KR101970793B1 - Absorption head of surface mount device - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adsorption head of a surface- The present invention relates to an adsorption head for a surface-orbital body, in which a shaft is rotatably mounted on an adsorption head body while being rotatably mounted around the shaft, and an adsorption nozzle for adsorbing an electronic component is mounted on a tip of the shaft, And a driving gear connected to a driving motor for rotating the shaft around the shaft is engaged with the backlashless gear.

Description

[0001] The present invention relates to an adsorption head of a surface-

The present invention relates to an adsorption head for adsorbing electronic components in a surface mounting machine for mounting an electronic component such as an IC chip on a printed substrate.

The surface mount machine is configured such that an electronic component is sucked from a component supply unit by an adsorption head having a suction nozzle and transferred onto a printed board and mounted at a predetermined position on the printed board.

The suction head of the surface seal organ generally has a structure in which a plurality of shafts can be lifted and lowered on the suction head body while being rotatably mounted around the shafts, and suction nozzles for suctioning the electronic components are mounted on the tips of the shafts For example, Patent Document 1). An air passage passing through the suction nozzle is formed in the shaft. When the suction nozzle sucks the component, a negative pressure is supplied through the air passage. When the component is mounted, a minute positive pressure is supplied do.

In such an adsorption head, a gear mechanism or a belt mechanism is generally used as a mechanism for rotating the shaft around the shaft. However, in the case of the gear mechanism, by the backlash, in the case of the belt mechanism, the lost motion is generated by the expansion and contraction (hysteresis) of the belt. Not only the lost motion, but also the rotation accuracy of the shaft around the axis is reduced.

Backlash of the gear mechanism can be reduced to a certain extent by performing one-way control that restricts the rotation direction of the gear in only one direction, but is not sufficient, and there is also a restriction on control in one-way control.

On the other hand, as the mechanism for rotating the shaft around the shaft in the above-described adsorption head, a mechanism that is generally ball sprung can be used (for example, Patent Document 2)

12 is a cross-sectional view showing a main part of a conventional adsorption head using a ball spline mechanism.

A shaft 41 is rotatably mounted on the suction head body 40 of the surface mount orbiting head along its axial direction and is rotatably mounted around the shaft and a suction nozzle 42 Respectively. As the ball spline mechanism, a spline nut 43 is mounted on the shaft 41 and a ball groove 44 is formed. The ball groove 44 is formed so as to extend upward to secure the lifting stroke of the shaft 41.

On the other hand, an air passage 45 passing through the suction nozzle 42 is formed in the shaft 41. The air supply port for supplying the air to the air passage 45 can not be provided at a portion where the ball spline mechanism portion, that is, the spline nut 43 and the ball groove 44 are provided. Therefore, in the example of Fig. 6, the air supply port 46 is provided above the ball spline mechanism portion. As a result, the air passage 45 becomes unnecessarily long and the responsiveness of the suction nozzle 42 to the negative pressure or the microstatic pressure supplied through the air passage 45 becomes worse. In addition, There is a problem that it becomes easy to accumulate. In addition, if the air passage 45 is long, the shaft 41 becomes long, which makes it difficult to shorten the shaft 41 and save space.

In order to shorten the air passage 45, it is also conceivable to provide the air supply port below the ball spline mechanism portion. In this case, too, the space (length) Shortening and space saving are difficult.

The conventional suction head using the ball spline mechanism has various problems.

Japanese Laid-Open Patent Publication No. 2010-157635 Japanese Patent Application Laid-Open No. 2002-370186

The embodiments of the present invention are directed to an adsorption head of a surface mount ornamental body mounted on a suction head body so that the shaft can be lifted and lowered and is rotatably mounted around the shaft so as to reduce the loss of motion when the shaft is rotated around the shaft, It is in providing a new mechanism to substitute.

