JPS61288946A - Absorbing type screw fastening device - Google Patents

Abstract

PURPOSE:To make it possible to confirm screw absorbing signals without dispersion,and make it possible to avoid incurring an accident of absorbing chip, by providing a pair of electrodes which are energized through a screw, in a screw absorbing unit so that signals indicating the absorption and release of a screw are detected by judging whether the electrode are energized or not. CONSTITUTION:When a screw fastening signal is received, a vertical drive actuator 2 descends to depress a bracket 3 which is secured to an absorbing pipe 10, and therefore, a rotary actuator 3, a bit 6 and a screw descend in the direction in which the screw is fastened. At this time since the bit 6 rotates, the bit 6 enters into a cruciform hole in a screw 8 when a screw fastening unit 7 is made into contact with an article 14 to be fastened by the screw 8, and initiates the rotation of the screw 8 which is therefore, tightened up. When the bit 6 depresses the screw 8, the head of the screw is separated from an electrode 9, and therefore, a separation signal is issued. Simultaneously, the suction of air through a suction hose 5 is stopped. Accordingly, chip which is produced during fastening of the screw and other dust are prevented from being sucked, thereby no failure occurs.

Description

Detailed Description of the Invention (Technical Field) The present invention adsorbs short screws sent out from a screw storage hopper to a screw suction unit, and tightens the screws at the corresponding location on the product (the member to be tightened). The present invention relates to a suction type screw tightening device that moves and performs rotational tightening using an actuator.

(Prior Art) Screw tightening using this type of suction type screw tightening device is widely applied to screws having a short overall length.

In this case, the suction hose is used to adsorb the screw to the suction unit; however, in this case, suction is confirmed by checking the degree of vacuum of the air from the suction hose.

However, with this suction confirmation method where a vacuum switch detects the screw suction and removal signals, the degree of vacuum varies due to chips and other debris during suction confirmation, and it takes time to confirm suction. It takes. In addition, since screw tightening also sucks in the inside, there is a drawback that sometimes generated chips are also sucked in when screw tightening is performed, resulting in failure of the device. For this reason, a method has conventionally been known in which a reed switch is used to stop the suction before the screw is tightened, but this method can only be applied when the tightening position is at a certain height. Therefore, there is a problem that there is no degree of freedom in the height direction.

(Objective) It is an object of the present invention to provide a suction-type screw tightening device that eliminates the drawbacks of the conventional example, allows the screw suction signal to be confirmed without variation, and prevents failure of the device due to the suction of chips. purpose.

(Structure) For this purpose, the present invention is characterized in that a signal for screw attraction and removal is detected based on whether or not an electrode attached to the screw attraction unit is energized.

In other words, the screw suction unit is energized by the screw! It has poles.

Hereinafter, the configuration of the present invention will be explained based on each illustrated embodiment.

FIG. 1 is a partial longitudinal sectional view of a suction type screw tightening device according to an embodiment of the present invention.

In the figure, reference numeral 1 denotes a rotation actuator for tightening a screw 8 by rotating a bit 6 attached to the tip of its shaft. 2 is an actuator for vertical driving;
It has a function of lowering and raising the suction vibrator 10, bit 6, and screw suction unit 7. A bracket 3 is fixed to the actuator 2 and the suction pipe 10, and transmits the driving force of the actuator 2 to the suction vibrator 10.

The suction pipe 10 has a hollow cylindrical shape, and the shaft portion of the actuator 1 and the bit 6 are fitted therein.

Further, a suction hose 5 is attached to the upper side of the screw tightening device, and this suction hose 5 sucks the air inside the screw tightening device to create a vacuum.

This screw tightening device is usually attached to the arm of the robot and the mounting surface 11 of the screw tightening device housing 4, and used as a screw tightening robot.

7 is a screw suction unit according to the main part of the present invention, and is made of an insulating material.

