JP2008013282A - Work pitch changing device, and work conveying system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a work pitch changing device capable of arbitrarily and collectively changing the pitches of a large number of works, and avoiding any inconvenience such as ejection of the works. <P>SOLUTION: The work pitch changing device 10 comprises a cam member 5 which is a rotatable member having a plurality of cams 5a while the pitches of the plurality of cams in the axial direction of rotation are changed in the rotational direction; and further comprises a plurality of work holding members 2 which are capable of respectively holding works 20, and engaged with the plurality of cams, respectively, and movable in the axial direction of rotation as the cam member 5 is rotated, a driving means 6 for rotating the cam member, and a control means 7 for controlling the rotational position of the cam member via the driving means. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a work pitch conversion device that changes a pitch of a plurality of workpieces, for example, a semiconductor device such as an IC chip or a memory card, and a workpiece transfer system including the workpiece.

  When transferring multiple workpieces such as BGA (ball grid array) and CSP (chip size package) from the previous process to the subsequent process, the work pitch in the previous process is the same as the work pitch in the subsequent process. It is necessary to adjust to.

  In such a case, a plurality of workpieces carried out from the previous process are once transported to the work pitch conversion device, and the work pitch is adjusted to the receiving pitch in the subsequent step by the conversion device, and then transferred to the subsequent step. There are many cases.

  An example of such a work pitch conversion device is disclosed in Patent Document 1. In this work pitch conversion device (hereinafter, referred to as a first conventional work pitch conversion device), two stages on which two works for which the previous process has been completed are mounted are a ball screw having a right screw portion and a left screw portion. The distance between the two stages is changed to match the work pitch of the subsequent process.

In addition, a plurality of stages arranged in a state of being spaced apart from each other in accordance with the work pitch of the previous process are pushed from one side by an actuator such as a pneumatic cylinder and brought into contact with each other, so that the work pitch is changed to There is also a work pitch conversion device (hereinafter referred to as a second conventional work pitch conversion device) adapted to the process.
Japanese Patent Laid-Open No. 9-55463 (paragraphs 0059 to 0070, FIGS. 4, 5 etc.)

  However, the first conventional work pitch conversion apparatus can be basically applied only when changing the interval between two works. When changing the pitch of a larger number of workpieces at a time, it is necessary to provide a plurality of mechanisms including a ball screw and two stages. Further, in the first conventional work pitch conversion device, both works always move when the interval between two works is changed. For this reason, it cannot be used when it is desired to change the interval by moving the other work while one work is stopped.

  In addition, the second conventional work pitch conversion device can only switch between two work pitches, a state in which a space is provided between the stages and a state in which the stages are in contact with each other. For this reason, when the work pitch in the previous process or the subsequent process is changed, a special work for adjusting the stage position in each state is required, and it takes time to quickly adjust the work pitch. Moreover, if the stages are brought into contact with each other at high speed, the impact may cause the workpiece to jump out of the stage. For this reason, the work pitch cannot be changed at high speed.

  An object of the present invention is to provide a workpiece pitch conversion device that can arbitrarily change the pitch of a large number of workpieces in a lump and can avoid inconveniences such as projecting of workpieces.

  Another object of the present invention is to provide a work pitch conversion device that can change the interval or pitch of these works by moving other works while stopping one work.

  A workpiece pitch conversion device according to one aspect of the present invention is a rotatable member having a plurality of cams, each of which is a cam member in which the pitch of the plurality of cams in the direction parallel to the rotation axis changes in the rotation direction. A plurality of workpiece holding members that can hold the workpiece and can be engaged with the plurality of cams and move in a direction parallel to the rotation axis as the cam member rotates, and driving means for rotationally driving the cam member And control means for controlling the rotational position of the cam member via the drive means.

  Further, the work pitch conversion device and a plurality of workpieces are conveyed to the work pitch conversion device at a first arrangement pitch, and the work pitch conversion device changes the second arrangement pitch to be different from the first arrangement pitch. A workpiece transfer system having a transfer device for transferring a plurality of workpieces also constitutes another aspect of the present invention.

