JPH0555259B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to X, Y, and Z axes in machine tools such as NC machines, automatic tool changers, automatic welding machines,
The present invention relates to a linear guide device that guides linear reciprocating motion in sliding parts of general industrial machines such as injection molding machines and industrial robots, and particularly relates to improvements in a linear guide device that can perform fine movement and rapid movement with high precision.

[Prior Art] Conventionally, this type of linear guide device consists of a track base provided on a fixed bed and a sliding base guided along the longitudinal direction of the track base via a guide mechanism. A ball screw shaft is pivotally supported on the fixed bed, and a ball nut that is screwed onto the ball screw shaft is connected to the sliding base, and a ball spline shaft is pivotally supported on the fixed bed, and the ball An outer cylinder fitted to the spline shaft is interlocked with the ball nut via an interlocking mechanism,
Furthermore, there is a device in which drive motors are connected to the ball screw shaft and the ball spline shaft, respectively (as disclosed in the patent application
58-198803).

According to this type, by appropriately adjusting the rotational direction and rotational speed of each of the drive motors, the sliding table can be moved slightly or quickly relative to the track.

[Problems to be Solved by the Invention] However, in such a conventional linear guide device, two drive motors, a ball screw, a ball spline, etc. are required to linearly move the slide table. Therefore, a problem arises in that the device becomes larger due to the need to secure mounting space for each. In addition, in the above conventional example, since a ball screw and a ball spline are used, rotational torque may cause twisting of the ball screw shaft or ball spline shaft, or between the ball screw shaft and the ball nut or between the ball spline shaft and the ball spline shaft. It is inevitable that bumps occur between the slider and the cylinder, and the responsiveness of the slider is correspondingly poor, making it difficult to significantly improve positioning accuracy. Furthermore, since ball screws and ball splines are attached to the slide table, the weight of the slide table increases, which increases the inertial force of the slide table, which worsens responsiveness when starting and stopping. There was a problem.

Therefore, the present inventor first developed a track base that extends along the longitudinal direction, a first sliding base that is guided along the longitudinal direction of one side of the track base via a guide mechanism, and a track base that is guided along the longitudinal direction of the track base. a second sliding table guided along the longitudinal direction on the other side of the track via a guide mechanism; and a large number of widthwise extending slides provided along the longitudinal direction on the first sliding table side of the track platform. The first movable element is composed of a first stator having teeth and a first movable element having a plurality of excitation parts attached to the first sliding table side while maintaining a predetermined clearance between the first stator and the first stator. a first linear motor mechanism that drives one sliding table; a second stator having a large number of teeth extending in the width direction provided along the longitudinal direction of the second sliding table side of the track; a second linear movable element having a plurality of excitation parts mounted on the sliding table side with a predetermined clearance maintained between the second stator and the second stator and driving the second sliding table; We have already provided a linear guide device consisting of a motor mechanism (patent application 1983-
221295).

According to this type, there is no need to provide a separate feeding mechanism, which allows the device to be made more compact.It also eliminates rotating parts that have rotational errors, such as ball screws and ball splines, and reduces the weight of movable parts. At the same time, it becomes possible to improve the responsiveness and positioning accuracy of the slide table.

However, even in this type,
If the slide table is to be temporarily stopped at a desired point for some kind of work, it becomes necessary to provide a separate fixing means such as a clamping device, and extra space is required to provide this separate fixing means. Not only is this necessary, but it also increases the cost of the equipment.
Regarding this fixing means, if high-precision movement is required for the linear guide device, high-precision movement corresponding to that is required, and if the precision of this movement is low, the accuracy of the movement of the linear guide device itself will be reduced. As a result, there is a problem in that the balance in smooth linear guidance is lost, and there is room for improvement in this respect.

[Means for Solving the Problems] The present invention has been made by focusing on the above problems, and is capable of fine movement and rapid movement without separately providing fixing means such as a feeding mechanism and a clamp device. The present invention provides a linear guide device that is capable of performing linear guide and stopping operations with high precision.

