JPH07276268A - Single axis robot and assembling method therefor - Google Patents

Abstract

PURPOSE:To improve assembling workability of a robot and reduce the unit price of the robot while maintaining support performance of a ball screw shaft at high accuracy. CONSTITUTION:This single axis robot is constituted so that a movable part 3 is mounted on a ball screw shaft 7 rotatably supported with supporting members 8, 15 through a nut member 20, and the movable part 3 is moved along fixed rails 6 according to rotation of the ball screw shaft 7. The supporting member 15 is constituted of a supporting bracket 16 and a bearing 17, the bearing 17 is fitted into a housing 18, and the bearing 17 is fitted to the supporting bracket 16 by fixing the flange part of the housing 18 to the supporting bracket 16. In this case, this device is constitutes so that plane fitting of the housing 18 to the supporting bracket 16 can be adjusted, and the bearing 17 can be rotated against the supporting bracket 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single-axis robot constructed such that a movable part moves along a guide member as the ball screw shaft rotates. The present invention relates to a single-axis robot capable of adjusting the degree and the like and an assembling method thereof.

[0002]

2. Description of the Related Art Conventionally, in the field of assembling machines and electrical parts, industrial robots such as shown in FIG. 7 have been applied in order to improve the assembling accuracy and the assembling efficiency by automating the assembling work. There is. The robot 100 shown in the figure is a so-called orthogonal robot configured by a combination of single-axis robots having a movable part that reciprocates in one direction, and specifically, the lower single-axis robot 1
The uniaxial robot 101b having the same structure as that of the uniaxial robot 101a is orthogonally attached to the movable part 102a of the uniaxial robot 01a.
A working member 103 is attached to the movable portion 102 of 1b. The movable member 102 moves in the X-axis direction and the Y-axis direction, so that the working member 103 moves in the X- direction.
A predetermined work is performed by the work member 103 while being moved in the Y direction.

Such single-axis robots 101a, 101
In b, the mechanism for operating the movable portion 102 is such that the movable portion 102 is screwed through a nut member to a ball screw shaft rotatably supported by a pair of support members erected on a base or the like, The movable part 102 is generally attached to a guide member provided in parallel with the ball screw shaft, and the movable part 102 is moved by rotating the ball screw shaft in the forward and reverse directions by a driving means such as a motor. It is adapted to reciprocate along the guide member.

[0004]

By the way, in the single-axis robot having the above-described structure, the inclination and parallelism of the ball screw axis with respect to the guide member affect the moving performance of the movable part, and therefore it is necessary to keep it properly. There is. For example, if the parallelism between the ball screw shaft and the guide member is not ensured, not only the smooth movement of the movable part is impaired, but also the drive source or the drive mechanism part is overloaded to the drive source due to friction. May be damaged. Therefore, in order to avoid such an inconvenience, in reality, the bearing is embedded in a metal block to strongly configure the supporting member, and at the same time, the processing accuracy of the supporting member and the dimensioning of the guide member are adjusted. By managing with extremely high precision,
It supports the ball screw shaft.

However, in this case, since the support position of the ball screw shaft is determined by the machining accuracy of the parts, the dimensional accuracy, etc., if this is not ensured, the moving performance of the movable part cannot be properly maintained. Become. Therefore, in such a case, it becomes necessary to secure the movement performance of the movable part by selecting a component and adjusting the height, or if it is not possible to perform additional work or shim adjustment. However, this causes a problem that the assembling work becomes complicated and requires skill.

Moreover, since each component of the single-axis robot is manufactured with high accuracy as described above, the cost of each component increases, and as a result, the cost of the robot itself rises.

The present invention has been made in order to solve the above problems, and by making it possible to adjust the support position of the ball screw shaft, it is possible to maintain the inclination and parallelism of the ball screw shaft with high accuracy, and to improve the robot. It is an object of the present invention to provide a single-axis robot capable of improving the assembling workability and reducing the robot price, and an assembling method thereof.

