Chuck Unit

Abstract

To provide a chuck unit which is so configured as to be capable of regulating oscillation of a chuck claw and to be capable of being easily designed.SOLUTION: A chuck unit 10 has a chuck body 20 through which a screw guide 60 is inserted, and a pair of chuck claws 30 capable of holding a fastening component is oscillatively arranged on the chuck body 20. The chuck unit comprises: a claw spring which always energizes the chuck claw 30 in a closing direction; a hose metal fitting 23 which crosses an oscillation face of the chuck claw 30 and extends obliquely backward; and a supply pipe 40 which is arranged between the hose metal fitting 23 and the chuck claw 30, and is capable of oscillating in a direction separating from the oscillation face of the chuck claw 30. The supply pipe 40 is provided with an oscillation regulation part 41 having a fitting claw 411 which fits to the closed chuck claw 30.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a chuck unit that holds a supplied fastening part. [Background technology]

[0002] A chuck unit for temporarily holding a fastening part such as a screw fed under pressure in a screw tightening machine or the like is disclosed in Prior Patent 1. This chuck unit includes a driver bit that can be fitted with a screw or a chuck body that guides a screw guide that includes the driver bit. The chuck body is equipped with a pair of chuck jaws that are attached so as to be able to swing, a supply pipe that supplies screws to the chuck jaws, and a torsion coil spring that constantly biases the supply pipe toward the chuck jaws. The chuck jaws of this chuck unit have holding holes formed on their opposing surfaces that can hold screws, and the supply pipe is always connected to the holding hole and is configured to swing in a direction away from the swinging surface of the chuck jaws as the driver bit advances toward the holding hole. The chuck unit is also provided with a swinging plate for regulating the swinging of the chuck jaws. The swing plate is provided between the supply pipe and the torsion coil spring, and includes a fitting portion that fits into the closed chuck jaws, an inclined surface that constantly abuts against the torsion coil spring, and an abutment portion that abuts against the supply pipe. Therefore, the swing plate is constantly biased toward the chuck jaws by the torsion coil spring, and can swing in conjunction with the swing of the supply pipe. The length of the fitting portion is set so that the fitting portion is completely disengaged from the chuck jaws just before the chuck jaws start to swing due to the tip of the screw guide passing through the chuck body. As a result, when the screw guide is connected to the holding hole, the swing plate can prevent the pressure-fed screw from pushing the chuck jaws open and jumping out, and can release the restriction before the screw guide pushes the chuck jaws open, allowing the chuck jaws to swing smoothly. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-107158 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the rocking plate used in the conventional chuck unit has a fitting portion that fits into the chuck jaws, an inclined surface that constantly contacts the torsion coil spring, and an abutment portion that contacts the supply pipe, as described above, and it was necessary to design these parts to match other components such as the supply pipe. In addition, the rocking plate is wider than the supply pipe and has a large configuration that extends from the same support shaft as the supply pipe to the chuck jaws, so the range of movement during rocking is wide. For these reasons, the conventional chuck unit has a problem that the design is complicated because it is necessary to design the rocking plate to match other components such as the supply pipe and to arrange the other components so as not to interfere with the rocking plate. [Means for solving the problem]

[0005] The present invention has been made in view of the above problems, and aims to provide a chuck unit that can regulate the swing of the chuck jaws and can be easily designed. To achieve this object, the present invention provides a chuck unit comprising a chuck body through which a driver bit engageable with a fastening part or a screw guide containing the driver bit is inserted, a pair of chuck jaws capable of holding the fastening part are arranged in a swingable manner on the chuck body, a jaw spring that constantly biases the chuck jaws in a direction to close the chuck jaws, a hose mounting bracket that crosses the swinging plane of the chuck jaws and extends diagonally backward, a supply pipe arranged between the hose mounting bracket and the chuck jaws and swingable in a direction away from the swinging plane of the chuck jaws, and a biasing member that constantly biases the supply pipe in a direction to connect the hose mounting bracket and the chuck jaws, characterized in that the supply pipe is provided with a swing regulating part having an engagement jaw that fits into the closed chuck jaws. It is preferable that the swing regulating part is detachable from the supply pipe. It is also preferable that the chuck body is provided with a sealing member for sealing the opening of the supply pipe swung by the screw guide. Furthermore, it is preferable that the opposing surfaces of the chuck jaws are formed with separate retaining holes for retaining screws, and the swing restricting portion is provided with a closing portion for closing the front of the retaining holes. Effect of the Invention

