JPH1061614A - Linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a linear actuator thin as a whole, which has high rigidity against a bending moment, rigidity secured for a work table itself and capable of providing high workability by reducing the number of part items. SOLUTION: A guide block housing groove 4 is formed in the upper surface of a cylinder main body 2 having a pair of extended piston rods, and a guide rail 5 is disposed in its bottom surface 4a. A guide block 6 fixed in the lower surface of a work table 3 is supported by the guide rail 5 and the lower part of the guide block 6 is housed in the guide block housing groove 4. A ratio of length between left and right directions with respect to the upper and lower direction length of the section of the guide rail 5 is set for 2 or more.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear actuator, and more particularly, to a linear actuator driven by a hydraulic cylinder device.

[0002]

2. Description of the Related Art FIG. 5 shows a linear actuator 50 used for repeatedly moving a jig, a work, and the like by a predetermined distance in a product manufacturing process or the like. Actuator 50
Is a cylinder body 5 provided with a pair of hydraulic cylinders.
A work table 53 is reciprocally supported by a guide rail 52 fixed to 1. The jig, the work, and the like are arranged on a work table 53 that is reciprocated by the same cylinder.

The linear actuator 50 drives the work table 53 with a pair of cylinders in order to obtain a high driving force for the work table 53 while reducing the overall thickness.

By the way, the linear actuator 50 is
It is necessary to support the work table 53 with high positional accuracy by securing high rigidity against the bending moments Mp, My, Mr in three directions (pitching, yawing, rolling) as shown in FIG. Therefore, for example, in the linear actuator shown in FIG. 6, one guide rail 61 having a relatively large cross-sectional area is provided on the upper side of the cylinder body 60, and this guide rail 61 is formed in a groove formed on the lower side of the work table 62. It is sandwiched between a pair of guide blocks 64 housed in 63. Therefore, the guide rails 61 and the guide blocks 64 are accommodated in the grooves 63 of the work table 62, so that the thickness is reduced. Further, since the work table 62 is supported by the guide rail 61 having a relatively large sectional area, high rigidity against bending moment is obtained.

In the linear actuator shown in FIG. 7, a pair of guide rails 71 having a relatively small cross-sectional area are provided in parallel on the upper side of a cylinder body 70, and a work table 7 is provided.
The four guide blocks 73 fixed to the lower surface of the two 2 are supported two by two on each guide rail 71. Therefore, since the guide rail 71 and the guide block 73 are small, the whole is thin. Further, since the work table 72 is supported by the pair of guide rails 71,
High rigidity against bending moment is obtained.

[0006]

In the linear actuator shown in FIG. 6, however, one guide rail 61 having a large cross-sectional area is provided on the work table 62.
Since the groove for accommodating the pair of guide blocks 64 for holding the pair 1 is formed, the thickness of the work table 62 itself is reduced. For this reason, the rigidity of the worktable 62 itself is insufficient.
2 itself may be deformed and high positional accuracy may not be obtained. However, if the thickness is increased to increase the rigidity of the worktable 62, the overall thickness cannot be reduced.

On the other hand, in the linear actuator shown in FIG. 7, the work table 72 is supported by two guide blocks 73 each provided on a pair of guide rails 71 having a small sectional area. If the dimensional accuracy of the guide block 73 is poor, the work table 7
2 has a problem that the operability is deteriorated. There is also a problem that the number of parts is large.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a linear actuator that drives a work table with a pair of cylinders, which is thin overall and has high rigidity against bending moment.
Moreover, it is an object of the present invention to secure the rigidity of the worktable itself, to reduce the number of parts, and to obtain high operability.

[0009]

According to a first aspect of the present invention, there is provided a guide block supported movably along one guide rail fixed to an upper surface of a cylinder body. In a linear actuator in which a work table is supported so as to be able to reciprocate via a front end of a pair of piston rods which are protruded and retracted from the cylinder body, the work table is provided along the guide rail on the upper surface of the cylinder body. An extended guide block receiving groove is formed, the guide rail is disposed on the bottom surface of the guide block receiving groove, and the guide block is fixed to the lower surface of the work table, and at least a part of the guide block is placed in the guide block receiving groove. And was supported by the guide rail.