According to an aspect of the present invention, there is provided an adsorption head for a surface-or-organ body in which a shaft is rotatably mounted on an axis of an adsorption head while being rotatably mounted around an axis, and an adsorption nozzle for adsorbing an electronic component is mounted on the tip of the shaft, The backlashless gear is fixed to the shaft and the driving gear connected to the driving motor for rotating the shaft around the shaft is engaged with the backlashless gear.

Further, in a configuration in which a plurality of shafts are mounted on the suction head body, the backlashless gears fixed to the adjacent shafts can be arranged so as to be alternately up and down.

In the configuration in which the plurality of shafts are arranged along the circumferential direction of the suction head body, one drive gear is disposed at the center of the suction head body, and the one drive gear is fixed to each of the shafts, As shown in Fig.

As the backlash-less gear, it is possible to use a gear incorporating a tension spring between the fixed gear fixed to the shaft and the rocking gear.

According to another aspect of the present invention, there is provided a method of manufacturing an adsorption apparatus, comprising: a shaft mounted on a suction head body, the shaft having a suction nozzle for sucking an electronic component at a tip thereof, A suction head of a practical long term, characterized in that the shaft passes through a hollow shaft housing, is mounted on the shaft housing so as to be movable up and down relative to the shaft housing, And is mounted so as to be rotatable around the axis.

As a concrete construction for mounting the shaft passing through the hollow shaft housing to the shaft housing so that the shaft can not be rotated about the shaft housing, the bearing is fixed to the shaft and the bearing is extended in the axial direction And the guide groove is inserted into the guide groove.

In the present invention, the air supply port for supplying air to the air passage may be provided in the shaft housing.

Since the embodiments of the present invention fix the backlashless gear directly to the shaft, the backlash can be substantially eliminated and the lost motion can be substantially eliminated.

In addition, embodiments of the present invention allow a shaft to be raised and lowered using a shaft housing instead of a conventional ball spline mechanism, while being rotatable around the shaft. Therefore, the problem of the ball spline mechanism can be solved. For example, in the present invention, since the air supply port can be provided in the shaft housing, a space for installing a new air supply port becomes unnecessary, so that the shaft can be shortened and the space can be saved.

1 is a cross-sectional view showing a main part of an adsorption head according to an embodiment of the present invention.
Fig. 2 is a perspective view showing a shaft structure in the adsorption head of Fig. 1;
Fig. 3 is a partially perspective perspective view showing the internal structure of the shaft structure shown in Fig. 2. Fig.
FIG. 4 is a perspective view showing a state in which the upper shaft and the lower shaft are separated from each other in FIG. 3;
5 is a front view showing an example of the arrangement of a backlash-less gear when a plurality of shafts are mounted on an adsorption head main body.
6 is a bottom view of the main part of Fig.
7 is a cross-sectional view illustrating a main part of an adsorption head according to another embodiment of the present invention.
8 is a perspective view showing the shaft structure in the adsorption head of Fig.
9 is a partially perspective perspective view showing the internal structure of the shaft structure shown in Fig.
10 is a perspective view showing a state in which the upper shaft and the lower shaft are separated from each other in FIG.
11 is an enlarged view of a cross-section AA in Fig.
12 is a cross-sectional view showing a main part of a conventional adsorption head using a ball spline mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on embodiments shown in the drawings. Also, in this specification, an electronic part is also referred to simply as a part.

1 is a cross-sectional view showing a main part of an adsorption head according to an embodiment of the present invention.

1, a shaft 20 composed of an upper shaft 21 and a lower shaft 22 is vertically movable up and down along the axial direction of the shaft 20 to the suction head body 10 of the suction head of a surface- And is rotatably mounted around the shaft 20. A suction nozzle 30 for suctioning an electronic component is attached to the tip (lower end) of the lower shaft 22.

