HK1164215B - Automatic screw tightening apparatus - Google Patents

Description

Automatic bolt fastening device

Technical Field

The present invention relates to an automatic bolt fastening device which automatically fastens a bolt to a predetermined threaded portion of a main body by a bolt fastening mechanism.

Background

In japanese patent application laid-open No. hei8-229752, there is disclosed an automatic bolt fastening device according to the related art for automatically fastening a bolt to a predetermined threaded portion of a main body by a bolt fastening mechanism, predetermined bolts being automatically fed one by one from a bolt feeding mechanism to a bolt fastening head at a front end of the bolt fastening mechanism. Then, the main body is fixed to a movable table, and the screw position of the main body is moved to a predetermined position while the bolt-fastening head of the bolt-fastening mechanism is moved. Next, the bolts are tightened to assemble the body.

In this case, the bolt is supplied to the bolt fastening mechanism through a supply hose. However, there are the following drawbacks. For example, the bolt tip often becomes lodged within the hose. Also, since the bolt feeding mechanism should be moved together with the supply hose connected to the bolt fastening head, the bolt feeding mechanism is large. Further, since the bolt fastening mechanism should have a wide movement range, the bolt fastening device is not advantageous in space. In addition, unexpected accidents may occur due to contact of workers or the main body with the hose or others.

Meanwhile, in japanese patent application laid-open No. hei8-229752 and japanese patent application laid-open by the applicant of the present application, No.2010-29559, and the like, a bolt fastening mechanism is disclosed in which a driver BIT unit sucks air from a gap between a driver BIT (BIT) and a bolt holder, thereby engaging a bolt with the driver BIT and holding the bolt.

Disclosure of Invention

The present invention has been made in view of the above problems, and provides an automatic bolt fastening device that can be smoothly and automatically assembled, automatically fastening a bolt to a predetermined threaded portion of a main body by a bolt fastening mechanism whose leading end portion smoothly moves up and down without being connected to a hose or the like, which is small and compact in size, and whose moving range is reduced.

In order to achieve the above object, according to an embodiment of the present invention, there is provided an automatic bolt fastening device which transfers a bolt from a bolt supply mechanism to a bolt fastening mechanism through a bolt transfer mechanism using compressed air from the bolt supply mechanism, engages the bolt with a driver bit portion at a front end of the bolt fastening mechanism, and fastens the bolt with respect to a threaded portion. In the automatic bolt fastening apparatus, a releasing unit that transfers a bolt in a transfer pipe of a bolt feeding mechanism in a head-ahead manner is installed in the bolt feeding mechanism. The feed head unit is installed at a front end of the discharge unit with a bolt feed hole having a diameter slightly larger than a head of the bolt, and a movable arm is provided to the feed head unit to horizontally rotate. The feed head unit is movable between a close contact position where the feed head unit is in close contact with the driver bit portion of the front end of the bolt fastening mechanism and an evacuation position where the feed head unit is away from the driver bit unit. In the close contact position, the driver bit portion of the front end of the bolt tightening mechanism contacts the bolt and absorbs the head of the bolt to engage with the bolt. The feed head unit has a longitudinal groove provided at a proper position and opened to the outside so that a bolt engaged with the driver bit portion can be horizontally moved to the outside. The longitudinal groove is connected to a vertically extending bolt feed hole, and only a threaded portion of the bolt can advance and retreat in the longitudinal groove.

In an automatic bolt tightening apparatus, a curved passage of a feed head is formed by forming a curved guide groove for guiding a bolt in a mating face of a divisible guide block assembly.

According to the automatic bolt fastening device of the embodiment of the present invention, since the bolt is transferred with the bolt head portion S1 ahead by the bolt transfer mechanism using the compressed air from the bolt supply mechanism, the damage of the inner wall of the transfer pipe is small, the bolt does not get stuck in the transfer pipe, and the posture of the bolt can be stabilized to firmly engage the bolt with the driver bit, so that the bolt can be stably supplied and the reliability can be improved.

Further, it is possible to automatically and quickly fasten a bolt which engages with a driver bit by the threaded portion of the body. Moreover, the structure of the engagement of the bolt and the driver bit is simple, easy to maintain and low in manufacturing cost.

According to the automatic bolt fastening apparatus of the embodiment of the present invention, since the curved guide groove for guiding the bolt is formed in the mating face of the dividable guide block assembly, the curved portion of the bolt guide passage formed by the guide groove is not flattened unlike the related art. Furthermore, it is possible to design freely so that the cross section of the bolt guide channel has a uniform true circular shape throughout the bolt guide channel or, if necessary, only a true exact circular shape at the curved portion.