[0008]

The invention according to claim 1 is
The base end side and the tip end side are rotatably supported by the robot main body via the base end side support portion and the tip end side support portion, respectively, and the base end side is a ball screw shaft connected to the drive means.
The robot body includes a movable portion that is screwed into the ball screw shaft and a guide member that is provided on the robot body and that guides the movable portion. The movable portion moves along the guide member as the ball screw shaft rotates. In the single-axis robot configured as described above, the tip side support portion includes a bearing for supporting the ball screw shaft and a bearing mounting portion fixed to the robot main body, and the bearing with respect to the bearing mounting portion. They are connected by a connecting means capable of adjusting the mounting position in the direction orthogonal to the axial direction.

According to a second aspect of the present invention, in the single-axis robot according to the first aspect, a bracket having a mounting surface in a direction orthogonal to the ball screw shaft is provided as the bearing mounting portion, and a bearing housing having a flange is provided. The bearing is held and the flange of the bearing housing is connected to the bracket by a connecting means capable of adjusting a mounting position.

According to a third aspect of the present invention, in the single-axis robot according to the second aspect, the bearing is attached to the bearing housing so that the axial center angle can be adjusted.

According to a fourth aspect of the present invention, in the single-axis robot according to the second or third aspect, the ball screw shaft is supported by the bearing so as to be axially positionally adjustable.

According to a fifth aspect of the present invention, there is provided the method for assembling a single-axis robot according to any one of the first to fourth aspects, wherein the base end side support portion is fixed to the robot body, and the base end side is fixed. While supporting the base end side of the ball screw shaft on the support part, the movable part is supported by the guide member installed on the robot body, and the movable part is moved to the tip side of the ball screw shaft by the rotation of the ball screw shaft, The bearing is connected to a bearing mounting portion fixed to the robot body.

According to a sixth aspect of the invention, in the method for assembling a single-axis robot according to the fifth aspect, guide members are installed on both sides of the ball screw shaft, and one of the guide members is first fixed to the robot body. After fixing the base end side support part to the robot body and moving the movable part to the ball screw shaft tip end side by the rotation of the ball screw shaft, the above bearing is coupled to the bearing mounting part and the other guide member is connected to the robot. It is fixed to the main body.

[0014]

According to the first aspect of the present invention, the support position of the ball screw shaft is adjusted by adjusting the mounting position of the bearing with respect to the bearing mounting portion.
As a result, the ball screw shaft is supported so that the movable portion can be moved most smoothly.

According to the second aspect of the invention, the support position of the ball screw shaft is adjusted by adjusting the mounting position of the flange of the bearing housing with respect to the bracket.

According to the third aspect of the present invention, the support position of the ball screw shaft is adjusted by adjusting the shaft center angle of the bearing with respect to the bracket.

According to the fourth aspect of the invention, the ball screw shaft is properly supported by adjusting the position of the ball screw shaft in the axial direction.

According to the fifth aspect of the invention, the support position of the ball screw shaft can be set to an optimum state at the assembly stage of the single-axis robot.

According to the invention described in claim 6, in particular,
The positions of the ball screw shaft and the other guide member can be set to an optimum state with reference to one guide member.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An example of a single axis robot according to the present invention will be described with reference to the drawings.

FIG. 1 is a plan view showing a single-axis robot, and FIG. 2 is a sectional view of the same. The single-axis robot shown in these figures has a robot body 1 including a base member 2 extending in one axis direction (the left-right direction in FIG. 1), a movable portion 3 provided on the robot body 1 so as to be reciprocally movable, and It is composed of a mechanism section for moving the section 3.

