JP2008057679A - Slide actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a slide actuator capable of correcting dislocation of a rolling body by minimum thrust, in a precompression state for realizing rigidity and straightness. <P>SOLUTION: A cylinder 10 with a linear guide has a cylinder 15 composed of a body 11, a piston and rod 14 connected to the piston, a linear guide rail 16, a slide table 12 and a slide mechanism of a tracked structure. When positional dislocation of a right side linear guide 17a and a left side linear guide 17b provided on a side surface of the linear guide rail 16, is caused by the minimum thrust of the piston determined from minimum pressure of fluid pressure of fluid supplied to the cylinder 15, an upper limit of the preload being pressure applied to a steel ball 18 in an installed state, is managed so that the positional dislocation can be corrected on the moving end of the slide table 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a technique related to a slide actuator, and particularly relates to a technique that has high rigidity with respect to a load and a moment and is excellent in straightness of a table.

As a means for conveying workpieces and the like used in factory equipment, there is a slide actuator having a function of moving to a predetermined position by reciprocating linearly. There are various types of slide actuators, and there is a system that uses a fluid pressure cylinder as an actuator to realize a small size and high rigidity.
As described above, as a slide actuator driven by a cylinder, technologies such as Patent Documents 1 to 3 are disclosed.

Patent Document 1 discloses a technique related to a slide actuator. A fluid pressure cylinder, a table that reciprocates on the body, and a slide mechanism that guides the reciprocating motion of the table include an upper surface of the body and a pair of side walls of the table. A slide actuator comprising a guide rail attached to each other, an inverted V-shaped guide groove created with the openings facing these guide rails, and a plurality of rolling members of a pair of opposed guide grooves. is there.
The rolling member of Patent Document 1 uses a cylindrical roller, and the cylindrical roller is accommodated by alternately changing the direction by 90 degrees between the guide groove and the side wall.
Patent Document 2 also discloses a technique related to a slide actuator using this cylindrical roller.

FIG. 8 is a cross-sectional view showing a guide using the cylindrical rollers of Patent Document 1 and Patent Document 2.
On the upper surface of the body 101 of the slide actuator 100, a table 102 that reciprocates on the body 101, a guide rail 103 having an inverted V-shaped first guide groove 103 a, and a second guide groove 105 a assembled to the table 102. And a roller bearing 104, which is a cylindrical roller held between the first guide groove 103a and the second guide groove 105a. Note that the structure of the cylinder portion is omitted.
The structure shown in FIG. 8 is the same as the technique used in Patent Document 1 and Patent Document 2, and the slide actuator 100 using such a roller bearing 104 is also described in Patent Document 2. Compared with the case where the load is supported by the point contact between the sphere and the plane, the area where the roller bearing 104 contacts the first guide groove 103a and the second guide groove 105a is enlarged, and the acting load is distributed by the roller bearing 104. It is possible to support.

The rolling members such as the plurality of roller bearings 104 are arranged in a line between the first guide groove 103a and the second guide groove 105a, and the first guide groove 103a and the second guide groove 105a are provided. A guide structure having a structure in which the length difference between the roller bearings 104 becomes a stroke by shortening the length in which the roller bearings 104 are arranged is referred to as a finite track structure.
Such a finite track structure has an advantage that machining is easy because the first guide groove 103a and the second guide groove 105a may be provided in a straight line.

On the other hand, Patent Document 3 discloses a technique related to a slide actuator in which a flat guide block in which a passage through which a plurality of rolling members circulate is formed is attached to a cylinder block, and a slide table having a guide groove is provided. ing.
Unlike Patent Document 1 and Patent Document 2, Patent Document 3 employs a so-called endless track structure in which a spherical rolling member is used and the rolling member is circulated and guided.
The endless track structure here refers to a structure in which the rolling member rotates around the track by making the track of the rolling member an oval type.
In Patent Document 3, by providing the track in the guide block, the width of the guide block can be increased, and the straight traveling accuracy of the guide table can be improved.

FIG. 9 shows a cross-sectional view of the slide actuator 100 having the same structure as that of Patent Document 3.
On the upper surface of the body 101 of the slide actuator 100, a table 102 that reciprocates on the body 101 and a guide rail 103 provided with a circulation passage 111 are provided. A steel ball 110 is interposed between the table 102 and the guide rail 103. Is retained.
Compared to FIG. 8, the slide actuator 100 of FIG. 9 has a larger ratio of the guide rail width L2 to the body width L1. Thus, by widening the guide rail width L2, the maximum allowable moment can be increased.

