Torque transmission device, and tape feeder

Abstract

To provide a torque transmission device capable of achieving a more compact size, and a tape feeder.SOLUTION: A torque transmission device 70 includes: a wheel 60 that has a cylindrical shaft part 81 extending along the rotation axis JX and is rotatable freely on the rotation axis JX; a first gear 61 that is rotatable freely on the rotation axis JX, and is rotatable freely relative to the wheel 60; and two plate springs 71 having a C-shaped portion 71c that is formed to have an overall C-shape, into which the shaft part 81 is inserted. The two plate springs 71 are each restricted from rotating on the rotation axis JX relative to the first gear 61. When the driving wheel 60 rotates, the rotational torque is transmitted to the first gear 61 as the driven gear via the friction between the inner edge 71N of the two plate springs 71 and the outer surface 81M of the shaft part 81.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present disclosure relates to a torque transmission device that transmits torque between two rotating bodies that are provided rotatably around the same rotation axis, and a tape feeder that includes this torque transmission device. [Background technology]

[0002] Conventionally, tape feeders have been known as one type of parts feeder for component mounting devices. Tape feeders are configured to transport a carrier tape, which has pockets containing components covered with cover tape, toward a component removal position. The cover tape is peeled off before the components in the pockets reach the component removal position, and the cover tape is fed to a cover tape storage section while being sandwiched between a cover tape feed section consisting of multiple rollers (for example, see Patent Document 1 below).

[0003] Because the cover tape feeding unit needs to feed the cover tape without affecting the feeding of the carrier tape, a torque limiting mechanism is used to limit the drive torque when tension acts on the feed cover tape. A known torque limiting mechanism for this purpose includes an inner member rotatable about the same axis of rotation, an outer member covering the inner member, and a coil spring inserted into the inner member and elastically abutting against the inner circumferential surface of the outer member (see, for example, Patent Document 2 below). In this torque limiting mechanism, torque is transmitted between the inner member and the outer member via the coil spring. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-125627 [Patent Document 2] Japanese Patent Application Laid-Open No. 2002-303335 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the torque transmission device equipped with the above-described conventional torque limiting mechanism has a problem in that the size of the device is large because the dimensions of the coil spring itself are large.

[0006] Therefore, an object of the present disclosure is to provide a torque transmission device and a tape feeder that can be made compact in size. [Means for solving the problem]

[0007] The torque transmission device of the present disclosure comprises a first rotating body that is rotatable about a rotation axis and has a cylindrical shaft portion extending along the rotation axis, a second rotating body that is rotatable about the rotation axis and is rotatable relative to the first rotating body, and a plurality of leaf springs that are formed into a C-shape overall and have the shaft portions inserted into the C-shaped portions, and the rotation of each of the plurality of leaf springs about the rotation axis relative to the second rotating body is restricted, and when the driving side of the first rotating body or the second rotating body rotates, the rotational torque is transmitted to the driven side of the first rotating body or the second rotating body through friction between the inner edges of the plurality of leaf springs and the outer peripheral surface of the shaft portion.

[0008] The torque transmission device of the present disclosure also includes a first rotating body that is rotatable about a rotation axis and has a cylindrical shaft portion extending along the rotation axis; a second rotating body that is rotatable about the rotation axis and rotatable relative to the first rotating body and has a hollow cylindrical portion that protrudes and extends toward the first rotating body; and a plurality of leaf springs that are formed into a C-shape overall, with the shaft portion inserted into the C-shaped portion, wherein rotation of each of the plurality of leaf springs about the rotation axis relative to the shaft portion is restricted, and when the driving side of the first rotating body or the second rotating body rotates, the rotational torque is transmitted to the driven side of the first rotating body or the second rotating body through friction between the outer edges of the plurality of leaf springs and the inner surface of the cylindrical portion of the second rotating body.

[0009] The tape feeder of the present disclosure also includes a conveying unit that conveys a carrier tape, which has pockets containing components covered with cover tape, toward a component removal position; a cover tape feeding unit that feeds the cover tape that has been peeled off from the carrier tape by rotating a plurality of rollers while holding the cover tape before the carrier tape conveyed by the conveying unit reaches the component removal position; and the torque transmission device of the present disclosure, wherein the cover tape feeding unit is driven by rotational torque output from the driven side of the first rotating body and the second rotating body provided in the torque transmission device. [Effects of the Invention]

