JPS624452Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention involves driving a screw having, for example, a hexagonal head into a material to be screwed to a certain depth using a driving member driven by compressed air or electricity. A screw tightening tool that applies rotational torque to the driven screw by a screw rotation part using compressed air or electricity as a drive source, and tightens the screw into the material to be screwed. The present invention relates to a screw guide member that guides the head of the screw being driven so that the head of the screw is accurately fitted and positioned in the screw rotating portion.

FIG. 1 is a sectional view showing the location of a screw guide member of a screw tightening tool previously filed by the present applicant. This screw guide member has a center hole 101 of a nose 100 with a screw insertion hole protruding from one end of the tool body.
The socket member 102 is assembled to the tip 100a of the nose 100 so as to coaxially communicate with the nose 100. On the outer periphery of this socket member 102, a first
A bevel gear 103 is assembled and fixed. This bevel gear 103 includes a second bevel gear 1 that is integrally assembled to the rotating shaft of an air motor (not shown).
04 are arranged in mesh. Therefore, the socket member 102 itself is a screw rotating member. The socket member 102 is supported so as not to move in the axial direction by a socket holder 106 that is assembled and fixed to the nose 100 with a set screw 105. Furthermore, at the tip 102a of the socket member 102, there is provided a contact arm 1 which is mechanically interlocked with a trigger device (not shown).
A contact block 108 for operating 07 is slidably inserted therein.

The inner circumferential wall of the screw insertion hole 109 of the socket member 102 is a circular surface that circumscribes each vertex of the head of a screw having a hexagonal head (not shown) on the inlet 109a side that is the connection part with the nose 100. 11
0, and each vertex of the head is connected to the exit 109b within the range from the circular surface 110 to the midway point in the axial direction.
It has six inclined surfaces 111 that guide to the side, and from the end 111a of each of these inclined surfaces 111 to the outlet 109b.
It has a hexagonal screw rotating part 112 for fitting, holding and positioning the head within the range of .

That is, the screw preloaded into the nose 100 is inserted into the screw insertion hole 109 of the socket member 102 by a driver member (not shown) that rapidly descends inside the nose 100 (moves downward in FIG. 1). When the screw enters the screw, each apex of the head is aligned with each of the inclined surfaces so that the screw can be accurately fitted into the screw rotating portion 112 regardless of the position of the apex of the head with respect to the direction of rotation. 111.

Therefore, in the case where the screw is loaded in the nose 100 in such a state that each vertex position of the head thereof does not coincide with the position of each corner portion 112a of the screw rotating portion 112, too,
Its head is adapted to fit accurately into the screw rotating portion 112 while its position is corrected within the screw insertion hole 109 of the socket member 102.

By the way, when the socket member 102 is driven in, the head of the screw touches the screw rotating part 112 as described above.
The screw head is guided so as to fit accurately into the screw insertion hole 109, but each inclined surface 111 and a hexagonal screw rotation portion 112 continuous to each of these inclined surfaces 111 are provided on the inner circumferential wall of the screw insertion hole 109. The only way to process it all at once is to perform electrical discharge machining using an electrode rod whose outer circumferential surface has a shape that matches the shape of the inner circumferential wall.

Although it is possible to form the inner circumferential wall of the screw insertion hole 109 by forging or the like, the outer circumferential shape may be such that an edge portion 111a is formed at the joint between the arc and the chord of each of the inclined surfaces 111. It is difficult to manufacture this working rod, and the portion of the working rod corresponding to the end portion 111a is subject to severe wear, which is not preferable.

Therefore, the inner circumferential wall of the screw insertion hole 109 of the socket member 102 is machined entirely by electrical discharge machining. However, in the above machining method using electric discharge machining, it is necessary to assemble the socket members 102 to be machined one by one into a processing machine, and gradually insert the electrode rod into the center hole of the socket member 102 for machining. First, it is a processing method that requires a long processing time for each item. Therefore, it is not suitable for mass production,
This results in high costs.

Therefore, the present invention was proposed in view of the above-mentioned circumstances, and its purpose is to provide a new screw guide member that does not impede the guide function of the screw head and is excellent in mass production. .

Hereinafter, one embodiment of the present invention will be described in detail with reference to FIGS. 2 to 7.

