Screw tightening device

Abstract

The present invention provides a screw tightening device that maintains the advantage of reduced working time while ensuring a longer cleaning time for deposits on the screw threads. [Solution] The screw tightening device T1 comprises a screw tightening unit 1 and a screw supply unit 2. The screw tightening unit 1 has a driver 12 that can rotate around a screw tightening shaft A1, and a suction pipe 11 that houses the driver 12, floats along the screw tightening shaft A1, and attracts screws N. The screw supply unit 1 has a pressure feeding section 43, a cutting section 44, and a lower dust collection section 47. The cutting section 44 has a screw catch section 46a directly below it that receives screws N on the screw side, and has a plurality of holes 45 in the circumferential direction through which screws N pass. The holes 45 and screw catch section 46, through which screws have been pressure-fed by the pressure feeding section 43, are rotated around the cutting shaft A4, so that they overlap in the order of the lower dust collection section 47 and the screw tightening shaft A4. The pressure feeding section 43 pressure-feds screws N to the screw catch section 46 through the holes 45.

Description

Technical Field

[0001] The present invention relates to a screw tightening device.

Background Art

[0002] Conventionally, before tightening the screws of electronic products that dislike foreign matter, a screw tightening device capable of sucking foreign matter from the screw part is known.

[0003] For example, Patent Document 1 includes a through member through which a screw can pass, a chuck connected to a transfer means and receiving the screw through a suspension hole, a screw guide capable of adsorbing the screw, and a bit engaging with the screw, and is a screw tightening machine in which a cleaning unit for collecting deposits on the screw part communicates with the suspension hole.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The invention according to Patent Document 1 has the advantage that the working time per cycle can be shortened by arranging mechanical elements in close proximity, and deposits on the screw part can be collected before screw tightening.

[0006] On the other hand, since it is a method of collecting deposits on the screw part every time one screw is supplied, the cleaning time per time is short, and there is a risk that the removal of deposits may be incomplete.

[0007] The present invention has been made in view of the above problems, and an object thereof is to provide a screw tightening device that improves the advantage of shortening the working time, ensures a longer cleaning time for deposits on the screw part to enhance the cleanliness of the screw, and improves the screw tightening quality.

Means for Solving the Problems

[0008] <First aspect> The screw tightening device (T1) of the first embodiment comprises a screw tightening unit (1) and a screw supply unit (2).

[0009] The screw tightening unit includes a screwdriver (12) that is rotatable around a screw tightening shaft (A1), and a suction pipe (11) that houses the screwdriver, floats along the screw tightening shaft, and attracts screws.

[0010] The screw supply unit includes a pressure feeding section (43), a cutting section (44), and a lower dust collection section (47).

[0011] The cutting section has a screw catch section (46a) directly below it that receives the screw on the threaded side, and has multiple holes (45) in the circumferential direction through which the screw passes. The holes and screw catch section into which the screw is pressurized in the pressurized feeding section are rotated around the cutting shaft (A4) so ​​that the lower dust collection section and the screw tightening shaft are aligned in that order. The pressurized feeding section pressurizes the screw through the holes to the screw catch section. The lower dust collection section communicates with the bottom side of the screw catch section and sucks in foreign matter from the threaded side of the screw.

[0012] The screw catch section includes a biasing member (46b) and a plurality of screw catch valves (46a), and is capable of receiving a screw on the screw portion side. Each of the plurality of screw catch valves is biased by the biasing member.

[0013] Under the above configuration, the screw tightening device (T1) works as follows: after the screw supply unit sucks up foreign matter, the screw tightening unit attracts and fixes the screw, and when it pushes it down, each screw catch opens radially outward from the screw tightening shaft, allowing the screw to pass through, and the screw tightening unit performs the screw tightening.

[0014] Preferably, the screw supply unit further includes a blow section (48) and an upper dust collection section (49). The blow section communicates with the bottom side of the screw catch section and blows the screw from the screw side to lift it up. The upper dust collection section sucks up foreign matter from the screw head side of the screw that has been lifted up by the blow section. The cutting section rotates the hole into which the screw has been pressurized by the pressurized feeding section and the screw catch section around the cutting axis (A4) so ​​that the lower dust collection section, the upper dust collection section, and the screw tightening axis are aligned in that order.

