JP2013230906A - Workpiece conveying mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost workpiece conveying mechanism capable of increasing a line speed, and also easily enhancing positional accuracy.SOLUTION: A crank 17 is included in a second track 14 shown in Fig.(a). In Figs.(d) to (e), a rotary driving wheel 24 travels on a straight part 17c. In this period, the rotary driving wheel 24 travels, but a workpiece table 13 is stationary. In the stationary period, desirable processing is applied to a workpiece. The rotary driving wheel 24 continuously rotates at a constant speed, then, turns at an exit corner 17b, and moves from left to right in a direction shown by an arrow (2) in Fig.(f). Since the rotary driving wheel 24 continuously rotates at a constant speed, a play does not occur, then, the line speed can be increased. Because of no play, positional accuracy is inevitably enhanced. Since the rotary driving wheel 24 keeps on rotating at a constant speed, high-cost servo motor control and a high-cost servo motor mechanism are not required.

Description

  The present invention relates to a work transport mechanism that stops a work at a station for a predetermined time and transports the work at a predetermined speed before and after the station.

  A workpiece transfer mechanism that targets a plurality of processing stations, supplies workpieces to the processing stations, receives processed workpieces, and transfers them to the next processing station has been put to practical use (for example, Patent Document 1 (FIG. 1, FIG. 1)). See FIG. 2).

  As shown in FIG. 1 of Patent Document 1, a pallet (21) (the numbers in parentheses indicate the codes described in Patent Document 1. The same applies hereinafter) is arranged on the conveyance path. The pallet (21) includes a chain (25), and a sprocket (31) meshes with the chain (25).

  The sprocket (31) is driven by a servo motor mechanism (32) as shown in FIG. Driving is performed by the controller (50), and the controller (50) stops the pallet (21) at a predetermined position, and controls the servo motor mechanism (32) to move the pallet (21) when the painting process is completed. To do.

The servo motor mechanism (32) is a precise mechanism capable of controlling the rotation angle of the motor shaft, and is more expensive than a general-purpose motor. Also, the controller (50) is expensive because the servo motor mechanism (32) is used for strict control based on feedback control and feedforward control.
Therefore, in the technique of Patent Document 1, the work transport mechanism is expensive.

  Further, the chain (25) is permanently extended in proportion to the frequency of use, and play with the sprocket (31) is increased. Even if the sprocket (31) is stopped to stop the pallet (21), the chain (25) moves forward by the amount of play, and the position of the pallet (21) is shifted.

When the stopped sprocket (31) is turned, the sprocket (31) is idled by the amount of play, and the chain (25) starts moving forward when the amount of play becomes zero.
That is, an impact force is applied to the chain (25).
Since the impact force is proportional to the square of the speed, measures to lower the line speed are taken from the viewpoint of protecting the chain (25). As a result, productivity decreases.
In addition, since the position accuracy is reduced by the amount of play, position correction by the position sensor becomes indispensable, and the workpiece transfer mechanism becomes more expensive.

  Considering the widespread use of work transfer mechanisms, cost reduction of work transfer mechanisms is required. That is, there is a need for a workpiece transfer mechanism that is inexpensive and can increase the line speed and easily increase the positional accuracy.

JP 2012-46134 A

  It is an object of the present invention to provide a workpiece transfer mechanism that is inexpensive and can increase the line speed and can easily increase the positional accuracy.

The invention according to claim 1 is a work transport mechanism that stops a work at a station for a predetermined time and transports the work at a predetermined speed before and after the station,
This workpiece transfer mechanism
A first track provided so as to pass through the station; a work table guided by the first track on which the work is placed; a second track provided along the first track; and the first track provided on the work table. Consisting of a propulsion mechanism that travels the work table by traveling on two tracks,
The second track has a crank portion bent in a direction intersecting the first track,
The propulsion mechanism includes a turning drive wheel that turns along the crank portion,
The work table includes a guide member that allows the turning drive wheel to move in a direction intersecting the first track.

