Paint system and paint method

1. A paint system comprising a paint unit that has a first paint robot configured to paint an upper region of an object to be painted and a second paint robot configured to paint a lower region of the object to be painted on a lower side with respect to the upper region, wherein:

the first paint robot includes a first robot base and a first robot arm operably mounted on the first robot base;

the second paint robot includes a second robot base and a second robot arm operably mounted on the second robot base;

the object to be painted and the paint unit are movable relative to each other along a horizontal direction, and when a virtual plane that extends in a vertical direction and along a direction of relative movement between the object to be painted and the paint unit is defined as a reference plane, the first paint robot and the second paint robot are disposed on the same side with respect to the reference plane;

a distance between the first robot base and the reference plane is set to be shorter than a distance between the second robot base and the reference plane; and

an arrangement height position of the first robot base is set to be higher than an arrangement height position of the second robot base, and a robot arm passage range that allows passage of the second robot arm is provided under the first robot base.

2. The paint system according to claim 1 , further comprising a single control device configured to control both operation of the first paint robot and operation of the second paint robot.

3. The paint system according to claim 2 , further comprising a paint booth that constitutes a painting space that houses a transfer path for the object to be painted and the paint unit and that is blocked from outside, wherein the single control device is arranged outside the paint booth.

4. The paint system according to claim 1 , wherein:

the first robot arm and the second robot arm each include a spray gun configured to spray paint toward the object to be painted; and

at least one of the spray guns is configured to electrostatically atomize the paint and spray the paint toward the object to be painted.

5. The paint system according to claim 1 , wherein:

a plurality of the paint units including the paint unit are arranged on a first side and a second side with respect to the reference plane;

a paint unit among the plurality of paint units which is arranged on the first side with respect to the reference plane is configured such that the first paint robot paints a region, on the first side, of an upper surface of the object to be painted and the second paint robot paints a side surface, on the first side, of the object to be painted; and

a paint unit among the plurality of paint units which is arranged on the second side with respect to the reference plane is configured such that the first paint robot paints a region, on the second side, of the upper surface of the object to be painted and the second paint robot paints a side surface, on the second side, of the object to be painted.

6. The paint system according to claim 1 , further comprising a rail configured to allow the first paint robot or the second paint robot to move along a transfer direction of the object to be painted.

7. The paint system according to claim 1 , wherein the first paint robot and the second paint robot are configured to paint the object to be painted by spraying paint toward the object to be painted.

8. A paint method in which the paint system according to claim 1 is used, the method comprising:

the first paint robot painting the upper region of the object to be painted while the object to be painted and the paint unit are moved relative to each other along the horizontal direction; and

the second paint robot painting the lower region of the object to be painted on the lower side with respect to the upper region.

9. The paint system according to claim 1 , wherein a distance between an installation position of the support column of the first robot and the reference plane is shorter than a distance between an installation position of the support column of the second robot and the reference plane.