JP2522741B2 - Dynamic control system for linear feeder - 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 feed device used in, for example, semiconductor manufacturing equipment, machine tools, various inspection equipment, etc., and more particularly to a system for controlling its dynamic characteristics.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for higher precision in fine processing as represented by semiconductor technology. Since NC (Numerical Control) was developed, position control has dramatically improved the machining accuracy. In order to make such position control highly accurate, a rolling contact type linear motion guide device is widely used for the linear guide portion.

This linear motion guide device comprises a track rail and a slide base slidably mounted on the track rail via rolling elements.

When performing positioning with high accuracy by such a linear motion guide device, a preload is applied to the linear motion guide device so that the gap between the rolling elements and the rolling element rolling grooves becomes zero. , The rigidity is increased to reduce the elastic displacement amount with respect to the load applied to the rolling elements.

[0005]

However, low friction, which was considered to be an advantage of the guide surface, becomes a problem from the viewpoint of dynamic characteristics.

That is, when a load is applied in the direction of the feed axis, the load must be received by the drive system because of low friction, and the positioning becomes oscillating, which requires a long establishment time.

It is known that the higher the friction in the feed axis direction, the smaller the amplitude displacement in the feed axis direction and the effect of shortening the establishment time of positioning, so that the dynamic characteristics are good. However, the friction of the guide surface increases the positioning error,
It is not preferable in terms of positioning accuracy.

The present invention has been made to solve the above-mentioned problems of the prior art, and an object thereof is to provide a system for controlling the dynamic characteristics of a linear feeding device.

[0009]

In order to achieve the above object, according to the present invention, a track rail, a slide base slidably provided along the track rail, and the track rail are slidable. A rolling element provided between rolling element rolling grooves facing each other provided on the moving table, a fed member such as a table attached to the sliding table, and a drive system for driving the fed member. In addition to the rolling element,
Preload detection means to detect the preload
It is provided in the part where the internal force generated by the preload of the table passes, and
It is characterized in that the dynamic characteristic of the linear feeding device is changed by making the preload applied to the rolling element variable based on the detection information detected by the pressure detecting means .

For adjusting the preload, at least one of the track rail and the slide base is provided with a preload adjusting telescopic portion for adjusting the interval between the rolling element rolling grooves facing each other in which the rolling elements are interposed, It is characterized in that it is performed by expanding and contracting the elastic part for adjusting the preload.

When a plurality of slides are provided, at least one of the slides may be provided with a preload adjusting expansion / contraction part.

The dynamic characteristic is a dynamic rigidity which is a ratio of a displacement amplitude to an external force, and is characterized in that the dynamic rigidity is variable according to an operating state.

The dynamic characteristic is a damping property which is a property of absorbing a vibration applied from the outside, and is characterized in that by increasing the preload, the damping property against an external force is enhanced and the positioning establishment time is shortened.

The dynamic characteristic is the natural frequency of the linear feeder, and is characterized in that the natural frequency is increased by increasing the preload to shift the resonance point.

[0015]

In the dynamic characteristic control system of the linear feeding device of the present invention, when low friction is required during running, the preload is reduced to move the vehicle lightly. Further, when it is desired to shorten the settling time when the positioning is stopped, the preload is increased to enhance the damping property.

Of course, not only when the vehicle is running or stopped, but when a fluctuating load is applied while the vehicle is running or stopped,
The preload is increased and the displacement amplitude is decreased to increase the dynamic rigidity.

Further, when the vibration applied from the outside is close to the natural frequency of the linear feeder, the resonance frequency can be shifted by increasing the natural frequency by increasing the preload to avoid resonance. Further, if the preload is increased, the damping property is enhanced as described above, so that the vibration is absorbed and the amplitude itself is reduced.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to illustrated embodiments.

