JP2543539B2 - Balance method and balancer mechanism for vertical articulated robot - Google Patents

Description

The present invention relates to a balancing method and balancer mechanism for a vertical articulated robot, and can be used even when the vertical articulated robot is installed on a wall or a slope. .

[Conventional technology]

Conventionally, a hydraulic or pneumatic balancer device has been used as a balancer mechanism for the load torque of the vertical articulated robot. However, hydraulic pressure sources, pneumatic pressure sources, piping, etc. are indispensable as auxiliary equipment to these balancer devices. A spring mechanism was applied to solve the problem of this auxiliary equipment.

[Problems to be solved by the invention]

However, in order to counter the load torque according to the load with only one spring, the stroke of the spring must be set theoretically large, which is impossible in the design of the spring.

Therefore, an object of the present invention is to provide a spring balancer mechanism that can counter the load torque and can be easily designed in order to solve the above problems.

[Means for solving problems]

In view of the above object, the present invention provides a balance method and a balancer mechanism in which a pull type spring mechanism and a push type spring are selectively combined or used alone.
That is, according to the first aspect of the present invention, in a vertical articulated robot having a revolving cylinder that is erected so as to be revolvable with respect to a base and an arm that is rotatable with respect to the revolving cylinder, it is possible to counter a load torque Then, as a balance method for assisting the rotating operation in which the arm rotates with respect to the swivel barrel, whether the pull type spring mechanism and the push type spring mechanism are used individually or in combination according to the load torque. A vertical articulated robot balancing method characterized by selecting

According to a second aspect of the present invention, in a vertical articulated robot having a revolving cylinder that is erected so as to be revolvable with respect to a base, and an arm that is rotatable with respect to the revolving cylinder, A balancer mechanism for a vertical articulated robot characterized in that a pulling spring mechanism and a pushing spring mechanism are attached to and detached from an arm, respectively.

[Work]

Various load torques can be counteracted by individually or in combination the torque characteristics of the pull-type or push-type spring mechanism shown according to the tilt angle of the arm in which the arm rotates and tilts with respect to the swing cylinder. The torque characteristic of the spring mechanism also varies depending on the set angular position where the spring has a free length, and the desired torque characteristic is obtained by appropriately combining the pull type and push type spring mechanisms in consideration of the set angular position. be able to.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to the embodiments shown in the accompanying drawings. FIG. 1 is an installation schematic diagram of a vertical articulated robot according to the present invention, and FIG. 2 is an explanatory diagram showing that load torque can be countered by a combination of springs.

First, according to FIG. 1, the base is set on the inclined surface 10 having an inclination angle φ.
12 is installed, and the swivel barrel for this base 12
Reference numeral 14 is attached so as to be rotatable about an axis θ perpendicular to the inclined surface 10, that is, perpendicular to the base 12.
Further, a W-axis arm 16 is rotatably attached to the upper part of the revolving cylinder 14 about an axis W which is vertical and horizontal to the axis θ. Further, a U-axis arm 18 which is rotatable about an axis U parallel to the axis W is attached to the tip of the W-axis arm 16. Further, the spring has a free length on a plane PL including the axes θ and W, and a pulling spring mechanism 20 is provided, one end of which is attached to the swivel barrel 14 and the other end of which is attached to the W-axis arm 16. In addition, one end is the swing barrel
14, the other end is attached to the protrusion 24 of the W-axis arm 16 and has a spring that becomes a free length when the W-axis arm 16 is located rearward of the plane PL (left side in FIG. 1). A push-type spring mechanism 22 is provided.

The terms "pulling type" and "pushing type" above refer to the pulling type spring mechanism 20 and the pushing type spring mechanism 22, respectively, which receive tension or compression within a desired rotational movement range of the W-axis arm 16. It means that it is set to receive and generate force. Further, the pull type spring mechanism 20 and the push type spring mechanism 22 are not limited to one each, but a plurality of them may be attached.

Installation angle of the vertical articulated robot is 90 degrees,
That is, the action of the balance will be described with reference to FIG. 2 by taking the case of being installed on the wall surface as an example. The horizontal axis _W represents the rotation angle of the W-axis arm 16, and _W = 0 ° when the _W -axis arm 16 is on the plane PL, and the clockwise rotation in FIG. 1 is positive. The vertical axis T shows the torque centered on the axis W. First, the curve T1 is a torque curve by the pulling spring mechanism 20, and the torque is zero at _W = 0 °. A curve T2 is a torque curve by the push type spring mechanism 22, and a straight line T3 is a torque value by the drive motor of the W-axis arm 16. A curve T5, which is a combination of the above torque curves T1, T2, and T3, is a generated torque curve centering on the axis W of the vertical articulated robot, and the operating angle shown in FIG. The torque value is large within the range. That is, it means that it can bear the load.

Next, the installation inclination angle φ becomes smaller than 90 degrees, for example φ
When it is around 60 °, the load torque curve becomes like the chain double-dashed line T6. In this case, the torque curve T5 is lower than the load torque curve T6 in the rotation angle region where _W is smaller than about -20 degrees. Therefore, if the robot is used in this angle range, for example, a pull type spring mechanism is used.
It is sufficient to remove 20 and use only the push spring mechanism 22. In this case, the torque generated by the vertical articulated robot around the axis W is the torque curve T7 (= T2 + T3)
And exceeds the load torque curve T6.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, it is possible to counter the load torque by appropriately combining the pulling spring mechanism and the pushing spring mechanism and using them independently. Therefore, even if the installation angle of the vertical articulated robot is variously set, it is possible to generate a counter torque corresponding thereto.

[Brief description of drawings]

FIG. 1 is a schematic view of installation of a vertical articulated robot according to the present invention, and FIG. 2 is an explanatory view showing that load torque can be countered by a combination of springs. 10 …… Robot installation slope, 12 …… Base, 14 …… Swivel barrel, 16 …… W axis arm, 20 …… Pulling spring mechanism, 22 …… Pushing spring mechanism, T1 …… By pulling spring mechanism Torque curve, T2 …… Torque curve by push type spring mechanism, T3 …… Torque straight line by motor, T4 …… Load torque curve, T5 …… T1 ＋ T2 ＋ T3 torque curve.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Ueda 3-5-5 Asahigaoka, Hino-shi, Tokyo Inside the Product Development Laboratory, Fanuc Co., Ltd. (56) Reference JP-A-62-148187 (JP, A) Sho 60-138676 (JP, U)

Claims (2)

(57) [Claims] 1. A vertical articulated robot having a revolving cylinder which is erected so as to be revolvable with respect to a base, and having an arm rotatable with respect to the revolving cylinder, said arm being opposed to a load torque. As a balancing method for assisting the rotating motion of rotating with respect to the revolving cylinder, it is selected whether the pulling spring mechanism and the pushing spring mechanism are used individually or in combination according to the load torque. A method for balancing a vertical articulated robot characterized by: 2. A vertical articulated robot having a revolving cylinder vertically rotatably mounted on a base and an arm rotatable with respect to the revolving cylinder. A balancer mechanism for a vertical articulated robot characterized in that a pull type spring mechanism and a push type spring mechanism are attached and detached respectively.