That is, the linear guide device according to the present invention includes a track base extending along the longitudinal direction, a first sliding base guided along the longitudinal direction on one side of the track base via a guide mechanism, and the track base. A second sliding table guided along the longitudinal direction of the other side of the platform via a guide mechanism, and a large number of widthwise extending slides provided along the longitudinal direction on the first sliding table side of the track platform. The first movable element is composed of a first stator having teeth and a first movable element having a plurality of excitation parts attached to the first sliding table side while maintaining a predetermined clearance between the first stator and the first stator. a first linear motor mechanism that drives one sliding table; a second stator having a large number of teeth extending in the width direction provided along the longitudinal direction of the second sliding table side of the track; a second linear movable element having a plurality of excitation parts mounted on the sliding table side with a predetermined clearance maintained between the second stator and the second stator and driving the second sliding table; The movable member of each linear motor mechanism is attached to each sliding base via a flexible member.

In such technical means, each linear motor mechanism interposed between the track base and each sliding base is either a variable reactance type, a permanent magnet type, or a composite type that combines these. However, in order to obtain high precision and high thrust, it is preferable to use a composite type equipped with a permanent magnet and a plurality of electromagnets in which a plurality of inductor teeth are provided at the tip of the excitation core facing the teeth of the stator. The one is good.

Furthermore, the method of excitation of a plurality of parts incorporated in the movable element of the linear motor mechanism may be a one-set excitation method in which only one set of current is always supplied to the movable element excitation section to feed the movable parts step by step. Furthermore, a two-phase excitation method may be used in which a two-phase current is constantly supplied to the movable excitation section for step feeding, but it is preferable that a high thrust can be obtained, there is little damped vibration, and there is a wide frequency range. A two-phase excitation type that can respond to a range is desirable.

Furthermore, various types of springs such as leaf springs, stacked leaf springs, and coil springs can be used as flexible members used when attaching the movable element of each of the above linear motor mechanisms to each slide table, but the operating range is limited. It is preferable to use a plate spring in view of the fact that it requires only a small amount of force and is easy to install.

Furthermore, regarding the method of attaching the movable element of each linear motor mechanism to each slide table via the above-mentioned flexible member, the movable element moves relative to each slide table by the amount of deflection of the flexible member. Although there is no particular restriction as long as it can be installed in such a way, it is preferable that an opening is formed in each sliding base, and a flexible member is used to loosely fit the movable element of the linear motor mechanism into this opening so that it can move in the vertical direction. It is best to install it using the following method.

In addition, there are no particular restrictions on the guide mechanism installed between this track base and each sliding base, but in order to perform stable linear sliding and linear guidance, it is necessary to use a large number of balls. Linear guide ball bearings with a linear guide ball bearing and linear guide roller bearings with a large number of rollers are preferred.

Further, as a mode of use of the linear guide device according to the present invention, one sliding table may be fixedly installed on a fixed member such as a fixed bed, and the other sliding table may be moved relative to the track base. Alternatively, the track base may be fixedly installed on a fixed member, and both sliding bases may be moved relative to each other. Especially in the former case,
guiding and supporting the track base with a plurality of guiding and supporting mechanisms;
It is necessary to design the track to prevent vibration during movement.

[Operation] According to the technical means described above, each movable element of the linear motor mechanism interposed between the track base and each sliding base is attached to each sliding base via a flexible member. Therefore, when fixing each sliding base to the track base, it is only necessary to increase the voltage applied to each linear motor mechanism, and the excitation part of each mover is strongly excited, which increases the flexibility of each slider. By elastically deforming the members, each movable element is attracted to and fixed to its corresponding stator, and also acts on each linear motor mechanism when moving each slide table relative to the track base. It is only necessary to lower the voltage, and the fixed state between each movable element and the stator is released, and each slide table is linearly guided relative to the track table.

[Example] Hereinafter, the present invention will be described in detail based on the example shown in the accompanying drawings.

1 to 5, a linear guide device according to a first embodiment of the invention is shown. The linear guide device of this embodiment includes a track base 1 extending along the longitudinal direction, a first sliding base 3 guided along the longitudinal direction on the upper surface side of the track base 1 via a guide mechanism 2, and the above-mentioned a second sliding base 5 guided via a guide mechanism 4 along the longitudinal direction of the lower surface of the track base 1;
A first linear motor mechanism 6 that is interposed between the track base 1 and the first sliding base 3 and drives the first sliding base 3
and a second linear motor mechanism 7 that is interposed between the track base 1 and the second sliding base 5 and drives the second sliding base 5.

