JP2594079Y2 - Screw driving device - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a driving screw driving device which drives a screw to a predetermined depth and then drives the screw continuously. The driving screw driving is excellent in engagement of a driver bit with a head groove of the screw at the time of driving. Related to the device.

[0002]

2. Description of the Related Art A driver bit having a tip shape engaged with a screw head groove is driven by a piston mechanism to drive a screw to a predetermined depth, and then the driver bit is rotationally driven to screw the screw. Japanese Utility Model Application No. Hei 4-78046 is known as a driving screwing device. In this method, the head of the screw is hit with the tip of the driver bit, the head groove of the screw is engaged with the tip of the driver bit at the time of driving, and then the driver bit is continuously rotated by the pinion rack mechanism. Then, the screws are screwed.

If the tip of the driver bit is not oriented in the same direction as the head groove of the screw at the time of driving, the engagement between the head groove of the screw and the driver bit becomes uncertain, and the screw may be damaged. For this reason, the driving and screwing device requires a mechanism for unifying and feeding the head grooves of the screws in a uniform manner, and a mechanism for stopping the tip of the driver bit so that it always has the same direction at the top dead center position. Since it is necessary, the structure becomes complicated as a whole.

[0004]

The object of the present invention is to solve the above-mentioned disadvantages and to engage the tip of the driver bit with the head groove of the screw without requiring a mechanism for unifying the head groove of the screw and the direction of the driver bit. It is an object of the present invention to provide a screw driving device for driving a screw, which can ensure the following.

[0005]

In order to achieve the above object, a screw driving device according to the present invention includes a driver bit and a bit guide for guiding the driver bit in a rotating direction, the driver bit being screwed into the driver bit. Forming a spiral groove and a spiral groove for applying a rotational force in the direction of returning the screw when driven in the direction, and linking the bit guide to a driving means for rotating in the screwing direction, thereby causing the driver bit to impact in the driving direction The driving piston is rotatably and slidably supported in the axial direction, the bit guide is kept stationary when the screw is driven by the driver bit, the bit guide is driven to rotate after the driving , and the driver bit is driven by the driving piston.
It is characterized in that it is screwed while being relatively moved with respect to.

[0006]

According to the above construction, when the striking piston is driven in the screw driving direction when the screw is driven, the bit guide does not rotate, whereas the screw is attached to the driver bit by the spiral strip between the driver bit and the bit guide. A rotational force is applied in the returning direction. Therefore, the driver bit operates in the driving direction while rotating counterclockwise to engage with the head of the screw.

Further, when screwing of the screw, by the helical strip when the bit guide is rotated, the driver bit because the thrust is generated in the screwing direction, the leading end engaging portion of the driver bit is urged driving direction Thus, the engagement of the screw with the head groove is ensured.

[0008]

FIG. 1 shows a longitudinal section of a main part of a driving screw driving device for a driving screw. A tool cylinder 1 has a driving cylinder 2 accommodating a driving piston 2 slidably, and one end of the driving cylinder 3. The formed injection part 4 and the striking piston 2
A driver bit 5 rotatably supported and guided in the injection unit 4 is provided, and a bit guide 6 for guiding the driver bit 5 in the axial direction is disposed inside the emission unit 4. Further, a piston 8 for rotating the bit guide 6 in the screwing direction is provided above the magazine 8 for supplying the driving screw 7 to the injection unit 4.
A cylinder mechanism 10 is provided. In this example, it is assumed that the head groove 7a of the driving screw 7 used in the tool body 1 is formed in a cross shape.

The striking mechanism constituted by the striking cylinder 3 and the striking piston 2 is operated by pulling the trigger lever 11 to operate a driving mechanism (not shown) using compressed air from a compressed air supply source P as a driving source. The main air chamber 12 formed in the tool body 1 based on the operation operation
Is supplied to the striking cylinder 3 to drive the striking piston 2 to impact the driver bit 5 in the striking direction. Further, the compressed air compressed at the striking operation of the striking piston 2 is supplied to the blowback chamber 13. The compressed air is used to cause the striking piston 2 at the bottom dead center to return to the top dead center. Such a driving mechanism is the same as that of a known pneumatic nailer.