[0015] As a result, the screw tightening device (T1) improves the advantages of reduced working time while also ensuring a longer time for cleaning off deposits from the screws, thereby enhancing the cleanliness of the screws and improving the quality of screw tightening.

[0016] <Second aspect> The screw tightening device (T2) of the second embodiment comprises a screw tightening unit and a screw supply unit, similar to the first embodiment. The details of the screw tightening unit are also the same. Here, we will describe the configuration that differs from the first embodiment.

[0017] The screw supply unit includes a pressure feeding section (43), a cutting section (44), and a lower dust collection section (47). The details of the cutting section differ from those of the first embodiment.

[0018] The cutting section has one or more receiving holes (45p) at the bottom of the hole to receive the threaded portion of the screw, and one or more punching holes (45q) through which the suction pipe can pass, alternating in the circumferential direction in a disc shape. The receiving holes and punching holes are rotated around the cutting axis (A4) and sequentially overlapped with the screw tightening axis. The pressure feeding section pressurizes the screw into the receiving holes. The lower dust collection section communicates with the bottom of the receiving holes and sucks in foreign matter from the threaded portion side of the screw.

[0019] Under the above configuration, the screw tightening device (T2) has a screw supply unit that sucks up foreign matter, then the screw tightening unit sucks and fixes the screw (up to this point it is the same as in the first embodiment), moves away from the cutting section, and when the cutting section aligns the hole with the screw tightening shaft, the screw tightening unit passes through the hole and performs screw tightening.

[0020] As a result, similar to the first aspect, the screw tightening device (T2) improves the advantage of shortening the working time while ensuring more cleaning time for the screw deposits to enhance the cleanliness of the screw and improve the screw tightening quality.

Brief Description of the Drawings

[0021] [Figure 1] It is a perspective view showing the screw tightening device of the first embodiment. [Figure 2] It is a perspective view showing a screw. [Figure 3] It is a side view showing the screw tightening unit. [Figure 4] It is a perspective view showing the screw supply unit of the first embodiment. [Figure 5] It is a perspective view showing the cutting part of the first embodiment. [Figure 6] It is a view seen in the direction of arrow VI in FIG. 4. [Figure 7] It is a cross-sectional view showing the screw tightening unit and the screw supply unit of the first embodiment. [Figure 8] It is a schematic view showing the opening and closing structure of the screw catching part (a) before screw tightening, (b) during screw tightening, and (c) after screw tightening. [Figure 9] It is a cross-sectional view showing the upper dust collection part. [Figure 10] It is a flowchart showing one cycle operation of screw tightening of the first embodiment. [Figure 11] It is a perspective view showing the screw tightening device of the second embodiment. [Figure 12] It is a perspective view showing the screw supply unit of the second embodiment. [Figure 13] It is a cross-sectional view showing the screw tightening unit and the screw supply unit of the second embodiment. [Figure 14] It is a flowchart showing one cycle operation of screw tightening of the second embodiment. [Figure 15] It is figure 1 showing one cycle operation of screw tightening of the second embodiment. [Figure 16] It is figure 2 showing one cycle operation of screw tightening of the second embodiment. [Figure 17]Figure 3 shows one screw tightening cycle operation in the second embodiment. [Figure 18] Figure 4 shows one screw tightening cycle operation in the second embodiment. [Figure 19] Figure 5 shows one screw tightening cycle operation in the second embodiment. [Figure 20] Figure 6 shows the screw tightening cycle operation of the second embodiment. [Figure 21] Figure 7 shows one screw tightening cycle operation in the second embodiment. [Figure 22] Figure 8 shows one screw tightening cycle operation in the second embodiment. [Figure 23] This is a perspective view showing a comparative example of a screw tightening device. [Figure 24] This is a cross-sectional view showing the lower dust collection section of the comparative example. [Modes for carrying out the invention]

[0022] <First Embodiment: Screw Tightening Device T1> The first embodiment will be described below with reference to the drawings. Figure 1 shows the screw tightening device T1 of the first embodiment. The screw tightening device T1 comprises a screw tightening unit 1 and a screw supply unit 4, and is a device that tightens screws N at one or more locations on a workpiece W that are to be tightened with screws during manufacturing.