FIG. 1 shows the system configuration of a dynamic characteristic control system for a linear feeding device according to the present invention. The linear feeding device includes a track rail 1, a slide base 3 slidably provided along the track rail 1 via rolling elements 2 such as balls and rollers, a table mounted on the slide base 3, and the like. And a drive system 101 such as a ball screw for driving the fed member 100. The rolling element 2 is interposed between the rolling element rolling grooves 4 and 5 provided on the track rail 1 and the sliding base 3 and facing each other, and the preload of the rolling element 2 is adjusted by the preload adjusting means 102. , It is designed to control the dynamic characteristics of the linear feeding device.

The preload amount is constantly detected by the preload detection means 9, and the detection information is fed back to the dynamic characteristic control circuit.

In the illustrated example, the fed member 100 is supported on the pair of track rails 1 via the four slides 3, and at least one of the slides 3 should be provided with a preload adjusting means. Dynamic rigidity can be changed. Also,
Apart from the four slides 3, as shown in FIG. 1 (b), slides 3 with preload adjusting means for varying the dynamic characteristics may be provided between the slides 3.

The dynamic characteristics refer to the ability to eliminate the influence of these external forces, such as when the feed load is subject to a time-varying load or an inertial force generated by acceleration or deceleration of a table or the like, and the preload is adjusted. To improve dynamic characteristics.

The dynamic characteristics improved by the preload are, for example, dynamic rigidity, damping property, and natural frequency.

The dynamic stiffness is the ratio of the displacement change amplitude to the load change amplitude when a time-varying load is applied from the outside. Loads and displacements are a function of frequency.

By applying a preload, the displacement amplitude with respect to an external force is reduced.

The damping property is a characteristic that the vibration applied from the outside is absorbed inside the machine. If the damping property is good, the positioning establishment time can be shortened.

The natural frequency is a frequency at which resonance occurs when a vibration is applied to a mechanical structure. By applying a preload, the natural frequency can be increased and resonance can be avoided.

That is, the movement state of the fed member 100 of the feeding device is monitored by the movement monitoring means 10 such as an acceleration pickup.
3, and obtains the dynamic characteristic information 105 relating to the dynamic characteristic from the program information 104 programmed in advance, and inputs this dynamic characteristic information 105 to the dynamic characteristic control circuit 106. The movement can be monitored by the preload detecting means 9 also by a change in the preload state, and this preload state may be used as the movement information.

Then, in the dynamic characteristic control circuit 106,
A preload amount for obtaining a predetermined dynamic characteristic is calculated, and a command signal is output to the preload adjusting means 102. Based on this command signal, the preload adjusting means 102 operates to adjust the preload amount to an appropriate amount.

FIG. 2 shows a state in which the dynamic characteristics are improved by the preload.

That is, FIG. 6 (a) shows the frequency characteristic, and shows the state where the resonance point is shifted from f0 to f1 and the amplitude A is reduced from A0 to A1 when preload is applied.

2 (b) and 2 (c) show a state in which the set time is shortened from t0 to t1 by increasing the preload.

Further, FIG. 2D shows an overshoot state at the time of stop. By increasing the preload, the amount of overshoot is shortened and the positioning accuracy can be improved.

As a desirable dynamic characteristic for stopping the traveling of the fed member 100, when it is moved at a high speed, the preload is reduced so that the member can be moved at a high speed. When stopped, the preload is increased to enhance the damping property and shorten the settling time. Such characteristics are determined by the operating state of traveling stop,
When the operating state is known in advance, if the preload amount is entered in advance as data according to the operating state, the appropriate preload amount is adjusted so that the dynamic characteristics are obtained according to this operating state.

Further, the operating state relating to the actual dynamic characteristic is constantly monitored as the dynamic characteristic information, and the preload may be adjusted based on the detected dynamic characteristic information so that the most appropriate dynamic characteristic in the operating state can be obtained. .

For example, in order to avoid the effect of externally applied vibration, when the state of the vibration is monitored and resonance occurs, the preload is increased so that the resonance does not occur, the natural frequency is increased, and the resonance point Shift.

