Screw with washer feeding device and method

Abstract

To provide a screw with washer feeding device and method capable of eliminating biting of a washer into an incomplete screw part of a screw with a washer, and stably supplying screws with washers in a usable state.SOLUTION: A screw with washer feeding device comprises a rail 1, a first drive part 2, a head tapping part 3, and a second drive part 4. The rail 1 accommodates a screw part of a workpiece W which is a screw with a washer in a groove 10 extending in a travel direction of the workpiece. The first drive part 2 drives the rail 1 to feed the workpiece W in the travel direction. The head tapping part 3 is provided above the rail 1 and contacts a workpiece head to apply rotational torque. The second drive part 4 drives the head tapping part 3 in the travel direction. Through cooperation of the rail 1 and the head tapping part 3 that are respectively driven, the screw with washer feeding device rotates the workpiece W in which the washer is constrained in an incomplete screw part about an axis of the screw part, thereby releasing a constrained state of the washer.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device and method for supplying a screw with a washer. [Background technology]

[0002] Conventionally, there are known devices and methods for feeding screws with washers. For example, Patent Document 1 discloses a screw component feeder that includes a rail for transporting screws with washers (sems or W-sems screws), a guide member for restricting the head of a workpiece from rising up, and a presser member that moves up and down intermittently to press down the head of the workpiece. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 9-216715 Summary of the Invention [Problem to be solved by the invention]

[0004] Previously, when a SEMS or W-SEMS screw (hereinafter referred to as SEMS) was placed in a parts feeder, there were frequent cases where the washer got stuck in the boundary area from the bottom of the incomplete thread to the shoulder of the thread, and the SEMS was fed as is.

[0005] For this reason, conventionally, attempts have been made to eliminate washer sticking by using a vertically moving head tap mechanism (FIGS. 7 and 8) as a comparative example.

[0006] This mechanism literally hits the SEMS from above, but the washer often does not get stuck, causing blockages in the chute and hindering stable supply.

[0007] There was also concern that the SEMS would be deformed or produce foreign matter when it was struck.Furthermore, the up and down movement of this mechanism interfered with the movement of the feeder that sent the workpiece, hindering its movement and reducing work efficiency.

[0008] The present invention has been made in view of the above-mentioned problems, and its object is to provide a device and method for supplying screws with washers that can stably supply screws with washers in an easy-to-use state by eliminating the bite of washers into the boundary region from the lower part of the incomplete thread part of a screw with washer to the shoulder part of the thread part. [Means for solving the problem]

[0009] The washer-equipped screw feeder of the present invention comprises a rail (1), a first drive unit (2), a head tap unit (3), and a second drive unit (4).

[0010] The rail accommodates the threaded portion of the workpiece (W), which is a washer-equipped screw, in a groove portion (10) extending in the direction of travel of the workpiece. The first drive portion drives the rail to feed the workpiece in the direction of travel.

[0011] The head tap unit is located above the rail and contacts the head of the workpiece to apply rotational torque. The second drive unit drives the head tap unit in the direction of travel.

[0012] The washer-attached screw supply device rotates the workpiece, whose washer is constrained by the incomplete thread portion, around the axis of the thread portion through the cooperation of the driven rails and head tap portion, thereby releasing the washer from the constrained state.

[0013] The method for supplying screws with washers of the present invention involves the following steps under the condition that the part of the space formed by the rail (1) and the inclined surface (30) of the head tap portion (3) with the smallest vertical distance is limited to the closest width, which is the minimum value of the distance from the top of the head of the workpiece (W), which is a screw with a washer, to the bottom of the washer.

[0014] The work is fed in the direction of travel by driving a rail that accommodates the threaded portion of the work in a groove portion (10) extending in the direction of travel of the work.

[0015] The head tapping section is installed above the rail and has an inclined surface that becomes lower in the direction of travel, and the workpiece with the washer restrained by the incomplete thread portion is accommodated between the rail and the inclined surface, and contacts the head of the workpiece to apply rotational torque.

