JPS61214927A - Automatic screw tightening machine - Google Patents

Abstract

PURPOSE:To enable a screw tightening machine to be formed in light portable weight further enable the machine to supply a screw corresponding to even the screw of any kind, by fixing a hopper, which stores the screw, in the vicinity of the main unit of the screw tightening machine. CONSTITUTION:The main unit of a screw tightening machine, consisting of a robot R, provides an electric motor driven driver D in an end wrist (d) of the second arm (c) in the main unit. A hopper H', storing a screw, is fixed to a bracket 3 protruding from a turning root part a'. The wrist (d) fixes an auxiliary chute 4 for conveying a screw to a screw supply part 9g) of the electric motor driven driver D. While the hopper H' connects with a hopper side chute 5 which connects with the auxiliary chute 4 and delivers to it a screw when the robot 4 comes to a screw supply position. A fixed quantity supply unit is provided in a connection part between the hopper side chute 5 and the auxiliary chute 4.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic screw tightening machine whose main body is a robot having multiple degrees of freedom.

``Prior Art'' Conventionally, automatic screw tightening machines are known in which an electric screwdriver is mounted on a Cartesian coordinate robot or a horizontal articulated robot.

Fig. 5 shows an electric screwdriver D attached to the wrist tip of the horizontal multi-joint robot R, and an electric screwdriver D attached to the wrist tip of the robot R.
This shows an automatic screw tightening machine equipped with a hopper H for stocking screws to be supplied to the machine.

That is, on the base a, there is a first
An arm b is attached, and a second arm C is attached to the tip of the first arm b, which can also work in a horizontal plane, and a wrist d provided at the tip of the second arm C is attached to the hopper H and the electric The driver D1 is further attached with an air cylinder e for driving the electric driver D up and down. rl and f are a motor that drives the first arm b and a motor that drives the second arm C, respectively, and the electric screwdriver D is moved to an arbitrary position by the operation of these motors '++'2 and the air cylinder e. Then, tighten the screws at that position.

A chute h is provided between the hopper H and the screw replenishing part g of the electric screwdriver D, and the screws picked up by the rake plate i of the hopper h pass through the screw replenishing part g. G is delivered in an aligned state to electric screwdriver D.
is supplied to

In the conventional device shown in FIG. 5, a hopper H is used to stock a large number of screws to be supplied to the electric screwdriver
is mounted on the tip of robot R's arm.

``Problems with the Prior Art'' By the way, such a hopper H usually weighs several tens of kilograms including the weight of the screws housed inside it, and since such a heavy object must be attached to the end of the arm,
It has the disadvantage that sufficient positioning accuracy cannot be guaranteed unless the rigidity of the entire robot is increased, and that the robot's movement speed cannot be increased very fast due to the increase in dynamic strain, resulting in poor work efficiency. are doing.

In order to eliminate the above-mentioned drawbacks, a hopper is fixedly installed near the robot R, and this hopper and the robot R
It is also possible to connect the screw replenishing part g of the electric screwdriver D at the tip of the screwdriver D with a flexible tube, and use compressed air supplied to this tube by pneumatic force to pneumatically transport the screws from the hopper to the screw replenishing part g. .

However, in this case, the shapes of screws that can be fed by pneumatic pressure are limited. For example, if the thread part of a screw is short compared to the screw head, the posture of the screw becomes unstable in the middle of the tube, so pneumatic feeding is not possible. Can not.

``Object of the Invention'' Therefore, the present invention fixes a hopper for storing screws near the main body of a screw tightening machine to reduce the allowable FM weight of the screw tightening machine, and also to reduce the weight of screws by fixing the hopper for storing screws in the vicinity of the main body of the screw tightening machine. An object of the present invention is to provide an automatic screw tightening machine that can be supplied.