Drawings

Fig. 1 is a perspective view showing an external appearance of an automatic bolt fastening apparatus according to an embodiment of the present invention.

Fig. 2 is a perspective view showing the appearance of the bolt feeding mechanism 1 of fig. 1.

Fig. 3 is an exploded perspective view of the bolt feeding mechanism of fig. 2.

Fig. 4 is a plan view of the bolt releasing unit of fig. 2 viewed from above the bolt feeding unit.

Fig. 5 is a partial right side view of the bolt releasing unit of fig. 4.

Fig. 6(a) to 6(b) are enlarged perspective views for explaining the operation of the bolt carrying disk of fig. 5.

Fig. 7(a) to 7(d) are enlarged perspective views for explaining the operation of the bolt releasing unit and the bolt feeding mechanism.

Fig. 8 is a plan view showing the releasing unit, the bolt fastening mechanism moving unit, and the main body moving unit in the embodiment of the present invention as seen from above.

Fig. 9 is a partial perspective view of the release unit of fig. 8.

Fig. 10 is a plan view of the release unit.

Fig. 11 is a sectional view of the supply head unit.

Fig. 12(a) to 12(c) are perspective views of the guide block assembly of the feed head unit of the embodiment of the present invention.

Fig. 13(a) to 13(e) are schematic views for explaining an operation of engaging a bolt with a driver BIT (BIT) at a feed head unit according to an embodiment of the present invention.

Fig. 14 is a flowchart illustrating this embodiment.

Fig. 15 is a perspective view illustrating a starting state of the automatic bolt feeding operation in this embodiment.

Fig. 16 is a perspective view of a state in which the feed head unit 331 for feeding bolts is located just below the driver bit portion 51.

Fig. 17 is a perspective view of a state in which the bolt is engaged with the driver bit 511.

Fig. 18 is a perspective view of a state in which the driver bit 511 is away from the feed head unit 331, engaging with the bolt.

Fig. 19 is a perspective view of an operation state in which the driver bit 511 is lowered and a bolt fastening operation is started.

Fig. 20(a) to 20(c) are sectional views of an automatic bolt fastening device according to the related art.

Fig. 21(a) to 21(b) are sectional views of another automatic bolt fastening device according to the related art.

Detailed Description

An embodiment of the present invention feeds bolts one by one into a bolt fastening mechanism (driver) from a bolt feeding mechanism via a feed pipe such as a vinyl pipe or a hose in such a manner that the heads of the bolts are in front of the feed pipe, and engages the head of each fed bolt with the front end of the driver bit portion of the bolt fastening mechanism by air suction of the bolt fastening mechanism, thereby automatically and continuously fastening the bolts to a desired threaded portion.

Hereinafter, an automatic bolt fastening apparatus according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Integral structure

An automatic bolt fastening apparatus having a bolt feeding mechanism according to an embodiment of the present invention will be described in an overall schematic manner with reference to fig. 1. Fig. 1 is a perspective view of the bolt supply mechanism 1 with a cover removed, the bolt feed mechanism 3, and the supply head unit 331.

This embodiment is an automatic bolt tightening robot. According to this embodiment, the bolt feeding mechanism 1 is provided near the bolt mounting table 4 or integrally with the bolt mounting table 4. The bolt feeding mechanism 1 transfers the bolts to the feed head unit 331 of the bolt assembling table 4 which moves horizontally and linearly through the delivery pipe 32 of the bolt delivery mechanism 3. Then, the driver BIT (BIT) part 51 of the front end of the vertically movable bolt fastening mechanism 5 mounted on the bolt mounting table 4 and the feed head unit 331 are aligned so as to be located on the same line. In this state, the driver bit portion 51 of the bolt fastening mechanism 5 descends and takes in the head of the bolt to engage with the head. Thereafter, when the bolt fastening mechanism 5 is moved left and right (along the X axis) by the bolt fastening mechanism moving unit 41 of the bolt installation stage, the main body 421 such as a camera and a cellular phone is moved forward or backward (along the Y axis) by the main body moving unit 42 so that the predetermined threaded portion of the main body 421 is located on the same line as the driver bit portion 51. Subsequently, the bolt is tightened.

[ bolt feed mechanism 1]

The bolt feeding mechanism 1 will be described in detail first with reference to fig. 2 to 6.