Further, when vibration occurs during sudden acceleration / deceleration while running, the acceleration is detected to increase the preload and absorb the vibration during acceleration / deceleration. Further, instead of detecting the acceleration, the vibration itself may be detected, and when the vibration starts to be generated, the preload may be increased so as to damp the vibration.

The preload adjusting means 102 used in the above-mentioned dynamic characteristic control system is not limited to a particular structure as long as it can adjust the preload, but the variable preload straight line shown in FIG. It is preferred to use exercise guidance devices.

FIGS. 3 (a) to 3 (d) show the basic structure of the variable preload linear motion guide device used in this dynamic stiffness control system. That is, A shows a guide device for linear motion as a whole, and a track rail 1 that extends linearly, and a slide base 3 that is mounted on the track rail 1 via two rows of left and right rows of balls 2 as rolling elements. ,,. The sliding base 3 is a block body having a U-shaped cross-section, the lower surface side of which is arranged so as to straddle the track rail 1. The upper surface 31 and the left and right skirts 3 extending downward from the left and right ends of the upper surface 31.
2, 33, and the like. Rolling element rolling grooves 4 and 5 are formed on the inner surfaces of the left and right skirt portions 32 and 33 of the slide base 3 facing the left and right side surfaces of the track rail 1, respectively. It is rotatably interposed between the moving body rolling grooves 4 and 5. And this track rail 1
At least one of the sliding base 3 and the slide base 3 is provided with a preload adjusting expansion / contraction part 6 for adjusting the interval between the rolling element rolling grooves 4 and 5. This preload adjusting expansion / contraction part 6 is provided with rolling element rolling grooves 4, 5
The space between the rolling elements can be expanded and contracted in a direction of enlarging and reducing the space, and the amount of preload is controlled by variably controlling the space between the rolling element rolling grooves 4 and 5. And the expansion / contraction part 6 for preload adjustment
Is provided with a preload detection means 9 for detecting the preload amount. The preload detection means 9 is shown only in FIG. 3 (a) as a typical example.

The place of the expansion / contraction part 6 for adjusting the preload is as shown in FIG.
As shown in (b), when it is installed on the slide base 3 side, and in Fig. 3 (c).
It may be provided on the track rail 1 side as shown in FIG.

FIG. 3 (a) shows a preload adjusting telescopic portion 6 which expands to the left and right on the upper surface portion 31 of the slide base 3. The preload is applied by contracting the preload adjusting telescopic portion 6. It is supposed to do.

FIG. 3B shows one skirt portion 3 of the slide base 3.
3 is formed with a preload adjusting expansion / contraction part 6 that expands / contracts left and right.

FIG. 3 (c) shows the track rail 1 provided with a preload adjusting expansion / contraction part 6 which expands / contracts to the left and right. That is, by extending the expansion / contraction part 6 for adjusting the preload, the left and right balls 2
Apply preload to.

FIG. 3 (d) shows that the moment is utilized to preload the left and right balls. That is, by expanding / contracting the preload adjusting expansion / contraction part 6, a moment for rotating the slide base 3 around the track rail 1 is applied, and it is applied in a direction in which the rolling element rolling grooves 4, 5 of the left and right balls are narrowed. A preload is applied to the ball 2 by pressing.

Incidentally, FIG. 3 (e) is a schematic perspective view of the linear motion guide device A.

FIGS. 4 (a) to 4 (f) show a linear motion guide device having a total of four rows of balls 2 on the left and right sides of the track rail 1, two rows in the upper and lower rows. 1
Various modifications in the case of forming the preload adjusting expansion / contraction part 6 in a linear motion guide device of a type arranged so as to sandwich the jetty part 7 projectingly formed on the left and right side faces from above and below are shown.