[0023] Figure 2 shows a screw N. The screw N includes a screw head Na and a threaded portion Nb, and the screw head Na includes a recess (engaged portion Nax) formed to be engaged with a protrusion (engaged portion 12x) at the tip of the driver 12.

[0024] (Screw tightening unit) Figure 3 shows a screw tightening unit 1. The screw tightening unit 1 includes a driver 12 and a suction pipe 11. The driver 12 is rotatable around the screw tightening shaft A1 by a screw tightening drive unit 1200. The suction pipe 11 houses the driver 12, floats along the screw tightening shaft A1, and attracts the screw N. In the first embodiment, the screw tightening shaft A1 is in the vertical direction and is the same as the axial direction of the driver 12 of the screw tightening unit 1.

[0025] The suction pipe 11 houses the driver 12. The suction pipe 11 is floating so as to slide along the outside of the driver 12 and moves together with the suction pipe 11. The suction pipe 11 has a screw head intake portion 1100. Here, in a plane perpendicular to the screw tightening shaft A1, the opening 11o, which is the tip of the suction pipe 11, has an inner diameter that can accommodate the outer diameter of the screw head Na in that plane. This plane is also perpendicular to the cutting shaft A4, which will be described later.

[0026] When the engaging portion 12x of the driver 12, which is a protrusion that can be fitted into the engaged portion Nax in an orthogonal plane, is fitted into and in contact with the engaged portion Nax of the screw N, and the inside of the opening 11o of the suction pipe 11 is adjacent to the outside of the screw head Na, the screw head intake portion 1100 sucks in and discharges air from inside the suction pipe 11 through the gap between the driver 12 housed inside the suction pipe 11 and the intake portion 1100. This maintains a negative pressure inside the suction pipe 11, causing the screw N to be attracted to the engaging portion 12x of the driver 12, and also sucking out and removing foreign matter attached to the screw head Na.

[0027] The screw tightening unit 1 has a axial drive unit 1000. The axial drive unit 1000 drives the suction pipe 11 and the driver 12 of the screw tightening unit 1 along the screw tightening shaft A1. The suction pipe 11 has a mechanism that is subjected to a downward force by a spring and floats upward when it comes into contact with the workpiece W. Normally, on the screw tightening shaft A1, the opening 11o of the suction pipe 11 is not lower than the engaging portion 12x of the driver 12 (closer to the cutting portion 44 described later).

[0028] The driver 12 is rotationally driven by the screw tightening drive unit 1200. The screw tightening drive unit 1200 rotates the driver 12 around the screw tightening axis A1 to perform the screw tightening operation. The screw tightening drive unit 1200 is also connected to a torque sensor and a control unit, and can detect and adjust the screw tightening torque to a set value.

[0029] (Screw supply unit) Figure 4 shows the screw supply unit 4. The screw supply unit 4 includes a cutting section 44, a pressure feeding section 43, a lower dust collection section 47, a blow section 48, and an upper dust collection section 49.

[0030] Figures 5 and 6 show the cutting section 44. The cutting section 44 has multiple holes 45 in the circumferential direction dR. As shown in Figure 6, the cutting section 44 is rotated by the cutting drive unit 4400 around the cutting shaft A4, rotating the holes 45 and screw catch section 46 along the circumferential direction dR, so that the lower dust collection section 47 (and pressure feeding section 43), the upper dust collection section 49 (and blow section 48), and the screw tightening shaft A1 are aligned in that order.

[0031] For the sake of clarity, in the following explanation, the location of the pressure feeding section 43 and the lower dust collection section 47 will be referred to as the "pressure feeding / lower dust collection stage PA," the location of the blowing section 48 and the upper dust collection section 49 will be referred to as the "upper dust collection stage PB," and the location of the screw tightening shaft A1 (i.e., the location of the screw tightening unit 1) will be referred to as the "screw tightening stage PC" (Figure 6).