Fig. 2 is a perspective view of the bolt supply mechanism 1 without an external frame, and fig. 3 is an exploded perspective view of the bolt supply mechanism except for the bolt storage unit 11. As shown in fig. 2, the bolts S are stored in the bolt storage unit 11 of the bolt feeding mechanism 1, and the stored bolts S are aligned and sequentially moved onto the front surface through the guide rail 12 protruding from the front sheathing plate 111 of the bolt storage unit 11 and the aligned bolt guide piece 122 installed at the front end portion 121 of the guide rail 12.

The mechanism for the bolt positioning mechanism may be a well-known mechanism. In this embodiment, the guide rail 12 is vibrated so as to advance the bolts S in the bolt storage unit 11, the surplus bolts S on the guide rail 12 are dropped by the oscillation brush 13, and the dropped bolts S are guided again to the guide rail 12 by the bolt collection unit 14 such as a rotating magnetic substance placed on the side. Brush rotating mechanism 131 rotates oscillating brush 13 left and right. The brush rotating mechanism 131 and the bolt collecting unit 14 are driven by a conduction mechanism or a pulley or a ring of the driving motor 15 provided at the front surface of the bolt storing unit 11.

[ bolt Release Unit 2]

Further, as shown in fig. 4 and 5, a bolt alignment cover 123 is provided on the alignment bolt guide 122, and the bolt releasing unit 2 is configured to guide the bolt S so that the head S1 of the bolt S is located ahead of the moving direction of the bolt S in the conveying pipe 32 of the bolt conveying mechanism 3 in the next step. As shown in the top view of fig. 4 and the left side view of fig. 5, the bolt releasing unit 2 is configured to contact the leading end surface 1221 of the alignment bolt guide 122.

The bolt releasing unit 2 performs a preparation step for the bolt conveying mechanism 3 described below and may be configured as a part of the bolt conveying mechanism 3. The main component of the bolt releasing unit 2 is a bolt carrying disk 21 (see fig. 6) which sequentially takes out the bolts S on the aligned bolt guide 122 by rotating clockwise and counterclockwise. The bolt carrying disk 21 rotates clockwise and counterclockwise about the rotation shaft 212. The turning surface 211 of the bolt bringing disk 21 is disposed at an appropriate angle with respect to the bolt moving direction of the aligning bolt guide 122 of the bolt feeding mechanism 1, and a bolt receiving groove 213 is provided in the turning surface 211 of the bolt bringing disk 21. The bolt receiving groove 213 is a groove corresponding to the posture of the bolt S supplied from the aligning bolt guide 122, and has a width slightly larger than the diameter of the threaded portion S2 of the bolt S.

Further, a drive gear 214 is fixed to the side opposite to the bolt carrying disk 21 to the side where the alignment bolt guide 122 is located. The gear 214 is engaged with a rack 215 that moves up and down. The vertical movement of the rack 215 is hydraulically controlled by the driving cylinder 216 in accordance with a control command device (not shown), thereby rotating the bolt carrying disk 21 in the clockwise direction and the counterclockwise direction.

[ bolt conveying mechanism 3]

Next, the operation of the bolt feeding mechanism 3 will be described in conjunction with the structure of the bolt carrying disk 21 constituting a part of the bolt feeding mechanism 3 with reference to fig. 7(a) to 7 (d).

As shown in fig. 7(a), in order to prevent the bolts from falling when the bolts are fitted into the bolt receiving grooves 213 of the bolt carrying disk 21 and the bolt carrying disk 21 is rotated clockwise in the drawing, one side bolt guide 124 (see fig. 4) is provided on the bolt supply mechanism 1 side, and a bolt top guide 125 is provided on the bolt head side along the outer circumference of the bolt carrying disk 21. In fig. 7(a), the bolt carrying disk 21 is stationary in a state in which a bolt is fitted into the bolt carrying disk 21.

Next, as shown in fig. 7(b), according to a rotation command of a control command device (not shown), the drive cylinder 216 is extended, the rack 215 is moved upward, and the gear 214 and the bolt carrying disk 21 are rotated clockwise by about 135 ° and then stopped.

Further, in the lower space of the frame body of the bolt supply mechanism 1 and the bolt release unit 2, a control unit 6 of the automatic bolt tightening apparatus is provided. The control unit 6 includes a control board denoted by reference numeral '61' in fig. 3 and a control circuit formed on the control board.

Here, the chute block 31 of the bolt feeding mechanism 3 is fixed to the bolt feeding mechanism 1 to be close to the bolt releasing unit 2, and the pipe connecting portion 315 of the chute block 31 is connected to the conveying pipe 32 connected to the bolt fastening mechanism 5.