Utility Model Registration No. 2565979 Utility Model Registration No. 2586276 Japanese Patent No. 3795968

However, the prior art has the following problems.
(1) When a preload is applied, it is difficult to restore the displacement of the rolling member.
In Patent Document 1 and Patent Document 2, the roller bearing 104 is used as the rolling member. However, when the straightness and rigidity of the slide actuator 100 are to be increased, there is a method of applying a preload to the roller bearing 104.
Here, the preload means that the gap formed by the first guide groove 103a and the second guide groove 105a is made smaller than the size of the roller bearing 104, so that pressure is always applied to the roller bearing 104 when assembled. This means that it is in a state, but it is a general technique for increasing the accuracy of the linear guide.
If the preload is increased, the contact area between the roller bearing 104 and the first guide groove 103a and the second guide groove 105a increases, resulting in an increase in frictional resistance. As described above, since the contact area between the roller bearing 104 and the first guide groove 103a and the second guide groove 105a is wide, the frictional resistance is increased. When the preload is increased, the thrust of the cylinder is insufficient and the movement is deteriorated. There is a problem.

Also, in such a finite track structure, a plurality of roller bearings 104 provided in the groove interfere with each other and resistance is generated, or the same number of roller bearings 104 that need to be provided on the left and right move separately from each other. If a load is applied, the roller bearing 104 may be displaced.
For example, when the position of the roller bearing 104 is shifted left and right, the roller bearing 104 on one side reaches the moving end first, so that the stroke of the slide actuator 100 is shortened by the amount of deviation. Due to this deviation, the roller bearing 104 generates not a rolling resistance but a sliding resistance having a resistance force several times that of the rolling resistance. Therefore, there is a possibility that the roller bearing 104 cannot be restored by the thrust of the cylinder under a preload.
In other words, when a guide structure with a high frictional resistance such as the roller bearing 104 is employed and preload is applied to improve straightness and rigidity, the rolling member is displaced even if the stroke is reduced and the stroke is reduced. There is a problem that is difficult.

(2) Using an endless track structure is disadvantageous in ensuring straightness and rigidity.
Even when the endless track structure shown in Patent Document 3 is used, frictional resistance is generated.
In this case, unlike the finite orbit structure, the steel ball 110 is circulated in the endless orbit structure, so that the deviation described in (1) does not become a problem. However, in the endless track structure, due to the characteristics of the structure, the circulation path 111 of the steel ball 110 is composed of a straight portion and a curved portion, and the resistance tends to increase at the curved portion.
In the circulation passage 111 through which the steel balls 110 pass, the interference between the steel balls 110 increases in the curved portion. In the curved portion, the distance between the inner peripheral surface and the outer peripheral surface is different, and the steel balls 110 interfere with each other and become resistance, so that the steel balls 110 are congested in the curved portion of the circulation passage 111. That is, it becomes resistance when the table 102 moves on the body 101. If a preload is applied to increase the accuracy, this tendency is further strengthened.
Further, since the endless track structure always requires a curved portion, there is a problem that the guide distance is shortened. As the guide distance becomes shorter, it means that the straightness and rigidity of the table 102 are affected. Therefore, when the slide actuator 100 is manufactured with the same size in the endless track structure as compared with the finite track structure, the straightness and rigidity are ensured. Is disadvantageous.

  The present invention has been made to solve the above-described problems, and provides a slide actuator capable of correcting a displacement of a rolling element with a minimum thrust in a state in which a preload is applied to achieve rigidity and straightness. For the purpose.

In order to solve the above problems, the slide actuator of the present invention has the following configuration.
(1) A cylinder part formed of a cylinder body having a hollow hole formed therein, a piston that slides in the hollow hole by a fluid pressure of a fluid to be supplied, and a cylinder rod connected to the piston; By a linear guide rail fixed to the upper part of the cylinder body, a table provided on the upper part of the cylinder body and connected to the cylinder rod, and a rolling member that rolls in a groove provided on a side surface of the linear guide rail. A slide mechanism having a finite orbit structure that guides the reciprocating motion of the table, wherein the rolling member is assembled between the table and a groove provided in the linear guide rail. When a preload is applied and a displacement of the rolling member provided on the side surface of the linear guide rail occurs, The preload is set to a pressure capable of correcting the positional shift at the moving end of the table with the minimum thrust of the piston obtained from the minimum pressure of the fluid pressure of the fluid supplied to the cylinder portion. And

(2) In the slide actuator described in (1), the minimum pressure includes sliding resistance between the hollow hole and the piston, sliding resistance between the cylinder rod and the packing provided in the cylinder body, It is determined based on the sum of the resistance caused by sliding friction of the rolling member.

(3) In the slide actuator described in (1) or (2), the displacement is generated by an external force applied to the table or acceleration / deceleration of the piston provided in the cylinder portion, and the thrust of the piston Is made larger than the resistance force generated by the sliding friction of the rolling member, whereby the displacement is corrected at the moving end of the table.