According to a second aspect of the present invention, in the first aspect, the ratio of the length in the left-right direction to the length in the vertical direction in the cross section of the guide rail is 2 or more. According to a third aspect of the present invention, in the first or second aspect, the number of the guide blocks is one.

According to the first aspect of the present invention, the work table is formed by one guide rail disposed on the bottom surface of the guide block receiving groove and one or a plurality of guide blocks fixed to the lower surface of the work table. Supported. While the guide block is fixed to the lower surface of the work table,
Since at least a part of the work table is housed in the guide block housing groove formed in the cylinder body, the work table supported by one guide rail can be formed without forming the guide rail and the groove for housing the guide block in the work table. It can be arranged close to the cylinder body. Therefore, it is possible to reduce the thickness of the entire work table while securing the rigidity of the work table itself. Also, 1
Since the work table is supported by the guide blocks supported by the guide rails, the influence of the dimensional accuracy of the guide blocks and the guide rails on the operability of the work table is reduced.

According to the invention described in claim 2, according to claim 1,
In addition to the effects of the invention described in (1), since the ratio of the length in the left-right direction to the length in the vertical direction in the cross section of the guide rail is 2 or more, it is possible to further increase the rigidity against the bending moment in the yawing direction.

According to the third aspect of the present invention, the first aspect is provided.
Alternatively, in addition to the effect of the invention described in claim 2, since there is only one guide block, the influence of the dimensional accuracy of the guide rail and the guide block on the operability of the work table is further reduced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 3 shows a linear actuator 1 according to the present embodiment. The linear actuator 1 includes a cylinder body 2, a work table 3, and the like.

As shown in FIGS. 1 and 3, a guide block receiving groove 4 is formed on the upper surface of the cylinder body 2 so as to extend in the length direction. A guide rail 5 formed so as to extend along the housing groove 4 is fixed to the bottom surface 4a of the guide block housing groove 4. The work table 3 is movably supported by the guide rail 5 via one guide block 6 which is movably supported by engaging with the guide rail 5. The guide block 6 is fixed to the lower surface of the work table 3, and the lower portion is accommodated in the guide block accommodation groove 4. The connecting plate 7 is fixed to the front end of the table 3.

As shown in FIG. 2, the guide rail 5 is formed such that the ratio of the horizontal length W to the vertical length H is 2 or more. FIG. 4 shows a plane cross section of the cylinder body 2. A pair of mutually parallel cylinder holes 8, 9 are formed in the cylinder body 2, and each of the cylinder holes 8,
In 9, piston chambers 12 and 13 are formed by a head-side piece 10 and a rod-side piece 11 disposed at both ends thereof. A piston 14 is provided in the piston chamber 12,
The piston 14 forms a head-side pressure chamber 15 and a rod-side pressure chamber 16. Similarly, the piston chamber 13
, A piston 17 is formed, and the piston 17 forms a head pressure chamber 18 and a rod-side pressure chamber 19. A head-side port 21 communicates with each head-side piston chamber 15, 18 via a flow path 20, and a rod-side port 2 communicates with each rod-side piston chamber 16, 19 via a flow path 22.
3 is communicated.

A piston rod 24 is fixed to the front side of the piston 14, and the piston rod 24 extends through the rod side piece 11 to the outside from the piston chamber 12. Similarly, a piston rod 25 is fixed to the front side of the piston 17, and the piston rod 25
Is drawn out of the piston chamber 13 through the rod side piece 11. Each piston rod 24, 25
Are connected to the connecting plate 7, respectively.

