JP7825201B2 - Parts Mounting Equipment - Google Patents

Description

The present invention relates to a component mounting device that mounts components onto a circuit board using a component holder attached to the lower end of an elevator shaft.

Conventionally, component mounting devices are known that move a mounting head between a component supply unit and a board to mount components on the board. The mounting head is equipped with a component holder at the lower end of an elevating shaft that extends vertically, and a rotation mechanism provided on the mounting head allows the nozzle to rotate together with the elevating shaft. Furthermore, some types of component mounting devices are equipped with a mechanism that uses pressurized air (pneumatic pressure) to press components against the board via the component holder when mounting the components on the board (for example, see Patent Document 1 below).

Japanese Patent Application Laid-Open No. 2002-301677

However, in a mounting head like the one disclosed in Patent Document 1, which is equipped with a mechanism for rotating the lifting shaft as well as a mechanism for pressing components using pressurized air, these two mechanisms are arranged side by side in the vertical direction of the mounting head. This inevitably increases the vertical dimension of the mounting head, making it difficult to reduce its size.

The present invention therefore aims to provide a component mounting device that allows for a smaller mounting head.

The component mounting device of the present invention is a component mounting device having a mounting head that mounts components onto a board, the mounting head comprising: a lift shaft that extends vertically and has a component holder at its lower end that holds components; a rotation mechanism that rotates the lift shaft; and a load mechanism that uses pressurized air to apply a load that pressurizes the component against the board via the component holder when the component is mounted on the board using the component holder. The rotation mechanism is a hollow motor with a hollow shaft as its rotation axis, and the lift shaft extends vertically within the internal space of the hollow shaft and is guided by a spline guide provided in the internal space so that it rotates integrally with the hollow shaft and can move up and down relative to the hollow shaft. The load mechanism comprises a pressurized air supply pipe that supplies pressurized air, and a pressure unit provided in the internal space that receives pressurized air supplied through the pressurized air supply pipe and presses the upper end of the lift shaft downward.

This invention allows the mounting head to be made smaller.

FIG. 1 is a plan view of a main part of a component mounting device according to an embodiment of the present invention. FIG. 1 is a front view of a head unit provided in a component mounting device according to an embodiment of the present invention. FIG. 1 is a partial cross-sectional side view showing one mounting head constituting a head unit provided in a component mounting device according to an embodiment of the present invention, together with a lifting unit. FIG. 1 is a partial cross-sectional side view of a mounting head provided in a component mounting device according to an embodiment of the present invention. 1A and 1B are enlarged side cross-sectional views of a portion of a mounting head provided in a component mounting device according to an embodiment of the present invention. FIG. 1 is a block diagram showing a control system of a component mounting device according to an embodiment of the present invention.

Embodiments of the present invention will now be described with reference to the drawings. Figure 1 shows a component mounting device 1 in one embodiment of the present invention. The component mounting device 1 is a device that mounts components BH on a board KB sent from the upstream side and then transports it downstream. For ease of explanation, the transport direction of the board KB in the component mounting device 1 will be referred to as the X direction, the horizontal direction perpendicular to the X direction as the Y direction, and the up-down direction as the Z direction.

In FIG. 1, the component mounting device 1 comprises a base 11, a transport conveyor 12, a tape feeder 13, a head unit 14, and a head unit movement mechanism 15. The transport conveyor 12 is mounted on the base 11 and supports both ends of the board KB from below, transporting it in the X-axis direction.

The tape feeder 13 is detachably attached to a feeder base 11B installed at the Y-direction end of the base 11. Multiple tape feeders 13 can be attached to the feeder base 11B in an array in the X-direction. Each tape feeder 13 pulls out and transports carrier tape (not shown) from a reel RL, and supplies components BH to a component supply port 13K located at the front end (the side facing the transport conveyor 12). Note that while the tape feeder 13 is one example of a component supply device, other component supply devices such as tape feeders that supply taped radial or axial components, and tray feeders that supply components stored in trays can also be used.