(4) In the slide actuator described in any one of (1) to (3), in the gap formed by the groove provided on the side surface of the linear guide rail and the table, the diameter larger than the gap. The preload is applied by disposing a rolling member.

(5) In the slide actuator described in any one of (1) to (4), the rolling member has a spherical shape, and includes a cage that can hold the plurality of rolling members at equal intervals. It is characterized by that.

Next, the operation and effect of the slide actuator having the above configuration will be described.
The present invention is the minimum piston thrust obtained from the minimum fluid pressure of the fluid supplied to the cylinder section. When the rolling member is displaced from the side surface of the linear guide rail, the displacement of the table at the moving end is detected. Because it is a slide actuator in which the preload applied to the rolling member in the assembled state is set, it is possible to correct even the lowest thrust generated by the piston even when the rolling member is displaced. There is no possibility that the moving end of the table changes. That is, the positional deviation of the rolling member can be corrected with the minimum thrust of the piston in a state where a preload is applied in order to realize rigidity and straightness.

When a slide mechanism having a finite track structure is adopted as the slide actuator, for example, a positional shift in a state where the relative position of the rolling members provided on the left and right of the linear guide rail has shifted due to factors such as an uneven load applied to the table. And the rolling member provided on one side surface reaches the moving end before reaching the moving end where the table is set. At this time, the rolling member provided on the other side surface does not reach the moving end. When the rolling member reaches the moving end only on one side in this way, the rolling member on the side reaching the moving end cannot roll between the linear guide rail and the table. Then, sliding friction much larger than rolling friction is generated between the rolling member on the side reaching the moving end and the linear guide rail or the table.
Such a positional shift phenomenon is caused by either the stopper provided on the table side before reaching the moving end where the table is set or the stopper provided on the linear guide rail. It can also occur by reaching.

  Therefore, in order to correct the displacement of the rolling member, it is necessary to generate a thrust force in the cylinder portion that is greater than the resistance due to sliding friction generated between the rolling member and the linear guide rail or the table. That is, it is necessary to increase the fluid pressure of the fluid supplied to the cylinder part.

  The resistance caused by the sliding friction generated between the rolling member and the linear guide rail or the table is greatly related to the preload applied to the rolling member. Although the rolling member is formed in a spherical shape or a cylindrical shape, the contact area with the groove provided on the side surface of the linear guide rail, which is a non-rolling portion, is increased by applying a preload. As the contact area increases in this way, the pressure receiving area increases and the rigidity of the slide actuator can be secured. However, the frictional force increases as the contact area increases against resistance due to sliding friction. Necessary thrust of the cylinder part becomes large.

Therefore, by controlling the preload applied to the rolling member from the minimum thrust of the piston obtained from the minimum pressure of the fluid pressure of the fluid supplied to the cylinder part to the extent that the positional deviation of the generated rolling member can be corrected, the slide In order to realize the rigidity and straightness of the actuator, it is possible to correct the displacement of the rolling member with the minimum thrust of the piston in a state where a preload is applied to the rolling member.
In the prior art, the setting of the preload applied to the rolling member is generally determined from the running accuracy, load bearing performance and rigidity of the rolling member. However, according to the present invention, since the preload is determined by the minimum thrust of the piston obtained from the minimum pressure of the fluid pressure supplied to the cylinder portion, it is possible to correct the displacement of the rolling member with the minimum thrust of the cylinder. The problem that the table cannot be moved to the set moving end due to the positional deviation of the rolling member can be solved.

  In the present invention, the minimum pressure is the sum of the sliding resistance between the hollow hole and the piston, the sliding resistance between the cylinder rod and the packing provided on the cylinder body, and the resistance due to sliding friction of the rolling member. Since the slide actuator is determined based on the minimum thrust of the piston required from the slide actuator, even if the rolling member is displaced, the displacement is corrected by the minimum thrust and the table is set to the moving end. Is possible.

Further, the present invention provides a resistance that is generated when the displacement of the rolling member is generated by an external force applied to the table or by acceleration / deceleration of the piston provided in the cylinder portion, and the thrust of the piston is generated by sliding friction of the rolling member. It is a slide actuator in which the displacement of the rolling member is corrected at the moving end of the table by making it larger than the force. The external force applied to the table here may be, for example, an uneven load, an impact, vibration, or the like applied to the table. Moreover, a particularly rapid change becomes a problem with respect to acceleration / deceleration of the piston.
Since the displacement of the rolling member is corrected at the moving end of the table, it can be corrected by making the thrust of the piston larger than the resistance force generated by the sliding friction generated by the rolling member. This eliminates the need for correction by external force.

