JPH079281A - Screw fastening machine - Google Patents

Abstract

PURPOSE:To make fastening of screws having different head diameters using a bit and enhance the versatility of a screw fastening machine by forming a suction pipe to hold screw with an inside surface in steps so that it corresponds to a plurality of head diameters CONSTITUTION:A screw fastening machine is so arranged that two sorts of screws 4, 5 having different head diameters are fed from a pallet 3 of a screw supply device 2 and screwed into tap holes 7 provided in an assembly 8 placed upon a working table 9, and a driver 11 equipped at the foremost with a bit 13 to be engaged by a tool hole in the heads of the screws 4, 5 is installed on a supporting table 12 capable of moving along a straight motion guide 16 on a fixation plate 15. The bit 13 is inserted into a suction pipe 6 fixed to this fixation plate 15 through a fixing arm 14, and the screw 4 or 5 held by the suction pipe 6 is screwed into an assembly 8. The suction pipe 6 is formed in steps having the inside circumferential surfaces 6a, 6b with a some larger diameter than the head diameters of the screws 4, 5, so that it is possible to handle two sorts of screws 4, 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screw tightening machine, and more particularly to a screw tightening machine capable of tightening screws having a plurality of head diameters.

[0002]

2. Description of the Related Art Conventionally, in a screw tightening machine that sucks a screw and tightens the screw, since the suction pipe that sucks the screw has a fixed inner diameter, the screw tightening machine has various screw sizes. In contrast, each is set uniquely. Therefore, in an assembly line for tightening screws, for example, when there are operations for tightening two kinds of screws, two workers need to perform a process of tightening the screws with a screw tightening machine corresponding to each of the two kinds of screws. Divided into processes or 1
Two workers change the two screw tighteners and operate them.
I was tightening some types of screws.

[0003]

However, as described above, since the conventional screw tightening machine is set uniquely for each size of screw, one screw tightening machine can be used for plural kinds of screws. I can't respond. For this reason, if the type of screw changes, the screw tightening machine must be replaced, and there is a problem that the amount of capital investment increases and the total cost for screw tightening becomes high. Although it is the mainstream of the production method, there is a problem in such a production method that a conventional screw tightening machine having no versatility cannot handle the production.

Further, in order to tighten the two types of screws, dividing the process of the assembly line for each type of screw requires an increase in the number of workers and makes the line configuration of the assembly line complicated and large. In addition, when one operator carries two screw tightening machines to perform screw tightening, the screw tightening machine suitable for the screw must be replaced every time. There is a problem that replacing the machine is a burden on the operator and a loss of time.

The present invention has been made in view of the above circumstances, and provides a screw tightening machine capable of tightening a plurality of types of screws without requiring replacement by an operator even if the screw head diameter changes. The purpose is to provide.

Further, according to the present invention, when tightening two kinds of screws, it is possible to cope with the screw tightening of two kinds of screws with a simple operation without requiring two screw tightening machines. The purpose is to provide a screw tightening machine.

[0007]

In order to achieve the above-mentioned object, the present invention uses a suction pipe provided around the tip of a bit to suck a screw, and the sucked screw is tapped into a tap hole. In a screw tightening machine, there are multiple bits to tighten the screw, a screwdriver that holds the bit rotatably and gives a rotational force to tighten the screw to the above bit, and multiple inner peripheral surfaces with diameters corresponding to the head diameters of multiple types of screws. The stepped suction pipe formed, a positioning means for relatively positioning the inner peripheral surface formed on the suction pipe and the tip of the bit according to the head diameter of the screw to be sucked, and the positioning means. And a moving means for moving the bit to the tightening position of the screw after the positioning by.

Further, the present invention is characterized in that the positioning means moves and positions the bit.

Further, the present invention is characterized in that the positioning means moves and positions the suction pipe.