That is, FIG. 4 (a) corresponds to FIG. 3 (a), in which the upper surface 31 of the slide base 3 is provided with a preload adjusting expansion / contraction part 6 which expands / contracts left and right.

FIG. 4B shows the left and right skirt portions 3 of the slide base 3.
2 and 33 are provided with precompression adjusting expansion and contraction portions 6 that expand and contract vertically, and precompression is applied to the upper and lower balls 2 by contracting the preload adjustment expansion and contraction portions 6.

In FIG. 4 (c), a preload adjusting telescopic portion 6 which expands and contracts in the vertical direction is formed on the upper surface 31 of the slide base 3. By extending the preload adjusting telescopic portion 6, the upper and lower balls 2 can be extended. It is designed to apply a preload to.

FIG. 4D shows one skirt portion 3 of the slide base 3.
3 is provided with a preload adjusting expansion / contraction part 6 which expands / contracts to the left and right, and is similar to the example shown in FIG.

FIG. 4 (e) shows the track rail 1 provided with a preload adjusting expansion / contraction part 6 which expands / contracts to the left and right, and is similar to FIG. 3 (c).

In FIG. 4 (f), the track rail 1 is provided with a preload adjusting elastic portion 6 which expands and contracts up and down. By extending the preload adjusting elastic portion 6, a preload is applied to the upper and lower balls 2. It is supposed to do.

FIGS. 5 (a) to 5 (f) show a linear motion guide device having a total of four rows of balls 2 on the left and right sides of the track rail 1 as shown in FIG. In particular, two rows of balls 2 on the left and right sides are provided on the left and right skirt portions 32, 3 of the slide base 3.
Now M track rail 1 on the left and right of the jetty formed on the inner surface of 3
Various modifications in the case where the preload adjusting expansion / contraction part 6 is formed in a linear motion guide device of a type arranged so as to sandwich the jetty part 8 projectingly formed on the left and right side faces from above and below are shown.

That is, FIG. 5 (a) corresponds to FIG. 3 (a), in which the preload adjusting expansion / contraction part 6 which expands / contracts to the left and right is provided on the upper surface part 31 of the slide base 3.

FIG. 5 (b) shows that the left and right skirt portions 32, 33 of the slide base 3 are provided with the precompression adjusting expansion / contraction parts 6 which are expanded / contracted vertically as in FIG. 4 (b). By extending the portion 6, preload is applied to the upper and lower balls 2.

FIG. 5 (c) shows a preload adjusting elastic portion 6 which is vertically expandable and contractible formed on the upper surface portion 31 of the slide base 3. By contracting the preload adjusting elastic portion 6, the upper and lower balls 2 are moved. It is designed to apply a preload to.

FIG. 5D shows one skirt portion 3 of the slide base 3.
3 is provided with a preload adjusting expansion / contraction part 6 which expands / contracts to the left and right, and is similar to the example shown in FIG.

FIG. 5 (e) shows the track rail 1 provided with a preload adjusting expansion / contraction part 6 which expands / contracts to the left and right, and is similar to FIG. 3 (c).

FIG. 5 (f) shows a track rail 1 provided with a preload adjusting telescopic portion 6 which extends vertically. By extending the preload adjusting telescopic portion 6, a preload is applied to the upper and lower balls 2. It is supposed to do. As the preload detecting means 7, as shown in FIG. 6 (a), a displacement detecting means 10 for detecting the displacement of the preload adjusting telescopic portion 6 is used to detect the preload from the displacement corresponding to the preload. As shown in b), the force detecting means 1 for detecting the load applied to the preload adjusting stretchable portion 6.
There is a method in which the preload is detected from the axial load corresponding to the preload by using 1.

