JPS6117762A - Device for putting controlled shaft in rectilineal motion and rotary motion alternatively and simultaneously - Google Patents

Abstract

PURPOSE:To obtain a driving device which can freely conduct rectilineal and rotary motion by fitting two rotary driving members having a spiral ball groove and a ball circulating groove to a main shaft having spiral driving grooves. CONSTITUTION:Two kinds of spiral driving shafts are provided on a main shaft 8. Both driving shafts have pitches in the opposite direction to each other, with which rotary driving members 2, 3 are engaged. The rotary members 2, 3 include balls B, ball circulating grooves 2b, 3b and ball grooves engaged with the driving grooves of the main shaft. Accordingly, the rotary and rectilineal motion of the main shaft can be freely obtained by suitably selecting the respective rotating directions of both rotary driving members 2, 3 or the driving condition thereof.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is a device that can be used in industrial robots, etc., and allows a controlled axis to perform linear motion and rotational motion either alternatively or simultaneously. It is related to.

(Prior art and its problems) Conventionally, as a device for causing a controlled object to perform linear motion and rotational motion, for example, a device that makes a rotational motion with respect to the main body is
There is a system in which a c-column is provided and the controlled object that moves linearly is supported using this column as a column. In this case, it is necessary to provide a rotation prevention guide separate from the support column for causing the controlled body to move linearly, resulting in a large amount of waste, weight, and size.

(Object of the Invention) The present invention has been made in view of the above-mentioned circumstances, and it is an object of the present invention to provide a device in which the guide can be omitted.

(Structure of the Invention) The present invention has a main body in which first and second rotating members are arranged in series so as to be rotatable around the same central axis, a controlled shaft is supported by both of the rotating members, and further, the first and second rotating members Between the rotating member and the controlled shaft, facing spiral first and third ball grooves are formed, and between the second rotating member and the controlled shaft, the first and third ball grooves are formed. Spiral-shaped second and fourth ball grooves are formed in opposite directions to the third ball groove, and first and second ball circulation parts are provided in each of the rotating members. By mutually rotating the first and/or second co-rotating members, the controlled shaft can be linearly moved by nine rotations.

(Example) In this example, a case will be described in which the present invention is applied to a four-axis horizontal multi-joint arc welding robot RB as an industrial robot, but the present invention is not limited to this embodiment.

1 is the main body of the robot RB.

Reference numerals 2.3 denote first and second rotating members which are arranged vertically in series on the main body 1 and are independently rotatably supported around the same central axis, and are formed in a cylindrical shape. That is, each rotating member 2.3 is integrally provided with a gear 4.5, and this gear 4.5 is meshed with a gear 6.7 that is integral with the output shaft of the power M1 and M2 attached to the main body 1. .

Note that the rotating member 2 has a first spiral ball groove 2a formed on its inner periphery, in which a large number of balls B1 are guided, and a first ball circulation part 2 that is continuous with this groove 2a.
b is formed.

Further, the rotating member 3 has a spiral second ball groove 3a (in the opposite direction to the first ball groove 2a) in which a large number of balls B2 are guided, and is continuous with this groove 8a. A second ball circulating section 3b is formed.

Reference numeral 8 denotes one controlled shaft supported on both rotating members 2.3 and coaxially with the rotation center axis thereof. A third ball groove 8a and a fourth ball groove 8b facing the first ball groove 2a and the second ball groove 3a are formed on the outer periphery of the controlled shaft 8.

In this embodiment, the slope of the grooves 2a, 8a and the grooves 3a, 8
The inclination of b is set at an angle that is mutually symmetrical with respect to the radial plane of the controlled shaft 8.

9 is a rear horizontal arm fixed to the upper end of the controlled shaft 8; 10 is a vertically pivoted support 10a at the tip of the arm 9; and a known power transmission mechanism (not shown) is connected by a power storage attached to the rear end of the arm 9. The front horizontal arm 011 is rotated via a vertical shaft 11a at the tip of the arm 10, and is rotated via a power transmission mechanism (not shown) via a power transmission mechanism attached to the rear end of the arm 9. Chill with rotating torch holder. Holder 11
A welding torch T is attached to the.

Furthermore, the operation of this embodiment will be described.

The robot) RB is driven by motive power M1 to M4, and its position is controlled via a control device (not shown).

The operation of the controlled shaft 8 by the powers M1 and M2 will be described below.

(1) First, it is assumed that the rotating member 2 is rotated in the direction of the arrow R in FIG. 2, and the rotating member 3 is rotated in the direction of the arrow L, at the same number of rotations.