[0010] According to the present disclosure, the torque transmission device and the tape feeder can be made compact in size. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a side view of a component mounting device including a tape feeder according to an embodiment of the present disclosure; [Figure 2] FIG. 1 is a perspective view showing a carrier tape used in a tape feeder according to an embodiment of the present disclosure, together with a reel; [Figure 3] FIG. 1 is a side view of a tape feeder according to an embodiment of the present disclosure. [Figure 4] FIG. 10 is a side view of a portion of a cover tape provided in a tape feeder according to an embodiment of the present disclosure. [Figure 5] 1 is a side view of a portion of a tape feeder according to an embodiment of the present disclosure; [Figure 6] FIG. 1 is a perspective view of a portion of a tape feeder according to an embodiment of the present disclosure. [Figure 7] 1A is a perspective view of a torque transmission device provided in a tape feeder according to an embodiment of the present disclosure; FIG. 1B is an exploded perspective view of the torque transmission device; [Figure 8] FIG. 1 is a side cross-sectional view of a torque transmission device provided in a tape feeder according to an embodiment of the present disclosure. [Figure 9]9 is a cross-sectional view of the torque transmission device provided in the tape feeder according to the embodiment of the present disclosure, taken along the line V1-V1 in FIG. 8; [Figure 10] 9 is a cross-sectional view of the torque transmission device provided in the tape feeder according to the embodiment of the present disclosure, taken along the line V2-V2 in FIG. 8 . [Figure 11] 1A and 1B are side views of a portion of a tape feeder showing a state in which a cover tape provided in the tape feeder is peeled off from a carrier tape according to an embodiment of the present disclosure; [Figure 12] 1A and 1B are diagrams illustrating a relationship between two leaf springs and a shaft portion of a torque transmission device provided in a tape feeder according to an embodiment of the present disclosure; [Figure 13] 1A and 1B are diagrams schematically illustrating the relationship between two leaf springs and a shaft portion as a reference example different from the torque transmission device provided in the tape feeder according to the embodiment of the present disclosure; [Figure 14] 10A and 10B are graphs showing changes in output torque output from a torque transmission device provided in a tape feeder according to an embodiment of the present disclosure. [Figure 15] FIG. 10 is an exploded perspective view of a torque transmission device provided in a tape feeder according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, with reference to the accompanying drawings, detailed descriptions of embodiments that specifically disclose the configuration and operation of a printing device and a printing method according to the present disclosure will be provided. However, unnecessary detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or redundant descriptions of substantially identical configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art. Note that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure and are not intended to limit the subject matter recited in the claims.

[0013] Fig. 1 shows a component mounting apparatus 1 equipped with a tape feeder according to an embodiment of the present disclosure. Fig. 1 is a side view of the component mounting apparatus 1 equipped with a tape feeder 13 according to an embodiment of the present disclosure. The component mounting apparatus 1 is an apparatus that repeatedly performs a component mounting operation of mounting components BH onto a board KB sent from an upstream process side and carrying the board out to a downstream process side.

[0014] The component mounting device 1 includes a pair of conveyors 12 that transport a substrate KB onto a base 11, the above-mentioned tape feeder (referred to as "13") that supplies components BH to a component removal position 13K by transporting a carrier tape CT containing the components BH, and a mounting head 15 that is moved in a horizontal plane by a head moving mechanism 14 provided on the base 11.

[0015] FIG. 2 is a perspective view showing the carrier tape CT used in the tape feeder 13 according to an embodiment of the present disclosure, together with a reel RL. As shown in FIG. 2, the carrier tape CT has a plurality of pockets PK and sprocket holes KH arranged in a row, with a cover tape TT attached to its upper surface. Each pocket PK contains one component BH, which is sealed with the cover tape TT. The carrier tape CT is wound around the reel RL. The tape feeder 13 is detachably attached to a feeder base 11F (FIG. 1) connected to the base 11, and pulls out the carrier tape CT from the reel RL for transport.

[0016] The head movement mechanism 14 is composed of, for example, an XY table mechanism. The mounting head 15 is equipped with multiple nozzles 15N extending downward, and the lower end of each nozzle 15N is capable of generating a vacuum suction force. The mounting head 15 is moved by the head movement mechanism 14 to pick up components BH supplied by the tape feeder 13, and then moves above the board KB to repeatedly perform a mounting turn in which the components BH are mounted onto the board KB. Once the mounting head 15 has repeatedly performed the mounting turns and all of the components BH to be mounted on the board KB, the conveyor 12 is activated and the board KB is transported to the downstream process side. This completes the component mounting operation for one board KB.

[0017] This embodiment is characterized by the configuration of tape feeder 13, which will be described below. For ease of explanation, the left-right direction of tape feeder 13 as seen from the operator OP when attached to feeder base 11F of component mounting device 1 is referred to as the X direction, the front-to-back direction as seen from the operator OP as the Y direction, and the up-to-down direction as the Z direction. In addition, within the Y direction, the back side as seen from the operator OP is referred to as the "front," and the front side as seen from the operator OP as the "rear."

[0018] Fig. 3 is a side view of tape feeder 13 according to an embodiment of the present disclosure. In Fig. 3, tape feeder 13 includes a main body 21 attached to feeder base 11F and a tape cover 22 attached to the upper front portion of main body 21. A transport path 31 for carrier tape CT is formed within main body 21. An opening of transport path 31 on the rear side of main body 21 serves as an inlet (tape inlet 31a) for carrier tape CT, and an opening on the front side of main body 21 serves as an outlet (tape outlet 31b) for carrier tape CT.

[0019] Tape cover 22 is made of a generally plate-shaped member provided at the upper front (downstream side) of main body 21, and is provided in a position so as to cover from above the portion of conveying path 31 that is exposed on the upper surface of main body 21. Tape cover 22 is provided with a component removal opening (not shown) that penetrates through the thickness at a position corresponding to component removal position 13K.

[0020] 3, a transport unit 32 for the carrier tape CT is provided within the main body 21. The transport unit 32 has three sprockets, in order from the upstream side (the left side of the paper in FIG. 3), namely, an introduction sprocket 33, a positioning sprocket 34, and a discharge sprocket 35. These three sprockets are driven in the same direction (clockwise in FIG. 3) by a motor 36 provided within the main body 21 via a transmission gear mechanism 37.