FIGS. 7 (a) and 7 (b) show the basic construction of the preload adjusting expansion / contraction portion 6, and in each of these examples, elastic deformation is possible in the preload adjusting direction and rigid elasticity is provided in other directions. Member 12
And a minute displacement means 13 for expanding and contracting the elastic member 12 in the axial direction. The example shown in Figure 7 (a) is
The elastic member 12 and the minute displacement means 13 are arranged side by side. In the example shown in FIG. 7 (b), only the elastic member 12 is interposed between the opposite end portions 14 and 15 which face each other through the preload adjusting expansion / contraction portion 6 of the slide base 3 or the track rail 1, and the opposite end portion is provided. The connecting member 16 that engages with the first and second flange portions 14a and 15a provided on the portions 14 and 15 is used. That is, the opposite ends 1 are provided at both ends of the connecting member 16.
The first and second seat portions 16a and 16b project so as to face the first and second flange portions 14a and 15a of the fourth and fifteenth flanges, respectively, and one of the first and second seat portions 16a and 16b is seated. Department,
In the illustrated example, the second seat portion 16b is fixed to the second flange portion 15a, and the minute displacement means 13 is interposed between the first seat portion 16a and the first flange portion 14a. Of course, the minute displacement means 13 may be interposed between the second seat portion 12b and the second flange portion 15a. This minute displacement means 13
Is a unit that expands and contracts in proportion to the command value when a command value is given. For example, in addition to a piezoelectric element or an electrostrictive element, a thermal actuator that expands and contracts by utilizing thermal expansion of an object, or FIG. It is possible to apply various actuators that expand and contract in proportion to the command value based on the command value, such as an actuator 13a that expands and contracts by fluid pressure as shown in (d) and other actuators using voice coils and magnetostrictive elements. it can. FIG. 7E shows an example of the elastic member. The elastic member 12A is a leaf spring composed of a flat plate-shaped thin portion, and has a shape that is elastically deformable in the expansion / contraction direction for preload adjustment and rigid in other directions. As the displacement detecting means 10, for example, FIG.
Resistance type sensor 10 such as strain gauge as shown in (a)
a, a voltage sensor 10b for detecting displacement as a voltage change using a piezoelectric element or an electrostrictive element as shown in FIG.
An electromagnetic induction type sensor 10c such as an operating transformer and an eddy current sensor as shown in FIG. 6 (c), a capacitance type sensor 10d as shown in FIG. 3 (d), and a light emission as shown in FIG. 2 (e). It is possible to use various known sensors capable of detecting a minute displacement, such as an optical interference type sensor 10e using a fiber or the like. 8 (f) and 8 (g) show an example of the force detecting means 11. That is, what is shown in FIG. 8 (f) is an elastic member 11b that is elastically deformed in the axial direction according to an axial load,
A resistance type sensor 1 for detecting the amount of strain of the elastic member 11b.
0a, and detects the axial load from the detected value of the strain amount of the elastic member 11b.

In the example shown in FIG. 8 (g), an elastic member 11b,
Piezoelectric element 11c arranged side by side with this elastic member 11b
It consists of and. Of course, as the force detecting means, various detecting means other than the illustrated example can be used. FIG. 9 shows a first specific example of the present invention.

This example embodies the basic structure of FIG. 4 (a), and adopts the structure of FIG. 7 (a) as the structure of the expansion / contraction part 6 for adjusting the preload. That is, the sliding base 3 surrounds the sliding base body 3A and the outer frame member 1 surrounding the outer periphery of the sliding base body 3A.
7 and the upper surface portion 31 of the sliding base body 3A has a structure shown in FIG.
A leaf spring-shaped elastic member 12A as shown in (e) is interposed, and a resistance type sensor 10a as a displacement detecting means is attached to the elastic member 12A. Then, the outer frame member 17
The minute displacement means 13 such as a piezoelectric element is interposed between the inner side surface and the back surfaces of the left and right skirt portions 32, 33 of the sliding table body 3A.