In Figures 2 and 3, the head unit 14 includes a head base 21 that extends along the XZ plane, and a mounting head 23 attached to the head base 21 via an elevating mechanism 22. In this embodiment, three mounting heads 23 are arranged side by side in the X direction, and three elevating mechanisms 22 are also arranged side by side in the X direction corresponding to the three mounting heads 23.

In Figure 1, the head unit movement mechanism 15 is a mechanism for moving the head unit 14 in a horizontal plane (XY plane), and includes a fixed beam 15a that is mounted on the base 11 and extends in the Y direction, and a movable beam 15b that is supported by the fixed beam 15a and extends in the X direction. The movable beam 15b is movable in the Y direction along the fixed beam 15a, and the head base 21 (i.e., the head unit 14) is attached so that it can move in the X direction along the movable beam 15b.

In Figure 3, the lifting mechanism 22 comprises a lifting unit 22a provided on the head base 21, a lifting motor 22c provided at the top of the lifting unit 22a with a feed screw 22b (drive shaft) facing downward, and a head connecting member 22e provided with a nut 22d that threads onto the feed screw 22b and extends horizontally from the lifting unit 22a. Rotation of the head connecting member 22e around the central axis of the feed screw 22b is restricted by a guide portion (not shown) provided on the lifting unit 22a. Therefore, when the lifting motor 22c operates and the feed screw 22b rotates, the head connecting member 22e rises and falls relative to the lifting unit 22a via the nut 22d.

In Figure 3, each mounting head 23 includes a hollow motor 31 as a rotation mechanism, an elevating shaft 32, a suction nozzle 33, a pressurized air supply pipe 34 for supplying pressurized air, and a diaphragm unit 35 as a pressurizing unit. The hollow motor 31 includes a housing 41, a hollow shaft 42, a stator 43, and a rotor 44.

In Figure 3, the housing 41 is connected to the head connecting member 22e via an elevating base 41B, which is a member extending in the Z direction, and the hollow shaft 42 extends vertically through the center of the housing 41. The hollow shaft 42 is supported rotatably around the Z axis (an axis extending in the Z direction) by bearings 45 provided above and below the center of the housing 41.

In Figure 3, the stator 43 is located inside the housing 41, and the rotor 44 is located on the outer surface of the hollow shaft 42. A coil is wound around the stator 43, and the rotor 44 is made of a permanent magnet. When current is applied to the coil of the stator 43, a magnetic field is generated, and the electromagnetic force generated between this magnetic field and the magnetic field generated in the rotor 44 (permanent magnet) causes the rotor 44 to rotate around the Z axis together with the hollow shaft 42. In this way, the hollow shaft 42 serves as the rotating shaft (drive shaft) of the hollow motor 31.

In Figure 3, two slide sections 41S are arranged side by side in the Z direction on the side of the lift base 41B. These two slide sections 41S are slidably engaged with mounting head lift guides 22G that are provided on the lift section 22a and extend in the Z direction. Therefore, when the lift motor 22c is operated to rotate the feed screw 22b around the Z axis, the housing 41 (i.e., the mounting head 23) moves up and down relative to the head base 21. By switching the rotation direction of the feed screw 22b by the lift motor 22c, the head connecting member 22e can be moved upward or downward.

In Figure 3, the lift shaft 32 extends vertically within the hollow shaft 42. The upper end of the lift shaft 32 is located midway within the hollow shaft 42, and the lower end protrudes below the hollow shaft 42. As shown in Figures 2 and 3, a nozzle holder 32H is provided at the lower end of the lift shaft 32, and the suction nozzle 33 is detachably attached to the nozzle holder 32H.

In Figures 3 and 4, the lift shaft 32 is guided by a spline guide 42G provided in the lower region of the internal space 42S of the hollow shaft 42. As a result, the lift shaft 32 can rotate integrally with the hollow shaft 42 and can move up and down freely relative to the hollow shaft 42.

In other words, in this embodiment, the lift shaft 32 extends vertically through the internal space 42S of the hollow shaft 42 and is guided by a spline guide 42G provided in the internal space 42S so that it rotates integrally with the hollow shaft 42 and can move up and down relative to the hollow shaft 42.