[0021] The three sprockets (introduction sprocket 33, positioning sprocket 34, and discharge sprocket 35) that make up the transport section 32 all have engagement pins on their outer peripheries positioned within the transport path 31. Each of the three sprockets is driven by a motor 36 to rotate, and transports the carrier tape CT by engaging the engagement pins on their outer peripheries with the feed holes KH of the carrier tape CT within the transport path 31. The carrier tape CT inserted into the transport path 31 from the tape inlet 31a is transported downstream by the introduction sprocket 33, positioning sprocket 34, and discharge sprocket 35 in this order, passing below the tape cover 22 and being discharged from the tape outlet 31b.

[0022] Before the carrier tape CT reaches the component take-out position 13K, the cover tape TT is peeled off from the carrier tape CT by a peeling mechanism 38 located upstream of the component take-out position, and then sent by a cover tape feed unit 39 to a cover tape storage unit 40 provided in the main body 21 (FIG. 3). Therefore, when the component BH reaches the component take-out position 13K, it is exposed in the pocket PK of the carrier tape CT.

[0023] The component BH, which is exposed in the pocket PK after the cover tape TT is peeled off from the carrier tape CT, is positioned at the component removal position 13K (directly below the component removal opening) by the positioning sprocket 34. This allows the mounting head 15 to remove the component BH positioned at the component removal position 13K from the pocket PK through the component removal opening.

[0024] Fig. 4 is a side view of a portion of cover tape TT provided in tape feeder 13 according to an embodiment of the present disclosure. In Fig. 4, peeling mechanism 38 is composed of tape presser 41 that presses carrier tape CT traveling on transport path 31 toward transport path 31, and air jetting unit 42 located below transport path 31 within main body 21. Tape presser 41 is provided with cover tape passing hole 41H penetrating in the thickness direction, and the downstream edge of cover tape passing hole 41H forms sharpened portion 41E that tapers toward the upstream side, and air jetting unit 42 is provided below cover tape passing hole 41H.

[0025] 4, the cover tape feeding section 39 includes a drive roller 51, a first driven roller 52, and a second driven roller 53. The first driven roller 52 is located downstream of the drive roller 51 and is in circumferential contact (mesh) with the drive roller 51. The second driven roller 53 is located above the drive roller 51 and is in circumferential contact (mesh) with the drive roller 51. When the drive roller 51 rotates, the first driven roller 52 and the second driven roller 53 each rotate in the opposite direction to the drive roller 51.

[0026] 4, a guide portion 54 is provided on the side of the first driven roller 52. The guide portion 54 has a guide surface 54G between the drive roller 51 and the first driven roller 52 that guides the cover tape TT peeled off from the carrier tape CT upstream.

[0027] Figure 5 is a side view of a portion of tape feeder 13 according to an embodiment of the present disclosure. Figure 6 is a perspective view of a portion of tape feeder 13 according to an embodiment of the present disclosure. In Figures 5 and 6, wheel 60 is disposed above introduction sprocket 33 within main body 21. Wheel 60 is located above introduction sprocket 33 across conveyance path 31, and is rotatable about rotation axis JX extending in the X-axis direction.

[0028] 4 and 5, wheel 60 has a plurality of pin engagement portions 60B on its outer periphery. When lead sprocket 33 rotates, feed pins 33P (FIGS. 4 and 5) provided on its outer periphery engage with pin engagement portions 60B of wheel 60. As a result, wheel 60 rotates in synchronization with lead sprocket 33, pitching in the opposite direction to lead sprocket 33.

[0029] 5 and 6, a first gear 61 is provided on the side of the wheel 60. The first gear 61 is arranged to rotate around the same rotation axis JX as the wheel 60. The wheel 60 and the first gear 61 are relatively rotatable around the rotation axis JX, and rotational torque is transmitted from the wheel 60 to the first gear 61 via a torque transmission device, which will be described later. The wheel 60, rotated by the lead-in sprocket 33, functions as a driving rotating body, and the first gear 61 functions as a driven rotating body.

[0030] 5 and 6, a second gear 62 is disposed downstream of the first gear 61, and a third gear 63 is disposed downstream of the second gear 62. The second gear 62 meshes with the first gear 61 and rotates in the opposite direction to the first gear 61. The third gear 63 meshes with the second gear 62 and rotates in the opposite direction to the second gear 62 (the same direction as the first gear 61).

[0031] 5 and 6, the aforementioned drive roller 51 that constitutes the cover tape feed section 39 is disposed to the side of the third gear 63. The drive roller 51 is provided coaxially with the third gear 63, and when the third gear 63 rotates, the drive roller 51 rotates integrally with the third gear 63 in the same direction as the first gear 61. The first gear 61 rotates in the same direction as the wheel 60, and the wheel 60 rotates in the opposite direction to the lead-in sprocket 33, so the drive roller 51 rotates in the opposite direction to the lead-in sprocket 33.

[0032] 4 (indicated by arrow R1 in the figure), the drive roller 51 rotates counterclockwise (indicated by arrow R2 in the figure), and the first driven roller 52 and second driven roller 53 rotate clockwise (indicated by arrow R3 in the figure). In this way, the multiple rollers (drive roller 51, first driven roller 52, and second driven roller 53) that make up the cover tape feed unit 39 are pitch-driven synchronously (i.e., at the same timing) by the same motor 36 that drives the three sprockets (indicated by entrance sprocket 33, positioning sprocket 34, and discharge sprocket 35) that make up the conveying unit 32.

[0033] Here, we will explain the aforementioned torque transmission device 70 that outputs the rotational torque to be applied to the drive roller 51 of the cover tape feeding section 39. Fig. 7(a) is a perspective view of the torque transmission device 70 provided in the tape feeder 13 according to an embodiment of the present disclosure. Fig. 7(b) is an exploded perspective view of the torque transmission device 70 provided in the tape feeder 13 according to an embodiment of the present disclosure. Fig. 8 is a side cross-sectional view of the torque transmission device 70 provided in the tape feeder 13 according to an embodiment of the present disclosure.

