JPH07110454B2 - Screw tightening device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a screw tightening device using a screw tightening machine of a type in which screws are pneumatically fed, and particularly suitable for use in a clean room. Regarding

(Prior Art) Conventionally, when a screw tightener is used in a clean room, an air pressure feed type is difficult to be adopted in a type in which a screw is pressure-fed by air because dust is emitted. Therefore, a method is adopted in which a screw positioned in advance at a predetermined supply position is grasped by a claw, air is sucked, and the screw is transferred to a work position (screw tightening position).

(Problems to be solved) However, such a method requires a step of returning the screw tightener to the screw supply position, gripping the screw again, and sucking air after each screw tightening work is completed. Therefore, the work efficiency cannot be improved.

(Means for Solving the Problem) The present invention has been made in view of the above circumstances, and includes a vertical screw tightener of a type that is attached to a support member and pressure-feeds a screw with air, and a screw feed position. A hollow arm rotatably supported between the lower side of the screw tightener and its horizontal retracted position, and a hollow arm that is provided in communication with the distal end of the hollow arm and has an opening on the upper surface and the lower end of the screw tightener. Suction pipe that can accommodate a portion, a notch formed in the side wall of the suction pipe, through which the lower end of the screw clamp can pass when the hollow arm is rotated, and a suction pipe connected to the proximal end side of the hollow arm. With a pump, the amount of air sucked from the suction pipe by the suction pump is set to be larger than the amount of air pressure fed by the screw, so that even a screw tightener that feeds the screw with air can be used without problems in a clean room. And the structure is simple The purpose of the present invention is to provide a screw tightening device with good work efficiency.

(Operation) When air is fed by force to the chuck of the screw tightener, the hollow arm is rotated to position the suction pipe from the retracted position to the lower part of the screw tightener, and the lower end of the screw tightener is placed inside the suction pipe. To house. Then, while sucking the air with the suction pump, the screw is pneumatically fed to the chuck portion of the screw tightener. At this time, since the amount of air sucked by the suction pump is larger than the amount of air to be pressure-fed by the screw, it is extremely unlikely that the air that pressure-feeds the screw will leak out from the opening or notch in the upper surface of the suction pipe. When the screw reaches the chuck portion, the air pressure feeding is stopped, the air suction by the suction pump is also stopped, and the suction pipe is retracted to the retracted position.

(Embodiment) In this embodiment, a description will be given of a case where a screw tightening machine SD of a system in which a screw S is pneumatically supplied is mounted as an end effector of a Cartesian robot RB having three degrees of freedom. It is not limited to the form.

1 is the base of the robot RB, and this base 1 has X
A horizontal horizontal guide 2 is provided. A movable body 3 is slidably supported on the guide 2, and a horizontal arm 4 is slidably supported on the movable body 3 in the Y direction. Further, a vertical arm 5 is supported at the tip of the horizontal arm 4 so as to be slidable in the Z direction. The screwing machine SD is supported by the vertical arm 5.

F is a supply device of the screw S, which is installed on the base 1. The supply device F is built in a guide 12 that guides the screw S carried out from a known feeder (not shown) to the base end of the air shooter 11, and a connecting portion 13 between the tip end of the guide 12 and the base end of the air shooter 11. The switching valve device 14, not shown in detail, is included.

A pressure source 15 is piped 16 upstream of the switching valve device 14.

SD is a screw tightener attached to a support member (lower part of the vertical arm 5) and is provided in the vertical direction. 21 is its main body, and a vertically movable rod 22 is inserted into this main body 21,
Moreover, it is urged downward by the force of the spring 23. A stopper 24 is provided on the upper end of the rod 22, and a stopper 24 is provided on the main body 21.
Dogs 25 facing 24 are provided to be adjustable. Reference numeral 26 is an upper driver case fitted on the rod 22 and vertically movable by a telescopic actuator A attached to the main body 21, and a motor 27 is erected on the upper end portion thereof. Reference numeral 28 denotes a driver connected to the output shaft of the motor 27, which is supported by the upper driver case 26 so as to be vertically movable, and is urged downward by the force of the spring 29. 30 is a lower driver case integrally provided at the lower end of the rod 22,
The upper driver case 26 is provided so as to be vertically slidable. The space between the driver cases 26 and 30 is covered with a bellows 31. Reference numeral 32 denotes a chuck portion integrated with the lower end portion of the lower driver case 30, and the tip portion of the air shooter 11 is connected to the chuck portion 32. An opening 26a is provided on the side of the upper driver case 26.
A suction pump 33 (a vacuum pump in the embodiment) is connected to the pipe 34 at 6a.
Has been done.

Reference numeral 41 is a suction pipe that is provided so as to be movable back and forth toward the lower portion (chuck portion 32) of the screw tightener SD and has an opening facing the lower surface of the chuck portion 32. The suction pipe 41 of this embodiment is vertically supported 43 by a member 42 projecting from the lower end of the vertical arm 5 and rotatable by a rotary actuator 44. A hollow arm 45 (horizontal pipe).
It is provided in communication with the tip. The communicating point is the lower end of the suction pipe 41. A pipe 46 is connected to the vacuum pump 33 on the base end side of the horizontal pipe 45. Further, on one side surface of the suction pipe 41, a notch 41a through which the lower part of the screw tightener SD can pass when the suction pipe 41 is rotated is formed.