[0016] The method of supplying screws with washers performs both of the above steps to rotate the workpiece around the axis of the threaded portion, thereby eliminating the washer from biting into the incomplete threaded portion (restraint state).

[0017] As described above, the device and method for supplying screws with washers of the present invention eliminates the problem of the washer getting stuck in the boundary area from the bottom of the incomplete thread portion of the screw with washer to the shoulder of the thread portion, and makes it possible to stably supply screws with washer in an easy-to-use state. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing a washer-equipped screw supplying device according to one embodiment. [Figure 2] FIG. 2 is a view taken in the direction of the arrow II in FIG. [Figure 3] (a) Workpiece configuration diagram, (b) an example of a workpiece being gripped. [Figure 4] FIG. 1 is a diagram illustrating a head tap unit according to an embodiment. [Figure 5] FIG. 5 is an enlarged view of region V in FIG. 4. [Figure 6] 6A is a view in the same direction as FIG. 5, and FIG. 6B is a view taken in the direction of an arrow VI in FIG. 5, illustrating the rotational torque generated in the biting workpiece. [Figure 7] FIG. 10 is a diagram showing a screw supply device of a comparative example. [Figure 8] FIG. 10 is a diagram showing a head tapping mechanism of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment (apparatus and method) of the present invention will be described below with reference to the drawings.

[0020] 1 and 2 show the washer-attached screw feeder of this embodiment. The washer-attached screw feeder includes a rail 1, a first drive unit 2, a head tap unit 3, and a second drive unit 4. As shown in FIGS. 1 and 2, a step-type parts feeder PF is used to feed screws to the rail 1.

[0021] This embodiment includes a staircase parts feeder PF, which is a component of the work supply device described in Japanese Patent Application Laid-Open No. 2023-40904 (Reference Document 1), and reference can be made to Reference Document 1. Therefore, details of the staircase parts feeder PF are omitted.

[0022] The rail 1 accommodates the threaded portion B of the workpiece W, which is a washer-equipped screw, in a groove portion 10 extending in the traveling direction dW of the workpiece W. The first driving unit 2 drives the rail 1 to feed the workpiece W in the traveling direction dW. In this embodiment, the first driving unit 2 is a vibrating feeder that vibrates the rail 1 in a vibration direction dV12 (FIGS. 4 to 6, which will be described later) to feed the workpiece W.

[0023] 3(a) shows the structure of the workpiece W to be fed (sent) in this embodiment. The workpiece W is a screw with a washer, that is, a sems or W sems screw (hereinafter referred to as sems), and has an incomplete thread portion I between the workpiece head H and the thread portion B.

[0024] A spring washer S and a washer F are fitted into the incomplete thread portion I. The spring washer S and the washer F cannot pass through the thread portion B and cannot leave the range of the incomplete thread portion I.

[0025] Washer F may become caught in a boundary region IB (the region where the threads gradually become higher) from the bottom of incomplete thread portion I to the shoulder of thread portion B, tilting obliquely and becoming semi-fixed (hereinafter referred to as "stuck"). Here, the workpiece W in which washer F has stuck in boundary region IB is referred to as "stuck workpiece Wk." Also, the workpiece W in which washer F has not stuck in boundary region IB is referred to as "steady workpiece Wnk." In this application, the state in which washer F has stuck in boundary region IB is also expressed as "washer F is constrained by incomplete thread portion I."

[0026] As described above, the rail 1 accommodates the threaded portion B of the workpiece W in the groove portion 10 (Fig. 1), and serves as a path for transporting the workpiece W. At this time, the threaded portion B of the workpiece W is accommodated in the groove portion 10 of the rail 1, and the boundary region IB and the incomplete thread portion I are also partially accommodated, but the total length (along the axial direction of the threaded portion) of the portion below the start point Io of the accommodated incomplete thread portion I at this time differs between the biting workpiece Wk and the steady workpiece Wnk.

[0027] For this reason, as shown in FIG. 3(a), the length of the steady-state workpiece Wnk from the top of the workpiece head H along the axial direction of the thread portion (steady-state length Lnk) and the length of the biting workpiece Wk from the top of the workpiece head H along the axial direction of the thread portion (biting length Lk) are also different. The steady-state length Lnk is the value when the steady-state workpiece Wnk is accommodated in the groove portion 10, and is the minimum value. Also, "steady-state length Lnk < biting length Lk".

