JPH0637869Y2 - Screw check device of screw tightener - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a screw check device provided in the screw tightening machine in order to monitor the screw tightening work in the screw tightening machine.

<Prior Art> A so-called screw tightener is used as an automatic device for attaching various mechanical parts to a device frame or the like.

FIG. 3 is a perspective view showing a main part of a driver mechanism portion of a conventional screw tightener, and FIG. 4 is a sectional view showing an internal structure of a portion to which the screw check device of FIG. 3 is attached. FIG. 5 shows an enlarged configuration diagram of the screw check device portion of FIG. FIGS. 6 (a) to 6 (c) are explanatory views of a screw floating determination operation by a conventional screw check device.

In the figure, reference numeral 1 is a main body of a driver mechanism D for executing a screw tightening operation of a screw tightener, and a casing pipe 2 having a screw check device A described later is screwed or integrally formed at a lower end thereof (FIG. 4). Indicates screwing). The casing pipe 2 has a suction pipe 3 of a required length that slides in the axial direction.
One end side (upper end side) of the is inserted. As shown in FIG. 4 showing the internal construction of the suction pipe 3, the end portion of the suction pipe 3 is
The casing pipe 2 is connected to a sliding bush 5 which is repulsively urged by a compression spring 4, and a suction pipe 3 and an air vacuum device ( (Not shown). The sliding bush 5 can slide within a set range in the casing pipe 2, and a long hole 2a corresponding to the sliding range is formed on the side wall of the casing pipe 2 from which the hose joint 5a projects. Reference numeral 2b is a stopper ring that restricts the sliding bush 5 from coming out of the casing pipe 2.

Reference numeral 6 denotes a bit, which is coaxially inserted through the suction pipe 3 so that the upper end is integrally fixed to a rotating shaft (not shown) in the main body 1 and the lower end is engaged with the head of the component screw SC to be tightened. It is formed to fit. The bit 6 has a lower end from the lower end opening of the adsorption pipe 3 when the screw tightening operation is not performed (as shown in FIG. 4, the sliding bush 5, that is, the adsorption pipe 3 is advanced to the lowest position). The length is such that it does not protrude and is pulled in slightly inside.

Next, the screw check device A will be described with reference to FIG.

For example, a flat surface portion 2c is formed on the side surface of the casing pipe 2, and the bracket plate 7 is attached with screws 8. The bracket plate 7 has a screw hole 7a formed as a long hole in the same direction as the axial direction of the bit 6 so that the position can be adjusted.

Reference numeral 9 denotes a micro switch, which activates a required warning lamp or the like depending on the fastening state in the work of fastening the component screw SC, and is fixed to the bracket plate 7. 10 is a switch lever, which is a post 11 protruding from the bracket plate 7.
The middle part is supported by and the seesaw can move freely. One end side 10a of the switch lever 10 is a micro switch 9
Face the switch button 9a (see FIG. 6) of the other end 10
b faces the surface of the long hole 2a of the casing pipe 2. The other end side 10b is pushed up by the hose joint 5a integrally connected to the suction pipe 3 when the casing pipe 2 (main body 1) is lowered by a required amount relative to the suction pipe 3. Then, this allows the switch lever
One end side 10a of the switch button 9 of the micro switch 9
The switch circuit is turned off by depressing a. In order to ensure that the above operation of the switch lever 10 is performed, one end side of the switch lever 10
10a urges the switch button 9a of the micro switch 9 in a direction of pressing it.

As shown in FIG. 3, the driver mechanism D having the above-described configuration has a holder H attached to a robot arm (not shown) of a screw tightener body (not shown) and a main body portion 1 or a casing pipe 2 portion. Be held.

The driver mechanism D sucks the component screw SC supplied to a predetermined position by a part feeder or the like (not shown) to the suction pipe 3
Hold in. Next, the robot arm conveys the work to the position to be fastened, and by driving the bit 6, the work is fastened by screwing it into the fastening member WB through the fastened member WA which is the work (see FIG. 6).

By the way, in the screw fastening, a fastening failure may occur. The main cause of this improper fastening is, for example, the lift of the component screw SC, and the other cause is the lack of the component screw SC.

The former floating of the component screw SC is caused by a defect in the tap processed on the fastening member WB side or a defect in the threaded portion, and the component screw SC cannot be tightened because the fastened member WA cannot be tightened. It means to be in a floating state.

