JPH04269132A - Screw tightening machine - Google Patents

Abstract

PURPOSE:To reduce a process time for work action of a screw tightening machine having a tightening device for taking a screw from a screw supplying part and tightening the screw to a screw tightening part of a subject material. CONSTITUTION:A pair of screw tightening devices for taking a screw from a screw supplying part, and tightening the screw to a subject material are provided, and whole screw tightening work is performed to the subject material in one tightening device, screw taking work from the screw supplying part for the other tightening device is performed simultaneously, and these actions are repeated respectively, so a process time for the screw tightening work is reduced.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention includes a pair of tightening devices, and when one tightening device is tightening a screw onto an object to be tightened, the other tightening device simultaneously grasps a screw from a screw supply section. This invention relates to a screw tightening machine that reduces the takt time of screw tightening work by repeating each of these operations.

0002

2. Description of the Related Art A conventional screw tightening machine will be explained based on FIG. FIG. 6 is a front view of a conventional screw tightening machine. In FIG. 6, one tightening device c is attached to a slide unit b that is moved left and right in the direction of arrow a. This tightening device c is moved up and down in the direction of arrow e by a cylinder d, and a bit g corresponding to a screwdriver that engages with the head of a screw f and rotates the screw f is mounted below it. A bit holder/vacuum chuck i, which is connected to a vacuum hose h and which sucks a screw f by vacuum action and also serves to hold a bit g, is attached to a tightening device c via a bracket (not shown). The above-mentioned tightening device c moves in the direction of arrow m,
It is moved as shown in n and p. In other words, the tightening device c controls the horizontal movement of the slide unit b in the direction of the arrow a,
In combination with the vertical movement of cylinder d in the direction of arrow e,
The bit holder/vacuum chuck i moves vertically as indicated by arrow m, horizontally as indicated by arrow n, and vertically as indicated by arrow p, and descends to position q directly above screw f which is in the supply position of screw supply section k.
, a position r raised from this position q, a position s moved leftward from this position r, and a reciprocating movement between this position s and a position t directly above the screw tightening portion of the object l.

The tightening device c of the conventional screw tightening machine has the following features:
Bit holder/vacuum chuck i picks up screw f at position q of screw supply part k, moves to position r by cylinder d, moves to position s by slide unit b, and from there moves to position t by cylinder d. At almost the same time, the bit g descends in the bit holder/vacuum holder i and engages with the head of the screw f, and this bit g tightens the screw f at the position t directly above the screw tightening part of the object l. Rotate and tighten the screw f to the object l. After tightening this screw f, the tightening device c moves from position t to position s, then to position r, and then returns to position q, and thereafter repeats the above operation. As a result, the next screw f is pitch-fed in the direction of arrow j and advanced to the supply position, and the next tightening position is prepared for the object l to be tightened.

In the above work process, the return process after tightening the screw f is an incidental time to the main work of screw tightening, so if it can be shortened as much as possible, it is a simultaneous process to shorten the takt time, and the work of the screw tightening machine can be reduced. It is desirable to improve efficiency. However, in conventional screw tightening machines,
Since there is only one tightening device c, a part of the series of steps described above from supplying the screw f to screw tightening cannot be performed simultaneously, making it difficult to shorten the takt time. was there.

[0005]

[Problems to be Solved by the Invention] In order to eliminate the above-mentioned drawbacks, the present invention provides a screw tightening machine with a configuration that allows simultaneous processes to be performed by changing the configuration of the screw tightening machine, thereby shortening the takt time. is intended to provide.

[0006]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention, as a first means, grips a screw from a screw supply section, carries the screw to a screw tightening section of an object to be tightened, and tightens the screw. A pair of tightening devices are provided, and the tightening operation of one tightening device and the operation of grasping screws from the screw supply section of the other tightening device are performed simultaneously and alternately.

As a second means, the pair of tightening devices each include a bit holder/vacuum chuck that attracts the screw by vacuum action and holds a bit that is engaged with and rotates the screw, and is attached to the vertical shaft by a support device. The support device is supported so as to be movable up and down in parallel to a symmetrical position, and the support device is rotated reciprocally through 180 degrees around the vertical axis to alternately move the pair of tightening devices to the screw tightening position. It also includes a driver device that engages with and rotates the bit of one of the tightening devices in the screw tightening position, and a driver device that moves the other tightening device in the screw supply section up and down. and a vertical movement device for moving.