FIG. 2 is a longitudinal sectional side view of a screw tightening tool to which the present invention is applied. This tool 1 uses compressed air as a driving source. This screw tightening tool 1 includes a driving device 4 for driving a screw N (see FIG. 3) supplied into a nose 3 protruding from a lower end 2a of a tool body 2 into a material to be screwed (not shown), and a driving device 4 for driving a screw N (see FIG. 3) into a material to be screwed (not shown). The screw N after the above driving is arranged on the tip 3a side of 3.
Screwing device 5 for screwing into the material to be screwed
It will be equipped with.

The driving device 4 includes a striking cylinder 6 disposed in the tool body 2, a striking piston 7 slidably and tightly fitted into the striking cylinder 6, and a driving piston 7 rigidly connected to the striking piston 7. driver 8 and
A main air chamber 9 is formed around the upper end of the percussion cylinder 6 and stores compressed air for forward movement of the percussion piston 7; A return air chamber 10 in which compressed air for dynamic operation is stored; The head valve 12 is configured to switch between the exhaust passage 11 and the exhaust passage 11.

Further, when the striking piston 7 reaches the bottom dead center, that is, when the driving of the screw N is finished, the screwing device 5 operates the return air chamber 1.
It is configured to start operating by the air pressure of compressed air supplied from 0.

An air motor is used as a drive source for the screwing device 5. This air motor is housed in a cylindrical housing 12 that is integrally formed at the bottom of a cylindrical magazine 11 for storing screws, which is disposed so as to protrude from one side of the tool body 2.
The drive shaft of this air motor is directed forward (to the left in FIG. 2) from one end (left end in FIG. 2) 12a of the housing 12 via a speed reducer (not shown) housed in the housing 12. It is connected to a protruding rotary drive shaft 13. A first bevel gear 14 is provided at the tip of this drive shaft 13.

Further, at the tip 3a of the nose 3, as shown in FIG. 3, a cylindrical first socket member 15 serving as a screw guide member is disposed. This socket member 15 holds the hexagonal head N of the screw N driven by the driver 8 into the socket member 15.
It has the function of guiding the screw to the second socket member 20 side, which will be described later, within the screw insertion hole 16 opened at the center.

A second bevel gear 17 that meshes with the first bevel gear 14 is integrally assembled on the outer periphery of one end (lower end in FIG. 3) 15a of the first socket member 15. The first socket member 15 is supported by a cap-shaped socket holder 18 such that the screw insertion hole 16 is coaxial with the center hole 3A of the nose 3. Note that the other end of the socket member 15 (the third
(upper end in the figure) outer periphery of 15b and the above socket holder 1
8 and the inner peripheral wall of the second bevel gear 1.
Bearings 19, 19 are interposed between the outer circumference of the socket holder 7 and the inner circumferential wall of the socket holder 18,
The socket member 15 is supported so as to be rotatable around the axis.

Then, one end 1 of the first socket member 15
A second socket member 20 serving as a screw rotating member is disposed on the side 5a. The second socket member 20 has a screw fitting hole 21 at its center with a hexagonal cross section into which the head N' of the screw N is fitted and held and positioned. It has the function of screwing the screw N driven into the material to be screwed into the material to be screwed through the screw insertion hole 16 of the socket member 15. The second socket member 20 is inserted into the first socket member 15 such that its screw fitting hole 21 is coaxial with the screw insertion hole 16 of the first socket member 15.
Its outer periphery is fitted and held by the second bevel gear 17 whose one end 17a protrudes from one end 15a. Note that the second socket member 20
is installed in a hole 22 opened at one end 17a of the second bevel gear 17, and is axially biased by a steel ball 24 elastically biased in the inner radial direction by a ring-shaped plate spring 23. movement is blocked.

Further, the tip 20 of the second socket member 20
On the outer periphery of the a side, a contact block 26 having a cushioning material 25 on the lower end surface 20A is attached to the socket member 20.
It is arranged so that it can freely reciprocate in the axial direction. This contact block 26 is assembled and fixed to one end 29a of a contact arm 29 that mechanically interlocks with a trigger device 28 provided at the base of a grip portion 27 protruding from one side of the tool body 2. . That is, the contact block 26 is first
The driving device 4 is not activated until the trigger lever 30 of the trigger device 28 is pulled up after the contact arm 29 is pushed up against the surface of the material to be screwed.
The configuration is such that an ON activation signal can be sent to the

An adjustment ring 31 for adjusting the amount by which the contact block 26 is pushed up is screwed onto the outer periphery of the socket holder 18 on the one end 18a side.

