction regulation are formed is a feed range. The guide body is provided over the guide body, and the guide body is provided with a space in the feed direction of the guide portion so that a space through which the guide body can pass can be formed on the outside of the guide body. A surrounding frame is installed, and the stators of the linear motors are mounted in the feed direction on the opposing surfaces of the upright portions of the frame, respectively, and the frame is slidably mounted on the guide. The body is formed with a sliding surface at the lower part thereof, which faces both the horizontal guide surfaces of the guide part in the horizontal direction and the upper and lower guide surfaces of the vertical guide, and the movable parts of the linear motor on the both side surfaces of the intermediate part. Is mounted in the feed direction.

Further, both side guide surfaces of the horizontal direction restriction of the frame body are formed above the stator mounting position of the linear motor of the frame body, and both sides of the horizontal direction restriction of the frame body are formed on the upper part of the moving body. A sliding surface is formed facing the guide surface,
A static pressure bearing of lubricating oil is supported on the sliding surface with respect to the guide surface.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION A wheel head feeder for a grinder according to an embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, a lower guide portion 2 in the feed direction is installed on the base 1 over the feed range, and a movable body 3 extending in the feed direction is provided on the lower guide portion 2. Is mounted slidably along the lower guide portion 2, and a grinding wheel 4 rotatably driven by a drive motor (not shown) is attached to the tip of the moving body 3.

The grinding wheel 4 is set to a height such that the height of the grinding point (the point where the grinding wheel contacts the workpiece) coincides with the height of the drive center of the linear induction motor described later. Then, a frame body 5 is provided on the base 1 so as to surround the lower guide portion 2 itself and the moving body 3 sliding on the lower guide portion 2 in an area in the feeding direction of the lower guide portion 2. is set up.

Specific structures of the base 1, the lower guide 2, the moving body 3 and the frame 5 will be described with reference to FIGS. 2 and 3 showing cross sections thereof. The guide main body 20 in the lower guide 2 has an upwardly U-shaped cross section, and a guide rail 21 having both side guide surfaces for horizontally restricting is attached to the center of the bottom surface of the concave groove and both leg portions. Guide rails 22 and 22 each having upper and lower guide surfaces that are vertically restricted are attached to the upper end so as to face each other.

The frame 5 provided in a region of the lower guide 2 in the feeding direction is erected upright along the outer side surfaces of the guide main body 20 so as to face the base 1, and the upper half is thick. And the upright portions 51 and 51 having opposite surfaces protruding inward and both upright portions 51 and 51.
The movable body 3 is inserted into a substantially quadrangular frame body formed of the frame body 5 and the lower guide portion 2, and the horizontal girder portion 52 is provided between the facing surfaces of the upper end portion.

In the frame 5, the stator portions (armatures) 61 of the linear induction motor 6 are mounted in the feed direction on the opposing surfaces of the upper half portions of the upright portions 51, 51, respectively, and the transverse beam portion 5
An upper guide portion 7 having a downward U-shaped cross section is attached to the lower surface of 2 in the feed direction, and a guide groove portion 71 of the upper guide portion 7 is attached.
Static pressure pockets 72 are formed on the guide surfaces facing each other.

The movable body 3 stands upright on the base 31 and the base 31 having a rectangular cross section which fits into the groove of the lower guide 2, and the upright plate whose upper edge fits into the guide groove of the upper guide 7. Shape 3
2 and. On both side surfaces of the plate portion 32, the mover portion 6 of the linear induction motor 6 is provided over substantially the entire length in the feeding direction.
2 is mounted, and each mover portion 62 faces the stator portion (armature) 61 mounted on the frame body 5 with a minute gap.

In the moving body 3, sliding grooves 33; 34, 34 into which the guide rails 21; 22, 22 are fitted are formed on the lower surface and both side surfaces of the base portion 31, and both side guide surfaces and the guide rails of the guide rail 21 are formed. Hydrostatic pockets 35; 36, 36 are formed on the sliding surfaces of the sliding grooves 33; 34, 34 facing the upper and lower guide surfaces of 22, 22, respectively. An oil passage communicating with and connected to a pressure oil supply source (not shown) through the throttle 80 opens in all the static pressure pockets 35, 36, 72.

As shown in FIG. 3, in the upright plate portion 32 of the moving body 3, the upper end sliding portion 3 fitted in the guide groove portion 71.
Both side surfaces of 7 are sliding surfaces facing the guide surface of the guide concave groove portion 71 of the upper guide portion 7, and are opened on both side surfaces of the upright plate-like portion 32 below the upper end sliding portion 37, and the central portion is directed downward. An oil drain hole 38 is drilled toward the bottom, and immediately below both side openings,
An oil pan 39 is attached so as to project to both sides. The oil drain hole 38 communicates with a drain pipe line 81 formed in the lower portion of the guide portion main body 20.

Further, drain grooves 82 are formed on both sides of the guide rail 21 on the bottom surface of the concave groove of the guide portion main body 20. When the grindstone head of the grinder is fed by cutting or returning, the stator portion (armature) 61 is energized and the linear induction motor 6
When the vehicle is driven, the moving body 3 having the mover portion 62 is guided by the guide rails 21; 22, 22 of the guide portion main body 20 and the upper guide portion 7 and slides along them.

At this time, the sliding grooves 34 on both sides of the sliding groove 33 on the lower surface and the sliding grooves 34, 34 on both the left and right sides of the guide unit main body 20.
In the static pressure pockets 35; 36, 36 of the upper and lower sliding surfaces and the static pressure pockets 72, 72 of the opposing guide surface of the guide groove portion 71 of the upper guide portion 7, a pressure oil supply source (illustrated in the figure) is provided via a throttle 80. Lubricating oil is supplied under pressure. Therefore, in FIG. 2, the vertical displacement of the moving body 3 is restricted by the upper and lower sliding surfaces of the left and right sliding grooves 34, 34 by the upper and lower guiding surfaces of the guide rails 22 on both sides through the static pressure bearing of the lubricating oil. The vertical position of the moving body 3 during movement is accurately maintained.

