JP4653627B2 - Screw feeder - Google Patents

Description

  The present invention provides a screw supply device that moves an appropriate amount of screws onto a rail from a place where a large number of screws having a head are stored, aligns them in a row in the rail, and supplies the screws to a predetermined take-out position in this state. About.

Conventionally, this type of screw supply device has a receiving portion for receiving a large number of screws and a guide groove for guiding the screws to a predetermined take-out position while supporting them in a row with the screw heads facing up. A rail, a feeding means for feeding the screws of the storage unit to the rail by a predetermined amount, and a brush that swings across the rail and sweeps away screws that are not properly supported by the rail. There are some (for example, refer to Patent Document 1).
JP-A-8-155758

  However, since such a screw supply device requires the above-mentioned feeding means, the structure becomes complicated and there is a limit to downsizing the device.

  Further, there are cases where a screw is caught on a rail and cannot be swept away. In such a case, an overload is applied to the brush driving motor, causing a failure.

  An object of this invention is to simplify a structure and to achieve size reduction of a screw supply apparatus.

  Another object of the present invention is to appropriately cope with a case where a screw is caught on a rail and is difficult to sweep away.

That is, the screw supply device according to the present invention is
A rail for guiding a screw, having an upper surface extending along the rail and an elongated groove provided on the upper surface, and engaging and supporting a screw head on the upper surface of the rail, A rail for guiding screws along the rail in a state received in the groove;
A brush that reciprocates across the rail and that contacts the screw conveyed along the rail so that the screw is properly supported by the rail;
A screw conveying device having a motor for driving the brush,
A load detecting means for detecting a resistance load received by the brush from a screw conveyed along the rail when the brush moves forward or backward;
Determination means for determining whether or not the resistance load detected by the load detection means is greater than or equal to a reference value;
Have
A motor that reverses the forward or reverse movement when the resistance load is determined by the determination means to be a reference value, and continues the forward or backward movement when it is determined to be equal to or less than the reference value. And a control means.

  Specifically, the load detection means is a motor current detection circuit for detecting the current of the motor, and the determination means is a reference for determining whether or not the detection value by the motor current detection circuit exceeds a reference value. It can be a value comparison circuit.

  That is, in this screw supply device, a screw that is not properly supported by the rail by reciprocating the brush so as to cross the rail is brought into a proper position by a contact action on the screw. When it protrudes greatly from the rail and the state is not corrected properly, the resistance load applied to the brush from the screw becomes overloaded, and when this is detected, the brush reverses immediately, and when it reverses, it immediately overloads. Therefore, when the screw is not in the proper position, the operation is continued again. Therefore, the screw is struck by the brush in a short cycle, and the position correction of the screw is promoted.

Moreover, the screw supply device according to the present invention includes:
A rail having an upper surface for engaging and supporting the head of the screw, and an elongated groove formed to receive a shaft portion of the screw whose head is supported by the upper surface;
Rail vibration means for vibrating the rail and thereby transporting the received screw of the shaft into the groove;
A housing set on the rail, the housing having an elongated opening communicating with the rail on the inner bottom surface for sending a screw to the rail, the inner bottom surface being inclined toward the opening Body,
An isolation wall that separates the inside of the housing into an upstream screw storage portion and a downstream screw alignment portion in the screw conveying direction, and an upper portion of the rail is provided at a distance from the rail With walls,
Have
The screws stored in the screw storage unit are transported along the rails through the isolation wall into the screw alignment unit, and the screws are properly supported by the rail in the screw alignment unit, and the screws are removed from the screw alignment unit. It is characterized by being sent out to the screw take-out part of the rail extending downward in the inclination direction.

  That is, in this screw supply device, there is no need to provide a special transfer means for transferring the screws from the screw storage portion to the rail by a certain amount, which is provided in the conventional device, and therefore the structure is simple and compact. Can be realized.