In addition, the latter missing of the component screw SC means a state where the fastening operation is performed without adsorbing the component screw SC, or the fastening operation is performed by dropping the component screw SC carelessly during transportation and leaving the missing component state. Is.

Therefore, conventionally, the floating of the component screw SC is detected by the screw check device A of the driver mechanism D described above. In addition, the missing of the component screw SC is relatively often caused by a supply error at the time of supply by a part feeder or the like, so that the presence or absence of the component screw SC at a predetermined position on the supply side is detected.

The operation of the screw check device A for detecting the floating of the component screw SC will be described below with reference to FIG.

FIG. 6 (a) shows the position of the bit 6 and the operation relationship of the screw check device A in the initial state before the fastening work of the component screw SC, and (b) shows the normal fastening completion state. (C) shows the floating state of the component screws.

In the initial state, as shown in FIG. 4, the suction pipe 3 is pressed by the compression spring 4 and is located at the lowermost end, and the bit 6 is relatively drawn at the lower end into the suction pipe 3 by a required amount. There is.

At this time, as shown in FIG. 6 (a), the switch lever
Since 10 is not pushed up by the hose joint 5a, its one end side 10a presses the switch button 9a of the micro switch 9, and for example, turns on the switch circuit.

In this state, the component screw SC
Is sucked, conveyed to the work position, and screwed into the fastening member WB through the fastened member WA.

When the fastening work is performed as expected, as shown in FIG. 6B, the suction pipe 3 that is in contact with the surface of the fastened member WA.
On the other hand, the bit 6 descends to a predetermined position. Then, the casing pipe 2 also compresses the internal compression spring 4 and slides and descends relative to the sliding bush 5 of the adsorption pipe 3.

At the time of normal fastening of the component screw SC, if the descending amount of the casing pipe 2 and the position of the hose joint 5a pushing up the switch lever 10 are aligned, the pressing of the switch button 9a of the micro switch 9 is released at the time of the above normal fastening, That is, the switch circuit is turned off.

When the fastening of the component screw SC becomes defective and the component screw SC floats from the surface of the fastened member WA by x amount as shown in FIG. 6C, if this exceeds the predetermined amount, Since the bit 6 does not descend, that is, the hose joint 5a cannot push up the switch lever 10, and the micro switch 9 eventually remains in the ON state to notify the fastening failure.

<Problems to be Solved by the Invention> The predetermined ON / OFF operation position of the microswitch 9 can be adjusted by moving the bracket plate 7 through its screw hole 7a.

However, the fine adjustment of ON / OFF of the micro switch 9 for the fastening failure that is likely to occur due to a slight floating is complicated, and it is difficult to make an accurate setting.

Further, even if there are few accidents in which the component screw SC sucked by the suction pipe 3 is dropped during the transportation, once it is dropped, the subsequent fastening work becomes completely defective. Therefore, the conventional device, which can easily determine that this is a normal fastening, still has a problem in practicability in this respect as well.

The present invention has been made in order to solve the above-described conventional problems, and its purpose is to detect a floating of a component screw as well as to detect a missing portion during fastening work of the component screw. An object of the present invention is to provide a screw check device capable of easily and accurately setting the position.

<Means for Solving the Problems> In order to achieve the above object, the present invention fixes a bit having a shape in which a tip is engaged with a screw head of a component to a rotary shaft of a driver mechanism of a screw tightening machine, and The part screw is held by a suction pipe that is inserted in the bit and is movable relative to the bit, and the part screw is screwed into the fastening member through the member to be fastened to the fastening member with the bit, and the tightening This is a screw check device that checks the fastening state.A holder arm that interlocks with bit movement is attached to the casing pipe of the driver mechanism, and a check shaft of an appropriate length is urged to this holder arm by a spring in one axial direction. Then, it is provided so as to be movable to the other side by an engagement lever provided in conjunction with the suction pipe, and a sensor for detecting both ends of the movement of the check shaft is provided on one side. Is for screwless detection, and the other side is provided for screw floating detection with a detection position adjusting mechanism.