In Figure 3, an air passage 51 within the lifting shaft is formed near the lower end of the lifting shaft 32. The air passage 51 within the lifting shaft is connected to an air passage 52 within the nozzle holder 32H. The suction nozzle 33 is provided with an air passage 53 within the nozzle, and when the suction nozzle 33 is attached to the nozzle holder 32H, the air passage 53 within the nozzle is connected to the air passage 51 within the lifting shaft via the air passage 52 within the nozzle holder.

In Figure 3, the air passage 51 inside the lift shaft is connected to an external vacuum pressure supply passage 62 that extends from the bottom of the lift shaft 32 through a rotary joint (lower rotary joint 61) to the outside of the mounting head 23. Rotation of the lower rotary joint 61 around the Z axis is restricted by an anti-rotation guide 41D extending downward from the lift base 41B. The lower rotary joint 61 functions to connect the air passage 51 inside the lift shaft to the external vacuum pressure supply passage 62 regardless of the rotation position of the lift shaft 32.

In Figure 3, the external vacuum pressure supply path 62 is connected to a positive pressure source 64 and a negative pressure source 65 via a valve mechanism 63 provided outside the mounting head 23. When positive pressure from the positive pressure source 64 or negative pressure from the negative pressure source 65 is supplied to the air passage 51 inside the lifting shaft through the valve mechanism 63, the positive pressure or negative pressure reaches the air passage 53 inside the nozzle via the air passage 51 inside the lifting shaft and the air passage 52 inside the nozzle holder, generating positive pressure (blow pressure) or negative pressure (vacuum suction pressure) at the lower end of the suction nozzle 33.

In Figures 3 and 4, the pressurized air supply pipe 34 extends vertically in the upper region of the internal space 42S of the hollow shaft 42. The pressurized air supply pipe 34 is formed with a pressurized air supply path 34L that supplies pressurized air supplied from outside (above) the hollow shaft 42 to the internal space 42S of the hollow shaft 42.

In Figures 3 and 4, the upper end of the hollow shaft 42 is closed by a cap 71. The cap 71 has a through-hole 71H that penetrates in the thickness direction (Z direction). The pressurized air supply path 34L is connected to a joint pipe 72 provided above the cap 71 via the through-hole 71H in the cap 71. The joint pipe 72 is connected to an external air pipe 74 via a rotary joint (upper rotary joint 73), and the external air pipe 74 is connected to a pressurized air supply source 76 via an air supply valve 75. The upper rotary joint 73 functions to communicate the air passage 72L (Figure 4) within the joint pipe 72 with the external air pipe 74, regardless of the rotational position of the joint pipe 72, which rotates around the Z axis integrally with the hollow shaft 42.

In Figures 4 and 5(a) and (b), the diaphragm portion 35 is provided in the middle of the internal space 42S of the hollow shaft 42 in the Z direction. The diaphragm portion 35 includes a diaphragm 81 that contacts the upper surface of the flange-shaped protrusion 32T formed at the upper end of the lift shaft 32, and a cover 82 that holds the outer edge 81E of the diaphragm 81 and covers the diaphragm 81 from above.

4 and 5(a) and (b), the cover 82 has a communication hole 82H that communicates with the pressurized air supply path 34L. The lower end of the pressurized air supply pipe 34 is connected to the upper surface of the cover 82 of the diaphragm portion 35, and the pressurized air supply path 34L is connected to the internal space of the diaphragm portion 35 (diaphragm portion internal space 35S) through the communication hole 82H in the cover 82. Therefore, when pressurized air is supplied from the pressurized air supply source 76, the pressurized air is supplied to the diaphragm portion internal space 35S through the air supply valve 75, external air piping 74, upper rotary joint portion 73, air passage 72L in the joint pipe 72, pressurized air supply path 34L, and communication hole 82H in the diaphragm portion 35.