[0008] In the screw tightening machine according to any one of the first and second means, the pair of screw tightening devices performs a tightening operation of one tightening device and a screw gripping operation from a screw supply section of the other tightening device. These operations are carried out simultaneously and alternately, and the supporting device is reciprocated by 180 degrees in the raised position of the pair of tightening devices, thereby simultaneously changing the working positions of the respective tightening devices.

[0009]

[Operation] According to this means, the screw tightening machine of the present invention has 1
Equipped with a pair of tightening devices, the tightening operation of one tightening device and the operation of grasping screws from the screw supply section of the other tightening device are performed alternately at the same time, and the tightening position of each and the work position are changed simultaneously. , it is possible to shorten the takt time of screw tightening work.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a screw tightening machine according to the present invention will be described with reference to FIGS. 1 to 5. FIG. 1 is a front view of a screw tightening machine according to an embodiment of the present invention, and FIGS. 2 to 5 are process explanatory diagrams showing enlarged portions A surrounded by a dashed line in FIG. First, Figure 1
The screw tightening machine includes a pair of tightening devices 1 and 2, and one of the tightening devices 1 grasps a screw 4 from a screw supply section 3 and conveys the screw 4 to a screw tightening section 6 of an object 5 to be tightened. Tighten this. At the same time, the other tightening device 2 grasps the screw 4 from the screw supply section 3, and thereafter repeats this operation to proceed with the screw tightening operation. A pair of tightening devices 1 and 2 attract screws 4 by vacuum action, and
Each bit holder/vacuum chuck 7 is provided to hold a bit 6 which is engaged with the screw 4 and rotated, and is supported by a support device 8 so as to be vertically movable parallel to a symmetrical position around a vertical axis 9. A vacuum hose (not shown) is connected to the vacuum chuck 7 as in the conventional case. The support device 8 is fixed to a vertical shaft 9, and as the vertical shaft 9 is driven by a rotary actuator 10, the support device 8 reciprocates 180 degrees, and at the end of rotation of the rotary actuator 10, a shock absorber 10a is activated. Absorbs shock at the end of rotation. A circular rail 11 is provided on the outer periphery of the bearing box of the vertical shaft 9, and a cam follower 12 rolling on the rail 11 is attached to the upper end of each of the pair of tightening devices 1 and 2, This supports the tightening devices 1 and 2 so that they do not move downward while the support device 8 is reciprocatingly rotated. At the end of the index rotation of the support device 8, the rail 11 is cut out, through which the cam follower 12 can freely pass, so that the tightening devices 1 and 2 can move up and down. A driver device 13 that engages with and rotates the bit 6 of one of the tightening devices 1 at the screw tightening position S is connected to the coupling portion 1 by a motor 13a through a transmission mechanism 13b.
3c, and the entire slide 13e is moved up and down by a cylinder 13d.
and the lower position T. At the end of this vertical movement, there is a shock absorber 1 that absorbs the shock when stopping.
4 is provided. The other tightening device 2, which is located at position R of one screw supply section 3, is moved up and down between an upper position R and a lower position Q by a vertical movement device 15. With the above configuration, one of the tightening devices 1 moves down from position S to position T with the screw 4 attracted in the previous process, and the bit 6 and the screw 4 are rotated by the driver device 13 to tighten the screw onto the object 5. 4 is tightened and moved up to position S, and at the same time, the other tightening device 2 moves down from position R to position Q, and the bit holder/vacuum chuck 7 attracts the screw 4 from the screw supply section 3. , rises to position R again. In this way, with the pair of tightening devices 1 and 2 elevated to positions R and S, the support device 8 reciprocates 180 degrees, with tightening device 1 moving from position R to position S, and tightening device 2 moving from position S to position S. Switch to position R. Thereafter, repeat the same operation to proceed with the screw tightening work. As described in the conventional example, the screw supply section 3 advances the next screw 4 to the supply position, and the object to be tightened 5 prepares the next tightening position.

Next, the operation of this screw tightening machine will be explained based on the process diagrams shown in FIGS. 2 to 5. FIG. 2 is an enlarged view of part A surrounded by a dashed line in the state shown in FIG. 1, and the process will be explained starting from this state. Figure 2
In this case, one of the tightening devices 1 is in the raised position S, and the screw 4 is attracted to the bit holder/vacuum chuck 7 in the previous process, and the driver device 13 is attached to the slide e by the cylinder 13d (Fig. 1). is about to be lowered. The other tightening device 2 at the same time is in the raised position R and is about to be lowered by the lifting device 15. In FIG. 3, one tightening device 1 is moved from position S to position T by lowering the driver device 13.
The screw 4 comes into contact with the tightening position of the object 5 to be tightened,
The other tightening device 2 is simultaneously lowered from position R to position Q by the vertical movement device 15, and the bit holder/vacuum chuck 7 attracts the screw 4 in the supply position of the screw supply section 3.