Further, according to the present invention, in a screw tightening machine for sucking a screw by using a suction pipe provided so as to surround the tip of the bit and tightening the sucked screw in the tap hole with the bit, a bit for tightening the screw, A driver that holds the bit rotatably and applies a rotational force to tighten the screw on the bit, a guide means that has a base portion slidable on the outer peripheral surface of the driver and a tip portion surrounding the bit, A stepped suction pipe that is elastically held at the tip of the guide means, moves in conjunction with the sliding movement of the guide means, and has a plurality of inner peripheral surfaces with diameters corresponding to the head diameters of a plurality of types of screws; The inner peripheral surface formed on the inner surface of the suction pipe that slides on the guide means and moves in conjunction with the sliding movement of the guide means moves in accordance with the head diameter of the screw sucked on the inner peripheral surface. And positioning means for positioning the tip, characterized in that the arranged is positioned located in the vicinity of the positioning means is provided with a switching means for switching in response to a screw which is adsorbed to the adsorption pipe.

Further, according to the present invention, in a screw tightening machine for sucking a screw by using a suction pipe provided so as to surround the tip of the bit and tightening the sucked screw in the tap hole with the bit, a bit for tightening the screw, A driver that rotatably holds this bit and applies a rotational force to tighten the screw on the bit, and an inner guide means that has a base portion slidable on the outer peripheral surface of the driver and a tip portion surrounding the bit, Corresponding to the outer guide means fixed to the driver and slidably holding the outer peripheral surface of the inner guide means, and the screw having the first head diameter elastically held at the tip of the outer guide means and tightened by the bit. And a first suction pipe having an inner diameter that allows the inner guide means to be elastically held at the tip of the inner guide means and move in conjunction with the sliding of the inner guide means. Second having an inner diameter with corresponding to the first head diameter screw is smaller than the second head diameter screw
And a positioning portion formed on the outer guide means for positioning the inner guide means at a suction position by the first suction pipe and a suction position by the second suction pipe, and on the inner guide means. A switching member that engages with the positioning portion to switch between suction of the screw having the first head diameter by the first suction pipe and suction of the screw having the second head diameter by the second suction pipe. Is characterized by.

[0012]

Since the screw tightener of the present invention is configured as described above, the inner peripheral surface of the suction pipe has a stepped shape having an inner peripheral surface having a diameter corresponding to the head diameters of a plurality of screws, and the tip of the bit is Tightening of screws with multiple head diameters by relatively positioning the inner peripheral surfaces of the diameters corresponding to the head diameters of the screws formed on the adsorption pipe at the positions corresponding to the screws to be adsorbed. It is possible to realize a general-purpose screw tightening machine, and it is possible to construct a production line for high-mix low-volume production with a small capital investment.

Further, according to the present invention, since the bit is moved and positioned, it is possible to cope with tightening of screws having a plurality of head diameters.

Further, according to the present invention, since the suction pipe is moved and positioned, the structure of the screw tightening machine is simplified and a compact screw tightening machine is realized.

Further, according to the present invention, the suction pipe is positioned when the guide means slidable on the outer peripheral surface of the driver is slid, and the positioning position is switched by the switching means arranged in the vicinity of the positioning means. Since it can be applied to both a hand tightening screw tightening machine and an automatic screw tightening machine, the application can be expanded.

Further, according to the present invention, since the second suction pipe for sucking the screw having the small head diameter is moved to position the screw having the small head diameter for the suction, the screw having the small head diameter is sucked. At this time, the suction pipe for sucking the screw having a large head diameter is not caught, and the screw having a small head diameter can be reliably sucked.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a view showing the structure of a screw tightening machine according to a first embodiment of the present invention, and FIG. 2 is a sectional view showing the details of the main parts thereof.
FIG. 3 is a diagram showing a configuration of a screw tightening machine according to a second embodiment of the present invention, FIG. 4 is a cross-sectional view showing details of essential parts thereof, and FIG. 5 is a screw tightening machine according to a third embodiment of the present invention. FIG. 6 is a diagram showing a configuration, and FIG. 6 is a diagram showing a configuration of a screw tightening machine according to a fourth embodiment of the present invention.