<Action> For example, if the circuits of both sensors are judged to be abnormal in the ON state and normal in the OFF state,
When the bit is lowered to a predetermined position, the engagement lever engages with the check shaft and lifts the check shaft by a required amount so that the bit moves away from the detection range of the screw floating detection sensor (moves upward). Then, the other screwless detection sensor is set outside the required range of movement. As a result, neither the screw lift detection sensor nor the screw non-detection sensor in the normally fastened state detects the set end positions of the check axis.
The state becomes F, that is, it can be determined to be normal.

Also, in the above setting, when the fastening is completed with the component screws floating, the bit does not descend to the predetermined position, so the engagement lever cannot engage with the check shaft and the check shaft does not move upward. Become. Then, since the screw floating detection sensor is still in the ON state, when the fastening end operation is performed in this ON state, the screw floating state is determined.

Next, when the component screw comes off from the suction pipe during transportation to the fastening member side and the fastening operation is started with the product missing, the bit further goes down beyond the normal screw fastening position.

Then, the engagement lever that engages the check shaft during the downward movement relatively moves the check shaft upward as the bit descends. As a result, when the screwless detection sensor detects the check axis, it is turned on, that is, the screwless state is determined.

In this way, a check shaft that moves in the axial direction relatively as a shaft parallel to the bit is provided, and both end positions of this check shaft are detected to detect the screw floating state and the screw-free state during fastening work. It is possible to reliably detect the screw fastening position.

In this case, if the detection position of the screw floating detection sensor is set by the scale of the adjusting mechanism in order to detect the slight amount of screw floating, more accurate setting can be performed.

<Embodiment> A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of an essential part showing a configuration of a screw check device according to the present invention, and FIGS. 2 (a) to (c) are operation diagrams for judging a fastening state of a component screw by the screw check device according to the present invention. It is an explanatory diagram, (a) shows the position of the bit and the operating state of the screw check device in the absence of screws, (b) shows the screw floating state, and (c) shows the normal screw fastening completed state. ing.

In the embodiment, the main body portion of the driver mechanism (not shown), the casing pipe 2, the suction pipe 3, the bit 6, etc.,
Since the operation mechanism part of the screw fastening work is the same as the mechanism of the part excluding the screw check device A of FIGS. 3 to 5, the same reference numerals are given and the repetitive description of the configuration is omitted.

In the figure, 20 is a holder arm for mounting the main part of the screw check device, which is vertically elongated on the side surface of the casing pipe 2 in the same direction as the axial direction of the bit 6 and fixed by a screw 21 or the like in an E-shape when viewed from the side. is doing. The upper stage of this E-shape is the upper arm 20a, the middle stage is the middle arm 20b, and the lower stage is the lower arm 20c.

Reference numeral 22 is a bracket attached to the upper arm 20a of the holder arm 20 with a screw 22a, and holds a sensor 23 for detecting no screw. The bracket 22 has a long hole 22b formed in a mounting portion with a screw 22a so that the setting position of the screwless detection sensor 23 can be adjusted with respect to the upper arm 20a. The screwless detection sensor 23 uses, for example, a photoswitch composed of a light emitting / receiving element, and detects one end (upper end) of a check shaft described later.

Between the middle arm 20b and the lower arm 20c, the position can be adjusted by an adjustment plate 24 having a long hole 24a.
The slide block 25 is disposed so as to be held by. 26
Is a compression spring that is provided between the middle arm 20b and the slide block 25 and urges both in a repulsive direction.
It is attached to a slide shaft 27 which penetrates 20b and the slide block 25 and is prevented from coming off by an E ring 27a. Although only the end is shown in the drawing, two slide shafts 27 are provided. This allows the slide block 25 to be carelessly placed on the side of the middle arm 20b when the screw 24b of the adjustment plate 24 is loosened to adjust the position of the slide block 25 when working as the driver mechanism DA in the vertically inverted posture in the drawing. I try not to move. In this case, if the end of the slide shaft 27 is a bolt screw and the E ring 27a is a nut, the slide block 25 can be operated by operating this nut.
Since the position can be adjusted, the adjustment plate 24 can be omitted to simplify the configuration.

On the upper surface of this slide block 25, a screw floating detection sensor 28 passed from the lower surface side is faced. The screw floating detection sensor 28 uses, for example, a so-called proximity switch, and detects the other end (lower end) of the check shaft described later.