[0032] Figure 7 shows the relationship between the pressure feeding / downward dust collection stage PA and the screw tightening stage PC in the cutting section 44. For illustrative purposes, in Figure 7, the pressure feeding / downward dust collection stage PA and the screw tightening stage PC are depicted as being on opposite sides rotated 180 degrees from each other, but the actual arrangement is as shown in Figure 6.

[0033] As shown in Figure 7, each of the multiple holes 45 has a screw catch portion 46 directly below it that receives the screw N on the screw portion Nb side, and is large enough to allow the screw N to pass through. The screw catch portion 46 is capable of receiving the screw N on the screw portion Nb side through a combination of multiple screw catch valves 46a and biasing members 46b.

[0034] Here, the pressurized feeding section 43 in the pressurized feeding / downward dust collection stage PA will be described. The pressurized feeding section 43 has a space inside through which a screw N can pass, and pressurizes the screw N to the screw catch section 46 from the outside through the space and the hole 45. The screw N is housed with its threaded portion Nb inserted toward the bottom side of the screw catch section 46.

[0035] Below the same pressurized / downward dust collection stage PA, a downward dust collection unit 47 is located. The downward dust collection unit 47 is in communication with the bottom side of the screw catch unit 46, and removes foreign matter from the screw portion Nb side of the screw N housed in the screw catch unit 46 by suction (first suction removal).

[0036] Subsequently, the cutting section 44 rotates the screw N together with the screw catch section 46, and the upper dust collection stage PB further removes foreign matter from the screw N (second suction removal). After that, the screw N is rotated again together with the screw catch section 46, and the screw is tightened in the screw tightening stage PC. The upper dust collection stage PB will be described later.

[0037] Figure 8 shows the opening and closing structure of the screw catch section 46 in the screw tightening stage PC. Each of the multiple screw catch valves 46a is biased by a biasing member 46b and maintains the position shown in Figure 8(a). The screw N, which is fed from the pressure feeding section 43 through the hole 45, is supported by the screw catch valve 46a, which is biased by the biasing member 46b, with the screw portion Nb facing downwards.

[0038] As shown in Figure 8(b), when the screw tightening unit 1 descends and attracts the screw N, the pair of screw catch valves 46a are pushed by the screw tightening unit 1 and open downward and radially outward with respect to the axial direction of the driver 12, allowing the screw N to pass through the screw tightening unit 1 that has attracted it.

[0039] Beyond the point where it passes, there is a location where screw tightening is planned (not shown), and the screw tightening unit 1 can proceed directly to the screw tightening operation. When the screw tightening unit 1 has finished the screw tightening operation and moves upward, the pair of screw catch valves 46a, which were open radially outward, are biased by the biasing member 46b and return to the same position as in Figure 8(a) (Figure 8(c)).

[0040] Figure 9 shows the relationship between the blow section 48 and the upper dust collection section 49 in the upper dust collection stage PB. Here, the airflow discharged by the blow section 48 and the airflow drawn in by the upper dust collection section 49 are indicated by dashed arrows. The blow section 48 is in communication with the bottom side of the screw catch section 46 and blows air from the screw section Nb side to lift the screw N.

[0041] In this manner, the upper dust collection unit 49 sucks up foreign matter from the screw head Na side of the screw N, which has been lifted up by the blow unit 48. By lifting the screw N with the blow unit 48 and allowing the airflow to pass alongside it toward the upper dust collection unit 49, it is possible to collect even foreign matter that cannot be removed by simply sucking the screw N from the screw head Na side, such as foreign matter adhering to the contact area between the screw head Na, washers placed at the connection between the screw head Na and the screw part Nb, and the screw catch valve 46a.

