JPH1047308A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and inexpensively manufacture a holding part of a seal member closing a moving space of a moving member. SOLUTION: A space is shielded by a top cover mounted in a frame 12. A moving member 16 except the space is moved in a slit 38. Seal members 48a, 48b closing the slit 38 and a holding part 32 formed with a holding groove 34 holding the seal members 48a, 48b are provided. The holding part 32 and the frame 12 are formed integrally or respectively as a separate unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for reciprocating a moving member along the axial direction of a frame under the driving action of a driving source.

[0002]

2. Description of the Related Art Conventionally, an actuator has been used as a means for transporting a work or the like.

This actuator has a moving member movably accommodated in a long frame, and reciprocates the moving member along the axial direction of the frame under the driving action of a driving source. The work placed on the moving member is transported. In this case, since the moving member and the workpiece move integrally, the frame cannot be closed, and a work provided outside and the moving member are connected to move the moving member with respect to the workpiece. It is necessary to form a space (slit) for transmitting the quantity.

In view of the above, the present applicant has provided a seal member for closing the slit while maintaining a structure in which the movable member is movable along the axial direction of the frame, and the seal member seals the dust and the like into the frame. An actuator capable of preventing entry and preventing the emission of dust from inside the frame to the outside has been proposed (see Japanese Patent Application No. 8-7813).

[0005]

SUMMARY OF THE INVENTION The present invention has been made in connection with the above-mentioned proposal, and it is possible to easily and inexpensively manufacture a holding portion of a seal member for closing a moving space of a moving member. It is an object to provide an actuator.

[0006]

In order to achieve the above object, the present invention provides an actuator in which a moving member reciprocates along an axial direction of a frame under a driving action of a driving source. A sealing member for closing a space in which the moving member moves except for a space shielded by the cover member mounted on the holding member; and a holding portion having a holding groove for holding the sealing member, wherein the holding portion And the frame are formed integrally or separately from each other.

According to the present invention, the holding portion having the holding groove for holding the seal member is drawn, extruded, or ground by using a metal material such as iron or aluminum. It can be manufactured simply and inexpensively.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An actuator according to the present invention will be described in detail below with reference to the accompanying drawings.

In FIGS. 1 and 2, reference numeral 10 denotes
1 shows an actuator according to an embodiment of the present invention. This actuator 10 has a long frame 12 having a U-shaped cross section and a rotary drive source (not shown) provided inside or outside the frame 12. A ball screw 14 that is connected to a driving shaft and rotates in a predetermined direction under the driving action of the rotary drive source; and reciprocates linearly along the longitudinal direction of the frame 12 under the screwing action of the ball screw 14. Moving member 16 and a sealing mechanism 18 for closing a slit (described later) that is a moving space of the moving member 16.
And

A pair of end blocks 20a and 20b are provided at both ends of the frame 12 in the longitudinal direction.
Are connected, and a top cover (cover member) 24 for closing a part of the opening 22 of the frame 12 is supported by the upper surfaces of the end blocks 20a and 20b.

[0011] As the rotary drive source, for example,
An AC servomotor, an AC induction motor, a DC servomotor, a step motor, an air motor, a hall motor, or the like may be used.

The inner wall surfaces of the side portions 26a, 26b rising from the bottom surface of the frame 12 have two ball rolling grooves 30a, 30 on which a plurality of ball bearings 28 roll.
b is formed along the longitudinal direction. Also, the side portion 26
A holding portion 32 formed integrally with the frame 12 is provided in each of a and 26b, and a holding groove 34 for holding a seal member described later is formed in the holding portion 32.
reference). The holding portion 32 is formed integrally with the frame 12 by, for example, drawing or grinding a metal material such as iron or aluminum.

As shown in FIG. 3B, after a rail-shaped holding portion 32a made of an aluminum material and a frame 12a made of an iron material are formed separately, the holding portion 32a and the frame 12a are integrated. You may comprise so that it may be combined. In this case, the holding portion 32a and the frame 12a are formed by drawing or extruding, respectively. Further, the holding portion 32a and the frame 12a may be formed by grinding if necessary.

The moving member 16 is a block body 36 which reciprocates linearly under the action of a ball screw 14 extending along the axial direction, and a bulging portion formed on the upper surface of the block body 36, and a holding portion. It has a pair of connecting portions 40a and 40b that protrude upward through a slit 38 formed between the upper cover 32 and the top cover 24.

As shown in FIG. 7, both ends 41 of the connecting portions 40a and 40b along the longitudinal direction are formed in a bow shape having a sharply inclined surface. That is, the horizontal plane 4
3 is gradually tapered to have a sharp apex 45, and an inclined surface 47 that is inclined in a curved manner from the apex 45 toward the lower end is formed. Thus, the connecting portion 40
By forming both ends 41 of the a and 40b in a bow shape, a pair of seal members 48a closed when the moving member 16 moves through the connecting portions 40a and 40b,
48b are smoothly separated and the connecting portions 40a, 40b
Can be reduced with the sealing members 48a and 48b which come into contact. As a result, the sealing members 48a,
48b can be improved in durability. The frame 12 functions as a guide when the moving member 16 moves.