[0028] The minimum steady length Lnk is approximately equal to the nearest width Lpr, which will be described later. In other words, the steady length Lnk is approximately equal to the nearest width Lpr.

[0029] In this embodiment, for example, the steady-state length Lnk is 3.6 mm and the gripping length Lk is 4.8 mm. In the right diagram of Fig. 3(a), the washer F is drawn as if it were attached to the bottom side for comparison with the left diagram of Fig. 3(a), but the actual gripping workpiece Wk is often as shown in Fig. 3(b).

[0030] If the bitten workpiece Wk shown in Figure 3(b) is fed as is, it will tilt even inside the groove 10 of the rail 1, preventing smooth feeding and hindering smooth feeding. For this reason, the bitten workpiece Wk must be returned to the steady workpiece Wnk shown in the left diagram of Figure 3(a) and fed.

[0031] A comparative head tapping mechanism is shown in Figures 7 and 8. The comparative example includes a bowl feeder PF-Z instead of the tiered parts feeder PF of this embodiment. It also includes a rail 1-Z equivalent to the rail 1 of this embodiment, a linear feeder 2-Z equivalent to the first drive unit 2, a vertically movable block 3-Z equivalent to the head tapping unit 3, and an air cylinder 4-Z equivalent to the second drive unit 4, and feeds a workpiece WZ, which is a screw with a washer, along the flow direction dW-Z.

[0032] As shown in Figure 8, in the comparative example, the head tapping mechanism, a vertically movable block 3-Z driven by an air cylinder 4-Z, strikes the heads of all workpieces WZ, including the stationary workpiece Wnk, from above in an attempt to forcibly eliminate washer sticking.

[0033] However, this mechanism was unable to reliably eliminate washer sticking, and a more effective means was needed. In this embodiment, by providing a head tap unit 3, which is a head tap mechanism with a different configuration from the comparative example, washer sticking is more effectively and reliably eliminated. The head tap unit 3 will be described below.

[0034] If "head tap" is interpreted literally, it means "to hit the head" (of a screw), and the name cannot be distinguished from the comparative example, but for simplicity, it is referred to as the head tap unit 3. In this embodiment, the head H of the workpiece is not hit by the up and down movement of the cylinder as in the comparative example, but rather, as will be described later, the head H of the workpiece is contacted and pushed from above.

[0035] 4 and 5 show the head tapping unit 3. The head tapping unit 3 is provided above the rail 1. The second drive unit 4 drives the head tapping unit 3 to feed the workpiece W in the traveling direction dW. In this embodiment, the second drive unit 4 is also a vibrating feeder like the first drive unit 2, and drives the head tapping unit 3 along the vibration direction dV34 to bring it into contact with the head H of the workpiece.

[0036] The head tap section 3 has an inclined surface 30 that becomes lower in the traveling direction dW. In other words, it is the inclined surface 30 that actually comes into contact with the workpiece head H. The height difference of the inclined surface 30 is designed so that the workpiece Wk can be accommodated between the rail 1 and the inclined surface 30 even if the gripping length Lk of the gripping workpiece Wk is long as shown in Figure 3(b).

[0037] On the other hand, the part of the space formed by the rail 1 and the inclined surface 30 of the head tap portion 3 (i.e., the space from the upper end of the groove portion 10 of the rail 1 to the inclined surface 30) with the smallest vertical distance is limited to a width (closest width Lpr) which is the minimum value of the distance from the top of the work head H to the bottom of the washer F.

[0038] Because the inclined surface 30 gradually becomes lower in the traveling direction dW, the bitten workpiece Wk cannot move along the traveling direction dW even if a driving force acts along the vibration direction dV12 of the rail 1. Even in this case, the inclined surface 30 continues to vibrate in the vibration direction dV34 as driven by the second drive unit 4, and comes into contact with the workpiece head H of the bitten workpiece Wk, pushing it from above.