In FIG. 4, the other tightening device 2 remains in the state shown in FIG. 3, and the driver device 13 of one of the fastening devices 1 is further lowered than in the state shown in FIG. 13c is engaged with the bit 6, and the bit 6 is driven by the driver device 13. In FIG. 5, in one tightening device 1, the bit 6 is rotated and lowered to engage the head of the screw 4 as the driver device 13 rotates and lowers in accordance with the pitch of the screw 4. Since the screw 4 is rotated, the screw 4 is tightened to the object 5 to be tightened, and the other tightening device 2 rises from position Q to position R and waits while adsorbing the screw 4. After the tightening of the screw 4 is completed, the tightening device 1 moves upward from the position T to the position S by stopping the rotation of the driver device 13 and moving upward.

With one tightening device 1 raised to position S and the other tightening device 2 raised to position R, the rotary actuator 10 rotates the support device 8 by 180 degrees, and one tightening device 1 is moved to position R. From position S to position R, the other tightening device 2 changes positions from position R to position S, respectively, and assumes the positions indicated by (1) and (2) in FIG. Thereafter, as shown in (1) and (2) in FIGS. 3 to 5, the screw tightening work is continued by repeating the same operations as described above. Note that while the support device 8 is rotating, the cam follower 12 attached to the upper end of each of the pair of tightening devices 1 and 2 rolls on the circular rail 11 on the outer periphery of the bearing box of the vertical shaft 9. Therefore, the pair of tightening devices 1 and 2 has a structure that prevents them from falling. According to the screw tightening machine of this embodiment, it is equipped with a pair of tightening devices, and the tightening work and the screw gripping work are performed alternately at the same time, and the respective work positions are changed at the same time, thereby saving operating time. This reduces the takt time for screw tightening work.

[0014]

According to the present invention, a screw tightening machine is equipped with a pair of tightening devices, and one tightening device can tighten a screw onto an object to be tightened, and the other tightening device can tighten a screw from a screw supply section. This screw tightening machine has a structure that allows the gripping work to be performed at the same time and alternately, and the tightening positions and work position changes to be performed at the same time, which saves machine operation time and shortens the takt time of screw tightening work. can be provided.

[Brief explanation of the drawing]

[Fig. 1] Front view of a screw tightening machine according to an embodiment of this invention

[Figure 2]
A process explanatory diagram showing an enlarged view of part A surrounded by the dashed line in Figure 1

[Figure 3] Process explanatory diagram following Figure 2

[Figure 4] Process explanatory diagram following Figure 3

[Figure 5] Process explanatory diagram following Figure 4

[Figure 6] Front view showing a conventional screw tightening machine

[Explanation of symbols]

1 Tightening device 2 Tightening device 3 Screw supply section 4 Screw 5 Tightened object 7 Bit holder/vacuum chuck 8
Support device 13 Driver device 15 Vertical movement device c Tightening device f Screw k Screw supply section l Tightened object

Claims (3)

[Claims] Claim 1: A pair of tightening devices that grasp the screws supplied from the screw supply section, transport them to the screw tightening section of the object to be tightened, and tighten the screws. A screw tightening machine characterized in that a screw gripping operation is performed simultaneously and alternately in a screw supply section of a tightening device. 2. The screw tightening machine according to claim 1, wherein each of the pair of tightening devices includes a bit holder and a vacuum chuck that sucks the screw by vacuum action and holds a bit that engages with and rotates the screw. , supported by a support device so as to be vertically movable in parallel at symmetrical positions around the vertical axis;
The pair of tightening devices is rotated back and forth twice, thereby alternately moving the pair of tightening devices to the screw tightening position and the screw supplying position, and further engages the bit of one of the tightening devices in the screw tightening position. A screw tightening machine characterized by comprising: a driver device that rotates the bit; and a vertical movement device that moves up and down another tightening device located at a screw supply section. 3. In the screw tightening machine according to claim 1 or 2, the pair of tightening devices simultaneously performs a tightening operation of one tightening device and a screw gripping operation of the other tightening device. Further, a screw tightening machine characterized in that the support device is reciprocated 180 degrees in the raised position of the pair of tightening devices, thereby simultaneously changing the working positions of the respective tightening devices.