An air passage 22a is formed in the lower shaft 22. One end of the air passage 22a passes through the air intake port 11 provided in the suction head body 10 through the air supply port 23c provided in the housing 23 described later and the other end passes through the suction nozzle 30). The intake and exhaust device 11 is connected to an automatically controlled intake and exhaust system. Thus, when the suction nozzle 30 sucks the component, negative pressure is supplied from the suction / discharge device 11 to the suction nozzle 30 through the air supply port 23c and the air passage 22a, and the component is mounted A minute positive pressure is supplied.

Fig. 2 is a perspective view showing a shaft structure mainly composed of the shaft 20 described above. 3 is a partially perspective perspective view showing the internal structure of the shaft structure. 4 is a perspective view showing a state in which the upper shaft 21 and the lower shaft 22 are separated from each other in Fig. The structure of the shaft structure will be described with reference to Figs. 1 and 2 to 4. Fig.

2 to 4, a shaft 20 composed of an upper shaft 21 and a lower shaft 22 is mounted through the shaft housing 23. Specifically, a pair of bearings 21a are fixed to the upper shaft 21, and the pair of bearings 21a are fitted into a guide groove 23a formed in the shaft housing 23. As shown in Fig. Thus, the shaft 20 is slidable (liftable) with respect to the shaft housing 23 within the range of the guide groove 23a. On the other hand, the shaft 20 can not rotate about the axis with respect to the shaft housing 23. [ That is, the shaft 20 rotates about the axis as being integral with the shaft housing 23 when the shaft housing 23 rotates about the axis.

The shaft housing 23 can not be moved vertically with respect to the suction head body 10 but can be rotated around the axis of the shaft 20 via bearings 24 at upper and lower positions Respectively. In order to rotate the shaft housing 23 around the axis of the shaft 20, a gear 25 is provided on the outer periphery of the shaft housing 23. The gear 25 is a backlash-less gear using a torsion spring and includes a fixed gear 25a fixed to the shaft 20 (lower shaft 22) and a torsion spring 25b interposed between the fixed gear 25a and the fixed gear 25a. (25c). The shaft housing 23 is rotated about the axis of the shaft 20 with respect to the suction head body 10 by engaging a driving gear connected to the driving motor to the gear 25 to rotate the driving gear. Thereby, the shaft 20 is also rotated integrally with the shaft housing 23 around the axis.

The shaft housing 23 is provided with an air supply port 23c for supplying air to the air passage 22a provided in the lower shaft 22. [ The air supply port 23c passes through the intake and exhaust port 11 provided in the suction head main body 10 and the air supplied from the air supply port 23c flows through the inlet of the air passage indicated by 22a- To the air passage 22a.

The rotating sliding surface 23b when the shaft housing 23 rotates about the axis of the suction head body 10 is mechanically sealed. The elevating sliding surface 20a when the shaft 20 moves up and down with respect to the shaft housing 23 is also mechanically sealed.

A coil spring 26 is arranged to surround the upper periphery of the upper shaft 21 of the shaft 20. The coil spring 26 is supported by a spring base 21b provided on the outer periphery of the upper shaft 21. When the shaft structure shown in Figure 2 is mounted on the suction head body 10 as shown in Figure 1 To the shaft 20 in the upward direction. Therefore, the shaft 20 is always elastically biased at its upper limit position. When lowering the shaft 20, the pressing member 27 located above the shaft head 21c fixed to the upper end of the upper shaft 21 is pushed. Thereby, the shaft 20 is lowered against the elastic force of the coil spring 26.

Next, the connection structure of the upper shaft 21 and the lower shaft 22 will be described. In the present invention, the lower shaft (22) is detachably mounted to the upper shaft (21). 4, a cylindrical insertion portion 22b is formed in the upper end portion of the lower shaft 22, and on the outer peripheral surface of the insertion portion 22b, And the joint pins 22c are provided at two positions spaced apart from each other. A hollow support portion 21d into which the insertion portion 22b can be inserted is provided in the lower end portion of the upper shaft 21 and a joint groove 21d in which the joint pin 22c can be fitted 21e. The base end of the joint groove 21e is open to insert the joint pin 22c.