In FIGS. 1 and 2 showing the first embodiment of the present invention, 1 is a screw tightening machine, and this screw tightening machine 1 has a diameter of a screw thread from a pallet 3 of a screw supply device 2, that is, a head diameter. Different first screws 4, eg M2.5 screws and first screws
The second screw 5 having a smaller head diameter than the screw 4 of the above, for example, two kinds of screws 4 and 5 of the M2 screw are supplied through the suction pipe 6. The screw supply device 2 has a pallet 3 on which two types of screws 4 and 5 are placed at predetermined positions, and a tap hole 7 to which the screws 4 and 5 sucked by the suction pipe 6 of the screw tightening machine 1 are tightened. Bench 9 on which the assembled assembly 8 is placed
And a motor for reciprocating this work table 9 in the direction of arrow X 1
It consists of 0, etc.

Further, 11 is a driver for tightening the screws 4 and 5, and the driver 11 has a built-in motor (not shown) as a driving source of the tightening torque and is fixedly supported by a support 12. A bit 13 that engages with the screw holes of the screws 4 and 5 and tightens the screws 4 and 5 into the tap hole 7 is transmitted to the driver 11 by the rotational force of the motor built in the driver 11 and is held rotatably. ing. This bit 12 is a driver
A fixing plate that extends downward from the lower end of 11 and through a fixing arm 14.
It is inserted into the suction pipe 6 fixed to 15, and its tip extends close to the tip of the suction pipe 6. The support base 12 that supports the driver 11 is movably held in a vertical direction by a linear guide 16 provided on a fixed plate 15, and one end is locked to the fixed plate 15 and the other end is a driver. 11 is fixed to the fixing plate 15 while being supported by the support base 12 by the spring 18 that is locked to the projecting piece 17 that is formed to project on 11 and that adjusts the pressing force when tightening the screw of the screw tightening machine 1. Biased in the direction.

Further, a bit position switching cylinder 19 is arranged on the support base 12 so as to be movable in the direction of the arrow Y, and a bit positioning stopper 20 for contacting the upper surface of the bit position switching cylinder 19 to position the tip of the bit 13. Are fixed to the fixing plate 15. That is, when the bit position switching cylinder 19 is interposed between the bit positioning stopper 20 and the support base 12, the tip of the bit 13 is located at the lower first position as shown in FIG. 2 (a). Then
When the bit position switching cylinder 19 is moved so that it is not interposed between the bit positioning stopper 20 and the support base 12, the driver 11 springs as shown in FIG. 2 (b).
The tip of the bit 13 is biased upward by 18 and is located at a second position which is higher than the first position.

On the other hand, the inner circumference of the suction pipe 6 has a first screw.
The diameter of the first screw 4 is slightly larger than that of the first screw 4 and corresponds to the head diameter of the first screw 4, and the diameter of the second screw 5 is slightly larger than that of the second screw 5. A second inner peripheral surface 6b corresponding to the head diameter is formed, and a step portion 6c is formed by these inner peripheral surfaces 6a and 6b. The suction pipe 6 is a fixed plate.
The driver 11 is fixed to the fixed plate 15, and the driver 11 is movably held with respect to the fixed plate 15.However, since the moving amount of the driver 11 is restricted by the bit position switching cylinder 19 and the bit positioning stopper 20, the bit 13 The tip of
A first position facing the first inner peripheral surface 6a engaged with the screw hole of the first screw 4 having a large head diameter, and a second position engaged with the screw hole of the second screw 5 having a small head diameter. Second facing the inner peripheral surface 6b of the
Are positioned respectively. In other words, when the bit position switching cylinder 19 is controlled by the control device (not shown) and the first screw 4 is sucked by the suction pipe 6, the tip of the bit 13 faces the first inner peripheral surface 6a. When the second screw 5 is positioned at the first position and the second screw 5 is sucked by the suction pipe 6, the tip of the bit 13 is positioned at the first position facing the second inner peripheral surface 6b.

By the way, the fixing plate 15 for holding the suction pipe 6 and the driver 11 is held at the L angle 22 by the motor 21 so as to be movable in the vertical direction.
When the motor 21 is driven, the suction pipe 6 attracts the screws 4 and 5, and the bit 13 moves the attracted screws 4 and 5 to the position where the bit 13 tightens the tap hole 7.