The base member 2 is, as shown in FIG.
The side wall portion 2 is provided at both widthwise ends (left and right ends in FIG. 3) of the bottom portion 2a.
It has a U-shaped cross section in which b and 2b are erected. Side casings 4a and 4b and a top casing 5 are attached to the longitudinal end and the upper opening of the base member 2, respectively. With these, a hollow robot body 1 is formed, and the movable portion 3 is movably provided inside thereof.

The base member 2 includes a pair of fixed rails (guide members) 6 extending in the longitudinal direction of the base member 2,
A ball screw shaft 7 extending in the longitudinal direction of the base member 2 is also arranged between the fixed rails 6. The fixed rails 6 are arranged parallel to each other and fixed to the bottom portion 2a of the base member 2 by a fixing means such as a bolt. In addition, the above-mentioned ball screw shaft 7
The base end portion (the right end portion in FIG. 1) is rotated by the support member (base end side support portion) 8 and the tip portion (the left end portion in FIG. 1) is rotated by the support member (front end side support portion) 15. It is supported freely and in parallel with each of the fixed rails 6.

As shown in FIGS. 2 and 4, the support member 8 is a substantially hollow support block 9 fixed to the bottom portion 2a of the base member 2, and one side of the support block 9 (in FIG. 2). The ball screw shaft 7 is rotatably supported via the bearing 10. A ball screw shaft driving servomotor 11 is fixed to the other side (right side in FIG. 2) of the support block 9, and the output shaft 11a of the servomotor 11 and the base end portion of the ball screw shaft 7 are connected to each other. Inside the support block 9, they are connected via a coupling 12.

On the other hand, the support member 15 is fixed to the bottom portion 2a of the base member 2, for example, a support bracket (bearing mounting portion) formed by pressing an iron plate.
16 and a bearing 17 for supporting the ball screw shaft, which is attached to the bearing 16.

As shown in FIGS. 5 and 6, the bearing 17 is attached to the support bracket 16 via the flange portion of the housing 18 in a state where the bearing 17 is fitted in the housing 18. In this mounted state, the tip of the ball screw shaft 7 is attached to the bearing 1
It is rotatably supported by 7.

Support bracket 16 for housing 18
Although not shown in detail at the time of attachment to the housing 18, fixing means such as a screw is screwed into a screw hole of the support bracket 1 through a screw hole formed in each unit housing 18a, 18b, so that the housing 18 is fixed. Support bracket 1
It can be attached to 6. Moreover, since the screw hole is formed to be larger than the shaft diameter of the screw, the mounting of the housing 18 on the support bracket 16 in a plane is adjusted, more specifically, on the plane orthogonal to the axial direction of the ball screw shaft 7. It is possible to adjust the installation.

Here, the outer shape of the bearing 17 is formed into a spherical shape as shown in FIG. 6, and the inner peripheral surface of the housing 18 is also formed into a spherical shape corresponding thereto. Moreover, the housing 18 is composed of a pair of unit housings 18a and 18b which can be divided in the axial direction, and the support bracket 16 with the bearing 17 sandwiched from both sides in the axial direction by the unit housings 18a and 18b. It can be attached to. That is, by having such a configuration, the bearing 17 is allowed to rotate while having an appropriate frictional force with respect to the housing 18, whereby the support bracket 1
The axis angle of the ball screw shaft 7 with respect to 6 can be changed.

The ball screw shaft 7 is provided with a non-screwed portion in the vicinity of its base end portion, and is supported by the bearing 10 of the support member 8 at this portion. In this non-screwed portion, a thick shaft portion is formed on the tip side of the portion supported by the bearing 10, and the base end portion of the ball screw shaft 7 in a state where the thick shaft portion is in contact with the bearing 10. The servo motor 11 through the coupling 12
Are linked to.

On the other hand, the above-mentioned non-threaded portion is not provided at the tip of the ball screw shaft 7, and the threaded portion of the ball screw shaft 7 is directly supported by the bearing 17 of the support member 15. It is like this. Moreover, the movement of the ball screw shaft 7 in the axial direction is restricted only by the side casing 4a on the tip side of the single-axis robot, and the bearing 17
With respect to, the axial movement is allowed.