3, the insertion portion 22b of the lower shaft 22 is inserted into the receiving portion 21d of the upper shaft 21, and the joint pin 22c is inserted into the joint 22b, The lower shaft 22 is pushed in the A direction to the position where the groove 21e is fitted to the base end, then rotated in the B direction, and further pulled in the C direction. As a result, the joint pin 22c is securely fitted in the joint groove 21e, and the lower shaft 22 is mounted on the upper shaft 21. Then, the lower shaft 22 can be separated from the upper shaft 21 by the reverse procedure described above.

In this embodiment, a coil spring 28 is attached to the lower side of the insertion portion 22b of the lower shaft 22. The coil spring 28 applies a force to pull the lower shaft 22 downward with respect to the upper shaft 21 in a state where the lower shaft 22 is attached to the upper shaft 21 in the above- . 3, when the lower shaft 22 is mounted on the upper shaft 21 by the action of the coil spring 28, the joint pin 22c is engaged with the wall of the joint groove 21e As shown in FIG. Therefore, the position in the axial direction (longitudinal direction) of the lower shaft 22 relative to the upper shaft 21 is fixed, and the entire length of the shaft 20 can be kept constant.

As described above, in the present invention, since the gear 25 for rotating the shaft 20 around the shaft is integrally fixed to the shaft 20 as the backlashless gear, the backlash can be substantially eliminated and the lost motion can be substantially .

5 is a front view showing an example of the arrangement of a backlash-less gear when a plurality of shafts are mounted on an adsorption head main body. 6 is a bottom view of the main part of Fig.

5 and 6, a plurality of shafts 20 are arranged at equal intervals (16 in the embodiment) along the circumferential direction of the columnar adsorption head body 10. A gear 25 (backlashless gear) is fixed to each shaft. The backlash-less gear has a larger diameter than ordinary gears. 5, the gears 25 of the adjacent shafts 20 are arranged alternately up and down so that the diameter of the suction heads (the suction head body 10) So that a plurality of shafts 20 can be mounted. One drive gear 29 connected to the drive motor is disposed at the center of the suction head body 10 and the drive gear 29 is engaged with the entire gear 25 of each shaft 20 .

Further, in the present invention, a backlashless gear having a built-in torsion spring is used. However, a backlashless gear incorporating a pulling spring may be used. However, in terms of small curing of the gear, a backlash-less gear incorporating a torsion spring is preferable.

7 is a cross-sectional view illustrating a main part of an adsorption head according to an embodiment of the present invention.

7, a shaft 120 composed of an upper shaft 121 and a lower shaft 122 is movable up and down along the axial direction of the shaft 120 to the suction head body 100 of the suction head of the surface- And is rotatably mounted around the shaft 120 of the shaft. A suction nozzle 130 for suctioning an electronic component is mounted at the tip (lower end) of the lower shaft 122.

An air passage 122a is formed in the lower shaft 122. One end of the air passage 122a passes through the air intake port 111 provided in the suction head body 100 via the air supply port 123c provided in the housing 123 to be described later and the other end passes through the suction nozzle 130). In addition, an intake and exhaust system that is automatically controlled is connected to the intake and exhaust device 111. Thus, when the suction nozzle 130 sucks the component, negative pressure is supplied from the suction and discharge device 111 through the air supply port 123c and the air passage 122a to the suction nozzle 130, and the component is mounted A minute positive pressure is supplied.

8 is a perspective view showing a shaft structure including the shaft 120 described above as a main body. 9 is a partially perspective perspective view showing the internal structure of the shaft structure. 10 is a perspective view showing a state in which the upper shaft 121 and the lower shaft 122 are separated from each other in FIG. The configuration of the shaft structure will be described with reference to Figs. 7 and 8 to 10. Fig.