In this screw supply device,
A screw storage hopper provided on the screw storage portion, the screw storage hopper having a screw discharge hole opening in the screw storage portion, and a bottom surface inclined toward the discharge hole;
By giving vibration to the screw storage hopper, it is possible to have hopper vibration means for gradually supplying the screw stored in the screw storage hopper into the screw storage portion.

  By doing so, it is not necessary to put a large number of screws all at once in the screw storage portion, and thereby it is possible to appropriately supply screws to the rail in the screw storage portion.

Furthermore, the screw supply device comprises:
Provided in the screw alignment section, reciprocated across the rail, and in contact with the screw being conveyed along the rail in forward or backward movement, the screw is supported properly by the rail. Have a brush for and
The brush is formed of a plurality of brush bristles whose upper end portions are gathered together by a holder fixed to a swing shaft set parallel to the longitudinal direction of the rail at an upper position of the rail. Each of the bristles is formed so as to wave instead of a straight line in its length direction, so that the rigidity in the reciprocating direction of the brush is greater than that formed by bundling straight bristles. be able to.

  In this case, it is preferable that the width in the longitudinal direction of the rail at the lower end or the front end portion of the brush bristles is wider than the width at the base end gathered by the holder. Since the tip portion is widened, the tip of the brush can be extended even near the wall of the screw aligning portion, and a more appropriate alignment work can be performed.

  According to the screw supply device of the present invention, no special means for transferring the screw by a predetermined amount is required to send the screw from the screw storage portion onto the rail, and thus the structure is simplified and the size is reduced. It is also possible. Further, the brush can also have appropriate rigidity, and the rail portion close to the wall of the screw alignment portion can be swept by the tip portion of the brush, thereby enabling more appropriate screw alignment.

  Further, according to the screw supply device of the present invention, even if an overload is applied to the motor, such as a screw being caught on the brush, the reverse rotation and forward rotation of the motor are repeated in a short cycle, and the screw is hit with the brush. By acting, the position of the screw can be made appropriate.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a front sectional view of a screw supply device according to an embodiment of the present invention, and FIG. 2 is a side view of the screw supply device of FIG.

  The screw supply device 1 includes a control unit 2 that controls the entire device, a housing 10, a rail 12 that guides the screws in a row, and a screw storage unit 14 that houses a large number of screws and is installed on the top of the rail 12. A screw alignment portion 18 connected to the screw storage portion 14 via the separation wall 16, a brush 20 incorporated in the screw alignment portion 18 so as to be able to swing across the upper surface of the rail 12, A swing shaft 40 of the brush 20, a motor 26 that is drivingly connected via a link mechanism 22 that swings the swing shaft, and a rail vibration that is installed below the rail 12 and imparts vibration to the rail 12. Part 28, a hopper 30 installed on the upper part of the housing 10 for supplying screws to the screw storage part 14, and a front end part (right end part in FIG. 1) of the rail 12 to be attached to the head of the reached screw. The driver bit And a guide 34 for guiding the guide 46.

  As shown in FIG. 2, the rail 12 is configured by facing a pair of plate-like members 12 ′ that are set in parallel with the groove 12 a interposed therebetween. The groove 12a has a space smaller than the diameter of the screw head and larger than the diameter of the shaft portion of the screw. The head of the screw is supported on the upper surface of the plate-like member 12 ′, the shaft portion is inserted into the groove 12 a, and is sent toward the front end portion by vibration from the rail vibration generating unit 28.

  The hopper 30 is attached with an inclined bottom plate 30a, and a screw discharge hole 38 is provided in the vicinity of the lower end of the inclined surface of the bottom plate 30a. As shown in FIG. 2, the screw discharge hole 38 has a smaller diameter than the width of the bottom plate, so that the screw is gradually dropped into the screw storage portion 14 along with the hopper vibration generating portion 32.