The ball rolling grooves 30a, 30a on the holding portion 32 are formed on both side surfaces of the block body 36 along the short direction.
b, a pair of ball rolling grooves 42a, 42b extending in the axial direction are formed, and the ball rolling grooves 4a are formed in portions adjacent to the ball rolling grooves 42a, 42b.
The ball circulation holes 44a and 44b penetrating along the axial direction substantially in parallel with 2a and 42b are formed (see FIG. 2).

In this case, the ball rolling grooves 30a and 30b formed on the holding portion 32 side and the ball rolling grooves 42a and 42b formed on the block body 36 side
4, or a rail member 46 having an arc-shaped cross section may be fixed to the inner wall surface of the frame 12 as shown in FIG. The moving groove 30a may be formed. It is more preferable that the rail member 46 is formed of an iron material that is easily polished. Also, ball rolling grooves 30a, 30b,
The rolling surfaces can be hardened by subjecting 42a and 42b to surface treatment by, for example, a shot blast method.

A pair of end plates (not shown) are connected to both ends of the block body 36 along the longitudinal direction, and the end plates have ball rolling grooves 30a, 3b.
Return grooves (not shown) for connecting the ball circulation holes 44a and 44b with the ball circulation holes 44a and 44b are formed. The ball circulation holes 44a, 44b and the ball rolling grooves 30a, 3b
0b, 42a and 42b are not at horizontal positions, respectively, and the ball circulation holes 44a and 44b and the ball rolling grooves 30a and
The lines connecting 0b, 42a, and 42b are arranged so as to be inclined. As a method of circulating the ball bearing 28, another method such as a return tube (not shown) may be employed without using an end plate.

A slit 38 is defined between the holding portion 32 and the top cover 24, and the slit 3
8 is closed by a pair of seal members 48a and 48b held by the holding portion 32 and the top cover 24, respectively. In this case, the sealing members 48a and 48b
For example, it is preferable to use an ultrahigh molecular weight polyethylene, an ultrahigh molecular weight polyethylene impregnated with an impregnating oil, polyethylene, polytetrafluoroethylene, or an elastic body such as polyurethane rubber or a flexible member.

When the connecting portions 40a, 40b of the moving member 16 do not contact the sealing members 48a, 48b, the pair of sealing members 48a, 48b formed in a planar shape are closed to close the slit 38, while the slit 38 is closed. When the connecting portions 40a, 40b come into contact with the seal members 48a, 48b under the displacement action of the moving member 16, the seal member 4
8a and 48b are formed so as to bend outward. At this time, by forming both end portions 41 of the connecting portions 40a and 40b sharply like a bow, the closed sealing members 48 are formed.
a and 48b can be smoothly bent.

Next, the sealing members 49a, 4
9b is shown in FIG. These sealing members 49a, 49b
A step portion 51 is formed at one end portion to be closed, and the step portion 51 of one seal member is provided with a convex portion 5 of the other seal member.
By combining 3, the sealing performance can be further improved. Further, the seal members 49a, 4
A curved portion 55 may be formed in the middle of 9b so that the sealing members 49a and 49b can be easily bent. Further, the connecting portion 4 with which the sealing members 49a and 49b come into contact.
0a (40b), the sealing members 49a, 49b
The groove 57 may be formed in accordance with the contact state b.

The ball circulation holes 44a and 44b in which a plurality of ball bearings 28 roll and the ball rolling grooves 30
a, 30b, 42a, 42b are the ball bearings 28
Function as a circular orbit. Also, the block body 36
Ball circulation holes 59a, 59b for circulating a plurality of ball bearings 28 rolling along the ball screw 14.
Is formed (see FIG. 2). Further, a linear sensor (not shown) such as a magnetic scale or an interferometer is provided between the bottom surface of the block body 36 and the bottom surface of the opening 22 of the frame 12.

The actuator 10 according to the embodiment of the present invention is basically configured as described above. Next, the operation and effect of the actuator will be described.

First, a rotary drive source (not shown) is driven to rotate the ball screw 14 in a predetermined direction. The moving member 16 reciprocates along the longitudinal direction of the frame 12 under the screwing action of the ball screw 14. At this time, the moving member 1
6 smoothly linearly moves under the guide action of the ball bearing 28 rolling along the ball circulation holes 44a, 44b and the ball rolling grooves 30a, 30b, 42a, 42b.

In this embodiment, the sealing members 48a, 48
Holding section 3 in which holding groove 34 for holding 8b is formed
2 can be easily and inexpensively manufactured by drawing or grinding using a metal material such as iron or aluminum. By using an SKD material as the iron material and subjecting the SKD material to vacuum quenching, the amount of distortion and the amount of grinding can be minimized. It should be noted that the iron or aluminum material is barrel finished.
Alternatively, by performing finishing processing such as shot peening, polishing processing becomes unnecessary, and post-processing can be simplified.