[0039] The situation that occurs at this time is explained with reference to Figure 6. As shown in Figure 6(a), when the inclined surface 30 comes into point contact with the curved surface of the workpiece head H of the gripping workpiece Wk at contact point A, the contact is rubbing, and the force of the load P pushes the entire gripping workpiece Wk diagonally downward.

[0040] As a result, at the workpiece head H of the bitten workpiece Wk pressed by the load P, a rotational torque Tq acting around the axis of the threaded portion B along the direction of travel dW is generated, as shown in Figure 6(b). In other words, even though the position of the contact point A gradually moves and the direction of rotation of the rotational torque Tq reverses along the vibration direction dV34, the rotational torque Tq is generated in a direction that advances mainly along the direction of travel dW.

[0041] In this way, when the rotational torque Tq in the direction of releasing the grip is repeatedly applied to the gripped workpiece Wk, the gripping state of the gripped workpiece Wk gradually relaxes in the space between the rail 1 and the inclined surface 30, and eventually the washer F is released from riding on the boundary region IB, and the workpiece Wk returns to a steady state.

[0042] In the process of returning to this steady workpiece Wnk (left diagram in Figure 3(a)), the biting length Lk of the biting workpiece Wk (Figure 3(b)) becomes equal to the steady length Lnk of the steady workpiece Wnk, which is the minimum value, and it becomes able to pass through the closest space between the rail 1 and the head tap section 3, which is limited to the closest width Lpr, and is fed normally.

[0043] With the above configuration, the device and method for supplying a washer-equipped screw of this embodiment can stably supply the workpiece W, which is a washer-equipped screw in which the washer F has been prevented from getting stuck in the boundary area IB, in an easy-to-use state.

[0044] (Other embodiments) In the above embodiment, the head tap unit 3 is provided directly above the rail 1 (see FIG. 1, etc.), but the arrangement of the head tap unit 3 is not limited to this. For example, it may be arranged so that it contacts the workpiece head H from diagonally above, in order to more easily generate rotational torque.

[0045] As described above, the present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0046] 1: rail, 10: groove portion, 2: first drive portion, 3: head tap portion, 4: second drive portion W: Work (screw with washer)

Claims

1. a rail (1) for receiving a threaded portion of a workpiece (W) which is a washer-equipped screw in a groove portion (10) extending in the direction of travel of the workpiece; a first drive unit (2) that drives the rail to feed the workpiece in the traveling direction; a head tap portion (3) provided above the rail and contacting the head of the workpiece to apply rotational torque; a second driving unit (4) that drives the head tap unit in the traveling direction; Equipped with The washer-attached screw supply device rotates the workpiece, whose washer is constrained by an incomplete thread portion, around the axis of the thread portion through the cooperation of the driven rails and head tap portion, thereby releasing the washer from its constrained state.

2. The head tap portion has an inclined surface (30) that becomes lower toward the traveling direction, and the workpiece with the washer constrained by the incomplete thread portion is accommodated between the rail and the inclined surface, the second drive unit is a vibrating feeder, 2. The washer-equipped screw supply device according to claim 1, wherein the portion of the space formed by the rail and the inclined surface where the height distance is smallest is limited to the closest width, which is the minimum value of the distance from the top of the work head to the bottom of the washer.

3. In a situation where the part of the space formed by the rail (1) and the inclined surface (30) of the head tap part (3) where the distance in the height direction is smallest is limited to the closest width, which is the minimum value of the distance from the top of the head of the work (W) which is a washer-equipped screw to the bottom of the washer, Driving the rail, which accommodates the threaded portion of the workpiece in a groove extending in a direction of travel of the workpiece, to feed the workpiece in the direction of travel; a head tapping unit provided above the rail, having an inclined surface that becomes lower in the direction of travel, the workpiece having the washer restrained by the incomplete thread portion being accommodated between the rail and the inclined surface, and contacting the head of the workpiece to apply a rotational torque; This rotates the workpiece around the axis of the threaded portion, thereby releasing the washer from its restrained state.

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