[0034] As shown in FIG. 7(a), the torque transmission device 70 is configured to have a wheel 60 as a first rotating body, a first gear 61 as a second rotating body, and multiple (here, two) leaf springs 71.

[0035] 7(b) and 8, the wheel 60 has a hollow cylindrical shaft portion 81 extending from its center along the rotation axis JX (in the X direction). The shaft portion 81 passes through a shaft portion insertion hole 61E formed in the center of the first gear 61 in the direction along the rotation axis JX. A shaft member SFT extending in the direction along the rotation axis JX is inserted into the shaft portion 81 (FIGS. 7(a) and 8).

[0036] In Figure 7(b), each of the two leaf springs 71 has a C-shaped portion 71c formed into an overall C-shape. A shaft portion 81 is inserted into the C-shaped portion 71c of each leaf spring 71 (see also Figure 8), and the two leaf springs 71 are positioned side by side in the direction in which the rotation axis JX extends (X direction) with their inner edges 71N (Figure 7(b)) in contact with the outer peripheral surfaces 81M of the shaft portions 81. Hereinafter, of the two leaf springs 71, the leaf spring 71 located on the wheel 60 side will be referred to as the "first leaf spring 71a," and the leaf spring 71 located on the first gear 61 side will be referred to as the "second leaf spring 71b."

[0037] The shaft portion 81 is press-fitted into the C-shaped portions 71c of the two leaf springs 71 (first leaf spring 71a and second leaf spring 71b), and the inner edges 71N of each leaf spring 71 are in elastic contact with the outer peripheral surface 81M of the shaft portion 81. Therefore, an elastic pressing force acts on the outer peripheral surface 81M of the shaft portion 81 from the inner edges 71N of each leaf spring 71.

[0038] In FIG. 7(b), each leaf spring 71 has an engagement protrusion 71T that protrudes outward from the outer edge 71G at a middle portion of the C-shaped portion 71c along the circumferential direction centered on the rotation axis JX. Meanwhile, the cylindrical portion 82 has a plurality of protrusion engagement holes 82H (here, two, the same as the number of leaf springs 71) at a position facing its inner circumferential surface 82M. Each leaf spring 71 has the engagement protrusion 71T engaged with the protrusion engagement hole 82H of the cylindrical portion 82. Therefore, rotation of each of the two leaf springs 71 around the rotation axis relative to the cylindrical portion 82 (i.e., movement in the circumferential direction centered on the rotation axis JX) is restricted. Hereinafter, the term "circumferential direction" will be understood to mean "the circumferential direction centered on the rotation axis JX."

[0039] 9 is a cross-sectional view taken along the line V1-V1 in FIG. 8 of torque transmission device 70 included in tape feeder 13 according to an embodiment of the present disclosure. As shown in FIGS. 8 and 9 (cross-sectional views taken along the line V1-V1 in FIG. 8), the positions of protrusion engagement holes 82H to which two leaf springs 71 are attached are offset from each other in the circumferential direction of inner circumferential surface 82M of cylindrical portion 82. That is, two leaf springs 71 are attached at positions offset from each other in the circumferential direction about rotation axis JX. In this embodiment, two leaf springs 71 are attached at positions offset from each other in the circumferential direction about rotation axis JX by an equal phase difference, the difference being 180 degrees.

[0040] Figure 10 is a cross-sectional view of torque transmission device 70 provided in tape feeder 13 according to an embodiment of the present disclosure, taken along line V2-V2 in Figure 8. In Figures 9 and 10 (cross-sectional views taken along line V2-V2 in Figure 8), not the entire inner edge 71N of each of two leaf springs 71 abuts against outer peripheral surface 81M of shaft portion 81, but only partial contact at multiple locations. More specifically, the inner edge 71N of C-shaped portion 71c of each leaf spring 71 abuts against outer peripheral surface 81M of shaft portion 81 in the area close to engagement protrusion 71T, but because both ends of C-shaped portion 71c are displaced (elastically deformed) in a direction opening outward, the inner edges 71N at both ends of C-shaped portion 71c do not abut against outer peripheral surface 81M of shaft portion 81.

[0041] The region indicated by the symbol P1 in Fig. 10 indicates the location where the inner edge 71N of the first leaf spring 71a, which is located on the wheel 60 side of the two leaf springs 71, abuts against the outer peripheral surface 81M of the shaft portion 81, and the region indicated by the symbol P2 in Fig. 9 indicates the location where the inner edge 71N of the second leaf spring 71b, which is located on the first gear 61 side of the two leaf springs 71, abuts against the outer peripheral surface 81M of the shaft portion 81. In this manner, in this embodiment, the locations where the inner edge 71N of the first leaf spring 71a, which is located on the wheel 60 side, abuts against the outer peripheral surface 81M of the shaft portion 81 (two locations P1) are different from the locations where the inner edge 71N of the second leaf spring 71b, which is located on the first gear 61 side, abuts against the outer peripheral surface 81M of the shaft portion 81 (two locations P2).