Reference numeral 29 is a micrometer as a detection position adjusting mechanism of the screw float detection sensor 28, and is fixed to the lower arm 20c from below so that the spindle 29a thereof comes into contact with the lower surface of the slide block 25. As a result, the spindle block 29a presses and slides the slide block 25 when required, and the slide amount is read on the scale 29b.

Reference numeral 30 is a check shaft of an appropriate length, which slidably penetrates the upper arm 20a and the middle arm 20b, the upper end 30a is near the position corresponding to the screwless detection sensor 23, and the lower end 30b is a screw float. It faces the vicinity of the position facing the detection sensor 28.
A flange 30c is formed on the upper surface side of the upper arm 20a of the check shaft 30, and a compression spring 31 and a receiving ring 32 are mounted on the lower surface side of the upper arm 20a to prevent the check shaft 30 from coming off the upper arm 20a. And a moving force is given to one side (lower side) in the axial direction. The upper end 30a of the check shaft 30 is a sensor for detecting no screw when the flange 30c is pulled by the compression spring 31 toward the upper arm 20a and is in contact therewith.
The length is set so that it does not reach the 23 shaft end detection position. This can actually be adjusted by adjusting the position of the screwless sensor 23 with the bracket 22.

The receiving ring 32 has a stop screw 32 for the operation described later.
By a, the check shaft 30 can be locked at any position.

Reference numeral 33 is an engagement lever, and one end side of the hose joint 5a integrally connected to the suction pipe 3 is a slot 33a and a tightening screw 33b.
The position can be adjusted freely with and the groove 33c is formed on the other end side.
The check shaft 30 is inserted into the groove 33c so as to face the lower portion of the receiving ring 32.

In such a configuration, the basic operations of the engagement lever 33, the receiving ring 32, and the check shaft 30 are related as follows.

When tightening the component screw SC (see FIG. 2) with the bit 6, the holder arm 20 fixed to the casing pipe 2 also descends as the bit 6 descends.
30 goes down as well. Further, since the engagement lever 33 is attached to the hose joint 5a of the suction pipe 3 that moves relatively to the bit 6, even if the check shaft 30 descends, the attachment position remains unchanged.

Then, when the bit 6 falls by the required amount, the receiving ring 32
Contacts the engagement lever 33. If the bit 6 descends even after this abutment, the check shaft 30 is prevented from further descending due to the abutment of the receiving ring 32 that is engaged with the engagement lever 33, so that the compression spring 31 is compressed. Holder arm
Rise relative to 20.

With such an operation, when used as a screw check device, first, it is necessary to set detection positions for the upper end portion 30a and the lower end portion 30b of the check shaft 30 of the screwless detection sensor 23 and the screw floating detection sensor 28. .

The above setting will be described with reference to FIG.

First, in setting the screwless detection position, as shown in FIG. 2A, the component screw SC is not held on the suction pipe 3 but is brought into contact with the surface of the member WA to be fastened in a missing state. Then, the bit 6 is lowered, and the tip 6a of the bit 6 is positioned at a position sufficiently lower than the head height of the component screw SC to be used (for example, a level almost in contact with the surface of the fastened member WA). In this state, the position of each of the engagement lever 33, the receiving ring 32, and the bracket 22 is adjusted, the engagement lever 33 lifts the receiving ring 32, and the upper end portion 30a of the check shaft 30 is detected by the screwless sensor 23. Set to detect and turn on.

Next, the screw floating detection position is set.

As shown in FIG. 2 (c), this first sets the state in which the bit 6 normally tightens the component screw SC. Then
The screw block detection sensor 28 raises or lowers the slide block 25 to the OFF position where the lower end 30b of the check shaft 30 is no longer detected. Then, read the scale of the micrometer 29 at the OFF position, and read the micrometer from that position.
29 is operated to lower the slide block 25, that is, the screw floating detection sensor 28 by about 0.25 mm and fix the position.

The reason for lowering the height by about 0.25 mm is that variations in the height of the component screw SC are generally likely to occur by about 0.1 to 0.2 mm, and this variation is absorbed to detect the screw lift accurately.

After the detection positions of the screwless detection sensor 23 and the screw lift detection sensor 28 are set in the above procedure, the screw check is used for the screw check.