In the stopped state of the bolt carrying disk 21 shown in fig. 7(b), the bolt S is at the position of the movement inlet 311 of the conveying mechanism 3 in such a manner that the bolt head S1 rotates downward by 180 °. Subsequently, as shown in fig. 7(c), the bolt S1 is moved into the bolt guide groove 312 by the weight of the bolt.

At this time, the bolt S falls into the chute block 31, and the fallen bolt S is detected by the sensor. Then the sensor inputs a signal to the control unit 6, and the control unit 6 controls the bolt releasing unit 2 to be in a standby state until a next bolt transmission command is received.

Next, in accordance with the instruction of the control instruction device (not shown), the compressed air is supplied to a compressed air inlet 313 provided in the chute block 31 and is released from a nozzle 314 provided upstream of the bolt S in the bolt guide passage 312, and at the same time, in accordance with the instruction of the control instruction device (not shown), suction of the bolt fastening mechanism 5 is applied to the delivery pipe 32, whereby the bolt S guided in the bolt guide passage 312 with the head S1 in front is sucked from a supply head unit 331 of the release unit 33 connected to the leading end of the delivery pipe 32 to be delivered to the bolt fastening mechanism 5 side.

Once the transfer of the bolt S is completed, the bolt releasing unit 2 should take out the next bolt S. For this reason, the bolt carrying disk 21 is rotated counterclockwise as shown in fig. 7(d) to return to the state shown in fig. 7(a), and stands by in a state in which the first bolt from the aligning bolt guide 122 is fitted into the bolt receiving groove 213 of the bolt carrying disk 21.

As described above, the bolt S moves in the delivery pipe 32 with the bolt head S1 leading, and is supplied to the bolt fastening mechanism 5. Further, a predetermined length of a transparent tube may be used as the delivery tube 32. The transparent tube is formed of synthetic resin, has elasticity, has a constant inner diameter, and has an inner wall using a material capable of preventing the bolt from being caught in the transparent tube. Needless to say, the inner diameter may vary depending on the bolt S used.

[ Release Unit 33 and driver bit portion 51]

Here, the discharge unit 33 at the leading end of the delivery pipe 32 and the supply head unit 331 as a main component of the discharge unit 33 will be described with reference to fig. 8 to 11.

First, referring to fig. 8, a summary of the relationship among the release unit, the bolt mounting table 4, and the bolt fastening mechanism 5 is described.

In fig. 8, the supply head unit and the like of the discharge unit 33 are covered with a cover 34. Along with the connecting portion of the delivery pipe 32, the feed head unit 331 is linearly moved in the horizontal direction (indicated by an X arrow in fig. 8) to be placed below the driver bit unit 51 of the bolt fastening mechanism 5. Then, the driver bit unit 51 is engaged with the bolt S conveyed by the conveying pipe 32 by suction. The driver bit unit 51 engaged with the bolt S is horizontally moved left and right at a predetermined position by a left/right (X-direction) moving mechanism while the main body moving unit 42 of the bolt assembling station 4 is moved back and forth so that the bolt S is accurately positioned on the threaded portion 422 of the main body 421. Then, the bolt fastening mechanism (driver) 5 and the driver bit unit 51 are lowered, and the bolt S is rotated to fasten the bolt to the threaded portion 422.

Here, the structure of the releasing unit 33 will be described in detail with reference to fig. 9 to 13.

In fig. 9, the releasing unit 33 is mounted to an appropriate portion of the bolt mounting station 4 by a mounting member 43, and mainly includes a base 332 mounted to the mounting member 43, a feed unit head 331 provided movably at a front end, and a cylinder member 333 as a moving member to linearly move the feed unit head 331 in the left-right direction.

The relationship of the feed head unit 331, the base 332, and the cylinder assembly 333 will be described in conjunction with the top view of fig. 10. The cylinder assembly 333 is connected to the base 332, and the feed head unit 331 is connected with the moving ends of a pair of draw-out piston rods 3331. The cylinder assembly 333 is connected to a pair of pneumatic conduits 3332. Therefore, if a solenoid valve (not shown) is operated by a command of the control command device, the supply head unit 331 moves to a position shown by a dotted line in fig. 10.

Referring to fig. 11, which shows a cross-sectional view of the feed head unit 331 of fig. 10, the feed head unit 331 includes a guide block 3311 having a U-shaped guide hole 3312. The upper surface portion of the guide block 3311 has one end 33111 connected to the feed pipe 32 through a connecting member 33122, and has the other end 33112 in which a bolt feed hole 3313 is formed to correspond to the driver bit unit 51. Near the bolt feed hole 3313, a bolt presence/absence detecting sensor 3314 is provided.