[0042] As described above, the positions where the inner edges 71N of the two leaf springs 71 abut against the outer peripheral surface 81M of the shaft portion 81 are different from each other because the two leaf springs 71 are attached at positions that are out of phase with each other along the circumferential direction. If the two leaf springs 71 were attached at positions that were in the same phase along the circumferential direction, the positions where the inner edges 71N of the two leaf springs 71 abut against the outer peripheral surface 81M of the shaft portion 81 would be the same for the two leaf springs 71.

[0043] In the torque transmission device 70 configured as described above, when the wheel 60, which is the rotating body on the driving side, receives power from the motor 36 and rotates (pitch rotates), the shaft portion 81 of the wheel 60 rotates (pitch rotates) about the rotation axis JX. With the engagement protrusions 71T attached to the cylindrical portions 82 of the two leaf springs 71, the inner edges 71N of the C-shaped portions 71c elastically abut against the outer peripheral surface 81M of the shaft portion 81. Therefore, when the wheel 60 pitch rotates as the driving side, the rotational torque is transmitted to the first gear 61 through friction (via frictional force) between the inner edges 71N of the two leaf springs 71 and the outer peripheral surface 81M of the shaft portion 81 of the wheel 60, and the first gear 61 on the driven side rotates (pitch rotates) together with the wheel 60.

[0044] As described above, when the rotational torque of the shaft portion 81 is transmitted to the first gear 61 via the two leaf springs 71, the first gear 61 outputs the rotational torque as the output portion of the torque transmission device 70. When the first gear 61 outputs the rotational torque, the rotational torque is transmitted to the second gear 62 meshed with the first gear 61, and then the rotational torque is transmitted from the second gear 62 to the third gear 63 meshed with the second gear 62, and from the third gear 63 to the drive roller 51, and finally the first driven roller 52 and second driven roller 53 meshed with the drive roller 51 rotate (pitch rotate).

[0045] When causing the tape feeder 13 to perform a component supply operation, the operator OP first pulls out the leading end of the carrier tape CT from the reel RL. Then, as shown in Figure 2, the operator OP processes the cover tape TT so that the leading end extends beyond the leading end of the carrier tape CT, and then inserts the leading end of the carrier tape CT into the tape inlet 31a of the tape feeder 13. The portion of the cover tape TT that extends beyond the leading end of the carrier tape CT as described above will hereinafter be referred to as the "extending portion ES" of the cover tape TT.

[0046] When the carrier tape CT is inserted into the tape entrance 31a, it is drawn into the transport path 31 by the aforementioned transport unit 32 provided in the main body 21 of the tape feeder 13. Then, when the leading end of the carrier tape CT reaches the introduction sprocket 33 and the feed holes KH in the leading end of the carrier tape CT engage with the feed pins 33P of the introduction sprocket 33, the motor 36 rotates the three sprockets (the introduction sprocket 33, the positioning sprocket 34, and the discharge sprocket 35). As a result, the carrier tape CT is transported downstream (towards the tape exit 31b).

[0047] 11(a) and 11(b) are side views of a portion of tape feeder 13 showing how cover tape TT provided in tape feeder 13 according to an embodiment of the present disclosure is peeled off from carrier tape CT. When the leading end of carrier tape CT conveyed by conveying unit 32 reaches between lead-in sprocket 33 and positioning sprocket 34, air blowing unit 42 blows air 42A upward (FIG. 11(a)). This causes extension portion ES of cover tape TT to be blown upward and pass upward through cover tape passing hole 41H provided in tape presser 41. Then, after passing upward through cover tape passing hole 41H, extension portion ES of cover tape TT is sandwiched and captured by drive roller 51 and first driven roller 52 driven by torque transmission device 70 (FIG. 11(a)).

[0048] After the extension ES of the cover tape TT is sandwiched and captured between the drive roller 51 and the first driven roller 52, the carrier tape CT is transported pitch by the transport unit 32, and the cover tape TT is peeled off from the carrier tape CT by the sharpened portion 41E of the tape presser 41, which is inserted between the carrier tape CT and the cover tape TT. By peeling the cover tape TT from the carrier tape CT, the components BH in the pockets PK of the carrier tape CT are exposed.

[0049] The cover tape TT, which has been peeled off from the carrier tape CT and captured by the drive roller 51 and the first driven roller 52, is sent upward, but is guided by the guide surface 54G of the guide section 54 located further ahead and directed upstream (FIG. 11(a) → FIG. 11(b)). The cover tape TT directed upstream is then sandwiched between the drive roller 51 and the second driven roller 53 meshing therewith and sent upstream (FIG. 11(b)), where it is stored in the cover tape storage section 40. The cover tape TT stored in the cover tape storage section 40 is then removed from the main body section 21 by the operator OP and discarded.

[0050] The cover tape feed unit 39 is configured to feed the cover tape TT at the same time that the conveying unit 32 conveys the carrier tape CT, but since the drive roller 51 and the first driven roller 52 attempt to feed the cover tape TT at a speed faster than the speed at which the conveying unit 32 conveys the carrier tape CT, tension acts on the cover tape TT sandwiched between the drive roller 51 and the first driven roller 52.

[0051] When tension acts on the cover tape TT as described above, the first gear 61, which is mechanically coupled to the drive roller 51 via multiple gears (the second gear 62 and the third gear 63 described above), is subjected to a large load. As a result, slippage occurs between the inner edges 71N of the two leaf springs 71 attached to the first gear 61 and the outer circumferential surface 81M of the shaft portion 81 with which the inner edges 71N are in contact. When slippage occurs between the inner edges 71N of the leaf springs 71 and the outer circumferential surface 81M of the shaft portion 81, the first gear 61 no longer follows the rotation of the wheel 60. This limits the rotational torque transmitted from the wheel 60 to the first gear 61, preventing the drive roller 51 and the first driven roller 52 from pulling the cover tape TT with excessive force and tearing the cover tape TT off.