  The screw storage portion 14 is formed in a V-shape that is open at the bottom as shown in FIG. 2 so that the screw from the hopper 30 can easily enter the groove 12a of the rail 12. The separation wall 16 has an upper portion of the rail 12 spaced apart from the rail, and the shaft portion is not properly inserted into the groove 12a. For example, a screw lying on the rail can be used as the separation wall. 16 through the screw alignment chamber.

  In the screw aligning portion 18, as described above, the brush 20 is swung across the rail 12, and the screws carried along the rail 12 are aligned with the rail. That is, as will be described in detail later, for example, a screw lying on the rail or a screw floating from the rail is swept away from the rail at one end, and the retreated screw is formed into a V-shape of the screw alignment portion 18. Due to the tilt of the bottom, it will return to the rail and enter the rail again. Further, even if the screw lifted off the rail is swept by the brush 20, if it does not come off the rail, the load on the brush increases, and when the load exceeds the reference value, the brush is reversed, Again, contact acts to sweep the screw. Therefore, in this case, the brush performs forward and reverse rotations in a short cycle and hits the screw, so that the screw can be brought into an appropriate position by the vibration.

  As shown in FIG. 1, when the screw SC is transferred to a position below the driver guide 34, it is sensed by a sensor (not shown), vibration on the rail 12 is temporarily stopped, and the operator turns the driver bit 46. It engages with the head of the screw SC via the guide 34 and removes it from the rail.

  As shown in FIG. 5A, the brush 20 is formed by bundling fibers subjected to corrugation processing in a flat plate shape by a holder. Since the fiber is corrugated, the width W1 thereof can be made wider than the width W2 of the holder 42, whereby both end portions of the brush 20 can come into contact with the front wall surface of the screw alignment portion 18, and the screw It is possible to perform the alignment action on the screws immediately before being discharged from the alignment portion 18. That is, FIG. 5B shows a brush 48 that has been used conventionally, which is made of straight hair fibers and is sandwiched between the holders 42 in an aligned state. The tip width W3 of the brush 48 cannot be made larger than the width W2 of the holder 42. On the other hand, the brush 20 according to the present invention shown in FIG. 5A can have a tip width W1 of W1> W2.

Further, since the brush 20 has a corrugated shape, the fibers are entangled with each other and the rigidity is increased , so that the fibers are resistant to bending and the screw can be easily swept.

  FIG. 6 is a block diagram illustrating a configuration of the control unit 2. The control unit 2 includes a motor control circuit 50 that controls the rotation of the motor 26, a resistor 54 connected between the current detection terminal 52 of the motor control circuit 50 and the ground, and a motor current that amplifies the terminal voltage of the resistor 54. A detection circuit 56; a reference value comparison circuit 58 that outputs an output signal to the motor control circuit 50 when the output voltage of the motor current detection circuit 56 exceeds a preset reference value; and a screw SC that has moved to the screw removal position. , A sensor signal output circuit 62 that sends a motor stop signal to the motor control circuit 50 when the sensor 60 detects the screw SC, and delays the start of motor stop control by the motor control circuit. Delay circuit 64, main control circuit 66 for controlling the entire motor control circuit 50 and screw supply device 1, a power switch 68a, a display (not shown), etc. And an operation panel 68 provided with.

  The motor 26 is a DC motor, and the motor control circuit 50 controls forward rotation, reverse rotation, and stop. The motor control circuit 50 is an IC specialized for controlling the motor 26. The resistor 54 has a low resistance value that does not affect the operation of the motor 26. The motor current detection circuit 56 can be configured using a differential amplifier. The reference value comparison circuit 58 is a comparator, for example, and outputs a signal for rotating the motor 26 forward or backward to the motor control circuit 50. The sensor 60 can be, for example, a transmissive optical sensor including a light emitting element and a light receiving element disposed on both sides of the groove 12a. The main control circuit 66 is configured to control the motor control circuit 50 in addition to the rail vibration generator 28 and the hopper vibration generator 32.

Based on FIGS. 1-4 and FIG. 6, operation | movement of the screw supply apparatus 1 is demonstrated below.