The amount of suction from the suction pipe 41 is set to be sufficiently larger than the amount of discharge from the pressure source 15 blown out from the chuck portion 32.

Further, the operation of this embodiment will be described.

Now, it is assumed that each component is in the position shown by the solid line in the figure. That is, the suction pipe 41 is located below the screw tightener SD, and the driver 28
It is in a position where the screw S can be received by the chuck portion 32.

Then, the vacuum pump 33 is driven to drive both driver cases 26, 30.
The air inside is sucked, and also the air is sucked from the upper surface of the suction pipe 41 and the notch 41a.

Then, when one screw S guided by the guide 12 is present in the switching valve device 14, the switching valve is switched and the screw S is pressure-fed by the pressure air from the pressure source 15.
The screw S passes through the air shooter 11 and is caught by the chuck portion 32 in a predetermined posture. At this time, the dust-containing air is blown out downward from the chuck portion 32, but the blowout amount is sufficiently smaller than the suction amount of the suction pipe 41. Therefore, the chuck part 32
The air containing dust blown out from is almost sucked from the suction pipe 41 and is appropriately discharged to the outside of the clean room, or is sent to the clean room through a high performance filter. Therefore, there is almost no happiness that dust is scattered in the clean room.

Next, the rotary actuator 44 is driven to retract the suction pipe 41 to the position indicated by the two-dot chain line in FIG. Further, each control axis of the robot RB is driven to position the screw tightener SD above the female screw of the work (not shown). Then, the expansion / contraction actuator A is extended, the motor 27 is driven, and the driver 28 is rotated. Then, the upper driver case 26 and the rod 22 are integrally lowered until the stopper 24 contacts the dog 25. When the stopper 24 contacts the dog 25, the chuck
32 The lower surface is slightly above the upper surface of the work (not shown). After that, since only the upper driver case 26 descends, the lower driver case 30 is stored in the upper driver case 26, and as a result, the driver 28 presses the head of the screw S of the chuck portion 32 with the force of the spring 29. , The screw S is rotated by the motor 27 to tighten the work. During this time, the air containing dust in both driver cases 26, 30 tries to be discharged to the outside, but the air is sucked by the vacuum pump 33 from the opening 26a, and the air is sucked in the same manner as the suction from the suction pipe. Is released outside the clean room,
Alternatively, it is sent to a clean room through a high performance filter. Therefore, the dust is not nice to be scattered in the clean room.

(Effects of the Invention) As described above, according to the present invention, when the screw S is pneumatically fed, the suction pipe 41 is rotated from the retracted position to the lower part of the screw tightener SD to suck the lower end of the screw tightener SD. Housed in pipe 41,
Then, while sucking air with the suction pump 33, the chuck section
Although the screw S is pneumatically fed to the screw 32, the amount of air sucked by the suction pump 33 at that time is set to be larger than the amount of the pumped air of the screw S, so that the air (including dust) for feeding the screw S is sucked into the suction pipe 41.
There is very little possibility of leaking from the upper surface opening or the notch 41a, and there is no hindrance to use in a clean room, and when the supply of the screw S is completed, the suction pipe 41 is horizontally rotated to the retracted position. The screw tightening machine SD can be moved directly to the screw tightening position only by itself. Therefore, the screw tightener SD
It is not necessary to adopt a complicated structural design such as providing a dustproof cover at the lower end, etc., and it is not necessary to install a separate air discharge pipe in parallel with the rotating hollow arm 45 (also used as an air discharge pipe). The efficiency is also better than before.

[Brief description of drawings]

Each of the drawings shows an embodiment of the present invention, FIG. 1 is an overall explanatory view, FIG. 2 is a view taken along the line II-II of FIG. 1, and FIG. 3 is a view taken along the line III-III of FIG. is there. SD …… Screw tightener, 5 …… Support member (lower part of vertical arm),
33 ... Suction pump, 41 ... Suction tube, 41a ... Notch, 43
…… Vertical axis.

Claims (1)

[Claims] 1. A vertical screw tightener SD of a type which is attached to a support member 5 and supplies the screw S by air, and between the screw tightener SD below the screw tightener SD and its horizontal retracted position at the screw supply position. A hollow arm 45 that is rotatably supported by, and a suction pipe 41 that is provided in communication with the distal end of the hollow arm 45, has an opening on the upper surface, and is capable of accommodating the lower end of the screw tightener SD. ,
A notch 41a formed in the side wall of the suction pipe 41, through which the lower end of the screw tightener SD can pass when the hollow arm 45 is rotated.
And a suction pump 33 connected to the proximal end side of the hollow arm 45,
The amount of air suctioned from the suction pipe 41 by the suction pump 33 is set to be larger than the amount of pressure-fed air of the screw S.
Screw tightening device.