FIG. 10 shows a control block diagram of the apparatus of FIG. That is, the minute displacement means 13 such as a piezoelectric element
D to convert the command value into an analog signal in order to operate
/ A converter 200, a drive amplifier 201 for amplifying this signal, and a strain amplifier 2 for reading the resistance value of the resistance type sensor 10a attached to the elastic member 12.
02, an A / D converter 203 for converting the analog detection value output from the strain amplifier 102 into a digital signal, and an arithmetic circuit 1 for processing and controlling the same.
04, and is composed. And the resistance type sensor 1
The preload state is constantly monitored by 0a, and the detected value is fed back to the arithmetic circuit 204 to control the minute displacement means 11 such as the piezoelectric element so that the preload state becomes appropriate.

However, as shown by the dotted line in the figure, the closed loop may be constructed so that the analog information from the resistance type sensor 10a is not converted into digital information and the analog information is directly compared.

Further, since the detection information from the resistance type sensor 10a changes in response to changes in dynamic characteristics such as changes in load, this detection information can be used as dynamic characteristic information for controlling dynamic characteristics.

FIG. 11 shows a second specific example of the present invention.

This example embodies the basic structure of FIG. 4 (b), and adopts the structure of FIG. 8 (b) as the structure of the expansion / contraction part for preload adjustment. That is, the elastic members 12 that expand and contract in the vertical direction are interposed between the left and right skirt portions 32 and 33 of the slide base 3. Further, side plates 18, 18 extend downward from the left and right ends of the upper surface 31 of the slide base 3, and are bent inward at the lower ends of the side plates 18, 18 to face the lower surfaces of the left and right skirts 32, 33. Engaging seat portions 18a, 18a
The engaging seat portion 18a and the left and right skirt portions 3 are provided.
Small displacement means 13, 13 are interposed between the lower surfaces of 2, 33.

FIG. 12 shows a third specific example of the present invention.

This example embodies the basic structure of FIG. 4 (c), and adopts the structure of FIG. 6 (a) as the structure of the expansion / contraction portion for preload adjustment. That is, the slide base 3 includes a race member 19 having ball rolling grooves 4 and 4 in which the upper balls 2 and 2 of the balls 2, 2 and 2 arranged on the left and right roll, and this race. An outer frame 20 having a U-shaped cross section with a substantially lip section provided so as to surround the member 19, and an elastic member 12 and a minute displacement means 13 are provided between the race member 19 and an upper surface portion 21 of the outer frame 20. Intervened.

FIG. 13 shows a fourth embodiment of the present invention. This embodiment embodies the basic structure shown in FIG. 4 (e). That is, the track rail 1 and the left and right ball rolling grooves 5,
This track rail 1 is divided vertically into 5 parts.
The minute displacement means 13 is interposed between the left and right halves 1A, 1A.

FIG. 14 shows a fifth specific example of the present invention.

In the fifth specific example, unlike the fourth specific example, the track rail 1 is not completely separated, but the track rail 1 is provided with the vertical groove 1A so that it can be elastically deformed to the left and right, and the vertical groove 1A is slightly displaced. The means 13 is interposed. Then, a thermal actuator of a different material having a higher thermal expansion coefficient than the track rail 1 is used as the minute displacement means 13, and a heat insulating material is interposed in a contact portion with the track rail 1. As the material of the thermal actuator 13A, for example, when the track rail 1 is an iron material, an aluminum material is used.

FIG. 15 shows a sixth specific example of the present invention.

This example embodies the basic structure of FIG. 3 (d), and adopts the structure of FIG. 7 (e) as the structure of the expansion / contraction part for preload adjustment. The slide base 3 has a separate structure in which the ball slide base body and the preload adjusting expansion / contraction part are separated.

That is, the ball located on the left side of the track rail 1 in the figure is a jetty 1A formed so as to project to the right of the track rail, and the left side of the sliding base body 31 provided so as to face the lower surface of the jetty 1A. It is interposed between the lip portions 34 formed on the skirt portion 32. On the other hand, the ball 2 located on the right side of the track rail 1 in the figure includes rolling element rolling grooves 5 formed on the right side edge of the upper surface of the track rail 1 and rolling element rolling grooves formed on the lower surface of the slide base body 31. It is interposed between four.