Further, the displacement of the moving body 3 in the left-right direction is as shown in FIG. 2, in which the both upper and lower sliding surfaces of the upper end sliding portion 37 have a static pressure bearing of the lubricating oil by the both side guiding surfaces of the guide groove portion 71 of the upper guide portion 7. And the both side sliding surfaces of the sliding groove 33 in the lower part are regulated by the both side guide surfaces of the guide rail 21 via the static pressure bearing of the lubricating oil, and the horizontal position of the moving body 3 during movement is Accurately maintained.

The regulation by the static pressure bearing of the lubricating oil with respect to the horizontal position of the moving body 3 being moved is performed at the upper and lower ends of the moving body 3 with the apparatus position of the two linear induction motors 6 being sandwiched between them. Even if an imbalance occurs in the attraction force of the two linear induction motors 6 provided in (target arrangement), the movable body 3 counteracts the imbalance, and the left and right positions are accurately maintained to slide.

The lubricating oil overflowing from the gap between the upper and lower sliding surfaces of the sliding grooves 34 and 34 and the upper and lower guiding surfaces of the guide rails 22 on both sides flows into the drain groove 82 and is discharged to an oil tank (not shown). Further, the lubricating oil overflowing from the gap between the both-side sliding surfaces of the upper end sliding portion 37 and the both-side guiding surfaces of the guide groove portion 71 is received by the oil pan 39 and flows into the drain conduit 81 through the oil drain hole 38. Is discharged to an oil tank (not shown),
The linear induction motor 6 is prevented from being contaminated by the oil drainage.

[0024]

The linear motor drive feed device for a machine tool according to the present invention is a substantially quadrangular frame in which two linear motors are provided in a back-to-back alignment (symmetrical arrangement) and are formed by a frame body and a lower guide portion. Since the moving body is inserted in the body, the influence on the guide surface intersecting the direction of the suction force of the linear motor and the influence on the static pressure sliding of the sliding surface facing the guide surface are eliminated.

Further, for example, when the linear motor drive feed device of the machine tool of the present invention is used for feeding the grindstone head of the grinder, the grindstone base can be attached to the tip of the moving body, and therefore the grinding wheel is ground. By matching the height of the points with the height of the driving center of the linear motor, it is possible to prevent pitching of the moving body due to grinding resistance.

Further, since the sliding surface opposite to the guide surface where the suction force of the linear motor intersects is supported at both end positions sandwiching the position where the suction force of the linear motor acts, two sliding units are mounted due to machining error or assembly error. Even if there is a difference in the attraction force acting in mutually opposite directions due to the difference existing in the gap between the stator part and the mover part in the linear motor, it is possible to counteract the difference and avoid the displacement effect. As a result, sliding of a moving body such as a grindstone head in the guide portion of the machine tool can be maintained with high accuracy.

[Brief description of drawings]

FIG. 1 is a front view of a grindstone head of a grinder equipped with a linear motor drive feed device according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is an enlarged detail view of the upper portion of FIG.

FIG. 4 is a cross-sectional view of a linear motor drive feed device according to a conventional technique.

FIG. 5 is a cross-sectional view of a linear motor drive feed device according to a conventional technique.

FIG. 6 is a cross-sectional view of a linear motor drive feed device according to a conventional technique.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Base 2 Lower guide part 20 Guide part main body 21,22 Guide rail 3 Moving body 31 Base part 32 Upright plate-shaped part 33,34 Sliding groove 35,36,72 Static pressure pocket 37 Upper end sliding part 38 Oil drain hole 39 Oil Pan 4 Grinding wheel 5 Frame 51 Upright part 52 Cross beam part 6 Linear induction motor 61 Stator part (armature) 62 Mover part 7 Upper guide part 71 Guide concave groove part 80 Throttling 81 Drain conduit

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor I ▲ Sat ▼ Masahiro 1-1, Asahi-cho, Kariya city, Aichi Toyota Koki Co., Ltd. (56) Reference JP 57-52365 (JP, A) Actual Kai 62-91585 (JP, U) Actual Kaihei 1-64349 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) B23Q 1/26 B23Q 5/28 H02K 41/02

Claims (3)

(57) [Claims] 1. A guide portion in the feed direction, which is provided with both side guide surfaces for horizontal regulation and upper and lower guide surfaces for vertical regulation, is installed over the feed range, and a section of the guide portion in the feed direction. Is provided with a frame body that surrounds the moving body on the outside so as to form, together with the guide portion, a space through which the moving body placed on the guide portion can pass. The stator portions of the linear motors are mounted on the facing surfaces in the feed direction, and the moving body slidably mounted on the guide portion has a lower guide on both sides of the guide portion for horizontal regulation of the guide portion. Also, a linear motor drive feed device for a machine tool in which sliding faces that face each other are formed on the upper and lower guide faces of the vertical direction regulation, and the mover parts of the linear motor are mounted in the feed direction on both side faces of the intermediate part. 2. A horizontal regulating both-side guide surface is formed above the stator mounting position of the linear motor of the frame body, and a horizontal regulating both-side guide surface of the frame body is formed on an upper portion of the moving body. The linear motor drive feed device for a machine tool according to claim 1, wherein a sliding surface facing the surface is formed. 3. The linear motor drive feed device for a machine tool according to claim 1, wherein the sliding surface is supported by static pressure with lubricating oil with respect to the guide surface.