Then, the rotating member 2 attempts to raise the controlled shaft 8 while rotating it in the R direction via the ball B1, while the rotating member 3 attempts to rotate the controlled shaft 8 in the L direction via the ball B1. trying to raise it.

Here, since the inclinations of the grooves 2a, 8a and the grooves 3a, 8b are set at symmetrical angles with respect to the radial plane of the shaft 8, the rotational force acting on the controlled shaft 8 is: canceled out.

In the end, the controlled shaft 8 rises without rotating.

On the contrary, the rotating member 2 is moved in the L direction, the rotating member 8 is moved in the R direction,
If they are rotated at the same number of rotations, the controlled shaft 8 will descend without rotating, although it will not be described in detail.

(2) It is assumed that both rotating members 2 and 3 are rotated in the R direction at the same rotation speed.

Then, the rotating member 2 tries to raise the controlled shaft 8 while rotating it in the R direction, while the rotating member 3 tries to lower it while rotating the controlled shaft 8 in the R direction. Therefore, the vertical forces acting on the controlled shaft 8 are canceled out, so that the controlled shaft 8 eventually rotates in the R direction without moving up or down.

On the contrary, if the rotating members 2 and 3 are both rotated in the L direction at the same rotation speed, the controlled shaft 8 will rotate in the L direction without moving up or down, although this will not be explained in detail.0 (3) The rotating member 2 will stop. Assume that only the rotating member 3 is rotated in the R direction while keeping the rotating member 3 in the R direction.

Then, a force to rotate the controlled shaft 8 in the R direction and a force to lower it act on the controlled shaft 8. Therefore, the controlled shaft 8 descends while rotating in the R direction.

Assuming that only the rotating member 3 is rotated in the L direction while the rotating member 2 is stopped in the pair of seats, the controlled shaft 8
will rise while rotating in the L direction.

(4) Even when only the rotating member 2 is rotated while the rotating member 3 is stopped, the controlled shaft 8 often moves up and down while rotating, as in (3) above, although it will not be described in detail. .

(5) By mutually changing the rotational speeds of the other rotating members 2.3, the rotational speed and lifting speed of the controlled shaft 8 can be changed.

As described above, by mutually controlling the rotation of the rotating members 2.3, it is possible to arbitrarily control the rotational position and vertical position of the controlled shaft 8.

The above description is an example, and for example, grooves 2a, 8a and groove 3
The inclinations of a and 8b may be set at an asymmetrical angle with respect to the radial plane of the axis 80. It goes without saying that substitutions with equivalents for each other structure are also included within the technical scope of this invention.

(Effect of the invention) Since this invention is as described above, the rotating member 2.3
The controlled shaft 8 can be caused to perform linear motion and rotational motion either alternatively or simultaneously. Furthermore, there is no need to provide a special anti-rotation guide for linear movement, unlike in the prior art. Therefore, the weight is reduced and the entire device becomes compact.

[Brief explanation of the drawing]

Each of the figures shows an embodiment of the present invention; FIG. 1 is an overall view of an industrial robot, and FIG. 2 is an explanatory view of the main parts. RB...Industrial robot, 1...Main body, 2...1st
Rotating member, 2a...first ball groove, 2b...first ball circulation part, 3...second rotation member, 3a...second ball groove, 3b...second ball circulation part, 8 ...Controlled axis, 8a...Third ball groove, 8b...Fourth ball groove, M1
~M4... Each has power.

Claims (2)

[Claims] (1) A main body, a first and second rotating member arranged in series with the main body and supported to be able to rotate independently around the same central axis, and a first and second rotating member supported on both rotating members and coaxially with the central axis. one controlled shaft, a spiral first ball groove is formed in the first rotating member, and a first ball groove continuous with the first ball groove is formed in the first rotating member.
A ball circulation section is formed, and the second rotating member includes:
A spiral second ball groove is formed in the opposite direction to the first ball groove, and a second ball circulation part is formed continuous with the second ball groove, and further, the controlled shaft is provided with the second ball groove. A device for causing a controlled shaft to perform linear motion and rotational motion either alternatively or simultaneously, in which third and fourth ball grooves facing the first ball groove and the second ball groove are formed. (2) The inclinations of the first and third ball grooves and the inclinations of the second and fourth ball grooves are set at mutually symmetrical angles with respect to the radial plane of the controlled shaft;
An apparatus for causing a controlled shaft according to claim 1 to perform linear motion and rotational motion either alternatively or simultaneously.