The invention according to claim 2 is a work transport mechanism that stops the work for a predetermined time at at least two stations, and transports the work at a predetermined speed before and after the station,
The work transport mechanism includes a first track provided so as to pass through the station, a work table guided by the first track on which the work is placed, and an endless drive chain provided along the first track and rotating. And an attachment attached to the drive chain, and an engagement portion provided on the work base and extending so as to intersect the first track, and engaging with the attachment.
In addition to the normal portion extending along the first track, a special portion extending so as to intersect the first track is provided in the loop of the drive chain corresponding to the station.

  The invention according to claim 3 is characterized in that the special portion is formed by adjacent sprockets.

In the invention according to claim 4, the drive chain has a pair of link plates that sandwich a chain roller that meshes with the sprocket,
The attachment has one engagement piece that extends from one link plate of the pair of link plates and engages the engagement portion, and the other engagement piece that extends from the other link plate,
The other engagement piece is characterized by being guided by a guide member extending along the special portion.

  The invention according to claim 5 is characterized in that the engagement piece is a cam follower.

In the invention according to claim 6, the work table includes a free roller that engages with the first track, a plate that is extended from a support member that supports the free roller and that is provided with an engagement portion, and downward from the support member. It consists of a columnar member that is extended and a workpiece receiving member that is provided at the bottom of this columnar member and receives the workpiece,
The columnar member is a cylinder unit, and is characterized in that the workpiece receiving member can be approached toward the support member.

  In the invention according to claim 7, since the machining head is provided in at least one of the stations, the guide bush fitted to the guide pin extended from the machining head, or the guide pin fitted to the guide bush provided to the machining head is provided. The workpiece receiving member is provided.

  In the invention which concerns on Claim 1, a work stand is driven by the propulsion mechanism which drive | works a 2nd track | orbit, and is conveyed along a 1st track | orbit. At this time, a crank portion is provided on the second track, and the work table is stopped without running while the propulsion mechanism runs on the crank portion. Therefore, the work platform is repeatedly transported at a predetermined speed and stopped for a predetermined time. During this time, the turning drive wheel continues to rotate at a constant speed.

Since the turning drive wheel continues to rotate at a constant speed, play does not occur and the line speed can be increased. Since there is no play, the positional accuracy is inevitably increased. Since the turning drive wheel continues to rotate at a constant speed, an expensive servo motor control and an expensive servo motor mechanism are unnecessary.
That is, according to the present invention, it is possible to provide a work transport mechanism that is inexpensive and can increase the line speed and can easily increase the positional accuracy.

In the invention which concerns on Claim 2, a work stand is driven by a drive tune and an attachment, and is conveyed along a 1st track | orbit. In addition to the normal portion extending along the first track, a special portion extending so as to intersect the first track is provided in the loop of the drive chain corresponding to the station.
When the attachment is in a special part, the work table does not move. When the attachment is at the normal site, the work table moves. Therefore, the work platform is repeatedly transported at a predetermined speed and stopped for a predetermined time. During this time, the drive tune continues to circulate at a constant speed.

Since the drive chain continues to rotate at a constant speed, play does not occur with the sprocket, and the line speed can be increased. Since there is no play, the positional accuracy is inevitably increased. Since the turning drive wheel continues to rotate at a constant speed, an expensive servo motor control and an expensive servo motor mechanism are unnecessary.
That is, according to the present invention, it is possible to provide a work transport mechanism that is inexpensive and can increase the line speed and can easily increase the positional accuracy.

  In the invention according to claim 3, the special part is formed by adjacent sprockets. A large number of sprockets are arranged as essential parts for the drive chain. A special part can be formed by a pair of sprockets. That is, since the special part is formed by skillfully using the existing sprocket, the special cost is not increased because the special part is formed. As a result, the cost increase of the workpiece transfer mechanism can be suppressed.

  In the invention according to claim 4, the attachment includes one engagement piece that extends from one link plate of the pair of link plates and engages with the engagement portion, and the other engagement that extends from the other link plate. The other engaging piece is guided by a guide member extending along the special portion.