That is, when this tool 1 presses the contact block 26 against the surface of the workpiece and turns on the trigger device 28, the driver 8 drives the screw N preloaded into the nose 3 into the first socket member. 15 into the material to be screwed through the screw insertion hole 16. After the screw N is driven in, an ON operation signal is sent to the screwing device 4, the rotation drive shaft 13 rotates, and the first and second socket members 15 and 20 rotate in the direction around the axis. do. By this rotation, the screw N fitted and held within the second socket member 20 is screwed into the material to be screwed.

As shown in FIGS. 4A and 4B, the first
In the inner circumferential wall of the screw insertion hole 16 of the socket member 15, there is an inlet 1 which is a connecting part with the nose 3.
The 6a side has a circular surface 32 that circumscribes each vertex of the head N' of the screw N. A tapered surface 33 is provided between the circular surface 32 and the other end 15b of the socket member 15, so that the head part can smoothly enter the screw insertion hole 16.

Further, as shown in FIGS. 4A, 4D, and 4E, in the inner peripheral wall of the screw insertion hole 16 of the first socket member 15, the range from the circular surface 32 to the outlet 16b side is Slanted surfaces 34, 34, 34 are formed inside for guiding non-adjacent vertices of the head N' of the screw N in the direction of the outlet 16b. Adjacent portions of these inclined surfaces 34, 34, 34 on the inner circumferential wall of the screw insertion hole 16 are arcuate surfaces that guide the vertices other than those guided by these inclined surfaces 34, 34, 34. 3
It has 5, 35, 35.

By forming the inner circumferential wall of the screw insertion hole 16 in this manner, the screw N driven out from inside the nose 3 by the driver 8 can be
As shown in FIG. 2, first, the head N' is guided by the tapered surface 33 so as to smoothly enter the screw insertion hole 16. Next, as shown in FIG.
4, 34, 34, and its movement is guided by these inclined surfaces 34, 34, 34 to the exit 16b side. And the head above
As shown in FIG.
1, the head N' is guided so as to fit straight into the screw fitting hole 21. In order for the head N' to fit straight into the screw fitting hole 21, the screw insertion hole 16 of the first socket member 15 must be inserted as shown in FIG.
Each inclined surface 34, 34, 3 on the exit 16b side of
4 and each corner portion 2 of the screw fitting hole 21 of the second socket member 20.
Needless to say, the condition is that the socket members 15, 20 are assembled so that the position 1a is located. In this way, the first
By forming the above-mentioned inclined surfaces 34, 34, 34 on the inner circumferential wall of the screw insertion hole 16 of the socket member 15, the position of each vertex of the head N' can be rotated when the screw N is driven. The head N' can be accurately fitted into the second socket member 20 regardless of its position in the direction.

Next, the respective inclined surfaces 34, 34, 34 are attached to the inner peripheral wall of the screw insertion hole 16 of the first socket member 15.
A method for forming the same will be explained with reference to FIGS. 6 and 7.

Figure 6A is an external perspective view of the processed rod, Figure 6B
is its bottom view. The outer periphery of this processing rod 36 includes inclined surfaces 37, 37, 37 and arcuate surfaces 38, 3 that match the shape of the inner peripheral wall of the screw insertion hole 16.
8 and 38 are formed every other time in the direction around the axis.

First, the first socket member 15 is formed by casting or the like so that a through hole 39 having a circular cross section is formed in the center of the first socket member 15 as shown in FIG. Note that during this processing, the tapered surface 33 is also formed at the same time. Next, the working rod 36 is pushed into the through hole 39, and the inclined surfaces 34, 34, 3 are pressed against the inner wall of the through hole 39.
form 4. In this embodiment, the socket member 15 is made of SCM steel.

In this way, the shape of the inner circumferential wall of the screw insertion hole 16 of the socket member 15 is adjusted to the respective inclined surfaces 34, 34,
By having arcuate surfaces 35, 35, 35 between 34, each of the above-mentioned inclined surfaces 34, 34,
The processing rod 36 that does not have an edge portion at the joint between the arc and the chord of each inclined surface 37 can be used as the processing rod forming the screw insertion hole 16.
Each of the inclined surfaces 34, 34, 34 of the inner circumferential wall can be formed by forging, and the machining time can be shortened compared to that by electric discharge machining as shown in FIG. This makes it highly suitable for mass production.