[0042] Under the above configuration, the screw tightening device T1 removes foreign matter twice by suction using the screw supply unit 4 to improve the cleanliness of the screw N. Then, when the screw tightening unit 1 adsorbs and fixes the screw N and pushes it downward, the screw catch valve 46a opens radially outward from the screw tightening shaft A1 to allow the screw N to pass through. Subsequently, the screw tightening unit 1 tightens the screw at the planned tightening location, then retracts upward again and waits until the timing for adsorption of the next screw N.

[0043] (One screw tightening cycle) Figure 10 shows a flowchart of one screw tightening cycle operation S1 performed using the screw tightening device T1 described above. Here, it is assumed that the screw tightening cycle operation S1 is performed continuously and repeatedly.

[0044] The pressurized feeding preparation step S1-1 is a step in which the hole 45 and screw catch section 46, which became empty after the screw N was used for screw tightening in the retraction step S1-5 described later, are returned from the screw tightening stage PC to the pressurized feeding / downward dust collection stage PA by the rotational movement of the cutting section 44.

[0045] The pressurized feeding and downward dust collection step S1-2 is a step that includes a substep in which a screw N to be used for the next screw tightening is pressurized by the pressurized feeding section 43, passes through the hole 45, and is housed in the screw catch section 46 directly below it with the screw portion Nb facing downwards, and a substep in which foreign matter attached to the screw portion Nb is sucked and removed by the downward dust collection section 47.

[0046] The upward dust collection step S1-3 is a sub-step in which the screw N, from which foreign matter has been removed in the pressure-feeding / downward dust collection step S1-2, moves from the pressure-feeding / downward dust collection stage PA to the upward dust collection stage PB by the rotational movement of the cutting section 44, and the blow section 48 and the upward dust collection section 49 suck up and remove any foreign matter attached to the screw head Na of the screw N that has been lifted on the screw catch section 46.

[0047] The screw suction and screw tightening step S1-4 includes a sub-step in which the screw N, whose screw head Na has been decontaminated in the upper dust collection step S1-3, moves from the upper dust collection stage PB to the screw tightening stage PC by the rotational movement of the cutting section 44, and a sub-step in which the screw N is adsorbed and fixed to the tip of the suction pipe 11 and the driver 12 by the descending screw tightening unit 1, passes through a set of spread screw catch valves 46a, and is tightened at the screw tightening location below.

[0048] Step S1-5 is the step in which the screw tightening unit 1, which has completed screw tightening in screw suction / screw tightening step S1-4, rises and moves away from the planned screw tightening location (screw tightening completion location).

[0049] In summary, the screw tightening cycle using the screw tightening device T1 provides the following benefits: continuous and concentrated collection of foreign matter by the lower dust collection unit 47 and the upper dust collection unit 49, ensuring a clear improvement in the cleanliness of the screw N before tightening; and seamless and rapid execution of screw suction and tightening operations thanks to the function of the screw catch valve 46a.

[0050] <Second Embodiment: Screw Tightening Device T2> Next, a second embodiment will be described based on the drawings. Figure 11 shows the screw tightening device T2 of the second embodiment. Like the screw tightening device T1, the screw tightening device T2 comprises a screw tightening unit 1 and a screw supply unit 4, and is a device that tightens screws N at one or more locations on a workpiece W that are to be tightened during manufacturing. The details of the target screws N and the screw tightening unit 1 are the same as those of the screw tightening device T1 (Figures 2 and 3).

[0051] (Screw supply unit) Figure 12 shows the screw supply unit 4. The screw supply unit 4 has a cutting section 44, a pressure feeding section 43, and a lower dust collection section 47. The cutting section 44 has one or more receiving holes 45p that receive the screw portion Nb at the bottom of the hole, and one or more punching holes 45q through which the suction pipe 11 can pass, alternately in the circumferential direction in a disc shape. In the second embodiment, three sets of receiving holes 45p and punching holes 45q are arranged alternately in the circumferential direction, with each receiving hole 45p and each punching hole 45q spaced 120° apart.

[0052] The receiving hole 45p is formed to match the shape of the threaded portion Nb of the screw N, with the bottom side being narrower, and receives the screw N so that the threaded portion Nb is inserted and its axis is aligned with the screw tightening shaft A1. The hole 45q is a space through which the screw tightening unit 1 can pass, and is formed to be at least larger than the outer diameter of the suction pipe 11.