On the other hand, the expansion / contraction part 6 for adjusting the preload is shown in FIG.
(e) The leaf spring-like elastic member 12 and the displacing means 13 are arranged side by side, and the displacing means 13 is positioned closer to the right side ball 2 in the figure.

With this arrangement, when the displacement means is extended, a moment acts to rotate the slide base body 31 around the track rail 1 in the clockwise direction in the figure. The interval between the rolling element rolling grooves 4 and 5 interposed and the interval between the rolling element rolling grooves 4 and 5 in which the ball 2 on the right side is interposed are narrowed to increase the preload.

FIG. 16 shows a seventh example of the present invention.

This seventh specific example corresponds to a modification of the third specific example shown in FIG. 12, and is different from the third specific example.
The expansion / contraction part 6 for adjusting the preload is constituted by only the fluid pressure actuator.

That is, a mounting base 21 for mounting a table or the like is provided on the outer frame 20, and the mounting base 21 and
The race member 19 provided in the outer frame 20 is connected to the connecting member 22.
Are integrally connected via. This connecting member 22 is
It is slidably inserted in a guide hole 23 provided in the outer frame 22 in a fluid-tight state, and a fluid chamber 24 for oil or the like is formed between the race member 19 and the outer frame 20. Then, a fluid 25 having a predetermined pressure such as oil is sealed in the fluid chamber 24, and by controlling the fluid pressure, the tightening force between the race member 19 and the outer frame 20 is changed to control the preload amount. .

By varying the preload applied to the ball 2 in this way, not only statically controlling the rigidity to an appropriate value but also varying the dynamic rigidity, the preload is reduced in the running state. It is possible to control the vehicle so that it can move lightly and at high speed, and increase the preload after stopping to increase the rigidity.

In order to make such dynamic rigidity variable,
The rolling element rolling grooves 4 and 5 are the same as those of the circular arc groove having an arc-shaped cross section which contacts at two points as shown in FIG. 17 (a).
It is preferable to adopt a Gothic arch groove configuration in which four points contact each other as shown in (b). However, it is not limited to the Gothic arch groove.

[0083]

As described above, according to the present invention, since the preload adjusting telescopic portion provided on at least one of the track rail and the slide base is expanded and contracted, the preload can be adjusted to an appropriate value. .

Further, by providing a preload detecting means to directly detect the preload and expand / contract the expanding / contracting portion to adjust the preload,
The preload state can be controlled accurately.

[Brief description of drawings]

FIG. 1 (a) is a diagram showing a system configuration of a dynamic rigidity control system of a linear feeding device of the present invention, and FIG. 1 (b) is a plane view of a linear feeding device provided with a slide table for dynamic rigidity control. Figure, Figure (c)
FIG. 3 is a sectional view schematically showing an example of a linear motion guide device.

FIG. 2 shows the contents of the dynamic characteristics shown in FIG. 2 (a), which is a graph showing the relationship between the vibration frequency applied to the feeder and the amplitude of the feeder when the preload is changed. ) And (c) are graphs showing the settling time when no preload is applied and when preload is applied, and (d) is a diagram showing the overshoot state of the positioning character.

3 (a) to 3 (d) are views showing a conceptual configuration of a variable preload linear motion guide device of the present invention, and FIG. 3 (e) is a schematic perspective view.

FIGS. 4 (a) to 4 (f) are views showing conceptual configurations of various modified examples of a variable preload linear motion guide device having two rows of balls each on the left and right.

5 (a) to 5 (f) are views showing a conceptual configuration showing various modified examples of another variable preload linear motion guide device having two rows of balls on each side.