By constructing the screw tightening machine 1 as described above, the screw tightening machine 1 can support screw tightening of screws 4 and 5 having two different head diameters, and realizes a versatile screw tightening machine. It is possible to construct a production line for high-mix low-volume production with a small capital investment.

In the first embodiment, there are two types of screws 4 to be sucked and tightened, but the diameter of the inner peripheral surface formed on the inner surface of the suction pipe 6 is 3 or more. The position switching cylinder 19 has a shape that changes stepwise or linearly, for example, so that the moving amount of the bit bit 13 can be obtained in three or more steps.
It is possible to switch between suction and tightening for screws with different head diameters.

Next, a second embodiment of the present invention will be described with reference to FIGS.

The above-mentioned first embodiment shows an example of a suction pipe fixed / bit moving type, while the second embodiment shows an example of a suction pipe moving / bit fixed type. 3 and 4 show the portion held by the fixing plate 15 in FIG. 1, and the other portions are the same as those in FIG. 1, and detailed description thereof is omitted.

In FIGS. 3 and 4, reference numeral 31 is a screwdriver for tightening the screws 4 and 5, and the screwdriver 31 has a motor (not shown) as a driving source of the tightening torque and has a fixed plate 15.
It is fixed to. This screwdriver 31 engages the screw holes of the screws 4,5 and tightens the screws 4,5 in the tap holes 7.
32 is rotatably held by transmitting the rotational force of a motor built in the driver 31. Also, 33 is an air cylinder held on the outer peripheral surface of the driver 31.
34 is attached to a part of the outer periphery of the base portion, and is a guide that is slidable on the outer peripheral surface of the driver 31 in the arrow Z direction by the operation of the air cylinder 34.
The guide 33 has a bit
A holder 35 surrounding 32 is attached.

The tip of the guide 33 or the holder
Adsorption pipe for adsorbing screws 4,5 between 35 and bit 32
36 are provided. The suction pipe 36 has a first pipe portion 37 having a diameter slightly larger than the head diameter of the first screw 4 having a large head diameter and having a first inner peripheral surface corresponding to the head diameter of the first screw 4. , A second pipe portion 38 having a second inner peripheral surface corresponding to the head diameter of the second screw 5 and having a diameter slightly larger than the head diameter of the second screw 5 having a small head diameter. The first pipe portion 37 and the second pipe portion 38 are integrally formed by adhesion or the like. Further, the suction pipe 36 has a bit formed by a first spring 39 elastically holding the first pipe portion 37 in the holder 35 and a second spring 40 elastically holding the second pipe portion 38 in the guide 33. It is always urged toward the tip side of 32 and moves in conjunction with the movement of the guide 33. The first spring 39 and the second spring 40 are used to adjust the pressing force of the screw tightener 1 when tightening the screw, and the elastic force of the second spring 40 is the elastic force of the first spring 39. It is set larger.

By the way, when the air cylinder 34 is in the non-operating state, the guide 33 is in the state shown in FIG. 3 or 4 (a), and the tip of the bit 32 has the head diameter of the first screw 4 having a large head diameter. It is located opposite to the corresponding first pipe portion 37 having the corresponding first inner peripheral surface, and engages with the screw hole of the first screw 4 sucked by the suction pipe 36.

When the air cylinder 34 is controlled and operated by the controller, the guide 33 slides on the outer peripheral surface of the driver 31 and moves downward in the Z direction. Along with the movement of the guide 33, the suction pipe 36 is urged by the first spring 39 and the second spring 40 to move downward in conjunction with the guide 33, and the state shown in FIG. . At this time, the tip of the bit 32 is located opposite to the second pipe portion 38 having the second inner peripheral surface corresponding to the head diameter of the second screw 5 having a small head diameter, and is sucked by the suction pipe 36. Engaged with the screw hole of the second screw 5. Then, when the air cylinder 34 returns to the non-operating state, the guide 33 and the suction pipe 36 move upward in conjunction with each other and return to the state shown in FIG. 3 or FIG.