  Since the other engaging piece is guided by the guide member, the other engaging piece is prevented from shaking. Then, the one engagement piece mechanically connected to the other engagement piece is also prevented from shaking and shaking. Since the position of the one engagement piece in which one engagement piece drives the work table via the engagement portion is accurately determined, the position of the work table is also accurate.

  That is, according to the present invention, it is possible to accurately position the work table without using an expensive servo motor mechanism.

In the invention according to claim 5, the engagement piece is a cam follower.
The engaging piece may be a pin that fits into the engaging portion. However, since the pin is in sliding friction contact, contact resistance is generated and a load is applied to the drive chain. Further, when the pin is worn, backlash occurs between the engaging portion.
In this respect, since the cam follower is a rolling contact, the contact resistance with the engaging portion is negligibly small. In addition, since it is a rolling contact, wear is negligibly small and there is no risk of play.

In the invention which concerns on Claim 6, a workpiece | work receiving member can be moved with a cylinder unit.
If a cutting tool is provided in the station, the workpiece can be brought close to the cutting tool by the cylinder unit, and machining can be performed smoothly.

  In the invention according to claim 7, the work receiving member is accurately positioned at the station by the guide pin and the guide bush. Machining is performed accurately.

It is a top view of the workpiece conveyance apparatus which concerns on Example 1. FIG. FIG. 2 is an enlarged view of part 2 of FIG. 1. 1 is a cross-sectional view of a work table according to Embodiment 1. FIG. 1 is a perspective view of a propulsion mechanism according to Embodiment 1. FIG. 1 is a cross-sectional view of a propulsion mechanism according to a first embodiment. FIG. 3 is a bottom view of the work table according to the first embodiment. FIG. 6 is an operation explanatory diagram of the workpiece transfer mechanism according to the first embodiment. FIG. 6 is a front view of a machine tool including a workpiece transfer mechanism according to a second embodiment. 6 is a front view of a work table according to Embodiment 2. FIG. FIG. 10 is a view taken in the direction of arrow 10 in FIG. 9. It is an 11-11 arrow directional view of FIG. 6 is a cross-sectional view of a main part of a machine tool according to a second embodiment. 6 is a loop diagram of a drive chain according to Embodiment 2. FIG. It is a perspective view of an attachment. FIG. 15 is a cross-sectional view taken along line 15-15 in FIG. 13. FIG. 10 is an operation diagram of a workpiece transfer mechanism according to a second embodiment. It is a principle figure of a work stand position detection mechanism. It is a change figure of the work stand shown in FIG. It is an action figure of the changed work stand. It is a change figure of the workpiece conveyance mechanism shown in FIG.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.

First, Example 1 of the present invention will be described.
As shown in FIG. 1, the work transport mechanism 10 is provided along a first track 12 provided so as to pass through a station 11, a work table 13 guided by the first track 12, and the first track 12. The second track 14 includes a propulsion mechanism (FIG. 4, reference numeral 20) that is provided on the work platform 13 and travels on the work track 13 by traveling on the second track 14.

The station 11 is a machining station that performs machining, a painting station that performs painting, or the like, but the application is not particularly limited.
As shown in FIG. 2, the first track 12 includes an inner rail 15 and an outer rail 16.
The second track 14 is laid between the inner rail 15 and the outer rail 16.

The second track 14 includes a crank portion 17 that is bent in a direction orthogonal to (or intersects) the first track 12. As shown in FIG. 1, the crank portion 17 is disposed in the vicinity of the station 11.
When there are a plurality of stations 11, a plurality of crank portions 17 are provided for each station 11.
In addition, positioning pins 18 and 18 are provided on the first track 12 side in the vicinity of the station 11.