The movable part 3 is thus constructed by the base member 2 as described above.
It is mounted on the fixed rail 6 and the housing 18 attached to the. Specifically, as shown in FIGS. 2 and 3, the back surface portion of the movable portion 3 is slidably mounted on each of the fixed rails 6, and the nut portion 20 fixed to the movable portion 3 includes the ball portion. It is screwed onto the screw shaft 9. That is, the movable portion 3 reciprocates along the fixed rail 6 by the forward and reverse rotation of the ball screw shaft 10 by the operation of the servo motor 11.

As shown in FIG. 3, a pair of mounting portions 3a, 3a for mounting working members and the like are provided on the upper portion of the movable portion 3 at both ends in the width direction (both left and right ends in the figure). Each of these mounting portions 3a is externally provided from a slit 21 which is opened in the longitudinal direction of the base member 2 between the upper end portion of the side wall portion 2b of the base member 2 and both widthwise end portions of the top casing 5. It is designed to project. By attaching a predetermined work member to the attachment portion 3a, the work member moves integrally with the movable portion 3 when the single-axis robot operates.

By the way, the ball screw shaft, the movable portion screwed on the ball screw shaft, and the fixed rail for guiding the movable portion are provided, and the movable portion is fixed to the fixed rail as the ball screw shaft rotates. In a single-axis robot with a mechanism that moves along, it is essential to maintain the parallelism between the ball screw shaft and the fixed rail, or the inclination of the ball screw shaft properly in order to ensure smooth operation of the movable part. In the single-axis robot of the above embodiment, the support position of the ball screw shaft can be adjusted by having the above-mentioned configuration.

That is, in the support member 15,
The housing 18 can be mounted and adjusted with respect to the support bracket 16, and more specifically, the mounting and adjustment can be performed on a plane orthogonal to the ball screw shaft 7 of the housing 18. When the parallelism with the fixed rail 6 is not maintained, or when the support height of the ball screw shaft 7 is different between the tip end portion and the base end portion, the support position of the tip end portion of the ball screw shaft 7 should be flat. It is possible to correct the parallelism between the ball screw shaft 7 and each of the fixed rails 6 to an appropriate state by moving the ball screw shaft 7 in a proper manner.

At this time, in the support member 15, as described above, the rotation of the bearing 17 with respect to the housing 18 is allowed, so that the axial angle of the ball screw shaft 7 with respect to the support bracket 16 can be changed. ,
As shown by the arrow in FIG. 6, the ball screw shaft 7 and the bearing 17 are integrally tilted with respect to the support bracket 16, so that when the above-mentioned support position of the ball screw shaft 7 is adjusted, the adjustment is performed. It can be performed in a wider range.

More specifically, when the ball screw shaft 7 is tilted such that the tip of the ball screw shaft 7 is lower than the base end, the mounting position of the housing 18 is simply changed to the tilt of the ball screw shaft 7. The load on the bearing 17 and the like in the support member 15 increases only by moving the bearing member in the direction. However, according to the configuration that allows the bearing 17 to rotate with respect to the support bracket 16 as described above, when the mounting position of the housing 18 is moved in the inclination direction of the ball screw shaft 7, the bearing 17 is moved by the above-mentioned load. The ball screw shaft 7 is rotated with respect to the support bracket 16, whereby the load acting on the bearing 17 and the like is eliminated, and the support position of the ball screw shaft 7 can be suitably moved.

Further, in the above-described single-axis robot, a screw is screwed up to the tip of the ball screw shaft 7, and the tip of the ball screw shaft 7 is directly supported by the bearing 17 at the screwed portion. 7 is allowed to move in the axial direction with respect to the bearing 17, so that, for example, when the stroke between the support member 8 and the support member 15 is shortened due to accumulation of dimensional error of each component, the ball screw shaft 7 Is the tip of bearing 17 (left side in Fig. 2)
It is possible to avoid the deterioration of the rotation performance of the ball screw shaft 7 by shifting so as to project inward, or by artificially shifting.