  According to the present invention, since the number of cams provided on the cam member can be arbitrarily selected, the number of workpiece holding members, that is, the number of workpieces whose pitch is collectively changed can be arbitrarily selected. Further, the work pitch before and after the change can be arbitrarily selected only by changing the rotational position of the cam member. Further, since no impact is generated when the work pitch is changed, the work pitch can be changed at high speed without causing inconvenience such as the work jumping out from the work holding member.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a side view of a work pitch conveying apparatus which is an embodiment of the present invention. 2 is a plan view of the work pitch conveying apparatus, and FIG. 3 is an enlarged view of a part of FIG. Further, FIGS. 4 and 5 show a front view and a rear view of the work pitch conversion device, respectively.

  In these drawings, reference numeral 10 denotes a work pitch conveying apparatus, and reference numeral 1 denotes a main body of the work pitch conveying apparatus 10.

  Reference numeral 2 denotes a movable stage as a work holding member, which can be moved in the left-right direction (the direction perpendicular to the paper surface of FIG. 1, the left-right direction in FIG. 2) with respect to the main body 1 by the first and second guide rails 3a, 3b. It is supported. In this embodiment, a case where seven movable stages 2 are provided will be described. In the following description, the side corresponding to the left side of FIG. 1 and the upper side of FIG. 2 is referred to as the “front” side, and the side corresponding to the right side of FIG.

  A slider holding portion 2b is formed at the front portion and the front-rear direction intermediate portion of each movable stage 2, and a slider 2c for improving the sliding with respect to the guide rail 3a or 3b is provided on the lower surface of each slider holding portion 2b. It is attached.

  Further, between the front and rear slider holding portions 2b in each movable stage 2, a pocket 2a is formed as a rectangular recess in which a workpiece is mounted and accommodated. The pockets 2a formed on all the movable stages 2 are arranged in a line in the left-right direction.

  Examples of the work include semiconductor devices such as BGA and CSP type memory chips and controller chips, QFP (Quad Flat Package), and SOP (Small Outline Package) cut out from a semiconductor substrate and separated into individual pieces. However, the workpiece is not limited to these, and the workpiece pitch conversion apparatus of the present embodiment can be applied to various types of workpieces.

  As shown in FIG. 2, the slider 2c attached to the odd-numbered movable stage (first movable stage) 2 from the left slides on the first guide rail 3a. Further, the slider 2c attached to the even-numbered movable stage (second movable stage) 2 from the left slides on the second guide rail 3b. The first and second guide rails 3a and 3b are arranged separately in the front and rear.

  In this way, by supporting the movable stages 2 adjacent to each other by different guide rails 3a and 3b, the slider holding part 2b protrudes in the left-right direction from the peripheral part of the pocket 2a (hereinafter referred to as pocket part) in these movable stages 2. Even so, the pocket portions can be brought close to each other. In other words, compared to the case where the slider holding parts of all the movable stages are provided on a common guide rail and the movable stages can only be brought close to the position where the slider holding parts come into contact with each other, the work pitch can be reduced. It becomes possible to do.

  In addition, a coil spring 11 is provided between adjacent movable stages 2 to urge them in a direction to separate them left and right. The role of the coil spring 11 will be described later.

  Further, a fixed stage 2 ′ fixed to the main body 1 is provided between the second and third movable stages 2 from the right. The fixed stage 2 ′ also has a pocket 2 a as a rectangular recess in which a work is mounted and accommodated, and is aligned with the pocket 2 a formed on the movable stage 2 in the left-right direction.

  Reference numeral 5 denotes a cylindrical cam as a cam member. The cylindrical cam 5 is disposed with the left-right direction as the rotation axis direction (direction parallel to the rotation axis), and the shaft 5b is rotatably supported by the bearing 9 shown in FIGS.