Therefore, the first screw is controlled by the control device.
When 4 is picked up by suction pipe 36, bit 32
Is positioned at a first position facing a first pipe portion 37 having a first inner peripheral surface corresponding to the head diameter of the first screw 4, and the second screw 5 is attached to the suction pipe 36. When sucked by, the tip of the bit 32 is positioned at a second position facing the second pipe portion 38 having the second inner peripheral surface corresponding to the head diameter of the second screw 5.

Since the suction pipe 36 is moved and positioned as described above, the structure of the screw tightening machine 1 is simplified and the compact screw tightening machine 1 is realized.

In the second embodiment, there are two types of screws 4 to be sucked and tightened, but the diameter of the inner peripheral surface of the pipe member constituting the suction pipe 36 is three or more. By adjusting the movement amount of the suction pipe 36 by the air cylinder 34 in three or more steps, it is possible to switch between suction and tightening for screws having three or more head diameters.

Further, in the second embodiment, the holder 35
However, the holder 35 and the guide 33 may be integrally molded to form the guide 33 as a whole.

Next, a third embodiment of the present invention will be described with reference to FIG.

The third embodiment of the present invention is such that the second embodiment can be applied to a hand tightening screw tightening machine.
The configuration is such that a changeover switch 41 for changing over the operation of the air cylinder 34 of the screw tightening machine shown in the embodiment is added. Other parts are shown in FIG. 3, FIG.
Since it is the same as (b), the description thereof is omitted.

The changeover switch 41 is the air cylinder 34.
Is installed in the vicinity of and turns on the operation of the air cylinder 34-
Switch for turning off, manual switching by the operator,
Alternatively, it is turned on / off by automatic switching, which is mounted on the robot and automatically switched from the outside.

When the changeover switch 41 is off, the air cylinder 34 is in the inactive state and the guide 33
As shown in FIG. 5, the tip of the bit 32 is located opposite to the first pipe portion 37 having the first inner peripheral surface corresponding to the head diameter of the first screw 4 having a large head diameter, It engages with the screw hole of the first screw 4 sucked by the suction pipe 36.

When the changeover switch 41 is turned on,
The air cylinder 34 is in an operating state, and the suction pipe 36 is also lowered in association with the downward movement of the guide 33, as in the second embodiment, and is in the state shown in FIG. 4 (b). At this time, the tip of the bit 32 is located opposite to the second pipe portion 38 having the second inner peripheral surface corresponding to the head diameter of the second screw 5 having a small head diameter, and is sucked by the suction pipe 36. Engaged with the screw hole of the second screw 5.

Therefore, when the first screw 4 is sucked by the suction pipe 36 by the on / off switching of the changeover switch 41, the tip of the bit 32 has a first inner diameter corresponding to the head diameter of the first screw 4. When the second screw 5 is positioned at the first position facing the first pipe portion 37 having the peripheral surface, and when the second screw 5 is sucked by the suction pipe 36, the tip of the bit 32 is the head of the second screw 5. It is positioned at a second position facing a second pipe portion 38 having a second inner peripheral surface corresponding to the diameter.

Further, 42 is an air feeding pipe, and air is supplied to the air cylinder 34 and the suction pipe 36 through the air feeding pipe 42.

As described above, the suction pipe 36 is positioned when the guide 33 slidable on the outer peripheral surface of the driver 31 is slid, and the positioning position is switched by the changeover switch 41 disposed near the air cylinder 34. Because,
It can be applied to both a hand tightening screw tightener and an automatic screw tightening machine, and the application can be expanded.

In the third embodiment, the changeover switch has two types of screws 4 to be attracted and tightened.
Although the switching of the positioning position by 41 is made to two places, the diameter of the inner peripheral surface of the pipe member constituting the suction pipe 36 corresponds to the head diameters of three or more kinds of screws, and the suction pipe 36 is positioned by the air cylinder 34. By making it possible to switch three or more positions and applying a switch having a plurality of contacts corresponding to the positioning position as the changeover switch 41, it is possible to switch between suction and tightening for screws having three or more kinds of head diameters. .