In each mounting head 23, a spring (not shown) is provided between the lifting shaft 32 and the hollow shaft 42 to bias the lifting shaft 32 upward relative to the hollow shaft 42. When pressurized air is not supplied from the pressurized air supply source 76 and the diaphragm internal space 35S is not pressurized (non-pressurized state), the spring biases the lifting shaft 32 to a position (referred to as the "preparation position") in which the upper end protrusion 32T is positioned in the middle of the diaphragm internal space 35S (middle in the Z direction) (Figure 5(a)).

When pressurized air is supplied to the diaphragm internal space 35S from the lift shaft 32 in the standby position, pressurizing the diaphragm internal space 35S. The diaphragm internal space 35S expands, and the diaphragm 81 pushes the upper end of the lift shaft 32 downward against the spring force. As a result, the lift shaft 32 is guided by the spline guide 42G and descends into the internal space 42S of the hollow shaft 42 until the protrusion 32T abuts the upper surface of the spline guide 42G (FIG. 5(a) → FIG. 5(b)). When the protrusion 32T of the lift shaft 32 is thus depressed to a position where it abuts the upper surface of the spline guide 42G, the lift shaft 32 is positioned (referred to as the "descended position") slightly lower than the standby position by a distance ΔH (FIG. 5(b); the amount of descent of the protrusion 32T) (FIG. 4).

Figure 6 shows the control system of the component mounting device 1. As shown in Figure 6, the control device 90 provided in the component mounting device 1 controls the operation of the transport conveyor 12, tape feeder 13, head unit 14, and head unit movement mechanism 15. The control device 90 controls the transport conveyor 12 to transport the board KB and position it at a predetermined work position, and controls the tape feeder 13 to supply components BH to the component supply port 13K of the tape feeder 13.

The control device 90 also controls the lifting and lowering of the mounting head 23 by each lifting mechanism 22 that constitutes the head unit 14, and the operation of the hollow motor 31 that rotates the lifting shaft 32 (i.e., the suction nozzle 33) in each mounting head 23. The control device 90 also controls the supply of pressurized air from the pressurized air supply source 76 to the diaphragm unit 35 by operating the air supply valve 75.

When the component mounting device 1 performs the task of mounting components BH on a board KB (component mounting task), the transport conveyor 12, controlled by the control device 90, first operates to receive and transport the board KB sent from the upstream process. After transporting the board KB, the transport conveyor 12 positions it at the specified work position, and the head unit movement mechanism 15 and head unit 14 operate in cooperation to cause each of the three mounting heads 23 to repeatedly perform mounting turns.

As the mounting head 23 repeatedly performs mounting turns, components BH are mounted on the board KB. During one mounting turn, each mounting head 23 performs the following operations: holds (sucks) a component BH supplied by the tape feeder 13 with the suction nozzle 33; and places the component BH held by the suction nozzle 33 at the target mounting position on the board KB.

When the mounting head 23 mounts the component BH held by the suction nozzle 33 onto the board KB, the control device 90 activates the lift motor 22c of the lift mechanism 22 corresponding to that mounting head 23 to lower the entire mounting head 23. However, before this, the control device 90 rotates the suction nozzle 33 around the Z axis together with the hollow shaft 42 of the hollow motor 31 to adjust the posture (angle) of the component BH picked up by the suction nozzle 33 when it is mounted onto the board KB.

In addition, before operating the lift motor 22c to lower the entire mounting head 23, the control device 90 supplies pressurized air from the pressurized air supply source 76 to the diaphragm portion 35 via the air supply valve 75, thereby pushing the lift shaft 32 down from the standby position to the lowered position (Figures 5(b) and 4). This allows the diaphragm portion 35 to function as an air spring when the lift shaft 32 presses the component BH against the board KB, allowing the component BH to be pressed against the board KB with an appropriate pressing force without placing a large load on the component BH.

When the head unit 14 (three mounting heads 23) has repeatedly made mounting turns to mount all of the components BH to be mounted on the board KB, the transport conveyor 12 operates to transport the board KB to the downstream process side of the component mounting device 1. This completes the component mounting work for one board KB.