  Reference numeral 6 denotes a motor as a drive source fixed to the main body 1, and an output shaft 6 a thereof is connected to a shaft 5 b via a coupling 8. For this reason, when the motor 6 operates, the cylindrical cam 5 rotates.

  As the motor 6, a motor capable of controlling the rotation position (rotation angle) such as a stepping motor is used. As a result, the rotational position of the cylindrical cam 5 can be controlled.

  The rotation of the motor 6 is controlled by a controller (computer) 7 as control means shown in FIG. The controller 7 controls the rotational position of the motor 6, that is, the cylindrical cam 5 in accordance with the workpiece pitch value before and after conversion input by the user through an input unit (not shown).

  As shown in FIGS. 2 and 5, on the outer peripheral surface (cylindrical surface) of the cylindrical cam 5, seven groove cams 5 a extending in the circumferential direction (rotational direction) are formed side by side in the rotational axis direction. In FIG. 8, seven groove cams 5a formed on the cylindrical cam 5 are shown developed in the circumferential direction.

  Of these seven groove cams 5a, the five pitches on the left side (lower side in FIG. 8) and the two pitches (intervals) on the right side (upper side in FIG. 8) are the same (equal pitch). The pitch continuously changes so as to be widest (MAX) at one end in the circumferential direction of the groove cam 5a and narrowest (MIN) at the other end. Hereinafter, the one end of the groove cam 5a is referred to as a MAX position, and the other end is referred to as a MIN position.

  Further, a space corresponding to the width of the fixed stage 2 'described above is provided between the second and third groove cams 5a from the right (from the top in FIG. 8), and the center of the fixed stage 2' is provided. The line is indicated by C in FIG.

  In FIG. 8, the first and fourth groove cams 5a and the second and third groove cams 5a from the top have symmetrical shapes with respect to the center line C, respectively. The distance between the center line C and the MAX position and the MIN position of the second and third groove cams 5a is equal to the distance between the MAX positions of the adjacent cam grooves 5a and the distance between the MIN positions. That is, the pitches of the seven cam grooves 5a and the center line C are equal.

  A cam follower 4 attached to the rear end of each movable stage 2 is engaged with each groove cam 5a. For this reason, when the cylindrical cam 5 is rotationally driven by the motor 6, the seven movable stages 2 move in the left-right direction, and the interval between them changes.

  Due to the relationship between the shape and arrangement of the seven groove cams 5a as described above, the seven movable stages 2 have a distance between all adjacent stages 2, 2 '(pocket 2a) including the fixed stage 2'. Move left and right in the same state. That is, the rotation of the cylindrical cam 5 increases or decreases the pitch while the eight pockets 2 a of the movable stage 2 and the fixed stage 2 ′ are arranged at an equal pitch. Furthermore, since the rotational position of the cylindrical cam 5 can be arbitrarily selected, the pitch of the eight pockets 2a can also be arbitrarily selected.

  In this embodiment, even in the minimum pitch state where the cam follower 4 is engaged with the MIN position of the groove cam 5a, an appropriate amount is provided between the movable stages 2 and between the fixed stage 2 'and the movable stage 2 adjacent thereto. The interval is set to be long.

  In addition, a predetermined play is provided between the cam follower 4 and the groove cam 5 so that the movable stage 2 can be driven smoothly, but each cam follower 4 is always driven by the biasing force of the coil spring 11 described above. It is pressed against one surface of each groove cam 5a. For this reason, the horizontal position of the eight pockets 2a can be controlled with high accuracy.

  The work pitch conversion device 10 configured as described above is used together with the transport device having the suction heads 15A and 15B shown in FIG. Thereby, a conveyance system is comprised. The conveyance system including the workpiece pitch conversion device 10 and the conveyance device performs, for example, a cutting device F that cuts and separates a workpiece as a pre-process device, and a predetermined process for a workpiece that is separated as a post-process device. It arrange | positions between the processing apparatuses R.