  First, a certain amount of screws are inserted into the screw storage portion, and a predetermined amount of screws are also stored in the hopper 30. Next, when an operator or the like turns on the power switch 68 a of the operation panel 68, power is supplied to the control unit 2, the motor 26, and the rail vibration generating unit 28. At this time, it is assumed that the motor 26 is initially set to forward rotation.

  Further, the rail vibration generator 28 operates when the power is turned on. As a result, the screw placed on the rail in the screw storage portion 14 is conveyed forward (to the right as viewed in FIG. 1) along the rail and is sent to the screw alignment portion 18. Screws are fed onto the rail and transported in the same way. Further, the hopper 30 also vibrates, so that the screws therein are supplied little by little from the screw discharge hole 38 to the screw storage portion 14.

  In the screw alignment part 18, the brush 20 reciprocated so as to cross the rail acts, for example, in contact with a screw that is not properly positioned such that it protrudes from the rail to bring the screw into a proper position. . That is, for example, when the screw almost protrudes from the rail, the screw is once removed from the rail by the brush and moved onto the bottom surface of the screw aligning portion 18, and the swing angle of the brush becomes large and the screw If it is in a state of being removed from the rail, it will be returned to the rail due to the inclination of the bottom surface and its shaft part will enter the groove and be in the proper position, or even if the screw returned on the rail does not return to the proper position completely It is touched by the brush, and it is made into an appropriate position.

  Further, since the screw protrudes from the rail, the screw remains as it is due to the action of the brush, and an excessive resistance load may be applied to the brush.

  In the present invention, the current flowing through the resistor 54 shown in FIG. 6 is detected by the motor current detection circuit 56. When an excessive resistance load is applied, a signal generated by the motor current detection circuit 56 at that time is applied. Is compared with the reference value in the reference value comparison circuit 58, and if it is larger than the reference value, a signal for reversely rotating the motor 26 is generated. As a result, the motor control circuit reversely rotates the motor and reverses the brush. However, when the reverse rotation is performed, the load on the brush is instantaneously reduced and the brush returns to the original swing motion. Therefore, while the screw is not returned to the proper position, such a movement of the brush is continuously performed, and the brush is operated so as to strike the screw. It is supposed to be a position.

  As shown in FIG. 3, when the screw SC on the rail 12 passes through the screw alignment portion 18, it is detected by the sensor 60. The detection signal from the sensor 60 is amplified by the sensor signal output circuit 62 and then notified to the motor control circuit 50 via the delay circuit 64. When the motor control circuit 50 receives the signal from the delay circuit 64, the motor control circuit 50 stops the motor 26 and sends a signal to the main control circuit 66 to stop the rail vibration generating unit 28 and the hopper vibration generating unit 32. 12 temporarily stops the movement of the screw. In this state, the operator operates the bit 46 and takes out the screw SC. Here, the reason why the delay circuit 64 is provided is to stop the motor 26 in a state where the screw following the screw SC detected by the sensor 60 approaches the detection position by the sensor.

  When the sensor 60 detects that the screw SC is lost, the detection signal is notified to the motor control circuit 50 (when the screw SC is lost, it is not passed through the delay circuit 64), and is further notified to the main control circuit 66. The As a result, the motor 26, the rail vibration generating unit 28, and the hopper vibration generating unit 32 are restarted, and the screw conveying operation is resumed.

  As mentioned above, although embodiment of the screw supply apparatus which concerns on this invention was shown, the structure of brush 20 grade | etc., Is not limited to the structure of the said embodiment.

  Further, the motor control circuit 50 and the main control circuit 66 may be integrated into one IC, for example.

