JP2005066782A - Thread fastening machine with synchronizing mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thread fastening machine with a synchronizing mechanism constituted to hardly generate frictional heat between a spindle, a driving shaft, or the like and the synchronizing mechanism. <P>SOLUTION: In this thread fastening machine 1 with the synchronizing mechanism, when a screw is set to the tip side of the spindle 5 to retreat the spindle 5 in an axial direction, the spindle 5 is first rotated receiving torque on the driving side through the synchronizing mechanism 4 and then rotated receiving torque on the driving side through a clutch 3, and the synchronizing mechanism 4 reduces impact at the beginning of rotation by the clutch 3. The synchronizing mechanism 4 is provided at a driving side member and constituted not to contact the spindle before retreating the spindle 5. When the spindle 5 is retreated, the synchronizing mechanism 4 contacts the spindle 5 to transmit torque on the driving side to the spindle 5 side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a screw tightening machine such as a screw driver for a board. In particular, the present invention relates to a screw tightening machine having a synchronization mechanism. That is, when a screw is set on the tip side of the spindle and the spindle is retracted in the axial direction, the spindle first receives the rotational force on the driving side via the synchronizing mechanism and then rotates on the axis, and then rotates on the driving side via the clutch. The present invention relates to a screw tightening machine with a synchronizing mechanism, which is configured to rotate on a shaft by receiving a force, and in which the synchronizing mechanism reduces the impact at the start of rotation by a clutch.

A general screw tightening machine has a meshing clutch, and the clutch is usually connected in a state where a driving member is rotated by a motor. And it was the structure which transmits the rotational force of a drive side to a spindle side by being connected. In recent years, the rotational speed tends to increase, and the impact at the start of clutch engagement tends to increase. And the increase in the impact promoted the wear of the clutch and shortened the mechanical life of the clutch.
As a countermeasure, a synchronize mechanism has been conventionally used for screw tighteners.

The synchronize mechanism is configured to reduce the impact at the beginning of meshing of the clutch by rotating the spindle before the clutch is engaged. For example, as shown in Patent Document 1, a configuration using a spring (compression coil spring) is used. Met.
The spring was inserted into the shaft hole of the spindle from the rear of the spindle. And the tip of the drive shaft was inserted from the back of the spring. For this reason, the outer peripheral surface side of the spring is in contact with the inner peripheral surface of the shaft hole of the spindle, and the inner peripheral surface side of the spring is in contact with the outer peripheral surface of the drive shaft. Therefore, when the drive shaft rotates, the rotational force is transmitted to the spindle via the spring.
JP-A-11-198979

However, the screw tightening machine has a stopper for preventing the spindle from idling before the screw tightening. Therefore, when the drive shaft is rotated before screw tightening, the spring rotates while in contact with the spindle or the drive shaft, and frictional heat is generated between the spindle and the drive shaft. The frictional heat deteriorates the lubricating performance of the lubricant, and the wear of the synchronization mechanism is promoted. Thus, problems such as a shortened life of the synchronization mechanism have occurred.
SUMMARY OF THE INVENTION An object of the present invention is to provide a screw tightener with a synchronization mechanism that has a synchronization mechanism, and the synchronization mechanism is less likely to generate frictional heat with a spindle, a drive shaft, or the like.

In order to solve the above-mentioned problems, the present invention is a screw tightening machine with a synchronization mechanism having the configuration as described in each claim.
According to the first aspect of the present invention, the synchronization mechanism is provided on a member on either the drive side or the spindle side. Before the spindle is retracted, it is not in contact with the other member, and when the spindle is retracted, it contacts the other member to transmit the driving side rotational force to the spindle side. It can be configured.

In other words, the synchronization mechanism is provided, for example, on a drive-side member, and is not in contact with the spindle-side member before the spindle is retracted. Therefore, when the drive side member is rotated in a state where the spindle is not retracted, the synchronize mechanism rotates without contacting the spindle side member. Therefore, frictional heat is not generated between the synchronization mechanism and the spindle side member.
Alternatively, the synchronize mechanism is provided on the member on the spindle side and is not in contact with the member on the driving side before the spindle is retracted. Therefore, when the drive side member is rotated without the spindle being retracted, the drive side member is rotated in a non-contact state with respect to the synchronization mechanism. Therefore, frictional heat is not generated between the synchronization mechanism and the drive side member.