  Moreover, since the rolling member of the present invention is a spheroid and is a slide actuator having a cage capable of holding a plurality of rolling members at equal intervals, the rolling member rolls when the table reciprocates. The members interfere with each other to generate friction and become resistance, so that the resistance against reciprocation of the table is not increased.

A slide actuator according to an embodiment of the present invention will be described in detail with reference to the drawings. First, the configuration of an embodiment of the present invention will be described.
FIG. 1 is a perspective view of a cylinder 10 with a linear guide according to this embodiment. Further, FIG. 2 shows a side view of the arrow A shown in FIG. FIG. 3 shows a finite track type linear guide 17 of the present embodiment. FIG. 3A is a side view of the linear guide 17, and FIG. 3B is a top view of the linear guide 17. 4 shows a YY sectional view of the cylinder 10 with linear guide shown in FIG. In FIG. 4, the linear guide rail 16 is not shown in cross section for convenience of explanation.
A cylinder 10 with a linear guide as a slide actuator shown in FIG. 1 includes a body 11 and a slide table 12 provided on the body 11. The body 11 is made of an extruded product made of aluminum in order to reduce the weight, and the slide table 12 uses a stainless material in order to maintain rigidity.
The slide table 12 is fixed to the tips of two rods 14 that are provided in a cylinder 15 provided inside the body 11 shown in FIG.
A U-shaped groove is provided on the upper surface of the body 11, and a U-shaped groove is similarly provided on the lower surface of the slide table 12, and the linear guide rail 16 is inserted into this groove. . The linear guide rail 16 uses steel in order to maintain rigidity.

As shown in FIG. 4, the slide table 12 and the linear guide rail 16 are provided with a table side groove 12a and a rail side groove 16a that are grooves for holding the linear guide 17, and between the table side groove 12a and the rail side groove 16a, A linear guide 17 is incorporated. As shown in FIGS. 3A and 3B, the linear guide 17 has a finite track structure including a steel ball 18 and a cage 19 provided as a cage for the steel ball 18.
Also, as shown in FIG. 4, the linear guide 17 is disposed on the left and right sides of the linear guide rail 16, so that for convenience, the linear guide 17 provided on the right side of the linear guide rail 16 is referred to as a right linear guide 17a. The linear guide 17 provided on the left side is referred to as a left linear guide 17b.

Since the right linear guide 17a and the left linear guide 17b are simply sandwiched between the table side groove 12a and the rail side groove 16a, the body 11 is provided with a body side stopper 11c, and the slide table 12 is provided with a table side stopper. 12b is provided. Therefore, even when the linear guide 17 is displaced, the body side stopper 11c and the table side stopper 12b prevent the linear guide 17 from being detached from the cylinder 10 with the linear guide.
As described above, the right linear guide 17a and the left linear guide 17b are provided between the slide table 12 and the linear guide rail 16, and are guided so that the slide table 12 can reciprocate in accordance with the reciprocation of the rod 14. .

Intake and exhaust to the cylinder 15 provided in the body 11 is performed by the air port 11a shown in FIG. 1, and a joint or the like is attached to the air port 11a, and the cylinder 15 drives the rod 14 by supplying and exhausting operation air. Let
In addition, in order to detect the position of the slide table 12, the body 11 is provided with a body groove 11b, and a magnetic detection switch 20 can be attached. If the rod 14 is provided with a magnet, the position of the slide table 12 can be detected by the magnetic detection switch 20.

Next, operation | movement of the cylinder 10 with a linear guide of a present Example is demonstrated.
FIG. 5 shows a YY sectional view of the cylinder with the linear guide according to the present embodiment in a state where the cylinder is moved to the moving end. FIG. 6 shows a YY cross-sectional view in a state where the right linear guide 17a reaches the moving end in a state where the right linear guide 17a and the left linear guide 17b are displaced.
5 and 6 show a state in which the linear guide cylinder 10 shown in FIG. 4 has moved to the moving end. In FIG. 5, the right linear guide 17a and the left linear guide 17b are not displaced. In FIG. In this state, the guide 17a and the left linear guide 17b are shifted by a shift α.
By supplying the operation air to the air port 11a of the cylinder 10 with the linear guide, the operation air is supplied to the cylinder 15 and the piston (not shown) and the rod 14 connected to the piston move. As the rod 14 moves, the slide table 12 connected to the rod 14 via the end plate 13 also moves.

Therefore, the stroke of the slide table 12 is the same as the stroke of the cylinder 15, and the stroke amount ST of the slide table 12 is determined by the stroke of the cylinder 15. FIG. 5 shows a state in which the slide table 12 has moved to the stroke end. In this state, the right linear guide 17a and the left linear guide 17b do not contact the body side stopper 11c and the table side stopper 12b and maintain a slight gap. ing.
The slide table 12 is linearly moved because it is guided by the linear guide rail 16 and the linear guide 17. At this time, the right linear guide 17 a and the left linear guide 17 b are moved together with the slide table 12 at the same position from the state of FIG. 4. Moving.