In this case, the frame 12 and the holding part 32 are integrally formed, or the rail-shaped holding part 32a made of aluminum material and the frame 1 made of iron material are used.
2a may be formed separately. Further, components other than the frame 12 and the holding unit 32, for example, the block body 3
6, the ball screw 14 and the like may be formed of an iron material.

It should be noted that the sealing members 48a and 48b
As shown in the figure, a pair of guide rails 50a, 50b
May be incorporated into an actuator 54 for moving the moving member 52 under the guide action of the moving member 52. Alternatively, as shown in FIG. 6, a moving member having a top cover 24a and a bent portion 56 projecting from the frame 12b in the width direction and being substantially orthogonal. It is also possible to incorporate the actuator 58 provided with 58 along the vertical direction. In FIG. 6, a pair of seal members 48a and 48b are bent outward, respectively.
It is also possible to exert a sealing effect while b is bent inward.

In the present embodiment, the rotational movement of the rotary drive source (not shown) is converted into a linear motion via the ball screw 14. However, the present invention is not limited to this. Instead of the screw 14, a linear motor, a linear pneumatic cylinder, a linear voice coil motor, a linear DC motor, a linear step motor, a linear induction motor, a linear VR motor, or the like (not shown) can be used as a drive source.

Further, the sealing members 48a, 48b, 49
a, all parts constituting the actuators 10, 54, 60 except the 49b, for example, the frames 12, 12a,
12b, ball screw 14, moving member 16, 52, 58,
End blocks 20a, 20b, top covers 24, 2
4a, forming components such as the ball bearing 28 from an aluminum material, performing a shot blast process on the aluminum component, and then performing a hard alumite process and then performing a shot blast process again. By EHL (Elasto Hydrodynamic Lubricatio)
n) The effect can be obtained.

That is, since the components constituting the actuator have substantially the same coefficient of thermal expansion, the amount of deformation due to thermal effects is constant, and the dimensional variation among the components can be eliminated.

[0031]

According to the present invention, the following effects can be obtained.

That is, the holding portion having the holding groove for holding the seal member and the frame are formed integrally or separately by a drawing process, a grinding process, or the like, so that they can be manufactured simply and inexpensively. It becomes possible.

[Brief description of the drawings]

FIG. 1 is a perspective view of an actuator according to an embodiment of the present invention.

FIG. 2 is a partial perspective view showing a state where an end block is removed from the actuator shown in FIG. 1;

3A and 3B are explanatory views of a holding portion constituting the actuator shown in FIG. 1. FIG. 3A shows a state in which the frame and the holding portion are integrally formed, and FIG. 3B shows a state in which the frame and the holding portion are formed separately. It is a figure showing a state.

FIG. 4 is a cross-sectional view showing a state where a ball rolling groove in which a ball bearing rolls is provided in a rail member.

FIG. 5 is a partial perspective view showing a state where a seal member is incorporated in another actuator.

FIG. 6 is a partial perspective view showing a state where the seal member is incorporated in another actuator.

FIG. 7 is a partial perspective view of a connecting portion constituting the moving member.

FIG. 8 is a sectional view showing a modification of the seal member.

[Explanation of symbols]

10, 54, 60 ... Actuators 12, 12
a, 12b ... frame 14 ... ball screw 16, 52,
58: moving member 18: sealing mechanism 20a, 20
b ... End block 24, 24a ... Top cover 28 ... Ball bearing 30a, 30b, 42a, 42b ... Ball rolling groove 32, 32a ... Holding part 34 ... Holding groove 36 ... Block body 38 ... Slit 40a, 40b ... Connecting part 44a , 44b, 59a, 59b: Ball circulation hole 46: Rail member 48a, 48b, 49a, 49b: Seal member

Claims (4)

[Claims] 1. An actuator in which a moving member reciprocates along an axial direction of a frame under a driving action of a driving source, wherein the moving member excludes a space shielded by a cover member mounted on the frame. A sealing member for closing a space in which the moving member moves, and a holding portion having a holding groove for holding the sealing member, wherein the holding portion and the frame are formed integrally or separately from each other. Actuator. 2. The actuator according to claim 1, wherein
An actuator characterized in that the holding portion is made of a metal material such as iron or aluminum, and is formed integrally with the frame by any one of a drawing process, an extrusion process, and a grinding process. 3. The actuator according to claim 1, wherein
An actuator, wherein a holding portion made of an aluminum material and a frame made of an iron material are separately formed by a drawing process or an extrusion process, respectively. 4. The actuator according to claim 1, wherein
The moving member has a block body, and a connecting portion that is formed so as to bulge out of the block body and that is in contact with the sealing member and exposed to the outside, and both end portions along the longitudinal direction of the connecting portion have a sharp inclination. An actuator formed in a bow shape having a surface.