[0053] The cutting unit 44 rotates around the cutting axis A4 by the cutting drive unit 4400, aligning the receiving holes 45p and the punching holes 45q with the screw tightening axis A1 in sequence. In the second embodiment, the cutting unit 44 is an index table, and with each cutting operation, three sets of receiving holes 45p and punching holes 45q are aligned with the cutting axis A4 in sequence.

[0054] The pressurized feeding unit 43, like the screw tightening device T1, has an internal space through which the screw N can pass, and is configured to pressurize the screw N from the outside through the space into the receiving hole 45p. The screw N is placed in the receiving hole 45p with its threaded portion Nb facing the bottom of the receiving hole 45p. The lower dust collection unit 47 is in communication with the bottom of the receiving hole 45p and sucks up and removes foreign matter adhering to the threaded portion Nb of the screw N.

[0055] Figure 13 shows the relationship between the screw tightening unit 1 and the screw supply unit 4. The screw tightening unit 1 engages the engaging portion 12x of the driver 12 with the engaged portion Nax of the screw N held in the receiving hole 45p, and the suction pipe 11 holds and fixes the screw N. Subsequently, the suction pipe 11 and the driver 12 move away from the cutting portion 44 along the screw tightening axis A1 and temporarily retract. After that, when the cutting portion 44 aligns the punching hole 45q with the screw tightening axis A1, the suction pipe 11 and the driver 12 pass through the punching hole 45q along the screw tightening axis A1 while holding the screw N, and tighten the screw.

[0056] Here, the screw tightening device T2 is configured such that when there is a receiving hole 45p of the cutting section 44 on the screw tightening shaft A1, there is always a punch hole 45q on the cutting shaft A4. For this reason, in addition to the "screw tightening operation" on the screw tightening shaft A1 mentioned above, the "screw supply and screw cleaning operation" by the pressure feeding section 43 can be performed in parallel on the cutting shaft A4.

[0057] In the second embodiment, three sets of receiving holes 45p and punching holes 45q are arranged at 30° intervals with respect to the cutting axis A4. However, in Figures 13, 15 to 22, for the sake of explanation, one set of receiving holes 45p and punching holes 45q are arranged at 180° intervals with respect to the cutting axis A4, and the positions of the receiving holes 45p and punching holes 45q are depicted as being on opposite sides of the cutting axis A4.

[0058] (One screw tightening cycle) Figure 14 shows the flow of one screw tightening cycle operation S2 by the screw tightening device T2. The operation of the screw tightening device T2 will be explained in more detail below, referring to Figures 15 to 22, which are shown with the same configuration as Figure 13. The second embodiment also assumes that the screw tightening cycle operation S2 is performed repeatedly and continuously.

[0059] Figure 15 shows the standby step S2-1. In standby step S2-1, the screw tightening unit 1 is retracted to a position above the screw tightening axis A1 and at least not interfering with the cutting portion 44 of the screw supply unit 4. This position becomes the original position for the screw tightening cycle operation S2, and is defined as the "retracted position".

[0060] Figure 16 shows the thread cutting step S2-2. In the thread cutting step S2-2, the cutting part 44 rotates around the cutting axis A4, aligning the receiving hole 45p with the screw tightening axis A1. At this time, the central part of the screw head Na of the screw N, which is fitted into the receiving hole 45p, is located directly below the axis of the engaging part 12x of the driver 12.

[0061] Figure 17 shows the screw suction step S2-3. In the screw suction step S2-3, the tip portion of the screw tightening unit 1 (= opening 11o + engaging portion 12x) moves downward along the screw tightening axis A1, and the engaging portion 12x engages with the engaged portion Nax of the screw N. Subsequently, the screw head Na of the screw N is attracted to the engaging portion 12x of the driver 12.