  Here, FIG. 6 shows a schematic configuration (bottom view) of the transfer device. The transport device 15 has a first suction head 15A and a second suction head 15B integrated. The first suction head 15A is provided with eight suction portions 15A1 arranged at a pitch α in the left-right direction (vertical direction in FIG. 6). On the other hand, the second suction head 15B provided behind the first suction head 15A (on the right side in FIG. 6) is provided with eight suction portions 15B1 arranged at a pitch β in the left-right direction.

  A vacuum generator (not shown) is connected to each suction part 15A1, 15B1. For this reason, each adsorption | suction part 15A1, 15B1 can adsorb | suck a workpiece | work with negative pressure.

  FIG. 7 shows the relationship between the workpiece and the workpiece pitch conversion device. A line C in FIG. 7 is a center line of the pocket 2a on the fixed stage 2 'that does not move during pitch conversion, as shown in FIG. 8, and is hereinafter referred to as a pitch conversion reference line. The work pitch conversion device 10 and the transport device 15 are positioned in the left-right direction so that the pitch conversion reference line C passes through the center of the third work 20 from the right (upper in FIG. 7) of the cutting device F and the processing device R. Is set.

  Hereinafter, operations of the work pitch conversion device 10 and the transport device 15 will be described.

  (1) At the “work piece separation position” on the cutting device F, there are eight workpieces 20 cut out by the cutting device F and arranged at a pitch α. The conveyance device 15 sucks these workpieces 20 by the eight suction portions 15A1 of the first suction head 15A (operation Z1 in FIG. 6), and the workpiece pitch conversion in the state before the pitch conversion shown in the lower side of FIG. It is transported onto the apparatus 10 (operation X1 in FIG. 6).

  On the other hand, in the work pitch conversion device 10 before the pitch conversion, the eight pockets 2a are arranged at the pitch α at the “work pitch conversion position”. For this reason, the eight workpieces 20 sucked by the first suction head 15A are accommodated in the eight pockets 2a as they are.

  (2) When the accommodation of the workpiece 20 in the pocket 2a is completed, the transport device 15 releases the suction of the workpiece 20 by the first suction head 15A and returns the first suction head 15A to the cutting device F side (FIG. 6). Medium operation X2). At the same time when the first suction head 15A returns to the cutting device F side, the second suction head 15B moves toward the workpiece pitch conversion position.

  (3) While the second suction head 15B moves to the work pitch conversion position, the work pitch conversion device 10 operates in the state after the pitch conversion shown on the upper side of FIG.

  Specifically, the motor 6 is driven by a command signal from the controller 7 shown in FIG. 1, and the cylindrical cam 5 rotates. As a result, the seven movable stages 2 move in the left-right direction by the cam action of the groove cam 5a and the cam follower 4, and the pitch of the eight pockets 2a including the pockets 2a of the fixed stage 2 'becomes β (> α). . In this way, the eight pockets 2a are in a state after pitch conversion at the same time or earlier than when the second suction head 15B reaches the pocket 2a.

  Therefore, immediately after the second suction head 15B reaches the pocket 2a, the transfer device 15 sucks the eight workpieces 20 arranged in the pitch β and accommodated in the eight pockets 2a (in FIG. 6). Operation Z2) can be carried to the processing device R side ("work alignment position").

  Focusing on the work pitch conversion device 10 in this regard, the work pitch conversion device 10 operates in a very short time from the state before the pitch conversion to the state after the pitch conversion, that is, at a high speed (hereinafter referred to as the state before the pitch conversion and the pitch). The operation between the state after the conversion can be called a pitch conversion operation). Moreover, even if the operation is performed at a high speed, the impact due to the collision between the stages 2 and 2 'does not occur by controlling the rising and falling speeds. Therefore, there is a possibility that the workpiece 20 jumps out of the pocket 2a by the pitch conversion operation. Few.