"Structure of the Invention" The main means adopted by the present invention to achieve the above object are a screw tightening machine body consisting of a robot, an electric driver installed at the end of an arm of the screw tightening machine body, and a screwdriver installed at or near the base of the robot. a hopper fixed to the arm end of the screw tightening machine body to transport the screws to the screw supply section for the electric screwdriver; This automatic screw tightening machine is characterized in that it has a hopper side chute that is connected to the auxiliary chute and delivers screws to the auxiliary chute when the main body of the screw tightening machine comes to the screw supply position.

``Example'' Next, embodiments embodying the present invention will be described with reference to the accompanying drawings of FIGS. 1 to 4 to provide an understanding of the present invention.

Here, FIG. 1 is a front view of an automatic screw tightening machine according to an embodiment of the present invention, FIG. 2 is a plan view of the same screw tightening machine, and FIG. 3 is a perspective view showing an example of a chute used in the same screw tightening machine. 4(a) to 4(C) are plan views of the chute joint portion showing a state in which screws are transferred from the hopper side chute to the auxiliary chute.

Furthermore, in the following description, the same reference numerals are used for the same elements as those constituting the conventional device shown in FIG. 5, and the description thereof will be omitted.

Note that the following example is only one specific example of the present invention, and is not intended to limit the technical scope of the present invention.

In the case of this implementation device, the horizontal articulated robot R is mounted on the base a
It has a swing base a' on the top that performs a swing movement around a vertical axis, and when this swing base a' is driven to swing by the motor [, the first arm b attached to this swing base a' is rotated from the base. A 27th arm C swings around the stand a and is driven swingingly by a motor f2 at the tip of the first arm b.
It is the same as the conventional automatic screw tightening machine shown in Fig. 5 in that it is attached and that an electric screwdriver D and an air cylinder e are provided on the tip wrist d of this No. 27-50. .

However, this embodiment differs greatly from the conventional apparatus in which the hopper H is attached to the tip end of the arm of the robot R in that the hopper H' is fixed to a bracket 3 protruding from the swing base a'.

Further, an auxiliary chute 4 is fixed to the wrist d for conveying screws to the screw replenishing part g of the electric screwdriver D, and a robot R is attached to the hopper H' as shown in solid lines in FIGS. 1 and 2. As shown, a hopper-side chute 5 is connected to the auxiliary chute when it comes to the screw replenishment position, and which transfers screws to the auxiliary chute 4. In FIGS. 1 and 2, the state in which the auxiliary chute 4 and the hopper chute 5 are connected is shown by a solid line, and the auxiliary chute 4 is moved from the hopper chute 5 to the hopper chute 5 by swinging. The state where the two points are separated is shown by the two-dot chain dashed line.

Auxiliary chute as above 4. The structure of the hopper side chute 5 is schematically shown in FIG. 3, in which two oblique guide plates 6.6 are arranged in parallel, screws S are inserted between them, and the screws are slid downward in an aligned state. An example is something that can be transported.

Further, a quantitative supply device is provided at the connection between the hopper chute 5 and the auxiliary chute 4 so that a fixed amount of screw is fed from the hopper chute 5 to the auxiliary chute 4 at the time of connection.

In the example shown in FIG. 4, such a quantitative feeding device is provided in the chute 5 on the hopper side. That is, a quantitative supply lever 8 is attached to the side end of the hopper chute 5 via a bracket 7 so as to be swingable about a pin 9 perpendicular to the plane of the paper in FIG. Reference numeral 16 denotes a spring that biases the quantitative supply lever 8 to rotate in the counterclockwise direction in FIG. The tip l of this quantitative supply lever 8
O is bent at 90 degrees, and a guide piece 11 is formed at the tip 10, for example, at an angle of 45 degrees with respect to the tip 10, and the other end of the metering lever 8 is provided with the A separation piece 12 parallel to the tip 10 is formed by being bent at 90 degrees. The length of the quantitative supply lever 8 is shown in Figure 4 (
As shown in a), the fixed amount supply lever 8 is moved by the spring 16 so that its tip 10 is fixed to the tip 5. of the hopper side chute 5.
When the tip part 1 is rotated in the direction of contacting the
0 is the top screw S in the chute 5 on the hopper side.