[0006] In the chuck unit of the present invention, the supply pipe is provided with a swing regulating part capable of regulating the swing of the chuck jaws, so that the swing regulating part can be made simpler and smaller in configuration than the swing plate used in the conventional chuck unit. Therefore, the chuck unit of the present invention has an advantage that it can be designed more easily than the conventional one using a swing plate. In addition, since the swing regulating part is smaller in configuration than the conventional swing plate used, and its movable range is narrower, it has an advantage that it can be installed in a narrow space. In addition, since the swing regulating part, which is relatively easily deformed and damaged by contact with the chuck jaws, is configured to be detachable, there is an advantage that only the swing regulating part can be easily replaced. Furthermore, the chuck body is equipped with a sealing member that seals the opening of the supply pipe that is swung by the tip of the screw guide, so that the next stage of screws can be supplied during the screw tightening operation, and there is an advantage that the cycle time is improved. Moreover, since the swing regulating part is provided with a closing part that can close the front of the holding hole, there is an advantage that even a screw that is easily popped out, such as a screw with a small difference in outer diameter between the head and the shaft, can be securely held. [Brief description of the drawings]

[0007] [Figure 1] 1A and 1B are diagrams showing the structure of a chuck unit according to the present invention, in which FIG. 1A is a plan view showing a state in which the chuck jaws are closed, and FIG. 1B is a plan view showing a state in which the chuck jaws are open. [Diagram 2] FIG. 2 is a side view showing the structure of a chuck unit according to the present invention. [Diagram 3] 5A and 5B are diagrams showing the structure of a chuck unit according to the present invention, in which FIG. 5A is a side cross-sectional view showing a state before a supply pipe oscillates, and FIG. 5B is a side cross-sectional view showing a state after the supply pipe oscillates. [Figure 4] FIG. 4 is a side view showing the structure of a second chuck unit according to the present invention. [Diagram 5] 5A and 5B are side views showing the structure of a second chuck unit according to the present invention, where (a) is a side cross-sectional view showing the state before the supply pipe oscillates, and (b) is a side cross-sectional view showing the state after the supply pipe has oscillated. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In Fig. 1 to Fig. 5, 10 is a chuck unit that temporarily holds a screw S, which is an example of a fastening part, pressure-fed from a supply device (not shown). As shown in Fig. 1, this chuck unit 10 is composed of a chuck body 20 that is installed on the movement path of a screw guide 60 that can suction and hold the screw S, a pair of chuck jaws 30, 30 that are supported by the chuck body 20 so as to be able to swing freely, and a supply pipe 40 that supplies the screw S to the chuck jaws 30, 30.

[0009] The screw guide 60 is a hollow member having a substantially cylindrical shape extending in the front-rear direction, and the hole diameter of the front opening is configured to be slightly larger than the head diameter of the screw S. A suction device (not shown) capable of sucking air is connected to the rear end of the screw guide 60, and the screw guide 60 is configured to be able to suck and hold the screw S at the front opening by driving the suction device. Furthermore, a driver bit 61 that can be fitted into a drive hole (not shown) formed in the head of the screw S is inserted inside the screw guide 60. The rear end of the driver bit 61 is connected to a rotary drive source (not shown), and is configured to be rotatable within the screw guide 60 by receiving the rotary drive. Moreover, the screw guide 60 and the driver bit 61 are connected to a reciprocating drive source (not shown), and are configured to be able to reciprocate in the axial direction by receiving the drive of the reciprocating drive source. In addition, the screw guide 60 is constantly biased forward by a cushion spring (not shown), and when this cushion spring flexes, the screw guide 60 moves axially relative to the driver bit 61, allowing the driver bit 61 to protrude from its front opening.