In this embodiment, the track 1 is integrally molded with a rigid rail member, and the track 1 has both left and right shoulders and both sides, as shown in FIGS. 1 and 2. Ball rolling grooves 11 (specifically, 11a, 11b) are provided along the longitudinal direction of the hem.
A stator 30, which is a component of the first and second linear motor mechanisms 6 and 7, is provided along the longitudinal direction of the center of the upper and lower surfaces of the track base 1. Note that this track base 1 does not necessarily need to be formed from a single rail member, and may be formed into a split type consisting of a pair of rails and a bolster.

Moreover, the first sliding table 3 and the second sliding table 5 are as follows:
As shown in Figures 1 to 3 and Figure 5,
A body main body 13 is formed of a rigid member into a rectangular frame shape and has a rectangular opening 14 formed in the center thereof, and fasteners such as screws are attached to the side surfaces of the track base 1 on both left and right sides of the body main body 13. A loaded ball groove 17 and a non-loaded ball 18 are attached at 15 and face oppositely to the ball rolling groove 11 of the wayway 1 along the longitudinal direction.
The guide mechanisms 2 and 4 interposed between the track base 1 and each sliding base 3 and 5 are composed of the bearing block 16 and a bearing block 16 formed therein, respectively. Block 16
A pair of direction changing grooves 21 which are attached to both ends of the ball with fasteners 19 such as screws and which communicate and connect the ball transfer groove 11, the loaded ball groove 17, and the unloaded ball groove 18 to form a ball endless track. side plate 20
and a large number of balls 22 that roll within the ball endless track while applying a load between the track base 1 and the bearing block 16 of each sliding base 3, 5. ing. In addition, the body main body 1 that constitutes each sliding table 3, 5
3, the sliding bases 3, 5, and the bearing block 16 constituting the guide mechanisms 2, 4 may be formed integrally.

Further, in this embodiment, the first and second linear motor mechanisms 6 and 7 each include a stator 30 and a movable element 40, and the stator 30 of the first linear motor 6 is located at the center of the upper surface of the track base 1. A large number of teeth 3 are integrally provided along the longitudinal direction and extend in the width direction.
The stator 30 of the second linear motor ₇ is integrally provided along the longitudinal direction of the center of the lower surface of the track 1, and has a large number of teeth 32 extending in the width direction. They are arranged for each pitch P ₂ (P ₁ ≠P ₂ ). Further, the upper part of the opening 14 in the body body 13 of the first sliding table 3 is closed with a top plate 36 made of a plate spring as a flexible member, and the opening in the body body 13 of the second sliding table 5 is closed. The lower part of the body 14 is closed with a bottom plate 37 made of a leaf spring as a flexible member, and both front and rear ends of the top plate 36 and the bottom plate 37 are attached to the front and rear sides of the body body 13 with fasteners 38 such as screws. At the same time, a movable element 40 of the first linear motor mechanism 6 is fixed to the lower surface side of the top plate 36, and a movable element 40 of the second linear motor mechanism 7 is fixed to the upper surface side of the bottom plate 37. In this example,
As shown in FIG. 2, FIG. 3, and FIG. 5, the movable element 40 is a composite type in which a permanent magnet 41a and an excitation core 41b are used together as the excitation part 41. A plurality of inductor teeth 41c are formed on the lower surface of the tip of the excitation core 41b, facing the teeth 31, 32 of each stator 30 while maintaining a predetermined clearance. As for the excitation method of each linear motor mechanism 6, 7, high thrust can be obtained, there is little damping vibration, and
A two-phase excitation method that can respond to a wide frequency range is adopted, and each linear motor mechanism 6, 7
The mover 40 of
It is designed to move by 1/4P ₁ and P ₂ with respect to the input pulse.