As shown in FIG. 3, the work base 13 includes a base body 21, an inner wheel 22 that freely rotates on the inner rail 15 while supporting the base body 21, and a free rotation on the outer rail 16 while supporting the base body 21. An outer wheel 23, a turning drive wheel 24 that is attached to the lower surface of the base body 21 so as to be turnable around a vertical axis and travels on the second track 14, a drive motor 25 that drives the turning drive wheel 24, and a base body And positioning recesses 26, 26 lowered from 21.
The work table 13 is positioned by fitting the positioning pins 18, 18 into the positioning recesses 26, 26.

  Further, the drive motor 25 rotates the turning drive wheel 24 by being supplied with power. For example, the power supply brush 27 is provided on the side surface of the outer rail 16, the power receiving shoe 28 is provided on the base body 21, and the power receiving shoe 28 is brought into sliding contact with the power supply brush 27.

FIG. 4 is a diagram in which the base body 21 is reversed and the lower surface is shown. Two guide members 29 and 29 are attached to the base body 21, and the slider 31 is movable to these guide members 29 and 29. The U-shaped member 33 is attached to the slider 31 via the turning support shaft 32, and the turning drive wheel 24 and the drive motor 25 are attached to the U-shaped member 33.
That is, the propulsion mechanism 20 includes guide members 29 and 29, a slider 31, a turning support shaft 32, a U-shaped member 33, a turning drive wheel 24, and a drive motor 25.

As shown in FIG. 5, since the drive motor 25 is attached to the U-shaped member 33, the turning drive wheel 24 can be rotated by this drive motor 25. The slider 31 is movable in the front and back direction of the drawing.
FIG. 6 is a bottom view of the work table 13, and the guide members 29, 29 extend at right angles to the first track (inner rail 15) indicated by an imaginary line. That is, the work table 13 includes guide members 29 and 29 that allow the turning drive wheel 24 to move in a direction orthogonal to the first track 12.

Next, the operation of the workpiece transfer mechanism having the above configuration will be described.
A crank portion 17 is included in the second track 14 shown in FIG. The work table 13 moves from the left to the right as shown by the arrow (1).
As shown in (b), the work base 13 moves at a predetermined speed as shown by the arrow (1) by the drive action of the turning drive wheel 24 on the second track 14.

The crank portion 17 includes an inlet corner portion 17a, an outlet corner portion 17b, and a straight portion 17 that connects both the corner portions 17a and 17b. Both corner portions 17a and 17b have a curve angle of 90 °.
As shown in (c), the turning drive wheel 24 turns along the inlet corner portion 17a when it is applied to the inlet corner portion 17a.

Between (d) and (e), the turning drive wheel 24 travels on the straight portion 17c. During this time, the turning drive wheel 24 travels, but the work table 13 stops. In this stationary period, the workpiece is processed as desired.
The turning drive wheel 24 continues to rotate at a constant speed, turns at the exit corner portion 17b, and moves from the left to the right as shown by the arrow (2) as shown in (f).

  Since the turning drive wheel 24 continues to rotate at a constant speed, play does not occur and the line speed can be increased. Since there is no play, the positional accuracy is inevitably increased. Since the turning drive wheel 24 continues to rotate at a constant speed, an expensive servo motor control and an expensive servo motor mechanism are unnecessary.

Next, a second embodiment of the present invention will be described with reference to the drawings.
In Example 2, the workpiece transfer mechanism according to the present invention was mounted on a machine tool.
As shown in FIG. 8, the machine tool 40 includes a base frame 42 that passes horizontally to a foundation or machine base 41, a plurality of columns 43 to 47 that stand from the base frame 42, and upper ends of these columns 43 to 47. A top frame 48 that extends horizontally, a middle frame 49 that extends horizontally to the columns 43 to 47 at a position lower than the top frame 48, and machining heads 51, 51 that are provided integrally with the middle frame 49. Spindle motors 52 and 52, and a workpiece transfer mechanism 10 that transfers workpieces to the machining heads 51 and 51.