[ guide blocks ]

The axial direction of the passage of the bolt feed hole 3311 provided near the center of the upper portion of the feed head unit 331 is almost opposite (at about 180 °) to the axial direction of the passage of the feed pipe 32 connected to the feed head unit 331. For this reason, in the supply head unit 331, a means for turning the passage into a curved shape should be prepared. However, in the case of merely bending a common pipe, the bent portion of the pipe is inevitably slightly flattened, and thus the bolt S is often caught therein.

Therefore, in this embodiment as shown in fig. 12, the guide block 3311 serves to freely design the shape of the passage. The guide block 3311 may be separated into two guide block components 3311a and 3311b (left and right), and the two guide block components 3311a and 3311b are joined together by an insert bolt 3317 to fill the joint hole 3316. A guide block component 3311a (or 3311 b) of the guide block 3311 has a shape shown in fig. 12(b) and 12 (c). When the guide block members 3311a and 3311b are coupled together, in the fitting surfaces 33121 where the guide block members 3311a and 3311b face each other, guide grooves 33122, which are bent when the guide block members 3311a and 3311b are coupled, form a bolt guide passage connecting the bolt feed hole 3313 and the U-shaped guide hole 3312.

In this case, the curved guide grooves 33122, which become the bolt guide passages, may be freely cut into the mating surfaces 33121 of the guide block assemblies 3311a and 3311b so that the cross-sections of the bolt guide passages have a uniform true circular shape over the bolt guide passages or, if necessary, a slightly larger true circular shape only at the curved portions. Thus, the bent portion of the bolt guide passage is not flattened.

Further, the curved passage portion of the feed head unit 331 is formed by the separable guide block components 3311a and 3311b, and the curved guide grooves 33122 are formed in the mating surfaces 33121 of the two guide block components 3311a and 3311b to smoothly guide the bolts.

Further, the bolt transfer hole 3313 of the feed head unit 331 is connected to a vertical groove 3318, and the vertical groove 3318 allows only a threaded portion of the bolt to pass therethrough. As shown in fig. 12(b) and 12(c), a vertical groove 3318 is formed perpendicular to the mating surface of the guide block assembly, with an opening 3318a, so that the bolt S and the driver BIT (BIT) 511 can be released to the outside from the supply head unit 331. Accordingly, the bolt S engaged with the driver bit portion 51 can be horizontally moved in the vertical groove 3318 to be moved to the outside of the guide block 3311 and the feed head unit 331.

That is, the inner diameter (denoted by the reference numeral "X1" in fig. 12) of the guide hole 3312 (bolt feed hole) of the feed head unit 331 of the discharge unit 33 is slightly larger than the head S1 of the bolt. However, the width of the vertical slot 3318 (indicated by the reference numeral "X2" in fig. 12), which is slightly narrower than the head S1 of the bolt and slightly wider than the threaded portion S1 of the bolt, is such that only the threaded portion S2 of the bolt can pass through the width of the vertical slot 3318.

[ supply head Unit ]

The operation of the feed head unit will be described in further detail with reference to fig. 13.

In fig. 13(a), if the control unit 6 issues a bolt fastening command, the bolt transfer hole 3313 of the feed head unit 331 driven by the cylinder assembly 333 will be positioned directly below the driver BIT portion 51, and the front end of the driver BIT (BIT) 511 is operated to be positioned precisely directly above the bolt transfer hole 3313.

The cylinder assembly 333 is provided with a pair of sensors (not shown) to advance and retreat. If the sensor detects that the feed head unit 331 has advanced, the bolt S is conveyed by the bolt conveying mechanism 3 through the conveying pipe 32 in the form of the head portion S1 of the bolt being advanced into the guide hole 3312 of the guide block 3311 and guided into the bolt conveying hole 3313 as an exit of the guide hole 3312. Then, by the suction of the bolt holder (protection tube) 512 of the driver BIT portion 51, the bolt head S1 is engaged with the leading end of the driver BIT (BIT) 511.

Fig. 13 (b) is a sectional view taken along the line b-b in fig. 13 (a). If the bolt presence/absence detecting sensor 3314 detects that the head S2 of the bolt is engaged with the front end of the driver BIT (BIT) 511, the piston rod 3331 is withdrawn into the cylinder assembly 333 so that the bolt transmission hole 3313 is likewise withdrawn.