Note that, like the socket member 15 of the above embodiment, there are surfaces 40, 4 on the exit 16b side of the screw insertion hole 16 that hold the non-adjacent sides of the head N' of the screw N.
0.40 (see FIG. 4C), the screw N can be rotated and screwed in using the first socket member 15 without using the second socket member 20. . That is,
At least two inclined surfaces are formed on the inner circumferential wall of the screw insertion hole 16 so that a surface for holding two non-adjacent sides of the head N' of the screw N is formed on the exit 16b side of the screw insertion hole 16. If the
The screw N can be rotated and screwed in by the socket member 15.

Further, in the case where the screw N is screwed into the second socket member 20 provided separately from the first socket member 15, the screw N is screwed into the inner circumferential wall of the screw insertion hole 16 of the first socket member 15. Even if only one inclined surface is formed, the screw N is sufficient.
The head N′ of can be guided.

Further, the present invention is not limited to the above-mentioned embodiments, but is applicable to screws having rectangular heads such as square or octagonal.

As is clear from the above description, the present invention is a screw in which a screw having a square head is driven into a material to be screwed, and the screw after driving is driven into the material to be screwed continuously with the driving operation. The tightening tool includes a socket member having a screw insertion hole that guides the head of the screw being driven into the material to be screwed so that it fits into the screw rotation part, and an entrance of the inner circumferential wall of the screw insertion hole. The side has a circular surface that circumscribes each apex of the head of the screw, and within the range from the circular surface to the exit side, there is at least one inclined surface that guides the apex of the head of the screw. In addition, the screw head is characterized in that a portion adjacent to the inclined surface has an arcuate surface that guides the apex of the head other than the apex guided by the inclined surface, and the head of the screw is The inclined surface can be formed by forging without interfering with the guiding function of the socket member, and compared to conventional socket members, the socket member can be mass-produced better and costs can be reduced. Can be done.

[Brief explanation of the drawing]

Fig. 1 is an enlarged longitudinal side view showing a conventional example, Fig. 2 is an enlarged longitudinal side view showing an embodiment of the present invention, Fig. 3 is an enlarged longitudinal side view showing its main parts, and Fig. 4 is an enlarged longitudinal side view showing an embodiment of the present invention. FIG. 4A is an enlarged vertical side view of the socket member, FIG. 4B is an enlarged plan view thereof, and FIG.
Figure C is an enlarged bottom view, Figure 4D is A of Figure 4A.
4E is a sectional view taken along line B-B of FIG. 4B, and FIG. 5B is a cross-sectional view when the head of the screw enters the first socket member from the nose; FIG. 5B is a cross-sectional view showing the head being guided by the inclined surface of the socket member; Figure C is a sectional view when the head passes from the first socket member to the second socket member, and Figure 6 shows an inclined surface formed on the inner peripheral wall of the screw insertion hole of the first socket member. 6A is an enlarged perspective view of its appearance, FIG. 6B is an enlarged bottom view thereof, and FIG. 7 is a diagram showing a state in which the inclined surface is formed by processing the forged rod. It is an enlarged sectional view. 1... Screw tightening tool, 15... First socket, 16... Screw insertion hole, 16a... Input, 16
b...Exit, 32...Circular surface, 34...Slanted surface, 35...Circular surface, N...Screw, N'...Head.

Claims (1)

[Scope of utility model registration request] In a screw tightening tool that drives a screw having a square head into a material to be screwed, and also drives the screw after driving into the material to be screwed continuously with the driving operation, the screw is driven into the material to be screwed. The socket member has a screw insertion hole that guides the head of the screw to fit into the screw rotation part, and the entrance side of the inner circumferential wall of the screw insertion hole has a circumferential connection with each apex of the head of the screw. It has a circular surface that
In the range from the circular surface to the exit side, there is at least one sloped surface that guides the apex of the head of the screw, and in a portion adjacent to the sloped surface, there is a vertex guided by the sloped surface. 1. A screw guide member for a screw tightening tool, characterized in that the screw guide member has an arcuate surface that guides the top of the head other than the top of the head.