  When the second suction head 15B moves from the pocket 2a to the processing device R side, the first suction head 15A sucks the next eight workpieces 20 cut by the cutting device F, These workpieces 20 are conveyed toward the workpiece pitch conversion position. Then, while the first suction head 15A moves to the work pitch conversion position (while the second suction head 15B moves to the processing device R), the work pitch conversion device 10 operates again to the state before the pitch conversion.

  By repeating the operations (1) to (3) in this way, the workpieces 20 cut out by 8 in the cutting device F can be conveyed to the processing device R at high speed while changing the arrangement pitch.

  Note that the speed of the pitch converting operation in the work pitch converting apparatus 10, that is, the driving speed of the cylindrical cam 5 by the motor 6, may be controlled by the controller 7 so as to be a speed corresponding to an arbitrary speed input value of the user. Good.

  Further, at the end of the pitch conversion operation, the rotational position of the cylindrical cam 5 is accurately stopped at a position corresponding to the target work pitch, and the possibility that the work 20 jumps out of the pocket 2a due to the shock of the stop is further reduced. In addition, the deceleration control of the motor 6 may be performed immediately before the end of the operation. Furthermore, immediately after the start of the pitch conversion operation, in order to reduce the possibility that the workpiece 20 jumps out of the pocket 2a due to the shock of movement start, gentle acceleration control of the motor 6 may be performed.

  The case where the pitch conversion operation for eight workpieces is performed by the workpiece pitch conversion apparatus 10 provided with the eight stages 2 and 2 ′ has been described above. However, in the work pitch conversion apparatus 10 of the present embodiment, it is also possible to perform the pitch conversion operation for a number of works less than eight. Hereinafter, an example of the pitch conversion operation will be described.

  FIG. 9 shows a case where the pitch (interval) between the two workpieces 20 is changed using the two movable stages 2. Here, the work pitch conversion apparatus 10 of the present embodiment has a structure in which each movable stage 2 can be attached to and detached from the guide rails 3a and 3b and the fixed stage 2 'can be attached to and detached from the main body 1.

  In addition, since the shape of the cam followers 4 provided on all the movable stages 2 and the width of all the groove cams 5a formed on the cylindrical cams 5 are the same as each other, the cam followers 4 of each movable stage 2 are in any groove. The cam 5a can also be engaged. That is, the user can arbitrarily select which groove cam 5a drives each movable stage 2.

  In FIG. 9, two movable stages 2 are provided on the guide rails 3a and 3b, and these movable stages 2 are arranged on the second and third groove cams 5a from the top in FIG. 8 (from the right in FIGS. 2, 3 and 5). This shows a case where the pitch conversion operation is performed using. A rectangular frame in the figure indicates the pocket 2a (that is, a workpiece). In the state before pitch conversion in FIG. 9, the cam follower 4 is positioned at the MIN position of the groove cam 5a, and in this state, the two pockets 2a are positioned close to each other.

  As described above, the first and fourth groove cams 5a have a symmetrical shape with respect to the pitch conversion reference line C. For this reason, the two pockets 2a arranged so as to be symmetric about the pitch conversion reference line C before the pitch conversion are arranged symmetrically about the pitch conversion reference line C even after the pitch conversion. In this way, the pitch (interval) between the two workpieces can be changed without changing their center.

  In FIG. 10, a fixed stage 2 ′ is used, and two movable stages 2 are arranged on both sides of the fixed stage 2 ′. These movable stages 2 are connected to the second and third groove cams 5a from the top in FIG. This shows a case where the pitch conversion operation is performed. In the state before the pitch conversion, the cam follower 4 is positioned closer to the MAX position than the MIN position of the groove cam 5a. In this state, the pockets 2a of the two movable stages 2 are fixed as shown by hatching in the figure. It is located close to the pocket 2a of the stage 2 '.

  As in the case of FIG. 9, the first and fourth groove cams 5 a have a symmetrical shape with respect to the pitch conversion reference line C. For this reason, in the case of FIG. 10, two workpieces before pitch conversion arranged at positions symmetrical with respect to the workpiece on the fixed stage 2 ′ passing through the center of the pitch conversion reference line C are fixed stage 2 ′ after pitch conversion. It is arranged in a symmetrical position with respect to the upper workpiece. In this way, the pitch of the three workpieces can be changed without moving the workpiece arranged at the center thereof.