In fig. 13 (c), if the bolt transmission hole 3313 is withdrawn, the driver BIT (BIT) 511 and the bolt S are not moved, but are placed outside the opening 3318a by the relative movement of the longitudinal groove 3318 corresponding to the threaded portion S2.

Referring to fig. 13 (c) and 13 (d), in the bolt assembling station 4, the bolt fastening mechanism moving unit 41 and the main body moving unit 42 are moved on the basis of a program set according to predetermined position information, and thus the screw portion 422 and the driver BIT (BIT) 511 of the bolt fastening mechanism (driver) 5 are located on the same line. Then, the bolt fastening mechanism (driver) 5 descends and rotates the driver BIT (BIT) 511 to fasten the bolt S to the threaded portion 422.

As shown in fig. 13(e), if the screw S is completely tightened, the bolt tightening mechanism (driver) 5 is returned to the normal standby position, and the series of operations ends.

Meanwhile, as shown in fig. 13(a) and 13 (b), a driver BIT (BIT) portion 51 at the front end of the bolt fastening mechanism (driver) 5 has a structure according to the related art of japanese patent application laid-open No. Hei8-229752 or a well-known structure. The driver BIT portion 51 sucks air from a gap between the driver BIT (BIT) 511 and the bolt holder 512, so that the driver BIT 511 engages with the bolt and holds the bolt.

For suction, as shown in fig. 1, the upper end portion of the main body portion 52 of the bolt fastening mechanism 5 is connected to a suction pipe 53 connected to a suction device (not shown) controllable by the system.

Further, the bolt fastening mechanism (driver) 5 and the driver base portion 54 of the bolt fastening mechanism 5 are configured to be vertically movable at a predetermined horizontal position by a vertical moving mechanism 55, and the vertical moving mechanism 55 is controlled by the control unit 6. Further, the rising position detection sensor and the falling position detection sensor are upper and lower limit sensors for limiting the moving range of the driver base portion 54.

Further, the bolt fastening mechanism (driver) 5 and the driving base portion 54 of the bolt fastening mechanism 5 are configured to be movable left and right by the bolt fastening mechanism moving unit 41 of the bolt assembling station 4 and controlled to stop at a predetermined position by a predetermined number of pulses.

[ brief description of the operation ]

The operation of the present embodiment described above will be described with reference to the flowchart of fig. 14 and the perspective views of fig. 15 to 19 illustrating the separated state.

First, fig. 15 is a schematic diagram illustrating a standby state of the automatic bolt fastening apparatus in which the supply head unit 331 is in a retreat state and the bolt fastening mechanism (driver) 5 is in an intermediate position between the supply head unit 331 and the main body moving unit 42.

In the standby state, when a bolt feed command of an upper-level device of the assembly robot is accepted, or the operation button 62 is manually pressed to transmit the bolt feed command, in step S1 in fig. 14, the automatic bolt feed operation is started. In step S2, the cylinder assembly 333 is started, and then the piston rod 3331 is advanced to directly move the feed head unit 331 in the horizontal direction (X direction) so that the driver BIT (BIT) is accurately positioned right above the bolt transmission hole 3313, as shown in fig. 16.

Next, in step S3, the presence or absence of the fallen bolt is detected by the bolt release detection sensor 16 connected to the chute block 31. If the supplied bolts S are ready (YES in step S3), the process proceeds to step S4. In contrast, if any prepared bolt S is not detected in step 3, the bolt carrying disk 21 is rotated by 180 ° to guide the bolt S from the movement inlet 311 to the bolt guide path 312, and is lowered so that the bolt falls into the chute block 31.

If there is a bolt S in step S3, first, suction by the bolt fastening mechanism (driver) 5 is started to prepare for receiving the bolt S.

Then, in step S4, the pressure-conveying operation of the bolt is started, and compressed air is injected from the compressed-air inlet 313 to move the bolt S to the bolt conveying hole 3313, which is the outlet of the feed head unit 331 of the discharge unit 33, with the bolt head S1 positioned immediately ahead.

Next, in step S6, as shown in fig. 17, it is detected by the bolt presence/absence detecting sensor 3314 whether the bolt S in the bolt transmission hole 3313 is engaged with the driver BIT (BIT) 511. If the bolt S is engaged with the driver BIT (BIT) 511 (YES in step S6), the process proceeds to the next step S7, in which the pressure transmission by the bolt feed mechanism 3 is stopped. If the bolt S is not engaged with the driver BIT (BIT) 511 (NO in step S6), the process returns to step S5 to further continue the pressure transmission of the bolt S.