[0052] In this embodiment, the wheel 60, first gear 61 and two leaf springs 71 that constitute the torque transmission device 70 are equipped with a torque limiting function that limits the rotational torque transmitted from the wheel 60, which is the driving rotating body, to the first gear 61, which is the driven rotating body.

[0053] As described above, tape feeder 13 in this embodiment includes: conveying unit 32 that conveys carrier tape CT, which has pockets PK storing components BH and covered with cover tape TT, toward component take-out position 13K; cover tape feed unit 39 that feeds cover tape TT peeled from carrier tape CT by rotating multiple rollers (here, drive roller 51 and first driven roller 52) while sandwiching cover tape TT between carrier tape CT conveyed by conveying unit 32 before it reaches component take-out position 13K; and torque transmission device 70 with the torque limiting function. Cover tape feed unit 39 is driven by rotational torque output from first gear 61, which is the driven side of wheel 60 and first gear 61 provided in torque transmission device 70.

[0054] In the torque transmission device 70 of this embodiment, when slippage occurs between the inner edges 71N of the two leaf springs 71 and the outer peripheral surface 81M of the shaft portion 81 as described above, the wheel 60 and the first gear 61 begin to rotate relative to each other, and the inner edges 71N of the two leaf springs 71 slide along the shape of the outer peripheral surface 81M of the shaft portion 81. Although it depends on the processing accuracy of the shaft portion 81, the cross-sectional shape of the outer peripheral surface 81M of the shaft portion 81 is generally not an exact circle, but has distorted portions that are distorted from an exact circle.

[0055] As described above, when the wheel 60 (i.e., the axle 81) rotates in a state in which the outer circumferential surface of the axle 81 has a distorted portion that is distorted from a precise circle, each of the two leaf springs 71 is intermittently elastically pressed outward in the radial direction of the axle 81 (i.e., toward the inner circumferential surface 82M of the cylindrical portion 82) by the distorted portion of the axle 81. Meanwhile, as a reaction force, the axle 81 is intermittently pressed by the two leaf springs 71 with a pressing force that is greater than normal. The moment the axle 81 receives a pressing force greater than normal from the two leaf springs 71, the outer circumferential surface 81M of the axle 81 and the inner edge 71N of the leaf spring 71, which had been sliding until then, instantly stop sliding, and the axle 81 is instantly connected to the leaf springs 71.

[0056] In this embodiment, as described above, the two leaf springs 71 are attached at positions that are out of phase with each other in the circumferential direction, and therefore, compared to when the two leaf springs 71 are attached at positions that are not out of phase with each other in the circumferential direction (positions that are in the same phase with each other in the circumferential direction), the maximum value of the pressing force that the axle 81 receives from the two leaf springs 71 can be reduced while the minimum value can be increased (i.e., the amount of fluctuation can be reduced), and as a result, the amount of fluctuation in the torque transmitted between the axle 81 and the wheel 60 is leveled out. The principle will be explained below using Figures 12(a) and (b), 13(a) and (b), and 14(a) and (b).

[0057] Figures 12(a) and 12(b) are diagrams schematically showing the relationship between two leaf springs 71 and shaft portion 81 of torque transmission device 70 provided in tape feeder 13 according to an embodiment of the present disclosure. Figures 13(a) and 13(b) are diagrams schematically showing the relationship between two leaf springs 71 and shaft portion 81 as a reference example different from torque transmission device 70 provided in tape feeder 13 according to an embodiment of the present disclosure. Figures 14(a) and 14(b) are graphs showing changes in output torque output from torque transmission device 70 provided in tape feeder 13 according to an embodiment of the present disclosure.

[0058] 12(a) and 12(b) schematically illustrate a state in which the circumferential mounting positions of two leaf springs 71 are offset from each other (the state of this embodiment), and FIGS. 13(a) and 13(b) schematically illustrate a state in which two leaf springs 71 are mounted in the same circumferential position as a reference example of this embodiment. To facilitate understanding of the principle, the cross section of the shaft portion 81, which is originally circular, is shown as a triangular shape. The two leaf springs 71 are both fixed, and when the shaft portion 81 rotates relative to the leaf springs 71, the shaft portion 81 rotates about the rotation axis JX (therefore, rotation of the triangular shaft portion 81 means that the shaft portion 81 rotates relative to the two leaf springs 71). In these figures, the points where each leaf spring 71 abuts against the three vertices of the triangle are the points where the shaft portion 81 presses with the greatest force (pressing points). Each leaf spring 71 receives a reaction force from the leaf spring 71 at the pressed portion, and the end side portion of the C-shaped portion 71c is elastically deformed so as to spread outward.

[0059] 12(a) and 12(b) and 13(a) and 13(b), the point where the inner edge 71N of the first leaf spring 71a abuts against the outer peripheral surface 81M of the shaft portion 81 is indicated by the symbol "P1," as in Figures 9 and 10. Also, the point where the inner edge 71N of the second leaf spring 71b abuts against the inner edge 71N of the shaft portion 81 is indicated by the symbol "P2," as in Figure 9.

