JP3632567B2 - Automatic screw tightening device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an automatic screw tightening device that automatically tightens a screw to an object to be tightened.
[0002]
[Prior art]
As shown in FIG. 4, the conventional automatic screw tightening device guides the screw 15 supplied through the screw feed hole with the guide tube portion and holds it with the catcher 3, and moves the catcher above the screw hole. By engaging the bit 4 and the screw head and rotating the bit, the screw is fastened to the object to be tightened.
[0003]
This catcher has a structure that can be opened and closed by a cylindrical member composed of two generally semi-cylindrical members so that both the holding and releasing of the screw can be performed. A cylindrical groove having substantially the same dimensions as the shaft portion of the shaft is formed, and the screw fed from the screw feeding hole can be held. In order to release the screw tightening device after tightening the screw, the catcher opens and releases the held screw.
[0004]
However, in the catcher, when a screw other than one optimum screw diameter is received, the screw cannot be accurately held because it is tilted in the catcher, so the bit and the screw head cannot be engaged, Only one type of screw diameter can be accepted by the catcher. Therefore, when it is required to tighten screws of different diameters, there is a problem in that a high number of screw tightening devices are required, resulting in high costs.
[0005]
[Problems to be solved by the invention]
In view of the problems as described above, an object of the present invention is to provide an automatic screw tightening device capable of tightening screws of two kinds of diameters with one screw tightening device.
[0006]
[Means for Solving the Problems]
As means for solving the above problems, an automatic screw tightening device according to the present invention includes a slidable suction pipe that surrounds a bit and can suck and hold a screw, and is provided inside the catcher. In order to be able to hold screws of two types of screw diameters, the suction tube holding portion for guiding the suction tube in order from the suction tube side to the catcher bottom surface, and a cross section smaller than the suction tube, A first screw holding portion that holds a thick screw, and a second screw holding portion that has a smaller cross section than the first screw holding portion and holds a thin screw of two types of screws, are formed in stages. An inclined portion is formed between the suction tube holding portion and the first screw holding portion so that the screw heads of two types of screws come into contact with each other. A thick screw has a screw head in the suction tube. Rotated by bit while held And a thin screw, by which is rotated by the bit, two screws are configured to be able to screw is tightened the object clamp object.
[0007]
With this configuration, each of the two types of diameter screws can be fastened to an object to be tightened in a state where the screws are stably held in the catcher or the suction pipe, and one screw fastening device Can be used to automatically tighten screws of two different diameters.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described. FIG. 1 is a sectional view of an automatic screw tightening device 1 of the present invention. The automatic screw tightening device 1 includes a base 2 and a catcher 3. The catcher 3 is composed of two semi-cylindrical members whose one end is connected to the base 2 so as to be pivotable around the pin 14 and can be opened and closed. The catcher 3 can take both a closed state in which the screws 15 and 16 can be received and held in the catcher 3 and a released state in which the screws 15 and 16 can be released from within the catcher 3. In the present specification, of the two types of diameters, the thicker screw is referred to as a “thick screw” and the thinner screw is referred to as a “thin screw”.
[0009]
Above the catcher 3, a suction pipe 5 and a bit 4 arranged in the suction pipe 5 are arranged to be movable independently of each other. As shown in FIG. 1, the bit 4 is shaped like a driver, and can fit the screw heads of the screws 15 and 16 to rotate the screws 15 and 16. The bit 4 is disposed in the suction pipe 5.
[0010]
A suction tube guide portion 6 is formed at the center of the catcher 3 so that the suction tube 5 can enter the catcher 3 and engage with a screw even when the catcher 3 is closed. With such a configuration, the catcher 3 is normally in a closed state with the base locking portion 11 and the catcher locking portion 12 being in contact with each other by spring bias. In this closed state, a stepped passage is formed inside the catcher 3 for guiding and receiving the suction pipe 5, the thick screw 16 and the thin screw 15, respectively.
[0011]
This passage is, from above, a suction guide portion 6 that guides and receives the suction tube 5, a first inclined portion 7 that contacts the screw heads of the thick screw 16 and the thin screw 15, and a first screw holding that holds the shaft portion of the thick screw. Portion 8, second inclined portion 9 that guides the tip of thin screw 15 to lower second screw holding portion 10, and the bottom of catcher 3 so that the shaft portion of thin screw 15 is held and the screw tip protrudes from catcher 3. A thin screw holding portion 10 is provided.
[0012]