The screw suction unit 7 has a hollow shape and is attached to the lower end of the suction pipe 10. The tip of the bit 6 faces the inside of this screw suction unit 7. Further, a screw 8 can be fitted from below.

FIGS. 3(a) and 3(b) are a vertical sectional view and a bottom view of the screw suction unit 7 portion.

In the present invention, a pair of electrodes 9 are provided in the splinter suction unit, and are energized when the screw 8 is suctioned, thereby making it possible to detect the suction of the screw 8. FIG. 4 shows the state at the time of adsorption, and FIG. 5 shows the state at the time of detachment.

Further, FIG. 6 is a circuit diagram of the electrode 9.9, and the electrode 9.9 is connected to the DC power supply 15 via a relay 16. When electrical conduction occurs between the electrodes 9 and 9, the relay 16 is turned on, and a detection mechanism (not shown) connected to the relay 16 detects whether the screw 8 is attracted or detached.

Next, its operation will be explained. Upon receiving a screw tightening signal, the vertical drive actuator 2 descends and pushes down the bracket 3. Then, since the bracket 3 and the suction vibrator 10 are fixed, the rotary actuator 1, the bit 6, and the screw 7 also move downward in the direction of tightening the screw. At this time, bit 6 is rotating. Screw tightening is performed when the screw suction unit 7 comes into contact with the product 14 (as shown in Figure 5).
The bit 6 enters the cross recess of the screw 8, rotates the screw 8, and performs a screw tightening operation. When the bit 6 pushes down the screw 8, the electrode 9 and the screw head separate, resulting in a separation signal, and the suction of air from the suction hose 5 is instantaneously stopped. Therefore, screw tightening does not attract chips and other debris generated inside.

In this way, in the present invention, at the same time that the screw 8 is attracted to the screw suction unit 7, the electrodes 9.9 are connected to detect this, so there is no variation in detection accuracy (and, moreover, there is no variation in the detection accuracy). Inside, the electrodes 9.9 are non-conductive and no air is sucked in from the suction hose, so chips and other debris are not sucked in, so there is no possibility of equipment failure.

FIG. 2 is a partial vertical sectional view of a suction type screw tightening device according to a second embodiment.

This example is a stand-type screw tightening device, which is used while being fixed to a certain stand. And the device itself has a screw storage hopper 12.

(Effects) The present invention is as described above, and according to the suction type screw tightening device according to the present invention, signals for screw suction and removal can be generated by energizing the electrode attached to the screw suction unit using a vacuum switch method. Since the method has been improved to detect the presence or absence of dust, there is no need to suck in chips or other debris.
It is possible to improve trustworthiness.

[Brief explanation of drawings]

1 and 2 are partial vertical sectional side views of suction type screw tightening devices according to different embodiments of the present invention, and FIG. 3 shows a screw suction unit that is the main part thereof, (a ) is a longitudinal cross-sectional view, (b) is a bottom view, and Figures 4 and 5 are diagrams showing the relationship between the screw and the suction unit. FIG. 6 is a diagram showing a state in which the screws are being tightened, and FIG. 6 is a diagram of the current supply circuit of the electrode. DESCRIPTION OF SYMBOLS 1... Rotation actuator, 2... Vertical drive actuator, 3... Bracket, 5... Suction hose, 6... Bit, 7... Adsorption unit, 8...
Screw, 9... Electrode, 10... Adsorption pipe. Figure 1 Figure 2 Figure 3 Figure 5 Figure 4

Claims (1)

[Claims] A rotation actuator, a screw rotation bit provided at the tip of the actuator shaft, a suction pipe that fits this shaft and bit, and a suction hose attached, and moves this suction pipe up and down. In a device consisting of a vertical drive actuator and a screw suction unit attached to the tip of a suction pipe, the screw suction unit is provided with a pair of electrodes that are electrically connected through the screw, and this energization generates a signal for screw suction and removal. A suction type screw tightening device characterized by being designed to remove the screws.