Particularly, when assembling the single-axis robot, one fixed rail 6 is fixed to the base member 2, while the other fixed rail 6 is temporarily fixed to the base member 2 and the housing 18 is temporarily fixed to the support bracket 16. If the fixed rail 6 and the housing 18 that are temporarily fixed are fixed after the movable portion 3 is moved by operating the servo motor 11, the above-mentioned synergistic action in the support member 15 can be achieved. The ball screw shaft 7 can be supported at the optimum position in the assembling stage of the single-axis robot. As a result, it becomes possible to assemble a single-axis robot capable of ensuring a very good operation of the movable part 3.

As described above, in the single-axis robot of the above-described embodiment, the support position of the ball screw shaft 7 can be adjusted by the support member 15 as described above. Therefore, each component of the single-axis robot or the like can be adjusted. It is possible to maintain the support position of the ball screw shaft 7 with high accuracy without requiring high-precision machining or dimensioning.

Further, by making it possible to adjust the support position of the ball screw shaft 7, when the support position is corrected as in the conventional case, a complicated and skilled assembly such as selection of parts or additional machining or shim adjustment is required. No work required,
As a result, the workability of assembling the single-axis robot can be improved.

Furthermore, since it is not necessary to perform high-precision machining and dimensioning for each component of the single-axis robot, the number of machining steps and machining cost for each component can be reduced, thereby reducing the robot price. It will be possible.

The above-mentioned single-axis robot is an embodiment of the single-axis robot according to the present invention, and its concrete configuration is as follows.
Modifications can be made as appropriate without departing from the scope of the present invention.
For example, in the above single-axis robot, the ball screw shaft 7
The adjustment function for the support position of the ball screw shaft 7 is provided only on the tip side of the ball screw shaft 7, that is, the support member 15, but the base end side of the ball screw shaft 7, that is, the support member 8 is also provided with the same adjustment function, It may be configured so that the support performance of the screw shaft 7 can be adjusted more flexibly.

Further, although the support bracket 15 obtained by pressing an iron plate is applied to the support member 15 of the single-axis robot, it may be formed of a metal casting or the like. However, from the viewpoint of reducing the processing man-hours and the processing cost of the component parts, the one manufactured by pressing the iron plate is preferable.

Further, in the above single-axis robot, the screw hole for mounting the housing 18 to the support bracket 16 is formed larger than the shaft diameter of the screw.
Although the housing 18 is formed so as to be able to be mounted and adjusted on the support bracket 16 in a planar manner, in this case, if the adjustment direction is empirically or experimentally limited, the screw hole should be long. You may make it form a hole.

[0045]

As described above, according to the present invention, in the single-axis robot, the support position of the ball screw shaft can be adjusted by adjusting the mounting position of the bearing supporting the ball screw shaft with respect to the bearing mounting portion. As a result, the ball screw shaft can be supported at a highly accurate position where the moving part can be moved most smoothly, and the moving performance of the moving part can be favorably maintained by appropriately adjusting it as necessary. it can. Therefore, when the supporting position of the ball screw shaft is not properly secured, the complicated work such as additional work for correcting it and the work requiring skill are unnecessary,
As a result, the workability of assembling the single-axis robot can be improved, and furthermore, it is not necessary to perform high-precision processing and dimensioning for each component of the single-axis robot, so the number of processing steps for each component is reduced. The processing cost is reduced and the robot price can be reduced.

At this time, a bracket having a mounting surface in a direction orthogonal to the ball screw axis is provided as the bearing mounting portion, the bearing is held by a bearing housing having a flange, and the mounting position of the flange of the bearing housing can be adjusted on the bracket. If they are coupled, the support performance of the ball screw shaft can be adjusted by moving the support position of the ball screw shaft in a plane.