Therefore, according to the linear guide device according to the first embodiment, if, for example, the second sliding table 5 is fixedly installed on a fixed bed (not shown), the first sliding table 3 moves in a straight line along the track table 1. While being guided, it is also restrained and held in a predetermined position.

Now, when linearly guiding the first sliding table 3 along the track 1, the suction force exerted between the stator 30 and the mover 40 of each linear motor mechanism 6, 7 is applied to the top plate 36. The attraction force may be reduced by lowering the voltage acting on the excitation portion 41 of each movable element 40 so as not to exceed the elastic force of the bottom plate 37. At this time, the inductor teeth 41c of each movable element 40 and the stator 3
A predetermined clearance is secured between the teeth 31 and 32 of 0, and the movable element 40 of each linear motor mechanism 6 and 7 is set to be movable relative to the stator 30. In this state, if the excitation directions of the input pulses of the linear motor mechanisms 6 and 7 are made to coincide with each other, the track base 1 is aligned with the second slide base 5 for each input pulse. /4P ₂
At the same time, the first sliding table 3 moves to the track table 1.
, the first sliding table ₃ moves by 1/4(P ₁ +
On the other hand, if the excitation direction of each input pulse of each linear motor mechanism 6 _, 7 is mutually reversed, the second sliding table 5 On the other hand, when the way base moves by 1/4P ₂ , the first sliding base 3 moves by 1/4P ₁ relative to way base 1 in the opposite direction to the moving direction of way base 1, and as described above. The first sliding table 3 is 1/4 (P ₁ - P ₂ ) for each input pulse for a fixed bed.
This results in a slight movement differentially.

On the contrary, when the first sliding table 3 is restrained and held on the fixed bed, the suction force exerted between the stator 30 and the movable element 40 in each linear motor mechanism 6, 7 is applied to the movable element 40. The excitation part 4 of the movable element 40 until the elastic force becomes greater than the elastic force of the top plate 36 and bottom plate 37, which are flexible members attached to each sliding table 3, 5.
What is necessary is to increase the voltage applied to 1 to increase its attractive force. At this time, the top plate 36 and the bottom plate 37 are elastically bent, and the inductor teeth 41c of each movable element 40 are attracted to the teeth 31 and 32 of the stator 30, and the clearance between them becomes zero, and each linear The maximum holding force is generated between each movable element 40 and the stator 30 of the motor mechanisms 6 and 7, and each movable element 40 is fixed to the corresponding stator 30.
Therefore, the way base 1 is fixed to the second slide base 5, the first slide base 3 is fixed to the way base 1, and the first slide base 3 is restrained and held on the fixed bed. It will be done.

In addition, in this embodiment, since the guide mechanisms 2 and 4 between the track base 1 and each sliding base 3 and 5 are constructed of linear guide ball bearings, the guide portions are in rolling contact using balls 22. Therefore, not only the wear on the guide part is suppressed to a minimum, but also the distance between the track base 1 and each sliding member 3, 5 during linear guidance is kept constant, so the thrust of each linear motor mechanism 6, 7 is reduced accordingly. becomes stable. Furthermore, in the guide mechanisms 2 and 4, if the ball rolling grooves 11 and the load ball grooves 17 are formed in a gossock arch shape, even if each of the guide mechanisms 2 and 4 is in a single row, each ball can Because they make contact at a point, loads from above and floating loads are reliably supported.
Therefore, there is no need to separately provide a guide mechanism in the thickness direction of the track base 1, and the situation in which the device itself becomes larger in the thickness direction can be effectively avoided.

Furthermore, in this embodiment, the mover 40, which is a component of each linear motor mechanism 6, 7, is structured to be housed in the opening 14 of the main body 13 of each slide table 3, 5. Therefore, not only the device itself becomes thin and compact, but also the weight of each slide table 3, 5 can be reduced.

Next, a second embodiment shown in FIGS. 6 to 9 will be described.