Next, a fourth embodiment of the present invention will be described with reference to FIG.

The fourth embodiment of the present invention shows another embodiment of the hand tightening screw tightening machine. In FIG. 6, 51 is a hand tightening screw tightening machine operated by an operator. The tightening machine 51 is a part of the suction pipe that moves and the bit is fixed.

52 is two kinds of screws having different head diameters, for example M
A screwdriver for tightening the first screw 53 of 2.5 and a second screw 54 of M2 having a head diameter smaller than that of the first screw 53. The driver 52 is a motor (not shown) that is a driving source of the tightening torque. Built in. A bit 55 that engages with the screw holes of two types of screws 53 and 54 and tightens the screws 53 and 54 is transmitted to the driver 52 by the rotational force of the motor built in the driver 52 and is rotatably held. There is. Also,
Reference numeral 56 is an inner guide that is slidable on the outer peripheral surface of the driver 52 and slidable on the inner peripheral surface of an outer guide 57 fixed to the driver 52. The tip end of the inner guide 56 is a bit 55.
Surrounds. Further, the tip of the outer guide 57 covers the tip of the inner guide 56 and surrounds the bit 55, and a holder 58 is attached to the tip of the outer guide 57 to surround the bit 55.

At the tip of the holder 58, a first suction member having a diameter slightly larger than the head diameter of the first screw 53 having a large head diameter and having a first inner peripheral surface corresponding to the head diameter of the first screw 53 is formed. pipe
59 is elastically held by the first spring 60, and a second screw having a small head diameter is attached to the tip of the inner holder 56.
The second suction pipe 61, which has a diameter slightly larger than the head diameter of 54 and has a second inner peripheral surface corresponding to the head diameter of the second screw 54, is elastically held by the second spring 62, and each bit is a bit. It is biased toward the tip side of 55. Then, the second suction pipe 61 moves in contact with the inner peripheral surface of the first suction pipe 59 in conjunction with the sliding movement of the inner guide 56. The first spring 60 and the second spring 62 are used to adjust the pressing force of the screw tightening machine 51 when tightening the screw.
The elastic force of the second spring 62 is set to be larger than the elastic force of the first spring 60.

In addition, at a predetermined position of the inner guide 56, an elastic piece 63 having a mountain-shaped protrusion in the vicinity of the center and a locking piece 64 formed integrally with the end of the elastic piece 63 are formed. A switching lever 65 is formed. On the other hand, at the portion of the outer guide 57 facing the switching lever 65, the elastic piece 63
6a, a moving hole 57a for moving the protruding portion of the second suction pipe 61 and the bit 55 without the second suction pipe 61 descending as shown in FIG.
A first engaging hole 57b that engages with the locking piece 64 to hold the inner guide 56 at a first position where the tip of the opposite to the first suction pipe 59, and FIG. Second, as shown
Second engaging hole which engages with the locking piece 64 to hold the inner guide 56 at the second position where the tip of the bit 55 is moved downward and the second suction pipe 61 faces the second suction pipe 61. 57c and 57c are formed respectively. Locking piece 64 and first engaging hole 57b
Alternatively, the engagement with the second engagement hole 57c is released by pressing the protruding portion of the elastic piece 63, and the inner guide 56 becomes slidable, and the protruding portion of the elastic piece 63 is moved along the moving hole 57a. The sliding movement of the inner guide 56 causes the inner guide 56 to move, the locking piece 64 engages with the first engaging hole 57b or the second engaging hole 57c, and the inner guide 56 moves to the first position or the second position. Held in position.

An inclined portion 56a is formed at a predetermined position on the rear end of the inner guide 56, and a changeover switch 66 is fixedly provided on the outer peripheral surface of the driver 52 so as to face the inclined portion 56a. The changeover switch 66 is in the ON state in the first position shown in FIG. 6 (a), and also in FIG. 6 (b).
In the second position shown in, the motor is turned off based on this on-off signal, and the torque for tightening the screws 53, 54 corresponds to the head diameter of the screws 53, 54. Set to an appropriate torque.