The length is such that the screw S does not fall from the hopper chute 5 when the screws come into contact with each other, and an opening 13 is formed in the side surface of the hopper chute 5, so that the fixed quantity supply lever 8 can be moved as shown in FIG.
When the separator piece 12 is swung until it is parallel to the hopper chute 5 as shown in b), the separator piece 12 is inserted into the opening 13, and the tip of the separator piece 12 comes into contact with one of the aligned screws. The screw is configured to prevent it from slipping down in the transport direction.

Next, the operation of the above configuration will be explained.

Normal screw tightening work is performed by guiding the tip of the electric screwdriver D to the screw tightening position on the workpiece, and this is done by swinging the first arm b as shown by arrow X in FIG. The tightening work is performed by swinging the arm C in the direction of arrow y and raising and lowering the electric screwdriver D using the air cylinder e. For example, the screws stored in the auxiliary chute 4 are at the position shown by the two-dot chain line in FIG. A command is issued to robot R.

Such a replenishment command may be issued, for example, by counting the number of times a screw is tightened and when the value reaches a certain amount.Also, as shown in FIG. An optical sensor consisting of a light projecting section 14b is provided,
From the light emitter tab to the light receiver 14. The command may be generated when it is detected that there is nothing blocking the light reaching the light source.

When the replenishment command is issued in this way, robot R temporarily suspends the screw tightening work, swings No. 27-5C, and
As shown by the solid line in the figure, the auxiliary seat 4 is connected to the hopper side chute 5. This state is shown in FIG. 4, and FIG. 4(a) shows a state in which the auxiliary chute 4 approaches the hopper side chute 5 as shown by arrow 2.As the 0M auxiliary chute 4 approaches, , its tip abuts against the guide piece 11, and since this side piece 11 is inclined with respect to the traveling direction of the auxiliary chute 4, the guide piece 11 is pushed away,
As a result, the quantitative supply lever 8 swings in the direction shown by the arrow 15 in FIG. , and the leading screw Sl and the screws following it slide down along the auxiliary chute 4 from the inclined water 7p side chute 5 (at this time, as described above, the fixed quantity supply lever 8 rotates in the direction of the arrow 15 and becomes approximately parallel to the hopper chute 5, so that the separation piece 12 formed at the rear end of the fixed quantity supply lever 8 is inserted into the hopper chute 5 through the opening 13, and as shown in the figure. In the example, the separation piece 12 comes into contact with the seventh screw Sb counting from the leading screw Sl, and prevents this screw Sb and the screws following it from sliding down along the hopper side chute 5. Therefore, the leading screw Only Sl and six screws including this are transferred to the auxiliary chute 4.

In this way, when the screw 6111 is transferred to the auxiliary chute 4, the second arm C is swung, and as shown in FIG. 4<c>,
The auxiliary chute 4 is far away from the hopper side chute 5 (,
As a result, the quantitative supply lever 8 is rotated in the direction opposite to the arrow 15 by the force of the spring 16, and the separation piece 12 is pulled out from the opening 13 and the contact with the screw Sl is released. , screw Sl and the screw following it are attached to the tip 5. of the hopper side chute 5 as shown by the arrow. At this time, as the quantitative supply lever 8 swings, its tip 10 touches the tip 5. of the hopper-side chute 5.
The screw Sk is stopped at the tip of the hopper chute 5 to prevent the screw from passing through, and the screws following it are also kept aligned and stored in the hopper chute 5 as shown in Fig. 4(a). ) returns to the initial state shown.

In this way, a fixed amount of screws are transferred to the auxiliary chute 4 each time the auxiliary chute 4 is connected to the hopper side chute 5. Therefore, there is no need to constantly connect a large hopper to the auxiliary chute 4 side, and the robot arm The load at the tip becomes very small.