In FIG. 4, the right linear guide 17 a and the left linear guide 17 b are at the same position with respect to the traveling direction, but the right linear guide 17 a and the left linear guide 17 b are given the same preload, so that the slide table 12 remains substantially at the same position. The right linear guide 17a and the left linear guide 17b move. Therefore, when the slide table 12 reaches the moving end, the state shown in FIG.
However, since the linear guide 17 has a finite orbit structure, the slide table 12 is moved in a state where an offset load is applied to the slide table 12, a strong vibration or impact is applied to the slide table 12, or the cylinder 15 is suddenly moved. The acceleration / deceleration may cause the positional relationship between the right linear guide 17a and the left linear guide 17b to shift as shown in FIG.
This is because the rolling friction of the steel balls 18 included in the right linear guide 17a and the left linear guide 17b is changed by applying an external force such as an unbalanced load to the slide table 12, and the right linear guide 17a or the left linear guide 17b is changed. This is because if either friction increases and a certain external force is exceeded, slipping may occur, leading to displacement.

Such an external force applied to the slide table 12 may be generated depending on the use environment of the cylinder 10 with the linear guide. The cylinder 10 with a linear guide is often used in a usage method in which an uneven load is applied to the slide table 12, such as being used for picking and pressing in a factory production line. Therefore, it is assumed that an excessive unbalanced load, impact, or vibration is applied to the slide table 12. In such a case, the relative positions of the right linear guide 17a and the left linear guide 17b may be shifted.
If the positional relationship between the right linear guide 17a and the left linear guide 17b is deviated, the stroke amount ST is reduced by the shift α as shown in FIG. 6 when moving to the moving end. In the case where the linear guide 17 shown in FIG. 6 has a shift α, rather than the linear guide 17 shown in FIG. 5, the slide table 12 is set by the shift α. You can see how it has not reached the edge.

As described above, the right linear guide 17a and the left linear guide 17b are composed of a plurality of steel balls 18 and the cage 19 held by the cage 19, and the slide table 12 is reciprocated by being guided by the linear guide rail 16 and the linear guide 17. In doing so, the steel ball 18 rotates. That is, the slide table 12 and the linear guide rail 16 reciprocate while being continuously guided by the rotation of the steel ball 18.
Thus, since the steel ball 18 rotates during the movement of the slide table 12, the slide table 12 can be moved by resistance due to rolling friction.

However, when a shift α as shown in FIG. 6 occurs, the right side linear guide 17a or the left side linear guide 17b in contact with the body side stopper 11c or the table side stopper 12b is made of steel with respect to the table side groove 12a and the rail side groove 16a. Since rotation of the sphere 18 is restricted, resistance due to sliding friction is generated instead of resistance due to rolling friction. That is, when the linear guide 17 contacts the body-side stopper 11c or the table-side stopper 12b, the linear guide 17 cannot move and the steel ball 18 becomes unable to rotate.
Since the resistance due to sliding friction is very large with respect to the resistance due to rolling friction, when the thrust of the cylinder 15 is insufficient, the slide table 12 stops in the state shown in FIG. It will decrease by minutes.

When using the cylinder 10 with a linear guide, it is not preferable that the slide table 12 cannot move to a prescribed stroke amount ST. Therefore, when the shift α as shown in FIG. 6 occurs, it is necessary to correct it.
The method of correcting the shift α is either correction by the thrust of the cylinder 15 or forced movement by the external force of the cylinder 10 with the linear guide, but the user is forced by the external force. The method of correcting automatically is not preferable.

Therefore, it is necessary to correct with the thrust of the cylinder 15.
FIG. 7 is a graph showing the relationship between cylinder thrust and preload of the cylinder 10 with linear guide.
The vertical axis represents cylinder thrust [N]. This cylinder thrust represents a slip resistance value, and indicates the thrust of the cylinder 15 when the deviation is corrected artificially.
The horizontal axis represents the oversize amount [μm], and represents whether the steel ball 18 is larger or smaller than the prescribed size. The positive side is larger than the specified size, and the negative side is smaller than the specified size.
A plurality of tests were performed, and FIG. 7 shows the sample 1 and the sample 2 showing typical values.
Sample 1 and sample 2 were prepared by preparing a linear guide cylinder 10 having the same size, and preparing linear guides 17 having different sizes of a plurality of steel balls 18 for the cylinder 10 with linear guide. The reason for requiring a plurality of samples is that variations due to processing accuracy are taken into account.