Further, 67 is an air supply pipe for supplying air, and the air is supplied to the first and second suction pipes 59, 61 through the air supply pipe 67.

By the way, a screw tightening machine for a worker to manually tighten
When tightening the screws 53, 54 using the 51, first, the switching lever 65 is manually operated to set the screw tightening machine 51 to a state according to the size of the tightening screw. When tightening the first screw 53 having a large head diameter, the elastic piece 63 of the inner guide 56 is operated to form the locking piece 64 on the outer guide 57.
Of the bit 55 by engaging with the engaging hole 57b of
The first suction pipe 59 having a first inner peripheral surface corresponding to the head diameter of 53 is positioned at a first position opposite to the first suction pipe 59. After this positioning, the first screw 53 is attracted to the first suction pipe 59, the screw hole of the first screw 53 engages with the tip of the bit 55, and the first screw 53 is screwed.

When the second screw 54 having a small head diameter is tightened, the switching lever 65 is operated in the same manner to lock the locking piece.
64 is engaged with the second engagement hole 57c, and the tip of the bit 55 has a second inner peripheral surface corresponding to the head diameter of the second screw 54.
It is positioned at a second position opposite to the suction pipe 61.
After this positioning, the second screw 54 is attracted to the second suction pipe 61, the screw hole of the second screw 54 engages with the tip of the bit 55, and the second screw 54 is screwed.

As described above, by moving the second suction pipe 61 for sucking the screw 54 having a small head diameter downward, the screw 54 having a small head diameter has a large screw diameter when sucking.
The first suction pipe 59 that sucks 53 is not caught, and the screw 54 having a small head diameter can be securely sucked.

In the fourth embodiment, the screw tightening machine is used.
Although 51 is applied for manual tightening, the mechanism for sliding the switching lever 63 can be slid by external control to mount the screw tightening machine 51 on a robot or the like to provide an automatic screw tightening machine. .

In the fourth embodiment, the holder 58
However, the holder 58 and the outer guide 57 may be integrally molded to form the outer guide 57 as a whole.

Further, although the switching mechanism for switching the torque at the time of tightening the screw is not shown in the first to third embodiments, the torque for tightening the screw is set to the screw head diameter as in the fourth embodiment. Alternatively, the torque may be set to an appropriate value corresponding to the magnitude of.

Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made without departing from the gist of the present invention.

[0059]

As described in detail above, according to the screw fastening machine of the present invention, the inner peripheral surface of the suction pipe has a stepped shape having an inner peripheral surface having a diameter corresponding to the head diameters of a plurality of screws. By relatively positioning the tip of the bit and the inner peripheral surface of the diameter corresponding to the head diameter of the plurality of screws formed on the suction pipe at the position corresponding to the screw to be sucked, Since it can handle screw tightening, a versatile screw tightener can be realized, and a production line for high-mix low-volume production can be constructed with a small capital investment.

Further, according to the present invention, by moving and positioning the suction pipe, the structure of the screw tightening machine is simplified and a compact screw tightening machine is realized.

Further, according to the present invention, the suction pipe is positioned when the guide means slidable on the outer peripheral surface of the driver is slid, and the positioning position is switched by the switching means arranged in the vicinity of the positioning means. It can be applied to both tightening screw tighteners and automatic screw tighteners.
Applications can be expanded.

Further, according to the present invention, the second suction pipe for sucking the screw having the small head diameter is moved to position the screw having the small head diameter for the suction so that the screw having the small head diameter is sucked. It is possible to reliably suck a screw having a small head diameter without being caught by a suction pipe that sucks a screw having a large head diameter.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a screw tightening machine according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing details of a main part of the first embodiment of the present invention, FIG. 2 (a) is a view showing suction of a screw having a large head diameter,
2 (b) is a diagram showing suction of a screw having a small head diameter.

FIG. 3 is a diagram showing a configuration of a screw tightening machine according to a second embodiment of the present invention.

FIG. 4 is a cross-sectional view showing details of a main part of a second embodiment of the present invention, FIG. 4 (a) is a view showing suction of a screw having a large head diameter,
And FIG. 4B is a diagram showing suction of a screw having a small head diameter.