[0060] 13(a) and 13(b), the inner edges 71N of the two leaf springs 71 contact the outer peripheral surface 81M of the shaft portion 81 at the same locations (P1 and P2 are aligned). The two leaf springs 71 press the outer peripheral surface 81M of the shaft portion 81 at the same locations with the same pressing force, so that the shaft portion 81 receives a pressing force from the two leaf springs 71 that is approximately twice the pressing force of a single leaf spring 71.

[0061] 12(a) and 12(b), when the two leaf springs 71 are attached at positions that are offset from each other in the circumferential direction, different points on the inner edges 71N of the two leaf springs 71 abut against the outer peripheral surface 81M of the shaft portion 81 (P1 and P2 do not coincide). Then, the two leaf springs 71 press different points on the outer peripheral surface 81M of the shaft portion 81 with the pressing force of one leaf spring 71 at each abutment point, so that the shaft portion 81 receives pressing forces from each of the two leaf springs 71, the magnitude of which corresponds to the pressing force of one leaf spring 71 at each pressing point.

[0062] 14(a) and (b) are graphs showing the change in output torque (the change in torque when slippage occurs between the inner edge 71N of the leaf spring 71 and the outer peripheral surface 81M of the shaft portion 81) of the driven-side rotating body (the rotational torque of the first gear 61) relative to the driving-side rotating body (the wheel 60) in response to the change in the relative rotation angle of the driven side relative to the driving side. Fig. 14(a) is a graph corresponding to Figs. 12(a) and (b) (i.e., corresponding to this embodiment), and Fig. 14(b) is a graph corresponding to Figs. 13(a) and (b) (i.e., corresponding to the reference example).

[0063] As can be seen from these graphs, the fluctuation amount T1 of the output torque when the two leaf springs 71 are mounted at positions offset from each other along the circumferential direction, as in this embodiment (FIG. 14(a)), is smaller than the fluctuation amount T2 of the output torque when the two leaf springs 71 are mounted at positions in the same phase along the circumferential direction, as in the reference example (FIG. 14(b)).

[0064] From the above, when the two leaf springs 71 are attached at positions offset from each other along the circumferential direction (as in the present embodiment), the amount of fluctuation in the torque transmitted between the shaft 81 and the wheel 60 is leveled out more than when the two leaf springs 71 are attached at positions in the same phase along the circumferential direction (as in the reference example). Therefore, according to the present embodiment, the torque transmitted between the shaft 81 and the wheel 60 is stabilized, and slippage occurs between them at a torque lower than the expected limit torque (slip torque), which prevents the necessary pulling force from being exerted when peeling the cover tape TT, causing the feed speed of the cover tape TT to slow down relative to the transport speed of the carrier tape CT, and preventing the cover tape TT from jamming near the position where it is peeled from the carrier tape CT.

[0065] 14(a) and 14(b), when the two leaf springs 71 are attached at positions offset from each other in the circumferential direction (as in the present embodiment), the frequency of torque fluctuation increases compared to when the two leaf springs 71 are attached at positions in the same phase in the circumferential direction (as in the reference example). This is because the inner edges 71N of the two leaf springs 71 abut against the outer peripheral surface 81M of the shaft portion 81 at different points. However, as long as the transmission torque can be leveled out, the increased frequency of torque fluctuation does not pose any particular problem.

[0066] As described above, torque transmission device 70 in this embodiment includes wheel 60 as a first rotating body that is rotatable about rotation axis JX and has a cylindrical shaft portion 81 extending along rotation axis JX, first gear 61 as a second rotating body that is rotatable about rotation axis JX and rotatable relative to wheel 60, and a plurality of leaf springs 71, each having a C-shaped portion 71c that is formed into a C-shape as a whole, through which shaft portion 81 is inserted. Rotation of each of the plurality of leaf springs 71 about rotation axis JX relative to first gear 61 is restricted, and when a driving side of wheel 60 or first gear 61 rotates, the rotational torque is transmitted to the driven side of wheel 60 or first gear 61 through friction (via frictional force) between inner edges 71N of the plurality of leaf springs 71 and the outer peripheral surface 81M of shaft portion 81. In the torque transmission device 70 of this embodiment, torque limitation is achieved by using multiple thin leaf springs 71 instead of large coil springs to transmit torque between the wheel 60 and the first gear 61, which allows the size of the torque transmission device 70, and therefore the size of the tape feeder 13, to be made compact.

[0067] Furthermore, in the torque transmission device 70 according to the embodiment, the plurality of leaf springs 71 are attached at positions that are out of phase with one another along the circumferential direction centered on the rotation axis JX. This makes it possible to level out the amount of fluctuation in the torque transmitted between the shaft portion 81 and the wheel 60, and to stabilize the torque transmitted between the shaft portion 81 and the wheel 60, thereby preventing the cover tape TT from jamming near the position where it is peeled off from the carrier tape CT.

[0068] While the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above and various modifications are possible. For example, in the above-described embodiment, the outer edges 71G of the C-shaped portions 71c of the plurality of leaf springs 71 are attached to the first gear 61, and torque is transmitted through friction between the inner edges 71N of the C-shaped portions 71c and the outer peripheral surface 81M of the shaft portion 81. However, the plurality of leaf springs 71 may be attached to the shaft portion 81, and torque may be transmitted through friction between the outer edges 71G of the C-shaped portions 71c and the inner peripheral surface 82M of the cylindrical portion 82 of the first gear 61.