[0062] Figure 18 shows the receiving hole retraction step S2-4. In the receiving hole retraction step S2-4, the screw tightening unit 1, with the screw N still attached to its tip by the screw suction step S2-3, retracts upward in the opposite direction to the screw suction step S2-3, returning to the same retracted position as in the standby step S2-1.

[0063] Figure 19 shows the hole cutting step S2-5. In the hole cutting step S2-5, the cutting part 44 rotates around the cutting axis A4, aligning the hole 45q with the screw tightening axis A1. At this time, the hole 45q is located directly below the axis of the engaging part 12x (and screw part Nb) of the driver 12.

[0064] Figure 20 shows the screw placement step S2-6. In the screw placement step S2-6, the tip of the screw tightening unit 1, which has attracted the screw N, moves downward along the cutting axis A4, passes through the hole 45q that was cut directly below in the hole cutting step S2-5, and brings the screw portion Nb to the planned screw tightening location on the workpiece W, which is located below the cutting axis A4, and aligns it.

[0065] Figure 21 shows the screw tightening step S2-7. In the screw tightening step S2-7, the driver 12 rotates around the screw tightening axis A1 and fastens the screw N, which was aligned in the screw placement step S2-6, into the screw hole to achieve the set screw tightening torque. After the screw tightening is complete, the suction state that maintained the suction state of the screw head Na is released (suction breakage).

[0066] Figure 22 shows the hole retraction step S2-8. In the hole retraction step S2-8, the screw tightening unit 1 returns to the retracted position after screw tightening is complete and suction has broken. Then, the screw tightening cycle operation S2 is completed and the process returns to the standby step S2-1.

[0067] In addition to the screw tightening operation described above, screw supply and screw cleaning operations are performed. Refer to Figure 14 here. The screw cleaning step S2-b is a step in which foreign matter is sucked out and removed from the screw part Nb by the lower dust collection unit 47. The screw cleaning step S2-b can be performed continuously over a total of four steps, from the screw placement step S2-6 to the screw tightening step S2-7, through the hole retraction step S2-8, and back to the standby step S2-1, thereby ensuring a longer cleaning time (blow time) for the screw part Nb before the screw tightening operation.

[0068] On the other hand, as shown in Figure 14, each step from the screw adsorption step S2-3 to the screw tightening step S2-7 includes a process of adsorbing and holding the screw, and foreign matter on the screw head Na is removed by suction. Therefore, in contrast to the screw cleaning step S2-b, it can be said that these steps function as a "screw head cleaning step S2-a".

[0069] <Comparison with the comparative example> Figures 23 and 24 show the screw tightening device hT and the lower dust collection unit h47 of the comparative example. In this comparative example, the lower dust collection unit h47 was installed separately from the screw tightening unit h1, and the screw tightening unit h1 had to move back and forth each time. As a result, the screw tightening cycle time per screw was long, resulting in poor work efficiency.

[0070] Furthermore, the prior art described in Patent Document 1 is a method that cleans the thread portion of each individual screw. While this method allows for high work efficiency by arranging the lower dust collection unit and the screw supply unit in close proximity, it is difficult to increase the time that can be spent cleaning the thread portion of each screw, and therefore, the quality of cleaning the thread portion could not be improved.

[0071] In contrast, according to the screw tightening device T1 of the first embodiment, the combination of the lower dust collection section 47, the blow section 48, and the upper dust collection section 49 ensures the removal of deposits from the entire screw N, including the screw head Na, thereby increasing the cleanliness of the screw N before tightening and improving the quality of screw tightening. Furthermore, by combining the screw catch section 46 with the hole 45 in which the screw N is housed, it becomes possible to perform a series of operations from screw suction by the screw tightening unit 1 to screw tightening seamlessly, thereby increasing work efficiency.

[0072] In the screw tightening device T2 of the second embodiment, the lower dust collection unit 47 is incorporated into the screw supply unit 4 and positioned close to it, thereby reducing travel time and maintaining high work efficiency. Furthermore, by ensuring a longer cleaning time for the screw portion Nb than in the comparative example, it is possible to remove adhering substances more reliably. As a result, screw tightening defects are reduced and screw tightening quality is improved.