If it demonstrates regarding the sample 1, five points are plotted on the line connected with the curve, This means that it replaced with the linear guide 17 of 5 types of size differences, and tested. The same applies to Sample 2.
From the results of this test, Sample 1 and Sample 2 showed the same tendency as shown in FIG. The difference in the oversize amount between the sample 1 and the sample 2 is due to variations due to the processing accuracy of the steel ball 18 and the cylinder 10 with the linear guide, and the results are considered to be the same under the same conditions.
That is, since the preload increases as the size of the steel ball 18 increases, the required cylinder thrust increases. When the oversize amount of the steel ball 18 is about 1.0 μm or more in the sample 1 and the oversize amount of the steel ball 18 is 1.5 μm or more in the sample 2, a cylinder thrust greater than the set minimum thrust is required. I understand that. The other samples showed almost the same tendency.

From these results, the cylinder 10 with a linear guide has a relative position between the right linear guide 17a and the left linear guide 17b with the set minimum thrust of the cylinder 15 if the preload is about 1.0 μm oversize of the steel ball 18. It can be seen that even if a deviation occurs, the state shown in FIG. 6 can be corrected to the state shown in FIG.
Accordingly, it is considered that an oversize amount of about 1.0 μm of the steel ball 18 is appropriate for the cylinder 10 with a linear guide.
In addition, since the preload to be set differs depending on the size of the cylinder 10 with the linear guide, it is necessary to set according to each case.

Further, as shown in FIGS. 5 and 6, the positional deviation of the linear guide 17 is not only caused by the relative positions of the right linear guide 17a and the left linear guide 17b being shifted, but also the right linear guide 17a and the left linear guide. There may be a case where the position shifts 17b at the same time.
Since it is an ideal state that the linear guide 17 guides the slide table 12 only with the resistance generated by rolling friction, the right linear guide 17a and the left linear guide 17b in the state shown in FIG. It is desirable not to contact the table side stopper 12b. Since the stroke of the slide table 12 is determined by the stroke of the cylinder 15, depending on the deviation of the linear guide 17, it occurs in the right linear guide 17 a or the left linear guide 17 b before the slide table 12 moves by the stroke amount ST. Since the drag force to be changed from the rolling frictional resistance to the sliding frictional resistance, the slide table 12 becomes difficult to move.
If the size of the steel ball 18 is determined to a size that can correct such a positional shift and the preload is managed, even if a positional shift occurs, this can be corrected by the thrust of the cylinder 15.

The following effects can be obtained by the configuration and operation of the present invention described above.
It is given by setting the steel ball 18 so that the preload applied to the steel ball 18 provided in the linear guide 17 in the state where it is incorporated in the cylinder 10 with the linear guide is less than the minimum thrust set as shown in FIG. Therefore, even if the linear guide 17 is displaced, the cylinder 10 with the linear guide does not stop in the middle of the stroke amount ST determined for the slide table 12 due to the displacement of the linear guide 17.
When using the cylinder 10 with a linear guide, it is not preferable that the slide table 12 cannot move to a prescribed stroke amount ST. This is because there are many cases where the cylinder 10 with linear guide is used in a manufacturing process where the positioning accuracy requirement is severe, such as pick and press. This is because the product yield may be affected.

  In particular, when the slide table 12 provided in the linear guide-cylinder 10 is moved slowly, a shock absorber or the like is provided at the end to attenuate the inertial force at the end, and the cylinder 15 provided in the linear guide-cylinder 10 is provided. For example, there is a case where it is necessary to correct the positional deviation between the right linear guide 17a and the left linear guide 17b with only the thrust. Even under such conditions of use, it is important that the slide table 12 moves to the set moving end according to the present invention, and the slide table 12 is designed to move to the set moving end without fail. Thus, for example, even when the linear guide cylinder 10 is used for picking and pressing a product, it does not cause a product chucking error and contributes to an improvement in product yield.

In addition, since a certain preload is applied to the linear guide 17 incorporated in the cylinder 10 with linear guide, it is possible to ensure the rigidity of the cylinder 10 with linear guide and the straightness of the slide table 12.
In the related art, in order to prevent the linear guide 17 from being displaced, the diameter of the steel ball 18 provided in the linear guide 17 is reduced with respect to the gap formed by the table side groove 12a and the rail side groove 16a without applying preload to the linear guide 17. However, measures such as giving backlash have been taken.
However, such a backlash of the linear guide cylinder 10 causes a reduction in rigidity and a deterioration in straight-ahead performance, and thus has been a problem in cases where accuracy is required for the linear guide cylinder 10.
In addition to this, in order to prevent such displacement of the linear guide 17, a method of increasing the air pressure of the operation air supplied to the cylinder 10 with linear guide more than necessary can be considered. In addition to increasing the amount, it is not possible to cope with a case where the moving speed of the cylinder 10 with the linear guide is to be reduced below a certain speed, and another problem such as an increase in shock generated at the moving end of the slide table 12 can be considered. .