The base end of the driver bit 5 is the striking piston 2
, And is slidably supported by a predetermined dimension in the axial direction, and is slidably guided in the injection section 4. On the peripheral surface of the driver bit 5, a loose clockwise spiral 20a (see FIG. 4) is formed. Further, a cross-shaped engaging portion 5a that engages with the head groove 7a of the driving screw 7 is formed at the distal end portion.

The bit guide 6 is rotatably supported inside the injection section 4, and the driver bit 5 is connected to the bit guide 6.
Is held inside. A spiral groove 20b (see FIG. 4) is formed on the inner surface of the bit guide 6 so as to mesh with the spiral strip 20a on the peripheral surface of the driver bit 5. The spiral groove 20b is also formed clockwise. A gear 18 is fixed outside the bit guide 6.

The magazine 8 accommodates the screws 7 and sequentially supplies the screws 7 to the injection unit 4 by a supply mechanism (not shown).

A piston / cylinder mechanism 10 for rotating and driving the bit guide 6 is disposed above the magazine 8 and near the injection section 4, and the driving piston 14 is reciprocated during a predetermined stroke. Drive cylinder 15
The rear end of the drive cylinder 15 is connected to the main chamber 12 via a three-way valve 22, and the switching operation of the three-way valve 22 supplies compressed air to the rear end of the drive cylinder 15 or exhausts the rear end of the drive cylinder 15. Being connected to the mouth. The three-way valve 22 is operated by the air pressure supplied from the blowback chamber 13 so that the air passage 1 is operated.
6. The piston / cylinder mechanism 10 for driving the bit guide 6 and the bit guide 6
Conversion mechanism 1 for converting the reciprocating operation of the bit guide driving piston / cylinder mechanism 10 into the rotational movement of the bit guide 6
7 are linked. The conversion mechanism 17 is configured by meshing a gear 18 fixed to the outside of the bit guide 6 with a rack 19a of a rack member 19 integrally connected to the drive piston 14.

In the above-described configuration, when the trigger lever 11 is operated, the striking mechanism operates, and the striking piston 2 is driven in the screw driving direction as shown in FIG. At this time, the spiral strip 2 of the driver bit 5
Since the bit 0a and the spiral groove 20b of the bit guide 6 are engaged with each other and the bit guide 6 does not rotate, a rotational force is applied to the driver bit 5 in a direction of returning the screw (counterclockwise). Therefore, since the driver bit 5 rotates in the counterclockwise direction and operates in the driving direction to engage with the head of the screw 7, the tip engagement portion 5a of the driver bit 5 is securely fitted into the head groove 7a of the screw. I do.

The amount of rotation of the driver bit 5 may be set so as to make a 1/4 to 1/2 rotation during the driving stroke.

The driver bit 5 slides along the inner surface of the bit guide 6, drives out the screw 7, and projects from the tip of the injection unit 4. In this state, the screw 7 is still 10 to 10
About 20% is in a state of floating from the surface of the work material.

Subsequently, the blowback chamber 1
A part of the compressed air stored in 3 passes through air passage 16 to 3
Operate the directional valve 22. The compressed air in the main chamber 12 is supplied to the rear end of the drive cylinder 15 of the piston / cylinder mechanism 10 for driving the bit guide 6 by the operation of the three-way valve 22, and the drive piston 14 is pushed out by the compressed air. The bit guide 6 is moved forward with the gear meshed with the rack 19a in the screwing direction, and the rotation also drives the driver bit 5 (see FIG. 2).