If the bearing is attached to the bracket so that the shaft center angle can be adjusted, the relative inclination of the ball screw shaft with respect to the bracket can be adjusted, thereby supporting the ball screw shaft. The position can be adjusted more effectively.

Further, if the position adjustment of the ball screw shaft in the axial direction is enabled, the bearing position of the bearing with respect to the ball screw shaft is changed in the axial direction of the ball screw so that the adjustment of the support position of the ball screw shaft is more effective. It becomes possible to do it.

When assembling the single-axis robot, the base end side support portion is fixed to the robot body, the movable portion is supported by the guide member, and the movable portion is moved to the tip side of the ball screw shaft. By connecting the bearing to the bearing mounting portion, the ball screw shaft can be supported at the optimum position during the assembly stage of the single-axis robot.

At this time, when the guide members are installed on both sides of the ball screw shaft, first, one guide member is fixed to the robot body, and the movable part is moved to the tip side of the ball screw shaft, and then the other. If the guide member is fixed to the robot body, the positional relationship between the ball screw shaft and the guide member can be effectively set when a plurality of guide members are provided.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of a single-axis robot according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

5 is a sectional view taken along line VV in FIG.

6 is a sectional view taken along line VI-VI in FIG. 5, showing a support member.

FIG. 7 is a perspective view showing an example of an orthogonal robot configured by using a single-axis robot.

[Explanation of symbols]

 1 Robot body 2 Base member 3 Movable part 3a Attachment part 4a, 4b Side casing 5 Top casing 6 Fixed rail 7 Ball screw shaft 8,15 Support member 9 Support block 10,17 Bearing 11 Servo motor 12 Coupling 16 Support bracket 18 housing 19 retaining ring 20 nut member 21 slit

Claims (6)

[Claims] 1. A ball screw shaft having a base end side and a tip end side rotatably supported by a robot body via a base end side support portion and a tip end side support portion, respectively, and a base end side connected to a driving means, A movable part that is screwed to this ball screw shaft,
A single-axis robot having a guide member provided on the robot body for guiding the movable part, wherein the movable part is configured to move along the guide member as the ball screw shaft rotates. The tip side support part consists of the bearing for the ball screw shaft support and a bearing mounting part fixed to the robot body, and the bearing is adjusted in the mounting position in the direction orthogonal to the axial direction with respect to the bearing mounting part. A single-axis robot characterized by being connected by a connecting means capable of 2. A bracket having a mounting surface in a direction orthogonal to the ball screw shaft is provided as the bearing mounting portion, and the bearing is held by a bearing housing having a flange, and the flange of the bearing housing is mounted to the bracket. The connection is made by a connecting means capable of adjusting a position.
The single-axis robot described. 3. The single-axis robot according to claim 2, wherein the bearing is attached to the bearing housing so that an axial center angle can be adjusted. 4. The single-axis robot according to claim 2, wherein the ball screw shaft is supported by the bearing so as to be axially positionally adjustable. 5. The method for assembling a single-axis robot according to any one of claims 1 to 4, wherein the base end side support portion is fixed to the robot body, and the base end side support portion has a ball screw shaft. While supporting the base end side of the robot, the movable part is supported by the guide member installed on the robot body, and the movable part is moved to the tip side of the ball screw shaft by the rotation of the ball screw shaft. A method for assembling a single-axis robot, characterized in that it is connected to a fixed bearing mounting portion. 6. A guide member is installed on both sides of the ball screw shaft, and first, one guide member is fixed to the robot main body, and the base end side supporting portion is fixed to the robot main body, and the ball screw shaft is rotated. The assembly of the single-axis robot according to claim 5, wherein after the movable part is moved to the tip side of the ball screw shaft, the bearing is coupled to the bearing mounting part and the other guide member is fixed to the robot body. Method.