  The work transport mechanism 10 includes a horizontal guide groove-shaped first track 12 provided in the middle frame 49, a work table 13 that is guided by the first track 12 and moves horizontally, and a top for moving the work table 13. An endless drive chain 54 provided between the frame 48 and the middle frame 49, an attachment 55 attached to the drive chain 54, and provided on the work table 13 side, which is orthogonal to the first track 12, that is, extends vertically. And a longitudinal groove-like engaging portion 56 that engages with the attachment 55. Details of the attachment 55 and the engaging portion 56 will be described later.

  The work moves from left to right in the figure. Then, along the movement of the workpiece, between the adjacent columns 43 and 44, the workpiece loading station 57, between the columns 44 and 45, the first machining station 58, between the columns 45 and 46, the second machining station 59 and the column 46, are provided. , 47 are the 3-1 processing station 61 and the 3-2 processing station 62.

  As shown in FIG. 9, the work table 13 includes a support member 64 (hereinafter referred to as a slider 64) including a free roller 63 that freely fits on the first track (FIG. 8, reference numeral 12) and the slider. A vertical wall-shaped plate 65 extending upward from 64 and provided with an engaging portion 56, rods 66 and 66 lowered from the slider 64, and guides 67 and 67 that are always fitted to these rods 66 and 66. The lower frame 68 includes a columnar member 69 which is provided on the lower frame 68 and extends upward and has an upper end connected to the slider 64.

The columnar member 69 is, for example, a fluid pressure cylinder unit, and the piston rod 71 is connected to the slider 64.
When the fluid pressure cylinder unit 69 is contracted, the lower frame 68 rises. At this time, since the guides 67 and 67 are fitted to the rods 66 and 66, there is no fear that the lower frame 68 is shaken. Since the rods 66 and 66 and the guides 67 and 67 are employed, it can be said that the number of fluid pressure cylinder units 69 can be minimized.
If it is not necessary to raise and lower the lower frame 68, the columnar member 69 can be replaced with a simple two tie rods, and the rods 66 and 66 and the guides 67 and 67 can be omitted.

As shown in FIG. 10, the lower frame 68 is integrally provided with a work receiving member 73 that receives a work 72 indicated by an imaginary line. A workpiece receiving surface 74, positioning pins 75, and a clamper 76 are attached to the workpiece receiving member 73. The horizontal position of the workpiece 72 is determined by the positioning pin 75, the height position of the workpiece 72 is determined by the workpiece receiving surface 74, and the workpiece 72 is fixed by the clamper 76.
Further, guide bushes 77, 77, 77 are provided on the work receiving member 73.

As shown in FIG. 11, the machining head 51 incorporated in the middle frame 49 has spindle shafts 78 and 78 that are rotated by a spindle motor 52. Cutting tools 79, 79 such as end mills can be attached to the spindle shafts 78, 78.
A chain support plate 60 is extended upward from one end (right end in the figure) of the middle frame 49.
Sprockets 81 and 81 are rotatably attached to the chain support plate 60, and the drive chain 54 is wound around the sprockets 81 and 81.

  A drive shaft 82 that supports the upper sprocket 81 extends through the chain support plate 60. Then, a driven sprocket 83 is attached to the tip of the drive shaft 82. A chain driving means 84 such as a motor with a speed reducer is attached to the chain support plate 60, a driving sprocket 85 is attached to the chain driving means 84, and a chain 86 is passed to the driving sprocket 85 and the driven sprocket 83.

The drive sprocket 85 is rotated by the chain drive means 84, the driven sprocket 83 is rotated by the drive sprocket 85, and the upper sprocket 81 is rotated by rotating the driven sprocket 83.
Note that the drive sprocket 85 may be replaced with a drive gear, and the driven sprocket 83 may be changed to a driven gear. Further, the drive shaft 82 may be directly driven by the chain drive means 84.

  In addition, guide pins 87, 87, 87 are extended downward from the middle frame 49. Guide bushes 77, 77, 77 shown in FIG. 10 are fitted to these guide pins 87, 87, 87.