Next, in step S8, as shown in fig. 18, the cylinder assembly 333 is actuated, and thus the piston rod 3331 and the feed head unit 331 are withdrawn, so that the feed head unit 331 is seated at the standby position, and the driver BIT (BIT) 511 engaged with the bolt S is exposed to the outside of the feed head unit 331.

If it is detected by a sensor (not shown) in step S9, the feed head unit 331 is located at the standby position, and the bolt transferring operation is completed and the driver bit part 51 is completely prepared in step S10.

Then, the process proceeds to step S21, where the bolt fastening operation process starts moving the bolt fastening mechanism (driver) 5 to a predetermined position by the bolt fastening mechanism moving unit 41.

The bolt fastening operation follows step S9. In step S21, the bolt fastening mechanism 5 is moved left and right (in the X direction) (in this embodiment, to the right) by the bolt fastening mechanism moving unit 41 of the bolt assembling station 4, and stays at a predetermined position set by the control instruction device. In step S22, the screw body 421 of various devices such as a camera or a portable telephone fixed to the body moving unit 42 of the bolt mounting station 4 is moved back and forth (in the Y direction) by the body moving unit 42 so that the screw portion 422 and the driver bit 511 are located on the same vertical line. Step S22 may be performed simultaneously with step S21.

In step S23, it is checked whether the threaded portion 422 and the driver bit 511 are located on the same vertical line. If the threaded portion 422 and the driver bit 511 are not located on the same vertical line (no in step S23), the process proceeds to step S22. If the threaded portion 422 and the driver bit 511 are located on the same vertical line (yes in step S23), in step S24, the vertical movement mechanism 55 is activated by the bolt fastening mechanism 5 to engage the driver bit 511 with the bolt at the set position. Next, in step S25, the driver BIT (BIT) 511 is rotated to start the bolt fastening operation.

In step 25, the driver BIT (BIT) 511 is rotated to start the bolt tightening operation. The perspective view of fig. 19 shows this operating state.

Then, in step S26, it is detected whether or not the rotation of the driver bit 511 is stopped. If the rotation of the driver bit 511 is stopped, the bolt fastening operation is completed in step S27, and at the same time, the suction of the driver bit 511 is stopped. In contrast, if the rotation of the driver bit 511 is continued, the process returns to step S25.

After step S27, in step S28, the bolt fastening mechanism 5 is moved left and right (left in this embodiment) by the bolt fastening mechanism moving unit 41 of the bolt assembling station 4, and the main body 421 is moved to a predetermined position set by the control instruction device. Then, in step 29, the bolt fastening operation is completed.

Subsequently, the above-described steps S1 to S29 of the automatic bolt tightening operation may be repeated for the assembly predetermined portion of the main body.

Here, by comparing the drawbacks of the pressure transmission using compressed air according to the related art shown in fig. 20 and 21, a bolt feed mechanism using air according to an embodiment of the present invention, which is sucked by a suction apparatus according to an embodiment of the present invention, will be described in detail.

As can be seen from the air flow indicated by the arrow in fig. 20(c), the air for pressure delivery forms a vortex between the Y-shaped path h and the holder c1 at the front end portion. As a result, the number of times the bolt seizes or reverses increases. Specifically, all the air for pressure delivery is not discharged from the outlet of the path, and the flow of the remaining air is reversed between the Y-shaped path h and the holder c1, thereby inducing a swirl state. Therefore, a rotational force is applied to the bolt. For this reason, the short bolt and the light bolt can be easily reversed.

Further, as shown in fig. 21(a), as a method for preventing the bolt from being reversed, there is proposed a structure in which a bolt reversal prevention mechanism i for preventing the bolt from being reversed in the vicinity of the Y-shaped path h is attached. However, as shown in fig. 21(b), in the bolt feed actuator unit having the above-described structure, if the length of the bolt is about 2 times or more the diameter of the bolt head and is a large-sized bolt (heavy bolt), if each of the bolt conveying pipes has an appropriate inner diameter, stable feeding is possible. However, if the length of the bolt is less than about 2 times the diameter of the bolt head, or a small bolt (light bolt), the likelihood of the bolt jamming or reversing direction between the Y-shaped path h and the clamp c1 is significantly increased.

Accordingly, the embodiment of the present invention solves the air swirling phenomenon occurring between the Y-shaped path h and the gripper c1 by changing the bolt feeding manner from pressure transmission to suction.

First, in the case of pressure delivery, as a method of suppressing the swirl, a method of adjusting the amount of air so as not to cause swirl is exemplified. In practice, however, it is very difficult to properly adjust the amount of air because there are too many factors for adjustment, such as changes in size or shape of individual bolts or changes in temperature or dew point of the supplied air.