[0010] A guide hole 21 having a diameter larger than the maximum diameter of the screw guide 60 is formed through the chuck body 20, and the screw guide 60 can be inserted into the guide hole 21 in the axial direction. The pair of chuck jaws 30, 30 are attached to both sides of the chuck body 20 so as to be able to swing about the guide hole 21, and the chuck jaws 30, 30 are always biased so that the front side is closed by a jaw spring (not shown) sandwiched between the chuck body 20. A holding hole 31 is formed on the opposing surface of the chuck jaws 30, 30 on an extension line of the guide hole 21. The holding hole 31 is formed to have a diameter larger than the head diameter of the screw S, and is continuous with a guide hole 32 having a diameter larger than the neck diameter and smaller than the head diameter of the screw S in front of it. 2(a) and 2(b), the chuck jaws 30, 30 hold the screw S by abutting the head seating surface against the boundary between the holding hole 31 and the guide hole 32. The chuck body 20 is also formed with an inclined hole 22 that is inclined with respect to the guide hole 21 and whose extension lines intersect, and a hose mounting bracket 23 is installed in the inclined hole 22 to which a supply hose 62 extending from the supply device is connected. The hose mounting bracket 23 is a cylindrical member configured to allow the screw S to pass through, and the supply pipe 40 is installed between the hose mounting bracket 23 and the chuck jaws 30, 30.

[0011] The supply pipe 40 is also a cylindrical member configured to allow the screw S to pass therethrough, and is attached so as to be swingable in a direction away from the swinging surfaces of the chuck jaws 30, 30, with set screws 24, 24 provided on both sides of the chuck body 20 as support shafts. The supply pipe 40 is always in communication with the hose mounting fixture 23, and is biased by a torsion coil spring 25 so that its tip portion continues to the rear end portion of the holding hole 31 of the chuck jaws 30, 30, and the torsion coil spring 25 has its end wound around the set screws 24, 24. A swing restriction portion 41 is detachably connected to the tip of the screw guide 60. The swing regulating part 41 has two-pronged fitting claws 411, 411, which are configured to abut against the outer side surfaces of the chuck claws 30, 30 when the supply pipe 40 is positioned on the extension line of the guide hole 21, and forcibly regulate the opening of the chuck claws 30, 30. The fitting claws 411, 411 are sized so as to be disengaged from the chuck claws 30, 30 before the chuck claws 30, 30 are pushed open by the screw guide 60. Furthermore, the swing regulating part 41 is fixed so that the fitting claws 411 are positioned rearward of the tip of the supply pipe 40. A slight gap is provided between the fitting claws 411 and the chuck claws 30, 30 so that the supply pipe 40 can swing smoothly.

[0012] Next, the operation of the chuck unit 10 configured as above will be described. When a drive signal is input, the supply device pressure-feeds the screw S toward the chuck unit 10. The pressure-fed screw S is supplied to the holding hole 31 of the chuck jaws 30, 30 through the supply hose 62 and the supply pipe 40. At this time, the fitting jaws 411, 411 are fitted into the chuck jaws 30, 30, so that the chuck jaws 30, 30 are prevented from being pushed open widely by the compressed air for pressure-feeding the screw S, the impact when the screw S changes direction at the connection point between the supply pipe 40 and the chuck jaws 30, and the impact when the head seat of the pressure-fed screw S contacts the boundary portion of the holding hole 31 and the guide hole 32. Since the chuck jaws 30, 30 are prevented from swinging in this way, the supplied screw S stops with its head seat abutting against the tip of the holding hole 31 as shown in FIG. 3. As a result, the screw S is held inside the chuck jaws 30, 30 in the correct posture with the head guided by the holding hole 31 and the shank guided by the guide hole 32.

[0013] After the screw S is supplied to the holding hole 31 as described above, the reciprocating drive source and the suction device are operated to advance the driver bit 61 and the screw guide 60 toward the screw S, and air suction is started from the tip of the screw guide 60. As a result, the supply pipe 40 is pushed by the advancing screw guide 60 and swings in a direction away from the swinging surface of the chuck jaws 30, 30. At this time, as shown in FIG. 5, the swing regulating part 41 also swings in a direction away from the swinging surface of the chuck jaws 30, 30 in conjunction with the supply pipe 40. As a result, the fitting jaws 411, 411 are released from the chuck jaws 30, 30, and the chuck jaws 30, 30 can swing freely. In addition, as described above, the swing regulating part 41 is fixed so that the fitting jaws 411 are located rearward of the tip of the supply pipe 40, and the movable range of the swing regulating part 41 is reduced, which has the advantage of enabling fastening in a narrow place, etc. Thereafter, the screw guide 60 enters the holding hole 31 and adsorbs and holds the screw S in its front opening. At this time, since the screw S is held in the correct position in the holding hole 31 as described above, the screw S can be reliably adsorbed and held at the tip of the screw guide 60.