Free rollers 63 and 63 shown in FIG. 10 are fitted to the first tracks 12 and 12 shown in FIG.
Then, as shown in FIG. 12, the work table 13 is supported so as to be suspended from the middle frame 49. The work table 13 moves in the drawing front / back direction with respect to the middle frame 49.

When the fluid pressure cylinder units 69 and 69 are contracted, the workpieces 72 and 72 are raised. These workpieces 72 and 72 are machined by cutting tools 79 and 79.
A predetermined process is performed by raising the workpieces 72 and 72 without moving the cutting tools 79 and 79 up and down. Since the guide pins 87, 87, 87 are fitted to the guide bushes 77, 77, 77 during processing, there is no fear of the workpieces 72, 72 swinging, and the processing accuracy can be increased.
And since the cutting tools 79 and 79 are not moved up and down, the structure of the processing head 51 becomes simple.

Next, how to hang the drive chain 54 will be described.
As shown in FIG. 13, the drive chain 54 is stretched so as to cover the workpiece carry-in station 57, the first processing station 58, the second processing station 59, the 3-1 processing station 61, and the 3-2 processing station 62. It is done. One attachment 55 is attached to the loop.

Four sprockets 81a, 81b, 81c, and 81d (alphabets are added to the reference numerals to identify the positions; the same applies hereinafter) are disposed at the work loading station 57. Two of the sprockets 81a and 81b are vertically arranged, and guide members 89a and 89b are provided so as to sandwich the drive chain 54 hung on these sprockets 81a and 81b from the left and right.
The remaining sprockets 81c and 81d are take-up sprockets, and the tension of the drive chain 54 can be adjusted by moving the sprocket 81c.

  In the first processing station 58, two sprockets 81e and 81f are arranged one above the other. Guide members 89c and 89d are provided so as to sandwich the drive chain 54 from the left and right.

  In the second processing station 59, two sprockets 81g and 81h are arranged one above the other. Guide members 89e and 89f are provided so as to sandwich the drive chain 54 from the left and right.

  In the 3-1 processing station 11, two sprockets 81i and 81j are arranged one above the other. Guide members 89g and 89h are provided so as to sandwich the drive chain 54 from the left and right.

  In the 3-2 processing station 11, two sprockets 81k and 81m are arranged one above the other. The upper sprocket 81m is rotated by the drive shaft 82. Guide members 89i and 89j are provided so as to sandwich the drive chain 54 from the left and right.

The structure of the attachment 55 will be described with reference to FIG.
As shown in FIG. 14, the drive chain 54 includes a chain roller 91, a pair of link plates 92 and 93 sandwiching the chain roller 91, and the link plates 92 and 93 supporting both ends to support the chain roller 91. It consists of a pin 94 that is rotatably supported.

  The attachment 55 includes a block 96 fixed to one link plate 92, rollers 97 attached to the upper and lower surfaces of the block 96, and one engagement extending from the outer surface of the block 96 and engaging with the engaging portion 56. It comprises a piece 98, a block 96 fixed to the other link plate 93, a roller 97 attached to the upper and lower surfaces of this block 96, and the other engagement piece 99 extending from the outer surface of the block 96.

  The engaging pieces 98 and 99 may be pins, but cam followers are suitable. The cam follower is configured such that a roller is integrally attached to a shaft via a bearing. With a cam follower, sliding friction can be changed to rolling friction, and the contact resistance can be made minute.

  As shown in FIG. 15, one engagement piece 98 is fitted into the engagement portion 56, and the other engagement piece 99 is fitted between the guide members 89c and 89d. A chain shoe 101 having an L-shaped cross section is extended from the middle frame 49, and the chain shoe 101 prevents the drive chain 54 from falling off.

  That is, the drive chain 54 does not contact the chain shoe 101 when the drive chain 54 is hooked on the sprocket 81e as prescribed. Since there is no contact, there is no contact resistance. When the drive chain 54 moves away from the sprocket 81e, the chain shoe 101 prevents the movement and prevents the dropout.

  When the rollers 97 come in contact with the chain shoe 101, the drive chain 54 is prevented from shaking.