It is front sectional drawing of the screw supply apparatus which concerns on embodiment of this invention. It is a side view of the screw supply apparatus of FIG. It is a front view which shows the structure of a screw accommodating part, a screw alignment part, and these peripheral parts. FIG. 4 is a right side view of FIG. 3. It is a schematic diagram of the brush of this invention. It is a schematic diagram of the conventional brush. It is a block diagram which shows the structure of the control part of the screw supply apparatus of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw supply apparatus 2 Control part 10 Housing 12 Rail 12a Groove 14 Screw accommodating part 16 Separation wall 18 Screw alignment part 20, 48 Brush 22 Link mechanism 26 Motor 28 Rail vibration generating part 30 Hopper 30a Bottom plate 34 (Driver) Guide 38 Screw Discharge hole 40 Oscillating shaft 42 Holder 46 Driver bit 48 Brush 50 Motor control circuit 52 Current detection terminal 54 Resistance 56 Motor current detection circuit 58 Reference value comparison circuit 60 Sensor 62 Sensor signal output circuit 64 Delay circuit 66 Main control circuit 68 Operation panel 68a Power switch SC screw

Claims (6)

A rail for guiding a screw, having an upper surface extending along the rail and an elongated groove provided on the upper surface, and engaging and supporting a screw head on the upper surface of the rail, and a shaft portion of the screw A rail for guiding the screw along the rail,
A brush that reciprocates across the rail and that contacts the screw conveyed along the rail to properly support the screw by the rail;
A screw conveying device having a motor for driving the brush,
A load detecting means for detecting a resistance load received from a screw conveyed along the rail when the brush moves forward or backward; and
Determination means for determining whether or not the resistance load detected by the load detection means is greater than or equal to a reference value;
Have
When the determination means determines that the resistance load is greater than or equal to the reference value, the forward or backward movement is reversed, and when it is determined that the resistance load is equal to or less than the reference value, the forward or backward movement is continued. A screw supply device comprising: a motor control means. The load detection means is a motor current detection circuit that detects a current of the motor,
2. The screw supply device according to claim 1, wherein the determination means is a reference value comparison circuit for determining whether or not a detection value by the motor current detection circuit exceeds a reference value. A rail having an upper surface that engages and supports the head of the screw, and an elongated groove formed to receive a shaft portion of the screw whose head is supported by the upper surface;
Rail vibration means for vibrating the rail and thereby transporting the received screw of the shaft into the groove;
A housing set on the rail, the inner bottom surface having an elongated opening that communicates with the rail and sends a screw to the rail, and the inner bottom surface is inclined toward the opening ; A V-shaped housing that opens upward when viewed in the length direction of the rail ;
An isolation wall that separates the inside of the casing into a screw storage portion on the upstream side in the screw conveying direction and a screw alignment portion on the downstream side, and an upper portion of the rail is an isolation wall provided at a distance from the rail When,
In order to make the support of the screw proper by contacting the screw which is provided in the screw alignment portion, reciprocated across the rail, and conveyed along the rail in forward or backward movement With a brush,
Have
The screw stored in the screw storage portion is transferred along the rail through the isolation wall into the screw alignment portion, and the screw is properly supported by the rail in the screw alignment portion, and the screw is removed from the screw alignment portion. A screw supply device for feeding to a screw take-out portion of the rail that extends. A screw storage hopper provided on the screw storage portion, the screw storage hopper having a screw discharge hole opening in the screw storage portion, and a bottom surface inclined toward the discharge hole;
The screw supply device according to claim 3, further comprising: hopper vibration means for gradually supplying the screw stored in the screw storage hopper to the screw storage portion by applying vibration to the screw storage hopper. .   The brush is formed of a plurality of brush bristles whose upper end portions are gathered together by a holder fixed to a swing shaft set parallel to the longitudinal direction of the rail at an upper position of the rail. Each of the bristles is formed so as to wave instead of a straight line in its length direction, and the rigidity in the reciprocating direction of the brush is made larger than that formed by bundling straight bristles. The screw supply device according to claim 3 or 4, characterized by the above. The screw supply device according to claim 5, wherein a width in a longitudinal direction of the rail at a tip portion of the brush bristles is wider than a width at a base end gathered by the holder.

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