However, according to the present invention, the amount of air consumed is not increased unnecessarily in this way, and it can be used when the linear guide cylinder 10 is desired to be used at a low speed. There are benefits.
Further, since the cylinder 10 with linear guide employs a finite track structure using steel balls 18, it is compared with the cylinder 10 with linear guide using an endless track structure or a finite track structure using roller bearings 104. Since resistance due to rolling friction is reduced, the thrust of the cylinder 15 necessary for moving the slide table 12 can be set small, which contributes to a reduction in the amount of air consumption.
In recent years, energy saving measures have also become important, and in factories that use a large number of cylinders 10 with linear guides, there is an effect of reducing the amount of air consumed, which is effective in reducing the running cost of the factories.
Moreover, since the groove | channel provided in the right side surface and left side surface of a linear guide rail, and the groove | channel provided in a table employ | adopted a finite track structure, what is necessary is just to process it to a straight line and can hold down the processing cost of the cylinder 10 with a linear guide. it can.
In addition, since the groove may be linearly processed, it is easy to increase the processing accuracy, and the rolling member has a shape that is relatively easy to obtain, such as a cylindrical shape or a spherical shape, so that a uniform preload can be set. It becomes easy.

According to the slide actuator of the present embodiment described above, the following excellent actions and effects can be obtained.
(1) A cylinder 15 comprising a body 11 having a hollow hole formed therein, a piston that slides in the hollow hole by the fluid pressure of the fluid to be supplied, and a rod 14 connected to the piston; A linear guide rail 16 fixed to the upper part, a slide table 12 provided on the upper part of the body 11 and connected to the rod 14, and a linear guide that rolls in grooves provided on the right side surface and the left side surface of the linear guide rail 16 In the cylinder 10 with a linear guide provided with a slide mechanism having a finite orbit structure that guides the reciprocating motion of the slide table 12 by 17, the linear guide 17 includes a rail side groove 16 a provided in the slide table 12 and the linear guide rail 16. The preload was applied in the state assembled between the two and provided on the right side surface of the linear guide rail 16. When the positional deviation between the side linear guide 17a and the left side linear guide 17b provided on the left side surface occurs, the minimum thrust of the piston obtained from the minimum pressure of the fluid pressure of the fluid supplied to the cylinder 15 portion is used. Since the preload is set to a pressure that can correct the position shift at the moving end, even if a position shift between the right linear guide 17a and the left linear guide 17b occurs, the correction is made with the minimum thrust generated by the piston. Thus, there is no possibility that the moving end of the slide table 12 changes. That is, in a state where a preload is applied to the steel ball 18 provided in the linear guide 17 in order to realize rigidity and straightness, the deviation between the right linear guide 17a and the left linear guide 17b can be corrected with the minimum thrust of the piston.

(2) In the linear guide cylinder 10 described in (1), the minimum pressure is the sliding resistance between the hollow hole and the piston, the sliding resistance between the rod 14 and the packing provided on the body 11, and the steel ball. 18 is determined based on the sum of the resistance due to sliding friction of 18, even if a deviation occurs in the relative position between the right linear guide 17a and the left linear guide 17b with the minimum required thrust of the piston. The shift α is corrected by the minimum thrust generated by the cylinder 15, and the slide table 12 can be moved to the set moving end.

(3) In the linear guide-cylinder 10 described in (1) or (2), the displacement α is generated by an external force applied to the slide table 12 or acceleration / deceleration of the piston provided in the cylinder 15 portion. Since the thrust is made larger than the resistance force generated by the sliding friction of the steel ball 18 provided in the linear guide 17, the shift α is corrected at the moving end of the slide table 12. In a state in which a preload is applied to the steel ball 18 provided in the linear guide 17 in order to achieve linearity, the deviation between the right linear guide 17a and the left linear guide 17b can be corrected with the minimum thrust of the piston.

(4) In the cylinder 10 with a linear guide described in any one of (1) to (3), a rail side groove 16a provided on the right side surface and the left side surface of the linear guide rail 16 and a table provided on the slide table 12. Since the preload is applied to the gap formed by the side groove 12a by providing a steel ball 18 having a diameter larger than the gap, the rail side groove provided on the right side surface and the left side surface of the linear guide rail 16 is provided. 16a and the table side groove 12a provided on the slide table 12 may be processed into a straight line, and the processing cost can be reduced.
Further, since the rail side groove 16a and the table side groove 12a may be linearly processed, it is easy to increase the processing accuracy, and the steel ball 18 is also spherical and has a shape that is relatively easy to obtain, so a uniform preload should be set. Becomes easy.