Referring to FIGS. 8 to 10, a shaft 120 including an upper shaft 121 and a lower shaft 122 is mounted through the shaft housing 123. Specifically, a pair of bearings 121a are fixed to the upper shaft 121, and the pair of bearings 121a are fitted into a guide groove 123a formed in the shaft housing 123. [ Thus, the shaft 120 is slidable (liftable) with respect to the shaft housing 123 within the range of the guide groove 123a. On the other hand, the shaft 120 can not rotate about the axis with respect to the shaft housing 123. That is, when the shaft housing 123 rotates about the axial line, the shaft 120 rotates integrally with the shaft housing 123 and around the axial line.

The shaft housing 123 is not movable (vertically movable) in the up-and-down direction with respect to the adsorption head main body 100, but is rotatable around the axis of the shaft 120 via two bearings 14124 at upper and lower portions Respectively. In order to rotate the shaft housing 123 around the axis of the shaft 120, a gear 125 is provided on the outer periphery of the shaft housing 123. The gear 125 is a backlash-less gear using a torsion spring and includes a fixed gear 125a fixed to the shaft 120 (lower shaft 122) and a swing gear 125b overlapping the fixed gear 125a. (125c). The shaft housing 123 rotates about the axis of the shaft 120 with respect to the suction head body 100 by engaging a driving gear connected to the driving motor to the gear 125 to rotate the driving gear. Thereby, the shaft 120 also rotates about the axis as being integrated with the shaft housing 123. [

The shaft housing 123 is provided with an air supply port 123c for supplying air to the air passage 122a provided in the lower shaft 122. [ The air supply port 123c passes through the intake and exhaust port 111 provided in the suction head body 100 and the air supplied from the air supply port 123c flows through the inlet of the air passage indicated by 122a- To the air passage 122a.

The rotating sliding surface 123b when the shaft housing 123 rotates about the axis of the suction head body 100 is mechanically sealed. The lifting sliding surface 120a when the shaft 120 is moved up and down with respect to the shaft housing 123 is also mechanically sealed.

A coil spring 126 is disposed to surround the upper periphery of the upper shaft 121 of the shaft 120. The coil spring 126 is supported by a spring base 121b provided on the outer periphery of the upper shaft 121. When the shaft structure shown in Figure 2 is mounted on the suction head body 100 as shown in Figure 1 To the shaft 120 in the upward direction. Therefore, the shaft 120 is always elastically biased at its upper limit position. When lowering the shaft 120, the pressing member 127 located above the shaft head 121c fixed to the upper end of the upper shaft 121 is pushed. As a result, the shaft 120 is lowered against the elastic force of the coil spring 126.

Next, the connection structure of the upper shaft 121 and the lower shaft 122 will be described. In the present invention, the lower shaft 122 is detachably mounted to the upper shaft 121. 4, a cylindrical insertion portion 122b is formed in the upper end portion of the lower shaft 122, and on the outer peripheral surface of the insertion portion 122b, And the joint pins 122c are provided at two positions spaced apart from each other. On the other hand, a hollow receiving portion 121d capable of receiving the insertion portion 122b is provided in the lower end portion of the upper shaft 121, and a joint groove 121d 121e. The base end of the joint groove 121e is opened to insert the joint pin 122c.

3, the insertion portion 122b of the lower shaft 122 is inserted into the receiving portion 121d of the upper shaft 121, and the joint pin 122c is inserted into the joint 121b, The lower shaft 122 is pushed in the direction A to the position where the groove 121e is fitted into the base end, then rotated in the direction B, and further pulled in the direction C. As a result, the joint pin 122c is securely fitted in the joint groove 121e, and the lower shaft 122 is mounted on the upper shaft 121. Then, the lower shaft 122 can be separated from the upper shaft 121 by the reverse procedure.