That is, as shown in FIG. 2A, when the suction pipe 3 does not hold the component screw SC when the fastening member WA and the fastening member WB are fastened, the bit 6 is excessively lowered. . Then, since the check lever 30 is lifted by the engagement lever 33, the screwless detection sensor 23 detects the upper end portion 30a of the check shaft 30 and issues an ON signal.

Further, as shown in FIG. 2B, when the fastening is completed with the component screw SC lifted by the amount x from the surface of the fastened member WA, the check lever 30 cannot be lifted by the engagement lever 33. Therefore, the lower end portion 30b of the check shaft 30 cannot be separated from the detection operation position of the screw floating detection sensor 28, whereby the screw floating detection sensor 28 keeps emitting the ON signal and notifies the abnormality.

If the component screw SC is properly tightened,
As shown in FIG. 3C, the check shaft 30 is lifted by a required amount by the engagement lever 33. With this lifting, the upper end portion 30a of the check shaft 30 does not reach the detection position of the screwless detection sensor 23, and the lower end portion 30b of the screw shaft detection sensor 28.
Since they are separated from the detection operation position of, the respective detection signals are turned off, and it can be determined that the normal screw fastening state is established.

In the above embodiment, each component of the screw check device is not limited to the shape and the like described above, but can be variously modified without departing from the intended purpose.

For example, the holder arm 20 may be C-shaped instead of E-shaped when viewed from the side, and the slide block 25 may have a slidable connection structure of a dovetail groove type with the body surface of the holder arm 20.

The screwless sensor 23 and the screw float sensor 28 are
Instead of detecting both end portions of the check shaft 30, it is also possible to use, for example, a reflection type photo sensor or the like that identifies a line or the like marked on a required portion of the check shaft 30 at both ends of its moving position.

Further, the engagement lever 33 may be attached to one side of the hose joint 5a by projecting a bracket or the like from the bush 5 in the same manner as the hose joint 5a, for example.

<Effect of Device> As described in detail above, according to the present invention, the screw check device provided in the driver mechanism detects the unthreaded state and the tightened state of the component screw at the fastening work position with respect to the member to be fastened. Since the determination can be made, the screw tightening work can be performed more accurately, and thus the occurrence of work failure can be suppressed very effectively.

Further, since the screw floating detection sensor is provided with the detection position adjusting mechanism, accurate fine adjustment can be performed by an extremely simple operation.

[Brief description of drawings]

FIG. 1 is a perspective view of a main part showing a configuration of a screw check device according to an embodiment of the present invention, and FIGS. 2 (a) to (c) are explanatory diagrams of a fastening state determination operation of component screws in the present invention, FIG. 3 is a perspective view of an essential part showing a driver mechanism portion of a conventional screw tightening machine, FIG. 4 is a sectional view showing an internal configuration of a portion to which a screw check device of the driver mechanism is attached, and FIG. FIG. 6A to FIG. 6C are principal part perspective views showing the configuration of the check device, and are explanatory diagrams of a conventional screw floating determination operation of component screws. 2 …… Casing pipe, 3 …… Suction pipe, 6 …… Bit, 20 …… Holder arm, 22 …… Bracket, 23 …… Screw block detection sensor, 25 …… Slide block, 28 …… Screw lift detection Sensor, 29 …… Detection position adjustment mechanism, 30 …… Check shaft, 31 …… Compression spring, 32 …… Receiving ring, 33 …… Engaging lever, SC …… Parts screw, DA …… Driver mechanism, WA …… Fastened member, WB ... Fastened member.

Claims (1)

[Scope of utility model registration request] 1. A bit having a shape in which a tip is engaged with a screw head of a component is fixed to a rotary shaft of a driver mechanism of a screw tightener,
The component screw in a screw tightening machine in which the bit is inserted and the component screw is held by a suction pipe provided so as to be movable relative to the bit, and the component screw is screwed into the fastening member with a bit through a member to be fastened and tightened. Is a screw check device that checks the fastening state of the driver mechanism.A holder arm that interlocks with the bit movement is attached to the casing pipe part of the driver mechanism, and a check shaft of an appropriate length is attached to this holder arm on one side in the axial direction with a spring. Energizing lever provided in conjunction with the suction pipe so that it can move to the other side, and a sensor that detects the both ends of the check shaft movement, one side for detecting no screw, and the other side for detecting position adjustment mechanism. A screw check device for a screw tightening machine, wherein the screw check device is provided to detect a screw lift.