[0069] Figure 15 is an exploded perspective view of torque transmission device 70 included in tape feeder 13 according to a modified example of an embodiment of the present disclosure. In such a case, for example, as shown in the modified example of Figure 15, a protrusion 71S that protrudes toward shaft portion 81 may be provided on inner edge 71N of each of a plurality of (two) leaf springs 71, and a protrusion engagement groove 81K may be provided on shaft portion 81, and protrusion 71S of each leaf spring 71 may be engaged with protrusion engagement groove 81K of shaft portion 81, and outer edge 71G of each leaf spring 71 may be elastically abutted against inner edge 71N of cylindrical portion 82. Even with such a configuration, it is possible to obtain the same effect as the configuration in the above-described embodiment.

[0070] In the above-described embodiment, the leaf springs 71 are mounted at positions offset from one another in the circumferential direction about the rotation axis JX. However, from the perspective of compact size, the leaf springs 71 do not necessarily have to be offset from one another in phase. In the above-described embodiment, the leaf springs 71 are mounted at positions offset from one another in the circumferential direction about the rotation axis JX at equal intervals. However, from the perspective of leveling out the fluctuations in the torque transmitted between the axle 81 and the wheel 60, the leaf springs 71 only need to be mounted at positions offset from one another in phase about the rotation axis JX, and the phases do not necessarily have to be offset by equal intervals. In addition, when the leaf springs are to be offset from one another in the circumferential direction about the rotation axis JX, the leaf springs 71 are preferably offset by 180 degrees in the above-described embodiment. However, if there are three leaf springs 71, it is preferable that the leaf springs be offset by 120 degrees.

[0071] Furthermore, in the above-described embodiment, the first rotating body (wheel 60) having the shaft portion 81 is the driving side, and the second rotating body (first gear 61) is the driven side, but the second rotating body may be the driving side and the first rotating body may be the driven side. Furthermore, in the above-described embodiment, the torque transmission device of the present disclosure is described as being applied to the cover tape feeding section 39 of the tape feeder 13, but the application of the torque transmission device of the present disclosure is not limited to the tape feeder 13, and it may also be applied to other devices, such as devices that transport tape materials, sheet materials, etc.

[0072] Although various embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that those skilled in the art can conceive of various modifications, alterations, substitutions, additions, deletions, and equivalents within the scope of the claims, and it is understood that these also fall within the technical scope of the present disclosure. Furthermore, the components of the various embodiments described above may be combined in any manner without departing from the spirit of the invention. [Industrial Applicability]

[0073] The present disclosure provides a torque transmission device and a tape feeder that can be made compact in size. [Explanation of symbols]

[0074] 1. Parts mounting device 13 Tape feeder 32 Conveyor 36 motor 38 Peeling Mechanism 39 Cover tape feed section 51 Drive roller 52 first driven roller 60 Wheel (first rotating body) 61 First gear (second rotating body) 70 Torque transmission device 81 Shaft 81M outer circumferential surface 81K Projection engagement groove 82 Cylindrical part 82M Inner surface 82H protrusion engagement hole 71 Leaf spring 71c C section 71N Inner edge 71G outer edge 71a First leaf spring 71b Second leaf spring JX rotation axis CT carrier tape TT Cover Tape

Claims

1. a first rotor that is rotatable about a rotation axis and has a cylindrical shaft portion that extends along the rotation axis; a second rotating body that is rotatable about the rotation axis and rotatable relative to the first rotating body; a plurality of leaf springs each having a C-shaped portion formed into an overall C-shape and the shaft portion inserted into the C-shaped portion; rotation of each of the plurality of leaf springs relative to the second rotor about the rotation axis is restricted; When a driving side of the first rotating body or the second rotating body rotates, the rotational torque is transmitted to the driven sides of the first rotating body and the second rotating body through friction between inner edges of the plurality of leaf springs and an outer circumferential surface of the shaft portion. Torque transmission device.

2. a first rotor that is rotatable about a rotation axis and has a cylindrical shaft portion that extends along the rotation axis; a second rotor that is rotatable about the rotation axis and rotatable relative to the first rotor, and has a hollow cylindrical portion that extends toward the first rotor; a plurality of leaf springs each having a C-shaped portion formed into an overall C-shape and the shaft portion inserted into the C-shaped portion; rotation of each of the plurality of leaf springs about the rotation axis relative to the shaft portion is restricted, When the driving side of the first rotating body or the second rotating body rotates, the rotational torque is transmitted to the driven side of the first rotating body or the second rotating body through friction between outer edges of the plurality of leaf springs and an inner circumferential surface of the cylindrical portion of the second rotating body. Torque transmission device.

3. The plurality of leaf springs are attached at positions that are out of phase with each other along a circumferential direction centered on the rotation axis.

3. A torque transmission device according to claim 1 or 2.

4. The plurality of leaf springs are attached at positions that are shifted in phase from one another at equal intervals along a circumferential direction centered on the rotation axis.

3. A torque transmission device according to claim 1 or 2.

5. a conveying unit that conveys a carrier tape, in which pockets containing components are covered with a cover tape, toward a component removal position; a cover tape feeding unit that feeds the cover tape peeled from the carrier tape by rotating a plurality of rollers while sandwiching the cover tape before the carrier tape conveyed by the conveying unit reaches the component removal position; and The torque transmission device according to claim 1 or 2, the cover tape feeding unit is driven by a rotational torque output from one of the first rotating body and the second rotating body provided in the torque transmission device, which is the driven side; Tape feeder.

6. the shaft portion of the first rotating body and the second rotating body provided in the torque transmission device, whichever is the driving side, is pitch-driven at the same timing as the conveying unit by a motor that operates the conveying unit; 6. The tape feeder of claim 5.

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