The operation of the workpiece transfer mechanism 10 having the above configuration will be described next.
FIG. 16 is a simplified diagram of FIG.
As shown in FIG. 16, the drive chain 54 is continuously rotated at a predetermined speed counterclockwise in the drawing.
In this endless drive chain 54, the portions extending left and right in the drawing are the normal portions 102a, 102b, 102c, and the portions extending vertically are the special portions 103a, 103b, 103c, 103d, 103e.

  In the special portions 103a to 103e, the drive chain 54 continuously moves at a constant predetermined speed, but the attachment 55 only moves up and down and does not move in the horizontal direction of the drawing. In the special parts 103a to 103e, the attachment 55 moves up and down while being guided by the guide members 89a to 89j.

Since the workpiece is apparently stopped at the special portions 103a to 103e, the workpiece can be processed.
Transport between the stations 57, 58, 59, 61 is performed by the normal parts 102a, 102b, 102c.

Since the drive chain 54 continues to rotate at a constant speed, play does not occur with the sprockets 81a to 81m, and the line speed can be increased. Since there is no play, the positional accuracy is inevitably increased. Since the turning drive wheel continues to rotate at a constant speed, an expensive servo motor control and an expensive servo motor mechanism are unnecessary.
That is, according to the present invention, it is possible to provide a work transport mechanism that is inexpensive and can increase the line speed and can easily increase the positional accuracy.

  Special portions 103a to 103e are formed by adjacent sprockets (for example, sprocket 81a and sprocket 81b). A large number of sprockets 81 a to 81 m are arranged as essential parts for the drive chain 54. A special part can be formed by a pair of sprockets. That is, the special portions 103a to 103e are formed by skillfully using the existing sprockets, so that no special cost increase occurs because the special portions 103a to 103e are formed. As a result, the cost increase of the workpiece conveyance mechanism 10 can be suppressed.

Incidentally, it is necessary to detect where the work table 13 is located in the stations 57 to 62. For detection, for example, a work table position detection mechanism 104 described below is recommended.
As shown in FIG. 17, the work table position detection mechanism 104 includes a reel 105 such as a cord take-up reel attached to a so-called electric vacuum cleaner, a detection unit 106 that detects the number of rotations of the reel 105, and a middle frame. 49 includes a relay pulley 107 disposed at one end of the cable 49 and a cord 108 that extends from the work table 13 and is wound around the reel 105 via the relay pulley 107.

  When the reel 105 is forcibly rotated by the code 108, the number of rotations of the reel 105 is detected by the detection unit 106. Based on this detection information, the relative position of the work table 13 is detected. The mechanism is simpler than arranging a large number of limit switches.

  In the Example, the workpiece conveyance mechanism provided with the special site | parts 103a-103e bent so that it might orthogonally cross the 1st track | orbit on the 2nd track | orbit was shown. However, the special portions 103a to 103e may be crossed in addition to being orthogonal to the first trajectory.

  For example, when the other work equipment is decelerated to a minute speed that can follow the moving speed of the work table and the other work equipment can perform the work in the previous process or the work in the subsequent process, the work table 13 is minute. When passing through a station at speed, it can be considered to be stopped at the station. In this case, since it is not necessary to completely stop the work table 13, the special portions 103a to 103e and the crank portion 17 may be bent in a direction intersecting with the first track even if they are not orthogonal to the first track. .

As shown in FIG. 18, in the work table 13, the guide members 29 and 29 may intersect the inner rail 15 at the intersection angle θ.
In addition, as shown in FIG. 19A, the crank portion 17 (more precisely, the straight portion 17c) intersects the inner rail 15 at an intersection angle θ.

In FIGS. 19C and 19D, although the turning drive wheel 24 travels along the straight portion 17c, the crossing angle θ on the work table 13 side and the crossing angle θ on the crank portion 17 side include the direction. Therefore, the work table 13 does not move in the horizontal direction of the drawing. The work table 13 remains stationary.
Therefore, the crank portion 17 and the guide members 29, 29 may be crossed in addition to being orthogonal to the first track (inner rail 15).