The basic configuration of the linear guide device according to this embodiment is almost the same as that of the first embodiment, but the guide mechanisms 2 and 4 interposed between the track base 1 and each sliding base 3 and 5 are as follows:
Unlike the first embodiment, it is composed of linear guide roller bearings. The linear guide roller bearing used in this embodiment consists of a pair of guide rails 51 and 52 with V-shaped guide grooves 51a and 52a carved in opposing wall surfaces, and an intervening structure between the guide rails 51 and 52. roller cage 53
As the roller cage 53, a large number of holding holes 55 are opened in the longitudinal direction of a long retainer 54, and a large number of rollers 56 are alternately orthogonally crossed in each holding hole 55 so as to be rotatable. While holding the roller 56 at an inclination, the end surface and peripheral surface of each roller 56 are
The guide grooves 51a and 52a in the shape of letters are used to make sliding contact therewith. Note that each guide rail 51, 52 is attached to the track base 1 and each sliding base 3, 5 via fasteners 57, 58 such as screws.

Therefore, the linear guide device according to this embodiment not only achieves the same functions and effects as those of the first embodiment, but also has a better ball bearing than the case where linear guide ball bearings are used as the guide mechanisms 2 and 4. Since it is no longer necessary to construct an endless track, the guide mechanisms 2 and 4
The structure of can be simplified.

〔Effect of the invention〕

As explained above, according to the linear guide device according to the present invention, sliding bases are disposed on both sides of the track base via guide mechanisms, and a pair of linear motor mechanisms are used as the feeding mechanism. Since one sliding table is differentially fed with respect to the other sliding table, the basic effect is that fine movement and rapid movement can be performed with high precision without the need for a separate feeding mechanism. In addition, by simply changing the voltage applied to each linear motor mechanism, each sliding base can be fixed or unfixed to the wayway, so each sliding base can be fixed to or unfixed to the wayway. There is no need to separately provide a clamping device, etc. for fixing the device, which eliminates the need for installation space for the clamping device, etc., making it possible to make the device itself more compact and reduce the device cost. Also, the accuracy of the stopping operation of the slide table can be made highly accurate without being affected by the accuracy of operation of the fixing means such as the clamp device.

[Brief explanation of the drawing]

FIG. 1 is a perspective explanatory view showing a first embodiment of the linear guide device according to the present invention, FIGS. 2 and 3 are sectional views taken along lines - and - in FIG. 5 is an exploded perspective view showing a slide table and a mover of a linear motor mechanism according to an embodiment, and FIGS. 6 and 7 are a line sectional view showing a second embodiment of a linear guide device according to the present invention. The explanatory views corresponding to FIGS. 2 and 3, and FIGS. 8 and 9 are enlarged explanatory views of the middle part of FIG. 6 and the middle part of FIG. Explanation of symbols, 1... Track platform, 2... Guide mechanism,
3...First sliding table, 4...Guiding mechanism, 5...Second sliding table, 6...First linear motor mechanism, 7...Second linear motor mechanism, 30...Stator, 40... …
Mover, 36... Top plate (flexible member) 37... Bottom plate (flexible member).

Claims (1)

[Scope of Claims] 1. A track base extending along the longitudinal direction, a first sliding base guided along the longitudinal direction on one side of the track base via a guide mechanism, and the other side of the track base. a second sliding base guided via a guide mechanism along the side longitudinal direction; and a second sliding base having a large number of teeth extending in the width direction provided on the first sliding base side of the track base along the longitudinal direction. The first sliding table is composed of a first movable element having a plurality of excitation parts installed on the side of the first stator and the first sliding table while maintaining a predetermined clearance between the first stator and the first stator. a first linear motor mechanism for driving the track, a second stator having a large number of teeth extending in the width direction provided along the longitudinal direction on the second sliding table side of the track, and a second sliding table side. and a second linear motor mechanism configured with a second movable element having a plurality of excitation parts, which is attached to the second stator while maintaining a predetermined clearance therebetween, and which drives the second sliding table. A linear guide device characterized in that the movers of each of the linear motor mechanisms described above are attached to each slide table via a flexible member. 2. The linear guide device according to claim 1, wherein the guide mechanism is a linear guide ball bearing having a large number of balls. 3. The linear guide device according to claim 1, wherein the guide mechanism is a linear guide roller bearing having a large number of rollers. 4. The linear guide device according to claim 1, wherein each slide table has an opening portion in which a mover of each linear motor mechanism is housed.