[0014] The screw guide 60, which has attracted and held the screw S as described above, is driven by the reciprocating drive source to move forward further. As a result, the screw guide 60 comes into contact with the chuck jaws 30, 30, gradually widening the chuck jaws 30, 30. At this time, the fitting jaws 411, 411 have already been disengaged from the chuck jaws 30, 30, and the chuck jaws 30, 30 can swing smoothly, so that the deflection of the cushion spring in the process of pushing the chuck jaws 30, 30 open is minimized. As a result, the driver bit 61 protrudes from the front opening of the screw guide 60, preventing the screw S from falling off, etc. After that, when the screw guide 60 protruding from the chuck jaws 30, 30 abuts against the surface of the fastened member (not shown), the cushion spring is deflected and only the driver bit 61 moves forward. At this time, the driver bit 61 rotates by being driven by the rotation drive source, and the driver bit 61 and the screw S are engaged in the screw guide 60, so that the screw S is fastened to the fastened member. Moreover, since the engaging claws 411, 411 are provided in the swing restriction portion 41, there is no need to provide a separate drive source for individually driving the torsion coil spring 25, the screw guide 60, etc., in addition to the reciprocating drive source for reciprocating the torsion coil spring 25, the screw guide 60, etc. This has the advantage of simplifying the control unit of a screw fastener or the like in which the chuck unit 10 is mounted.

[0015] The chuck unit 10 configured as described above can regulate the oscillation of the chuck jaws 30, 30 by the oscillation regulation part 41 provided at the tip of the supply pipe 40. Moreover, since the oscillation regulation part 41 has a simple structure consisting of a connection part with the supply pipe 40 and two-pronged fitting jaws 411, 411, it can be designed more easily than the oscillation plate used in the conventional chuck unit. Furthermore, since the oscillation regulation part 41 is configured smaller than the oscillation plate, there are advantages such as a narrower movable range and easier arrangement and design of other components. Moreover, since the oscillation regulation part 41 is configured to be detachable from the supply pipe 40, it is possible to easily replace only the oscillation regulation part 41 when it is deformed or damaged.

[0016] A chuck unit 10' according to another embodiment of the chuck unit 10 of the present invention will now be described with reference to FIG. The chuck unit 10' has the same basic configuration as the chuck unit 10, but differs in that a closing member 26 is provided on the chuck body 20 for closing the tip opening of the screw guide 60 when the screw guide 60 swings, and that the swing restricting portion 41 is provided with a closing portion 412 that is positioned on the extension line of the holding hole 31 of the chuck jaws 30, 30 when the supply pipe 40 is positioned on the extension line of the guide hole 21 and is capable of closing the front of the holding hole 31. The closing portion 412 is disposed within a range in which the distance to the tips of the chuck jaws 30, 30 is shorter than the axial dimension of the screw S and the distance to the boundary portion between the holding hole 31 and the guide hole 32 is longer than the axial dimension of the shank of the screw S. As a result, when the screw S is supplied, the head of the screw S is clamped between the chuck jaws 30, 30, and the head seating surface of the screw S can come into contact with the boundary portion of the retaining hole 31 and the guide hole 32, and at this time a slight gap is provided between the closure portion 412 and the tip of the shank of the screw S. In addition, the dimensions of the closure portion 412 are set so that it leaves the extension line of the retaining hole 31 before the screw guide 60 protrudes from the chuck jaws 30, 30, and opens the front of the retaining hole 31.