  In FIG. 11, a fixed stage 2 ′ is used, and two movable stages 2 are arranged on both sides of the fixed stage 2 ′. These four movable stages 2 are first, second, third from the top in FIG. In addition, the pitch conversion operation is performed using the fourth groove cam 5a. In the state before the pitch conversion, the cam follower 4 is positioned closer to the MAX position than the MIN position of the groove cam 5a. In this state, the four movable stages 2 and the five pockets 2a on the fixed stage 2 'are close to each other. Is located.

  Even in this case, the four workpieces before pitch conversion arranged at positions symmetrical with respect to the workpiece on the fixed stage 2 'through which the pitch conversion reference line C passes the center are symmetric with respect to the workpiece on the fixed stage 2' even after pitch conversion. It is arranged in the position. In this way, the pitch of the five workpieces can be changed without moving the workpiece arranged at the center thereof.

  Note that pitch conversion operations other than the examples shown in FIGS. 9 to 11 are also possible. For example, if the three movable stages 2 are driven using the first, third, and sixth groove cams 5a from the top in FIG. 8, three works arranged at equal pitches before pitch conversion can be obtained. The pitch can be changed while maintaining the equal pitch even after the pitch conversion.

  Further, the pitch (interval) between two workpieces may be changed using the fixed stage 2 ′ and one movable stage 2.

In the present embodiment, the center line C is placed between the second and third groove cams 5a so that the second and third groove cams 5a are symmetrical with respect to the fixed stage (center line C). Although set, the fixed stage is not necessarily provided between the second and third groove cams 5a. For example, a fixed stage (center line C) may be disposed between the first and second groove cams. In addition, a fixed stage is provided on the first outer side, and the pitch between the center line C and the plurality of groove cams 5a is set so as to spread toward the opposite side to the center line C side in the direction parallel to the rotation axis. Also good.
In the present embodiment, the work pitch converting apparatus having the seven movable stages 2 driven by the cylindrical cam 5 in which the seven groove cams 5a are formed and the stationary stage 2 'which is stationary is described. The invention is not limited to this, and the number of groove cams and movable stages and whether or not to provide a fixed stage are arbitrary. For example, the present invention also includes a work pitch conversion apparatus having only a plurality of movable stages without providing a fixed stage. In this case, the plurality of cams that drive the plurality of movable stages in the direction parallel to the rotation axis are arranged on the cylindrical cam at an equal pitch and the pitch changes in the rotation direction (decreases toward one of the rotation directions, It may be provided so as to increase toward the other.

  In the present embodiment, the case where the fixed stage is fixed to the main body has been described. However, the cylindrical cam is provided with a groove or rib (projection) having no lift in a direction parallel to the rotation axis, and the groove or A fixing stage may be engaged with the rib. In this case, the grooves or ribs and the plurality of cams may be provided at an equal pitch so that the pitch changes in the rotation direction (decreases toward one side of the rotation direction and increases toward the other side). .

  Further, in this embodiment, the case has been described in which the groove cam 5a is provided in the cylindrical cam 5, and the cam follower 4 provided in the movable stage 2 is inserted inside the groove cam 5a. However, the present invention is not limited to this. For example, a rib-like cam (projection cam) may be provided on the cylindrical surface of the cylindrical cam, and the cam may be sandwiched between a pair of cam followers (rollers) provided on the movable stage.

  Further, only one cam is formed on the cam member (cylindrical cam), and the pitch (interval) between the two workpieces is changed by using one movable stage and a fixed stage that are engaged with the cam. Good.