(5) In the cylinder 10 with a linear guide described in any one of (1) to (4), the steel ball 18 has a spherical shape, and includes a cage 19 that can hold the plurality of steel balls 18 at equal intervals. Therefore, when the slide table 12 is reciprocating, the steel balls 18 interfere with each other to generate friction and become resistance, so that the resistance of the slide table 12 to reciprocation does not increase.

Although the embodiments of the present invention have been described, the present invention is not limited to the above-described embodiments, and various applications are possible.
For example, in this embodiment, the cylinder 10 with a linear guide has a dual rod structure in which two rods 14 provided in the cylinder 15 are provided, but the present invention has a single rod structure in which one rod 14 is provided. Applying is not disturbed.
In addition, some of the materials such as the body 11 and the slide table 12 are shown, but this is an example of the embodiment and the present invention is not limited thereto, so other materials can be selected without departing from the scope of the present invention. You may do it. For example, it is conceivable to change the steel material to stainless steel in order to improve corrosion resistance, or to change aluminum to iron in order to increase rigidity, or to increase the number of aluminum members for weight reduction. Using a resin partly is also effective in reducing weight and improving corrosion resistance.
Moreover, although the type which hold | maintained the steel ball 18 with the cage 19 is selected for the linear guide 17, you may use only the steel ball 18 or a cylindrical roller guide.
In this embodiment, the operation air is supplied to the air port 11a of the cylinder 10 with the linear guide to move the cylinder 15. However, the present invention is applied to a hydraulic or other type of cylinder. Not disturb.

1 is a perspective view of a slide actuator according to an embodiment of the present invention. The side view of the arrow A shown in FIG. 1 of the slide actuator which concerns on the Example of this invention is shown. (A) The side view of the linear guide which concerns on the Example of this invention is shown. (B) The top view of the linear guide which concerns on the Example of this invention is shown. The YY sectional view of the cylinder with a linear guide shown in Drawing 2 concerning the example of the present invention is shown. The YY sectional view in the state where the slide actuator concerning the example of the present invention moved to the movement end is shown. FIG. 9 is a YY sectional view showing a state where the right linear guide and the left linear guide of the slide actuator according to the embodiment of the present invention are displaced and the one linear guide first reaches the moving end. The relationship between the cylinder thrust and preload of the slide actuator which concerns on the Example of this invention is shown. 1 shows a cross-sectional view of a slide actuator that employs a finite orbit structure of the prior art. FIG. 3 shows a cross-sectional view of a slide actuator employing a conventional endless track structure.

Explanation of symbols

10 cylinder 11 with linear guide body 11a airport 11b body groove 12 slide table 12a table side groove 13 end plate 14 rod 15 cylinder 16 linear guide rail 16a rail side groove 17 linear guide 17a right side linear guide 17b left side linear guide 18 steel ball 19 cage 20 magnetism Detection switch α Deviation ST Stroke amount

Claims (5)

A cylinder body including a cylinder body having a hollow hole formed therein, a piston that slides in the hollow hole by a fluid pressure of a fluid to be supplied, and a cylinder rod connected to the piston; and the cylinder body A linear guide rail fixed to the upper part, a table provided at the upper part of the cylinder body and connected to the cylinder rod, and a rolling member that rolls in a groove provided on a side surface of the linear guide rail. A slide actuator having a finite orbit structure that guides reciprocating motion,
The rolling member is preloaded in a state assembled between the table and a groove provided in the linear guide rail,
When a displacement of the rolling member provided on the side surface of the linear guide rail occurs, the minimum thrust of the piston obtained from the minimum pressure of the fluid pressure of the fluid supplied to the cylinder portion is used. A slide actuator characterized in that the preload is set to a pressure capable of correcting the positional shift at a moving end. The slide actuator according to claim 1, wherein
The minimum pressure is
Sliding resistance between the hollow hole and the piston;
Sliding resistance between the cylinder rod and the packing provided in the cylinder body;
The slide actuator is determined based on a sum of resistance due to sliding friction of the rolling member. In the slide actuator according to claim 1 or 2,
The positional deviation is generated by an external force applied to the table or acceleration / deceleration of the piston provided in the cylinder part,
The slide actuator is characterized in that the displacement is corrected at the moving end of the table by making a thrust of the piston larger than a resistance force generated by sliding friction of the rolling member. The slide actuator according to any one of claims 1 to 3,
The slide is characterized in that the preload is applied by disposing the rolling member having a diameter larger than the gap in a gap formed by a groove provided on a side surface of the linear guide rail and the table. Actuator. The slide actuator according to any one of claims 1 to 4,
The said rolling member is a spherical form, It is provided with the holder | retainer which can hold | maintain the said several rolling member at equal intervals, The slide actuator characterized by the above-mentioned.

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