Meanwhile, as in the embodiment of the present invention, when the bolt is conveyed by suction, the amount of air flowing into the driver depends on the amount of air discharged by the suction device for suction, which means that no air remains. Therefore, the swirling state of the air does not occur. Therefore, the bolt can be conveyed in a stable posture.

Since the automatic bolt fastening apparatus according to an embodiment of the present invention has the above-described structure and function, it has the following advantages.

(1) Since the bolt conveying mechanism 3 using compressed air from the bolt supply mechanism side conveys the bolt S with the bolt head S1 ahead, the bolt is less likely to damage the inner wall of the conveying pipe 32 and not to get stuck in the conveying pipe 32, and the posture of the bolt S can be stabilized, the bolt and the driver bit are firmly engaged, and the bolt is stably supplied, so that the reliability can be improved.

(2) Moreover, since the supply head unit has a longitudinal groove in which the bolt can be moved in parallel in the horizontal direction, the supply head unit can be moved only horizontally, the action and structure of the supply head unit 331 can be simplified, the bolt engaged with the driver bit 511 can be automatically and quickly fastened to the screw portion 422 of the main body, and the supply head unit 331 can be made compact. In particular, in the engaging operation of the head S1 of the bolt with the driver bit 511 at the feed head unit 331, the driver bit 511 can be simply linearly moved in the horizontal direction (left and right) without being moved vertically (in the Z-axis direction). Thus, the bolt S can be engaged with the driver bit 511 very quickly and with a very small number of components.

As described above, it is possible to automatically and rapidly fasten the bolt engaged with the driver bit to the threaded portion of the main body. And the engagement structure of the bolt and the driver drill bit is simple, the maintenance is convenient, and the manufacturing cost is low.

(3) Unlike the prior art, since the feed head unit 331 has a curved guide groove for guiding the bolt, which is formed in the mating surface of the separable guide shoe assembly, the curved portion of the bolt guide passage is not flat. Furthermore, it is possible to design freely so that the cross section of the bolt guide channel has a uniform true circle shape throughout the bolt guide channel, or if necessary only in the bent portion.

Further, it is apparent that the present invention is not limited only to the above-described embodiments as long as the features of the present invention are destroyed. For example, although there is only one supply head unit 331 in the embodiment, it is apparent that two or more supply head units are provided to cooperate with the driver bit unit 51. Also, although the feed head unit 331 is linearly moved in the left-right direction (X direction) by the cylinder assembly 333, the feed head unit 331 may be moved back and forth (Y axis). The point is that the bolt tightening mechanism (actuator) 5 need not move up and down (Z axis) when engaged with the bolt.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. Therefore, it should be understood that the above-described embodiments are not restrictive but illustrative in all aspects. The scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes and modifications that fall within the metes and bounds of the claims, or equivalence of such metes and bounds are therefore intended to be embraced by the claims.

Claims (2)

1. An automatic bolt fastening device which uses compressed air of a bolt supply mechanism to convey a bolt from the bolt supply mechanism to a bolt fastening mechanism via a bolt conveyance mechanism, engages the bolt with a driver bit portion at a front end of the bolt fastening mechanism, and fastens the bolt to a predetermined threaded portion, characterized in that:

the releasing unit is installed in the bolt feeding mechanism, the bolt is transferred in the conveying pipe of the bolt feeding mechanism with the head of the bolt in front,

the feed head unit is installed at the front end of the discharge unit, has a bolt feed hole with a diameter slightly larger than the head of the bolt, and is provided with a movable arm so that the feed head unit can horizontally rotate,

the feed head unit is provided movably between a close contact position where the feed head unit is in close contact with the driver bit portion of the front end of the bolt fastening mechanism and an evacuation position where the feed head unit is away from the driver bit unit, and where the driver bit portion of the front end of the bolt fastening mechanism is in contact with the bolt and attracts the head of the bolt to come into engagement with the bolt, and

the feed head unit includes a longitudinal groove opened outward so that a bolt engaged with the driver bit can be horizontally moved outward, the longitudinal groove being connected to a vertically extending bolt feed hole, and only a threaded portion of the bolt can be laterally advanced and retracted in the longitudinal groove.

2. The automatic bolt-tightening apparatus according to claim 1, characterized in that:

the curved passage of the feed head unit is formed by forming a curved guide groove for guiding the bolt in the mating face of the divisible guide shoe assembly.