  Furthermore, although the case where the stage which accommodates a workpiece | work in a pocket was used as a workpiece | work holding member in the said Example, the suction nozzle which adsorb | sucks a workpiece | work under negative pressure is also contained in the workpiece holding member said to this invention. . As a result, the pitch of the plurality of workpieces can be changed during transfer of the plurality of workpieces sucked by the suction nozzle, and can be transferred to a subsequent process.

The side view of the work pitch conversion apparatus which is an Example of this invention. The top view of the work pitch conversion apparatus of an Example. The elements on larger scale of FIG. The front view of the work pitch conversion apparatus of an Example. The rear view of the work pitch conversion apparatus of an Example. Schematic of the conveying apparatus used with the work pitch conversion apparatus of an Example. Schematic which shows the mode of the pitch conversion operation | movement in the work pitch conversion apparatus of an Example. The expanded view of the groove cam provided on the cylindrical cam in the workpiece | work pitch conversion apparatus of an Example. Schematic which shows the usage example in the work pitch conversion apparatus of an Example. Schematic which shows the usage example in the work pitch conversion apparatus of an Example. Schematic which shows the usage example in the work pitch conversion apparatus of an Example.

Explanation of symbols

2 movable stage 2 'fixed stage 2a pocket 3a, 3b guide rail 4 cam follower 5 cylindrical cam 5a groove cam 6 motor 7 controller 8 coupling 10 work pitch conversion device 15 transport device 20 work

Claims (10)

A rotatable member having a plurality of cams, wherein a pitch of the plurality of cams in a direction parallel to the rotation axis is changed in the rotation direction;
A plurality of workpiece holding members that are capable of holding the workpieces, respectively, and that can be engaged with the plurality of cams and move in a direction parallel to the rotation axis as the cam members rotate,
Driving means for rotationally driving the cam member;
And a control means for controlling the rotational position of the cam member via the driving means.   2. The work pitch conversion device according to claim 1, wherein a pitch of the plurality of cams decreases toward one of rotation directions of the cam member and increases toward the other.   2. The work pitch conversion device according to claim 1, wherein pitches of the plurality of cams are equal pitches, decreasing toward one of rotation directions of the cam member and increasing toward the other.   Each of the workpiece holding members can be attached to and detached from the workpiece pitch conversion device, and the number of the workpiece holding members to be used and the structure with which the cam with which the workpiece holding member is engaged can be changed. The work pitch conversion apparatus according to any one of claims 1 to 3.   5. The work pitch conversion apparatus according to claim 1, wherein the control unit controls a rotation speed of the cam member via the driving unit.   6. A fixed work holding member capable of holding a work and having a fixed position in a direction parallel to the rotation axis regardless of the rotation of the cam member. Work pitch conversion device described in 1.   The pitch in the direction parallel to the rotation axis of the position corresponding to the fixed work holding member on the plurality of cams and the cam member is an equal pitch, and decreases toward one of the rotation directions of the cam member, The work pitch conversion apparatus according to claim 6, wherein the work pitch conversion apparatus increases toward the other side.   Among the plurality of workpiece holding members, a first guide member that guides the first workpiece holding member in a direction parallel to the rotation axis, and a second workpiece holding member adjacent to the first workpiece holding member as the rotation shaft. The work pitch conversion device according to claim 1, further comprising: a second guide member that guides in a direction parallel to the workpiece. A rotatable cam member having a cam;
A movable workpiece holding member that can hold the workpiece and slides in a direction parallel to the rotation axis as the cam member rotates by engaging the cam;
A fixed workpiece holding member capable of holding a workpiece and fixed in a direction parallel to the rotation axis regardless of rotation of the cam member;
Driving means for rotationally driving the cam member;
And a control means for controlling the rotational position of the cam member via the driving means. The work pitch conversion device according to any one of claims 1 to 9,
A plurality of workpieces are conveyed to the workpiece pitch conversion device at a first arrangement pitch, and the plurality of workpieces changed to a second arrangement pitch different from the first arrangement pitch by the workpiece pitch conversion device are conveyed. A work transfer system comprising a transfer device.