  It is expected that the turning angle of the turning drive wheel 24 will be smaller and the operation will be smoother if the two are made to intersect rather than perpendicularly.

Similarly, as shown in FIG. 20, the special portions 103a to 103e may intersect with the first trajectory (FIG. 8, reference numeral 12). In this case, the vertically long engaging portion 56 is also intersected with the first track at the same intersection angle. By matching the crossing angle and the azimuth, the work table 13 can be stopped at the special portions 103a to 103e.
Therefore, the special portions 103a to 103e may be crossed in addition to being orthogonal to the first trajectory.

  The workpiece transfer apparatus of the present invention is suitable for a machine tool having a plurality of processing stations.

  DESCRIPTION OF SYMBOLS 10 ... Work conveyance mechanism 11, 57-62 ... Station, 12 ... 1st track, 13 ... Work stand, 14 ... 2nd track, 17 ... Crank part, 20 ... Propulsion mechanism, 24 ... Turning drive wheel, 29, 89a 89j ... guide member, 40 ... machine tool, 51 ... machining head, 54 ... drive chain, 55 ... attachment, 56 ... engaging portion, 63 ... free roller, 64 ... support member (slider), 65 ... plate, 69 ... Columnar member (cylinder unit), 71 ... piston rod, 73 ... work receiving member, 81, 81a to 81m ... sprocket, 84 ... chain drive means, 91 ... chain roller, 92, 93 ... link plate, 98 ... one engagement Numeral 99, other engagement piece, 102a to 102c, normal region, 103a to 103e, special region.

Claims (7)

A work transport mechanism that stops a work at a station for a predetermined time and transports the work at a predetermined speed before and after the station;
This workpiece transfer mechanism
A first track provided so as to pass through the station; a work table guided by the first track on which the work is placed; a second track provided along the first track; and the first track provided on the work table. Consisting of a propulsion mechanism that travels the work table by traveling on two tracks,
The second track has a crank portion bent in a direction intersecting the first track,
The propulsion mechanism includes a turning drive wheel that turns along the crank portion,
The work platform is provided with a guide member that allows the turning drive wheel to move in a direction crossing the first track. A work transport mechanism that stops the work for a predetermined time at at least two stations and transports the work at a predetermined speed before and after the station;
The work transport mechanism includes a first track provided so as to pass through the station, a work table guided by the first track on which the work is placed, and an endless drive chain provided along the first track and rotating. And an attachment attached to the drive chain, and an engagement portion provided on the work base and extending so as to intersect the first track, and engaging with the attachment.
A workpiece transfer mechanism characterized in that a special portion extending so as to intersect the first track is provided in the loop of the drive chain in addition to the normal portion extending along the first track corresponding to the station.   The workpiece conveyance mechanism according to claim 2, wherein the special portion is formed by adjacent sprockets. The drive chain has a pair of link plates that sandwich a chain roller that meshes with the sprocket,
The attachment has one engagement piece that extends from one link plate of the pair of link plates and engages the engagement portion, and the other engagement piece that extends from the other link plate,
The work conveying mechanism according to claim 3, wherein the other engaging piece is guided by a guide member extending along the special portion.   The work conveying mechanism according to claim 4, wherein the engagement piece is a cam follower. The work table includes a free roller that engages with the first track, a plate that extends from a support member that supports the free roller and is provided with the engagement portion, and a columnar member that extends downward from the support member. And a work receiving member that is provided at the bottom of the columnar member and receives the work,
The workpiece conveying mechanism according to any one of claims 2 to 5, wherein the columnar member is a cylinder unit, and the workpiece receiving member can be moved toward the support member. .   A work head is provided in at least one of the stations, and a guide bush fitted to a guide pin extended from the work head, or a guide pin fitted to a guide bush provided in the work head, the work receiving member The workpiece transfer mechanism according to claim 6, wherein the workpiece transfer mechanism is provided on the workpiece.

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