The linear actuator 1 according to the present embodiment configured as described above has the following features. (A) A part of one guide block 6 fixed to the lower surface of the work table 3 is received in the guide block receiving groove 4 formed on the upper surface of the cylinder body 2. Accordingly, the work table 3 is provided with one guide rail 5 having a comparatively large cross-sectional area.
, It is possible to obtain high rigidity against bending moment. Further, since a groove having a large sectional area for accommodating the guide block 6 and the guide rail 5 is not provided on the lower surface of the work table 3, the rigidity of the work table 3 itself can be secured without making the work table 3 thick. Further, a part of the guide block 6 is housed in the guide block housing groove 4, and the work table 3 can be made to approach the cylinder body 2, so that the whole can be reduced in thickness. Moreover, one guide rail 5
One guide block 6 engaging with the same guide rail 5
Since the work table 3 is supported, the number of components can be reduced, and the influence on the operability of the work table 3 due to the variation in the dimensional accuracy of the members 5 and 6 can be reduced to improve the operability.

(B) Since the ratio of the length W in the left-right direction to the length H in the vertical direction in the cross section of the guide rail 5 is 2 or more, the rigidity against the bending moment in the yawing direction can be further increased.

(C) Since only one guide block 6 is used, the influence on the operability of the work table 3 due to variations in the dimensional accuracy of the guide block 6 and the guide rail 5 is further reduced. Therefore, the operability of the work table 3 can be further improved.

The present invention is not limited to the above embodiment, but may be configured as follows. (1) The ratio of the length W in the left-right direction to the length H in the cross section of the guide rail 5 is less than 2, for example, 1.
A reasonable ratio such as 5 may be used. Also in this case, the rigidity of the worktable 3 itself can be ensured, and the whole can be reduced in thickness. In addition, the number of parts can be reduced, and high operability of the work table 3 can be obtained.

(2) Two or more guide blocks 6 may be provided. In this case, the rigidity of the work table 3 with respect to the bending moment in the yawing direction can be further increased.

(3) The present invention may be applied to a linear actuator having a fluid pressure cylinder driven by a gas other than air or a liquid such as oil. The technical ideas other than the claims that can be grasped from the embodiment will be described below together with their effects.

(1) The linear actuator according to claim 1 is driven by air. According to this configuration, with regard to the linear actuator 1 driven by air, the rigidity of the worktable 3 itself can be increased and the whole can be made thinner, and the number of parts can be reduced and high rigidity can be obtained.

[0025]

As described in detail above, according to the first aspect of the present invention, the whole is thin and has high rigidity against bending moment, and the rigidity of the work table itself can be ensured. It can be configured with a small number of parts and can obtain high operability.

According to the invention described in claim 2, according to claim 1
In addition to the effects of the invention described in (1), the rigidity against the bending moment in the yawing direction can be further increased. According to the third aspect of the invention, in addition to the effects of the first or second aspect, the operability of the work table can be further improved.

[Brief description of the drawings]

FIG. 1 is a front view of a linear actuator.

FIG. 2 is a front view of a guide rail.

FIG. 3 is a perspective view of a linear actuator.

FIG. 4 is a plan sectional view of the same.

FIG. 5 is a schematic view showing a bending moment in a conventional example.

FIG. 6 is a front view of the linear actuator.

FIG. 7 is a front view of the same.

[Explanation of symbols]

2 ... Cylinder body, 3 ... Work table, 4 ... Guide block accommodation groove, 4a ... Bottom, 5 ... Guide rail, 6 ... Guide block, 24,25 ... Piston rod, H ... Length in vertical direction, W ... Length in horizontal direction Oh.

Claims (3)

[Claims] A work table (3) via a guide block (6) movably supported along one guide rail (5) fixed to the upper surface of a cylinder body (2).
A linear actuator in which the ends of a pair of piston rods (24, 25) protruding and retracting from the cylinder main body (2) are connected to the work table (3). A guide block receiving groove (4) extending along the guide rail (5) is formed on the upper surface, and the guide rail (5) is disposed on a bottom surface (4a) of the guide block receiving groove (4). The block (6) is fixed to the lower surface of the work table (3) and supported by the guide rail (5) in a state where at least a part of the guide block (6) is housed in the guide block housing groove (4). Linear actuator. 2. The linear actuator according to claim 1, wherein a ratio of a horizontal length (W) to a vertical length (H) in a cross section of the guide rail (5) is 2 or more. 3. The linear actuator according to claim 1, wherein the number of the guide blocks is one.