In the present embodiment, a coil spring 128 is mounted on the lower side of the insertion portion 122b of the lower shaft 122. The coil spring 128 applies a force to pull the lower shaft 122 downward against the upper shaft 121 in a state where the lower shaft 122 is attached to the upper shaft 121 in the above- . 3, when the lower shaft 122 is mounted on the upper shaft 121 by the action of the coil spring 128, the joint pin 122c is engaged with the wall of the joint groove 121e As shown in FIG. Accordingly, the position of the lower shaft 122 in the axial direction (longitudinal direction) with respect to the upper shaft 121 is fixed, and the entire length of the shaft 120 can be kept constant.

Fig. 11 is an enlarged view of section A-A in Fig. 7, which shows a portion where the bearing 121a is fitted into the guide groove 123a.

11, in the present embodiment, the bearing 121a fixed to the upper shaft 121 is fitted into the guide groove 123a provided in the shaft housing 123, To the shaft housing (123). At this time, if there is a gap between the bearing 121a and the guide groove 123a, a lost motion occurs. Thus, in this embodiment, the clearance tolerance and the dimensional tolerance are managed as described below so that the bearing 121a is preloaded with respect to the guide groove 123a.

1. Clearance tolerance

1-1 Target tolerance of groove width of guide groove 123a: + 0.02 mm

1-2 Outer diameter tolerance of the bearing ball 121a-1: -0.004 mm

1-3 Radial clearance of the bearing (121a): 0.005 to 0.01 mm

When the accumulation is calculated by the least squares method, it becomes 0.01217 mm.

2. Dimensional tolerance

2-1 Symmetry of the hole in which the pin 121a-2 of the bearing 121a is mounted: 0.02mm

2-2 Symmetry of the guide groove 123a: 0.01 mm

2-3 Shaking of the inner ring 121a-3 of the bearing 121a: 0.004 mm

2-4 Shaking of the outer ring 121a-4 of the bearing 121a: 0.005 mm

If the accumulation is calculated by the least squares method, it becomes 0.01233 mm.

As described above, since the dimensional tolerance accumulates more than the accumulation of the clearance tolerance, the bearing 121a assumes a preloaded state (preload amount: 0.0015 mm (diameter)). Thereby, the rotation error in the shaft portion does not occur.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such modifications and variations as fall within the true spirit of the invention.

10, 100: adsorption head body
11, 111: the intake and exhaust port
20, 120: Shaft
20a, 120a: a lift-up sliding surface
21, 121: upper shaft
21a, 121a: Bearings
21b, 121b: spring base
21c, 121c: Shaft head
21d, 121d:
21e, 121e: joint grooves
22,122: Lower shaft
22a, 122a: Air passage
22a-1, 122a-1: inlet of air passage
22b, 122b:
22c, 122c: joint pins
23,123: Shaft housing
23a, 123a: Guide groove
23b, 123b: rotation sliding surface
23c and 123c: an air supply port
24,124: Bearings
25,125: Gear (backlashless gear)
25a, 125a: fixed gear
25b, 125b:
25c, 125c: Torsion spring
26, 126: coil spring
27, 127:
28, 128: coil spring
30,130: Adsorption nozzle
140: suction head body
141: Shaft
142: Adsorption nozzle
143: Spline nut
144: Ball groove
145: Air passage
146: Air supply port

Claims (7)

A suction head for a surface-or-organ body in which a shaft is rotatably mounted on an axis of an adsorption head while being rotatable around an axis, and an adsorption nozzle for adsorbing an electronic component is mounted on a tip of the shaft,
A backlashless gear is fixed to the shaft and a driving gear connected to a driving motor for rotating the shaft around the shaft is engaged with the backlashless gear,
A plurality of shafts are mounted on an adsorption head body, and backlashless gears fixed to adjacent shafts are arranged alternately up and down,
A plurality of shafts are disposed along the circumferential direction of the suction head body and one drive gear is disposed at the center of the suction head body and the one drive gear is engaged with all of the backlashless gears fixed to the shafts Wherein the adsorbing head is a surface-active agent adsorbing head. delete delete delete delete delete delete

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