As explained above, in the component mounting device 1 of this embodiment, the mounting head 23 includes a hollow motor 31 with a hollow shaft 42 as its rotation axis, as a rotation mechanism for rotating the lift shaft 32, which has a suction nozzle 33 attached to its lower end. The lift shaft 32 extends vertically through the internal space 42S of the hollow shaft 42 and is guided by a spline guide 42G provided in the internal space 42S so that it rotates integrally with the hollow shaft 42 and can move up and down relative to the hollow shaft 42. The load mechanism, which applies a load by air to press the component BH against the board KB via the suction nozzle 33, includes a pressurized air supply pipe 34 that supplies pressurized air to the internal space 42S of the hollow shaft 42, and a pressure unit (diaphragm 35) provided in the internal space 42S of the hollow shaft 42. The pressurized air is supplied through the pressurized air supply pipe 34, and the pressure unit presses the upper end (protrusion 32T) of the lift shaft 32 downward.

In other words, in the component mounting device 1 of this embodiment, the loading mechanism of the mounting head 23 is provided inside the rotation mechanism, which allows for a smaller vertical dimension than in conventional cases where the rotation mechanism and loading mechanism are arranged one above the other. Therefore, according to this embodiment, the mounting head 23 equipped with both the rotation mechanism and loading mechanism can be made smaller.

As explained above, in the component mounting device 1 of this embodiment, the rotation mechanism (hollow motor 31) and load mechanism (diaphragm portion 35) of the mounting head 23 are not arranged one above the other, but rather the load mechanism is arranged inside the rotation mechanism, thereby reducing the vertical dimension and enabling the mounting head 23 to be made smaller. Furthermore, by making the mounting head 23 smaller, the mounting head 23 can be moved stably at high speed, making it possible to improve the takt time of the component mounting work performed by the component mounting device 1.

Although the present invention has been described above in terms of embodiments, it is not limited to the above and various modifications are possible. For example, in the above-described embodiment, the head unit 14 is provided with three mounting heads 23, but this is merely an example and the number is not critical. Furthermore, the configuration in which the hollow motor 31 in the above-described embodiment rotates the hollow shaft 42 (e.g., a combination of a stator 43 made of a coil and a rotor 44 made of a permanent magnet) may differ from that in the embodiment.

It can be used in component mounting devices that mount components onto a board using a component holder attached to the lower end of a lifting shaft.

1 Component mounting device 23 Mounting head 31 Hollow motor (rotation mechanism)
32 Lifting shaft 33 Suction nozzle (component holder)
34 Pressurized air supply pipe (load mechanism)
34L: Pressurized air supply path 35: Diaphragm portion (pressurizing portion) (loading mechanism)
41 Housing 42 Hollow shaft 42G Spline guide 42S Internal space 43 Stator 44 Rotor 76 Pressurized air supply source 81 Diaphragm 82 Cover 90 Control device BH Part KB Board

Claims (3)

A component mounting device comprising: a mounting head for mounting components onto a substrate, the mounting head comprising: an elevating shaft extending in the vertical direction and having a component holder at its lower end for holding components; a rotation mechanism for rotating the elevating shaft; and a load mechanism for applying a load by pressurized air to pressurize the components against the substrate via the component holder when the components are mounted onto the substrate by the component holder;
the rotation mechanism is a hollow motor with a hollow shaft as a rotation axis,
the lifting shaft extends vertically through the internal space of the hollow shaft, and is guided by a spline guide provided in the internal space so as to rotate integrally with the hollow shaft and to be able to move up and down relative to the hollow shaft;
The loading mechanism of the component mounting device comprises a pressurized air supply pipe that supplies pressurized air, and a pressure unit that is provided in the internal space and receives the pressurized air supplied through the pressurized air supply pipe and presses the upper end of the lifting shaft downward. The component mounting device according to claim 1, wherein the pressurized air supply pipe is provided in an area of the internal space above the pressurizing unit. The component mounting device of claim 1, wherein the pressure applying unit includes a diaphragm.