[0073] (Other embodiments) In the second embodiment, there are three receiving holes 45p and three punching holes 45q in the cutting section 44, but this is not limited to other embodiments. For example, to ensure a longer cleaning time for the threaded section Nb, four or more sets of these may be provided, or the number of lower dust collection sections 47 may be increased.

[0074] The recessed shape of the engaging portion Nax is not limited to a shape that can accommodate a Phillips screwdriver; it may also be shaped like a flathead screwdriver or a more specialized, dedicated shape.

[0075] The present invention is not limited in any way to the embodiments described above, and can be implemented in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0076] 1: Screw tightening unit, 11: Suction pipe, 12: Driver 4: Screw supply unit, 43: Pressure feeding section, 44: Cutting section, 45: Hole 45p: receiving hole, 45q: punching hole 46: Screw catch part, 46a: Screw catch valve, 46b: Biasing member 47: Lower dust collection unit A1: Screw tightening shaft, A4: Cutting shaft, T1, T2: Screw tightening device

Claims

1. It comprises a screw tightening unit (1) and a screw supply unit (4), The screw tightening unit comprises a driver (12) rotatable around a screw tightening shaft (A1), and a suction pipe (11) that houses the driver, floats along the screw tightening shaft, and attracts screws. The screw supply unit has a screw catch portion (46) directly below it that receives the screw on the screw side, and has a plurality of holes (45) in the circumferential direction through which the screw passes, and has a cutting portion (44), a pressurizing portion (43) that pressurizes the screw to the screw catch portion through the holes, and a lower dust collection portion (47) that communicates with the bottom side of the screw catch portion and sucks foreign matter from the screw side of the screw, and the cutting portion rotates the holes and the screw catch portion through the pressurizing portion around the cutting shaft (A4) so ​​that they overlap in the order of the lower dust collection portion and the screw tightening shaft, After the foreign matter is sucked up by the screw supply unit, the screw catch section is capable of receiving the screw on the screw side by a plurality of screw catch valves (46a) which are each biased by a biasing member (46b). After the screw supply unit sucks up foreign matter, the screw tightening unit sucks and fixes the screw and pushes it downward, causing each of the screw catches to open radially outward from the screw tightening shaft, allowing the screw to pass through, and the screw tightening unit performs screw tightening, in a screw tightening device (T1).

2. The screw supply unit further includes a blowing section (48) that communicates with the bottom side of the screw catch section and blows the screw from the screw side to lift it up, and an upper dust collection section (49) that sucks up foreign matter from the screw head side of the screw that has been lifted up by the blowing section. The screw tightening device according to claim 1, wherein the cutting section rotates the hole and the screw catch section, into which the screw has been pressure-fed by the pressure-feeding section, around the cutting shaft (A4) so ​​that they overlap in the order of the lower dust collection section, the upper dust collection section, and the screw tightening shaft.

3. It comprises a screw tightening unit (1) and a screw supply unit (4), The screw tightening unit comprises a driver (12) rotatable around a screw tightening shaft (A1), and a suction pipe (11) that houses the driver, floats along the screw tightening shaft, and attracts screws. The screw supply unit has one or more receiving holes (45p) that receive the threaded portion of the screw at the bottom of the hole and one or more extraction holes (45q) through which the suction pipe can pass, alternately arranged in a disc-shaped circumferential direction, and includes a cutting section (44) that rotates the receiving holes and extraction holes around a cutting shaft (A2) so that they overlap the screw tightening shaft in order, a pumping section (43) that pumps the screw into the receiving holes, and a downward dust collection section (47) that communicates with the bottom of the receiving holes and sucks up foreign matter from the threaded portion side of the screw, A screw tightening device (T2) in which, after the screw supply unit sucks up foreign matter, the screw tightening unit sucks and fixes the screw, moves away from the cutting part, and when the cutting part aligns the hole with the screw tightening shaft, the screw tightening unit passes through the hole and tightens the screw.

4. The screw fastening device according to claim 3, wherein the cutting portion comprises multiple sets of the punching holes and receiving holes arranged in the circumferential direction.

Images