[0017] Next, the operation of the chuck unit 10' will be described. In the chuck unit 10', when the supply pipe 40 is oscillated by the screw guide 60 during a screw tightening operation, the tip opening of the screw guide 60 is closed by the sealing member 26. Therefore, it is possible to supply the next screw S while the supply pipe 40 is oscillating, as shown by the two-dot chain line in FIG. 5(b). Since the next screw S can be supplied during the screw tightening operation, the cycle time is improved. In this way, the screw S supplied to the supply pipe 40 is supplied into the holding hole 31 when the screw guide 60 retreats and the supply pipe 40, which is urged by the torsion coil spring 25, continues to the holding hole 31. At this time, since the oscillation of the chuck jaws 30, 30 is restricted by the fitting jaws 411 as shown in FIG. 4, it is possible to urge the screw S by compressed air or the like during the supply. By urging the screw S by compressed air in this way, the screw S can be supplied to the holding hole 31 regardless of the direction in which the chuck unit 10 is facing, and for example, it is possible to tighten the screw upward, and the cycle time is further improved. In addition, since the front of the holding hole 31 is closed by the closing portion 412 provided on the swinging restriction portion 41, the supplied screw S is prevented from slipping out of the chuck jaws 30, 30. Therefore, even a screw having a small difference between the head diameter and the shank diameter and a head seating surface that is likely to come off the boundary portion of the holding hole 31 and the guide hole 32 can be stably held, and damage to the workpiece due to the screw that has come out colliding with the workpiece is prevented. Furthermore, since the front of the holding hole 421 is closed by the closing portion 412 in both cases when the screw S is pressure-fed from the supply device to the supply pipe 40 and when it is pressure-fed from the supply pipe 40 to the holding hole 421, the compressed air for pressure-fed the screw S is prevented from being ejected from the tip of the holding hole 421 and directly hitting the workpiece. As a result, it is possible to tighten the screw even in a workpiece such as an electronic board on which the adhesion of foreign matter such as dust and moisture contained in the pressure-fed air is undesirable. Furthermore, as described above, the closure portion 412 is set so that when the head seat of the screw S abuts against the tip of the retaining hole 31, there is a slight gap between the closure portion 412 and the tip of the screw S, and only the screw S that does not stop in the retaining hole 31 is positioned in a position where it can collide.This prevents the screws S from flying out, while at the same time making the closure portion 412 less likely to deform or break compared to a configuration in which all of the screws S collide with the closure portion 412, allowing for long-term use.

[0018] 5, the closure part 412 moves with the supply pipe 40 and leaves the path of movement of the screw guide 60 before the screw guide 60 projects from the chuck unit 10. Therefore, the closure part 412 does not interfere with the screw guide 60. As a result, the closure part 412 and the screw guide 60 come into contact with each other, and the screw S held in the screw guide 60 is prevented from falling out or losing its position. This prevents poor engagement between the screw S and the driver bit 61 and displacement from a pilot hole (not shown) formed in a workpiece (not shown), improving the screw fastening accuracy.

[0019] The chuck unit 10 according to the present invention is not limited to the above, and various modifications are possible within the scope of the invention. For example, in the present invention, as long as the swing of the chuck jaws 30, 30 is restricted by the swing restricting portion 41 provided on the supply pipe 40, there is no problem even if only the driver bit 61 is inserted into the chuck body 20 or only the screw guide 60 is inserted into the chuck body 20. In addition, the torsion coil spring 25 is an example of a biasing member for biasing the supply pipe 40 in the direction connecting the hose mounting bracket 23 and the chuck jaws 30, and there is no problem even if it has another configuration. [Explanation of symbols]

[0020] 10,10′… Chuck unit 20 … Chuck body 30 ... Chuck jaws 31 … Retaining hole 32 ... Guide hole 40 … Supply pipe 41 ... Swing control part 411 ... Interlocking claws 412 … Closing part 60 ... Screw guide 61 ... Driver bit S: Screw

Claims

1. a chuck unit including a chuck body through which a driver bit engageable with a fastening part or a screw guide containing the driver bit is inserted, a pair of chuck jaws capable of holding the fastening part are arranged in a swingable manner on the chuck body, a claw spring which constantly urges the chuck jaws in a direction to close, a hose mounting bracket which intersects with the swinging plane of the chuck jaws and extends diagonally backward, a supply pipe which is arranged between the hose mounting bracket and the chuck jaws and swingable in a direction away from the swinging plane of the chuck jaws, and a biasing member which constantly urges the supply pipe in a direction to connect the hose mounting bracket and the chuck jaws, The supply pipe is provided with a swing regulating portion having an engagement claw that is engaged with the closed chuck claw, The chuck jaws have opposing surfaces each having a holding hole formed therein for holding a screw, The chuck unit is characterized in that the swing regulating portion is provided with a closing portion that closes the front of the holding hole.

2. 2. The chuck unit according to claim 1, wherein the swing restriction portion is configured to be detachable from a supply pipe.

3. 3. The chuck unit according to claim 1, wherein a sealing member is attached to the chuck body for sealing an opening of the supply pipe swung by a screw guide.

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