FIG. 6 (a) is a configuration diagram in the vicinity of an expansion / contraction part for preload adjustment when displacement detection means is used as preload detection means, and FIG. 6 (b).
FIG. 4 is a configuration diagram of the vicinity of a preload adjusting expansion / contraction part when a force detecting means is used as the preload detecting means.

FIG. 7 (a) is a diagram showing the basic configuration of a preload adjusting expansion / contraction part, FIG. 7 (b) is a diagram showing the configuration of a preload adjusting expansion / contraction part using a connecting member, FIG. 7 (c), (d) is a diagram showing a schematic configuration when a fluid pressure cylinder is used as the minute displacement means, and FIG.
FIG. 4 is a cross-sectional view of an essential part showing an example of an elastic member.

8A to 8G are configuration diagrams schematically showing various aspects of a displacement detecting means.

FIG. 9 is a schematic sectional view showing a first specific example of the guide device for variable preload linear movement of the present invention.

FIG. 10 is a control block diagram of the apparatus of FIG.

FIG. 11 is a schematic sectional view showing a second specific example of the guide device for variable preload linear movement of the present invention.

FIG. 12 is a schematic sectional view showing a third specific example of the variable preload linear motion guide device of the present invention.

FIG. 13 is a schematic sectional view showing a fourth specific example of the variable preload linear motion guide device of the present invention.

FIG. 14 is a schematic sectional view showing a fifth specific example of the variable preload linear motion guide device of the present invention.

FIG. 15 is a schematic sectional view showing a sixth specific example of the guide device for variable preload linear movement of the present invention.

FIG. 16 is a schematic sectional view showing a seventh specific example of the variable preload linear motion guide device of the present invention.

FIG. 17 (a) is a sectional view of the circular arc groove,
FIG. 2B is a sectional view of the Gothic arch groove.

[Explanation of symbols]

 1 track rail 2 ball (rolling element) 3 sliding base 4,5 ball rolling groove 100 driven member 101 drive system 102 preload adjusting means 103 motion monitoring means 104 program information 105 dynamic characteristic information 106 dynamic characteristic control circuit

Claims (6)

(57) [Claims] 1. A track rail, a slide base slidably provided along the track rail, and a rolling element rolling groove provided between the track rail and the slide base and facing each other. In a linear feed device including a rolling element, a fed member such as a table attached to the slide table, and a drive system for driving the fed member, a preload detecting means for detecting a preload applied to the rolling element. The above
Portion where internal force generated by preload of track rail and sliding table passes
The detection information detected by the preload detection means.
Based on a report, a dynamic characteristic control system for a linear feeder is characterized in that the dynamic characteristic of the linear feeder is changed by varying a preload applied to a rolling element. 2. A preload adjusting expansion / contraction part for adjusting the interval between rolling element rolling grooves in which rolling elements are interposed is provided on at least one of the track rail and the slide base, and the preload adjusting is performed. 2. The dynamic characteristic control system for a linear feeding device according to claim 1, wherein the preload is adjusted by expanding and contracting the expansion / contraction part. 3. A dynamic characteristic of the linear feed device according to claim 1, wherein a plurality of slides are provided, and at least one slide of the plurality of slides is provided with a preload adjusting expansion / contraction part. Control system. 4. The dynamic characteristic control system for a linear feeder according to claim 1, wherein the dynamic characteristic is a dynamic rigidity which is a ratio of a displacement amplitude to an external force, and the dynamic rigidity is variable according to an operating state. . 5. The dynamic characteristic is a damping characteristic that absorbs vibration applied from the outside, and by increasing the preload, the damping characteristic against an external force is increased and the positioning establishment time is shortened. A dynamic characteristic control system for a linear feeder according to. 6. The linear feeder according to claim 1, wherein the dynamic characteristic is the natural frequency of the linear feeder, and the resonance frequency is shifted by increasing the natural frequency by increasing the preload. Characteristic control system.