FIG. 5 is a diagram showing a configuration of a screw tightening machine according to a third embodiment of the present invention.

6A and 6B are views showing a configuration of a screw tightening machine according to a fourth embodiment of the present invention, FIG. 6A showing adsorption of a screw having a large head diameter, and FIG. 6B showing a head diameter. It is a figure which shows adsorption | suction of a small screw.

[Explanation of symbols]

 1… Screw tightener 4,5… Screw 6… Suction pipe 11… Driver 13… Bit 19… Bit position switching cylinder (positioning means) 20… Bit positioning stopper (positioning means) 21… Motor (moving means) 31… Driver 32 … Bit 33… Guide (guide means) 34… Air cylinder (positioning means) 36… Adsorption pipe 41… Changeover switch (changeover means) 51… Screw tightener 52… Driver 53… First screw 54… Second screw 55 Bit 56 ... Inner guide (inner guide means) 57 ... Outer guide (outer guide means) 57b ... First engaging hole (positioning portion) 57c ... Second engaging hole (positioning portion) 59 ... First suction Pipe 61 ... Second adsorption pipe 65 ... Switching lever (switching means)

Claims (5)

[Claims] 1. A screw tightening machine that sucks a screw by using a suction pipe provided around the tip of the bit and tightens the sucked screw with a bit in a tap hole by rotating the bit and the bit that tightens the screw. A screwdriver that holds the bit as much as possible and gives a rotational force to tighten the screw to the above bit, a stepped suction pipe with a plurality of inner peripheral surfaces with diameters corresponding to the head diameters of multiple types of screws, and this suction pipe. Positioning means for relatively positioning the inner peripheral surface and the tip of the bit according to the head diameter of the screw to be sucked, and after positioning by this positioning means, the driver is driven to move the bit to the screw tightening position. A screw tightening machine comprising a moving means for moving. 2. The screw tightening machine according to claim 1, wherein the positioning means moves and positions the bit. 3. The screw tightening machine according to claim 1, wherein the positioning means moves and positions the suction pipe. 4. A screw tightening machine for adsorbing a screw by using an adsorbing pipe provided around the tip of the bit and tightening the adsorbed screw in the tap hole with the bit. A driver that holds the bit so that it gives a rotational force to tighten the screw on the bit, a guide means having a base portion slidable on the outer peripheral surface of the driver and a tip portion surrounding the bit, and a tip of the guide means. Stepped suction pipe that is elastically held by a portion and moves in conjunction with the sliding of the guide means, and that has a plurality of inner peripheral surfaces having a diameter corresponding to the head diameters of a plurality of types of screws; and the guide means. The inner peripheral surface formed on the inner surface of the suction pipe that slides along with the sliding of the guide means is positioned at the tip of the bit according to the head diameter of the screw sucked. And a switching means arranged near the positioning means for switching the positioning position corresponding to the screw sucked by the suction pipe. 5. A screw tightening machine for sucking a screw by using a suction pipe provided around a tip of the bit and tightening the sucked screw with a bit in a tap hole by rotating the bit and the bit for tightening the screw. A driver that holds the bit so as to give a rotational force for tightening a screw to the bit, and an inner guide means having a base portion slidable on the outer peripheral surface of the driver and a tip portion provided around the bit.
Corresponding to the outer guide means fixed to the driver and slidably holding the outer peripheral surface of the inner guide means, and the screw having the first head diameter elastically held at the tip of the outer guide means and tightened by the bit. A first suction pipe having an inner diameter that allows the inner guide means to move elastically at the tip of the inner guide means and to move in conjunction with the sliding of the inner guide means, and a second smaller than the screw having the first head diameter. A second suction pipe having an inner diameter corresponding to the head diameter screw,
A positioning portion formed on the outer guide means for positioning the inner guide means at a suction position by the first suction pipe and a suction position by the second suction pipe; and a positioning portion formed on the inner guide means. A screw including a switching member that is engaged and switches between suction of a screw having a first head diameter by the first suction pipe and suction of a screw having a second head diameter by the second suction pipe. Fastener.