In the above embodiment, the quantitative feeding device is provided on the chute 5 on the hopper side, but the structure of such a quantitative feeding device is not limited to that shown in FIG. Furthermore, when an appropriate amount of screws that can fit into the auxiliary chute 4 side is supplied, the auxiliary chute 4 can be separated from the hopper side chute, thereby omitting the constant supply device.

As in the previous embodiment, the hopper described above can be integrally attached to the rotating base of the robot so that its direction can be changed as the rotating base rotates, so that it can simply be attached to the second hopper, regardless of the direction of the robot itself. The auxiliary chute 4 is connected to the hopper chute 5 by swinging only the arm C (replenishment position)
This reduces the time required for screw replenishment work.

However, if the hopper is particularly heavy or if a large number of hoppers storing various screws are used in parallel, such hoppers should be fixedly placed near base a to avoid placing a large load on the robot. It is also important to consider that there are no

In the above embodiment, an example was explained in which a horizontal articulated robot R was used as the main body of the screw tightening machine. An articulated robot may be used as the main body of the screw-driving machine, or the main body of the screw-driving machine according to the present invention may be constructed of a Cartesian coordinate robot or any other robot having l or more degrees of freedom.

"Effects of the Invention J As described above, the present invention includes a screw tightening machine body made of a robot, an electric driver provided at the end of the arm of the screw tightening machine body, and a screw storage device provided at or near the base of the robot. an auxiliary chute fixed to the arm end of the screw tightening machine body to transport screws to the screw replenishment section for the electric screwdriver; Since this automatic screw tightening machine has a hopper-side chute that is connected to the auxiliary chute and transfers screws to the auxiliary chute when the robot comes to the auxiliary chute, the load on the tip of the robot arm is reduced and the rigidity of the robot is increased. In addition to reducing dynamic strain, it has become possible to use a relatively low-cost, simple robot.

In the case of this invention, the hopper is installed at or near the base of the robot away from the screw tightening work area, so it is possible to replenish the hopper with screws even during screw tightening work, improving the continuity of the screw tightening work. This increases work efficiency. Furthermore, since there is no need to consider the weight of the hopper, a plurality of hoppers accommodating different types of screws can be provided, and a single robot can tighten various types of screws.

Furthermore, although the hopper can be installed near the base of the robot, there is no need for a tube for pneumatically feeding screws, making it possible to use short screws that cannot be fed using tubes, etc. became.

[Brief explanation of the drawing]

FIG. 1 is a front view of an automatic screw tightening machine according to an embodiment of the present invention, FIG. 2 is a plan view of the same screw tightening machine, and FIG. 3 is a perspective view showing an example of a chute used in the same screw tightening machine. Figure 4 (
1) to (C) are plan views of the chute joint showing the state of screw transfer from the hopper side chute to the auxiliary chute;
FIG. 5 is a perspective view showing a conventional automatic screw tightening machine. (Explanation of symbols) R...Robot D...Electric screwdriver H
'... Hopper a... Base b... 1st
Ar5 C...Second arm e...Air cylinder r,, r2...Motor g...Screw supply section 4...Auxiliary chute 5...Hopper side chute S...Screw 8.・Quantitative supply lever
12... Separation piece lO... Tip part. s1 Figure 2 Figure 5 f.

Claims (1)

[Scope of Claims] 1. A screw tightening machine body consisting of a robot; an electric driver provided at the end of an arm of the screw tightening machine body; a hopper provided at or near the base of the robot for storing screws; An auxiliary chute fixed to the end of the arm of the screw tightening machine body to transport screws to the screw supplying section to the driver, and an auxiliary chute fixedly connected to the hopper, so that when the screw tightening machine body comes to the screw supply position, Connected to the auxiliary chute,
An automatic screw tightening machine comprising: a hopper-side chute for delivering screws to an auxiliary chute; 2. The automatic screw tightening machine according to claim 1, wherein the hopper is installed at or near the pivot base of the robot.