When the driving of the screw 7 is completed by the impact of the impact piston, the distal end of the driver bit 5 and the head groove 7a of the screw 7 are fitted, and when the bit guide 6 is driven to rotate thereafter. The engagement between the spiral groove 20b of the bit guide 6 and the spiral ridge 20a of the driver bit 5 causes a rotational force to act on the driver bit 5 to drive the screw 7 to rotate in the screwing direction. A resistance force acts between the bit 5 and the bit guide 6, and the driver bit 5 slides in the axial direction following the screwing of the screw 7. As described above, the bit guide 6 drives the driver bit 5 to rotate, so that a thrust acts on the driver bit 5 simultaneously with the rotational force.

Therefore, when the driver bit 5 is completely fitted in the head groove 7a of the screw 7, the thrust of the driver bit 5 is suppressed, and the screw 7 rotates immediately. However, due to the reaction at the time of driving of the screw 7, the driving screw driving device separates from the screw 7, or the driver bit 5 and the screw 7
If the fitting of the screw 7 with the head groove 7a is incomplete, the driver bit 5 moves in the driving direction by the thrust, and the fitting of the screw 7 with the head groove 7a is completely completed. become. Therefore, the screw 7 is securely screwed.

After the screwing is completed, when the operation of the trigger lever 11 is released, the striking piston 2 is returned by the remaining compressed air in the blowback chamber 13, and the driving piston of the piston / cylinder mechanism 10 for driving the bit guide 6 is driven. 14 also returns by the spring, the rack member 19 retreats, and the bit guide 6 rotates in the return direction together with the gear meshing with the rack 19a. With this rotation, the driver bit 5 moves upward while rotating rightward. The next shot is prepared.

Incidentally, the rotation driving means of the bit guide 6 is not limited to the one using the above-described pinion rack mechanism. For example, it may be configured to be rotated by an air motor.

The above embodiment is an example in which the helical groove 20a is formed in the driver bit 5 and the helical groove 20b is formed in the bit guide 6, but the helical groove is formed in the driver bit and the helical groove is formed in the bit guide. You may.

[0023]

According to the present invention, the spiral groove formed between the driver bit and the bit guide meshes with the spiral groove.
When the driver bit is driven in the axial direction when the screw is driven, the driver bit rotates in the direction to return the screw. Therefore, the driver bit operates in the driving direction while rotating counterclockwise and engages with the head of the screw, so that the tip engagement portion of the driver bit aligns with the groove of the head of the screw during rotation,
Securely fits into the head groove of the screw. Therefore, the head groove of the screw is not damaged. Further, at the time of screwing the of screws the helix conditions thrust acts on the driving direction to the driver bit through, because is biased in the driving direction always fit with the head groove of the front end engaging portion and the screw If it is complete. Therefore, screwing is reliably performed, there is no such thing as the head groove of the screw is destroyed.

Further, when the screw 7 is screwed, a thrust is applied to the driver bit in the driving direction by the helical thread, and the driver bit is constantly urged in the driving direction. The fit is complete. For this reason,
The screwing is performed securely, and the head groove of the screw 7 is not broken.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an outline of a screw driving device according to the present invention.

FIG. 2 is an operation explanatory view of the driving and screwing device.

FIG. 3 is an enlarged view of a main part of the driving and screwing device.

FIG. 4 is a sectional view of a bit guide.

[Explanation of symbols]

 2 Impact piston 5 Driver bit 6 Bit guide 7 Screw 20a Spiral strip 20b Spiral groove

Claims (1)

(57) [Scope of request for utility model registration] A helical strip and a helical groove for meshing with a driver bit and a bit guide for guiding the driver bit in a rotational direction to apply a rotational force in a direction to return the screw when the driver bit is driven in a screw driving direction. And the bit guide is linked to driving means that rotates in the screwing direction, and the driver bit is supported rotatably and axially slidably on a striking piston that performs an impact operation in the driving direction. When the screw is driven by the driver bit, the bit guide is kept stationary, and after driving, the bit guide is driven to rotate and the driver bit is driven.
A screw driving device for screwing a screw while moving the screw relative to the striking piston .