Regarding the dimensions, the diameter of the suction tube guide portion 6 is slightly larger than the outer diameter of the suction tube 5 so that the suction tube 5 is aligned. Further, a first screw holding portion 8 is formed downstream of the suction pipe guide portion 6 in the passage. The first screw holding portion 8 and the second screw holding portion 10 are slightly larger in size than the screws 16 and 15 so that the thick screw 16 and the thin screw 15 are aligned.
[0013]
Regarding the operation of the automatic screw tightening device 1 of the present invention, a case where a thin screw is used first will be described. FIG. 2 is a view showing a state of the screw tightening device 1 when the thin screw 15 is fed. In a state where the suction pipe 5 is disposed above the suction holding pipe 6 of the catcher 3, the thin screw 15 is pumped into the catcher 3 through a feed hole (not shown), and the suction pipe guide portion 6 and the first screw The thin screw 15 is guided by the holding portion 8 and descends. The thin screw 15 is held at the first inclined portion 7 and the screw shaft portion is held at the second screw holding portion 10, and the screw tip is downward from the catcher 3. Protruding state.
[0014]
Next, the bit 4 is lowered and engaged with the screw head of the thin screw 15. In this state, the catcher 3 is lowered, and the tip of the thin screw 15 is engaged with the screw hole 18 formed in the article 17 to be tightened. After the catcher 3 is lowered while the bit 4 is rotated and the thin screw 15 is screwed in and stabilized, the screw can be tightened to the end without opening the catcher 3 and holding the screw 15 with the catcher 3.
[0015]
Next, the case where a thick screw is used will be described. FIG. 3 is a diagram illustrating a state of the screw tightening device 1 when a thick screw is fed. In a state where the suction pipe 5 is disposed above the suction holding pipe 6 of the catcher 3, the thick screw 16 is pumped into the catcher 3 through a feed hole (not shown) and guided by the suction pipe guide portion 6. The screw head is held by the first inclined portion 7, the screw shaft portion is held by the first screw holding portion 8, and the screw tip is held by the second inclined portion 9. At this time, the suction pipe 5 is lowered to contact the first inclined portion 7. As a result, the suction pipe 5 is hermetically sealed and suctioned in the suction pipe 5, the thick screw 16 is raised vertically upward, and the screw head of the thick screw 16 is disposed above the suction pipe 5. Engage with. In this way, the thick screw 16 is securely engaged by the bit 4 in the suction pipe 5 and the catcher 3 is opened. Then, the catcher 3 is lowered, and the screw tip is engaged in the screw hole 18 so that the screw 16 Is fastened to the assembly 17. Thus, the screw can be held by either the first screw holding portion or the second screw holding portion in the catcher and can be screwed by the above-described methods.
[0016]
Since the screw heads of the thin screw and the thick screw are in contact with the first inclined portion, the two types of diameter screws used in the automatic screw tightening device of the present invention include the possible screw heads of thin screws. The relationship that the outer diameter is larger than the outer diameter of the shaft portion of the thick screw that can be taken, the shaft of the thin screw is longer than the distance from the first screw holding portion to the second screw holding portion, the shaft of the thick screw is holding the first screw It is necessary to satisfy the relationship of being shorter than the part.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an automatic screw tightening device 1 of the present invention.
FIG. 2 is a diagram showing a state when a thin screw is tightened.
FIG. 3 is a diagram showing a state when a thick screw is tightened.
FIG. 4 is a cross-sectional view of a conventional automatic screw tightening device.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Automatic screw fastening apparatus 2 ... Base part 3 ... Catcher 4 ... Bit 5 ... Suction pipe 6 ... Suction pipe guide part 8 ... First screw holding part 10 ... Second screw holding part 15 ... Thin screw 16 ... Thick screw 17 ... Fastened object

Claims (1)

A catcher for receiving and holding a screw;
In an automatic screw fastening device comprising a bit for fastening a screw to an object to be fastened by engaging and rotating with a screw head of the screw,
Comprising a slidable suction tube in the catcher that surrounds the bit and can hold the screw by suction;
In order to be able to hold screws of two types of screw diameter inside the catcher, in order from the suction tube side to the catcher bottom surface,
A suction tube holding part for guiding the suction tube;
A first screw holding portion having a smaller cross section than the suction pipe and holding a thick screw of the two types of screws;
A second screw holding portion that has a smaller cross section than the first screw holding portion and holds a thin screw of the two types of screws, and is formed stepwise.
An inclined portion is formed between the suction tube holding portion and the first screw holding portion, for contacting the screw heads of the two types of screws,
By rotating the thick screw by the bit while the screw head is held in the suction pipe, the two types of screws are screwed onto the object to be tightened by rotating the thin screw by the bit. Automatic screw tightening device characterized in that can be tightened.

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