Thus, the synchronization mechanism is configured to hardly generate frictional heat.
On the other hand, when the screw tightening operation is performed, the spindle is retracted, and the synchronization mechanism comes into contact with the member on the spindle side or the member on the driving side. Therefore, the synchronizing mechanism transmits the driving side rotational force to the spindle side.
Further, the conventional screwing machine requires a stopper that prevents the spindle from rotating before the spindle is retracted. However, in the present invention, the synchronization mechanism and the spindle-side member are not in contact with each other before the spindle is retracted, and the spindle is less likely to rotate. Therefore, in the present invention, the stopper can be omitted. However, the present invention may have a form having a stopper.

According to the second aspect of the present invention, the synchronization mechanism has the radial deformation member that elastically deforms in the radial direction by retreating the spindle. The radial direction deformation member is provided on either the drive side or the spindle side, and is configured to come into contact with the other side member by elastically deforming in the radial direction.
That is, the synchronizing mechanism has a radial deformation member, and the radial deformation member is elastically deformed in the radial direction by the movement of the spindle.
Therefore, the synchronizing mechanism has an easy structure by utilizing the elastic deformation of the radially deformable member.

According to a third aspect of the present invention, the radially deforming member has a configuration in which a slit extending in the axial direction is provided in the cylindrical member, and a moving member that moves in the cylinder is provided in the cylinder. . The radial deformation member has a large inner diameter portion having an inner diameter larger than the diameter of the moving member, and a small inner diameter portion having an inner diameter smaller than the diameter of the moving member. The moving member is configured to move in the axial direction when the spindle is retracted, thereby moving from the large inner diameter portion to the small inner diameter portion, and elastically expands the radial deformation member in the radial direction.
That is, the radial direction deformation member is formed in a substantially cylindrical shape, and is elastically deformed in the radial direction by the movement of the moving member that moves in the cylinder. Therefore, the radial deformation member is elastically deformed in the radial direction with an easy configuration.

According to invention of Claim 4, the compression spring is provided in the cylinder of a radial direction deformation member. The moving member is pressed against the spindle-side member or the driving-side member by a compression spring, is configured to make point contact with the pressed member at the axial rotation center position, and the spindle is retracted. In some cases, the cylinder moves against the compression spring.
Therefore, the moving member is in point contact with the pressed member at the axial rotation center position. Therefore, when the moving member rotates relative to the pressed member, it rotates about the point contact point and the contact position does not move. Therefore, little frictional heat is generated between these members. Thus, the synchronization mechanism is configured to hardly generate frictional heat.
Further, since the moving member is pressed against the spindle side member or the driving side member, the moving member is pushed and moved by the pressed member by retreating the spindle.

According to the fifth aspect of the invention, the synchronization mechanism has the axial displacement member that can be displaced in the axial direction. The axial displacement member is brought into contact with the drive side or spindle side member by retracting the spindle, and when the spindle is further retracted, the axial displacement member is displaced in the axial direction to connect the clutch. It is an acceptable configuration.
That is, the axial direction displacement member is provided, for example, on a member on the spindle side, moves in the axial direction together with the spindle, and contacts the member on the driving side. Or it is provided in the member on the drive side, and contacts the member on the spindle side by retreating the spindle. The axial displacement member allows the spindle to further move backward by being displaced in the axial direction, and allows the clutch to be engaged when the spindle moves backward.
Thus, the synchronization mechanism has an easy structure by using the axial displacement member.

  The screw tightening machine according to the present invention has a synchronize mechanism, and the synchronize mechanism has a configuration that hardly generates frictional heat with a spindle, a drive shaft, and the like. Therefore, the lubrication failure due to heat generation is eliminated, and the durability of the screw tightening machine is improved.

(Embodiment 1)
A first embodiment of the present invention will be described with reference to FIGS.
The present embodiment exemplifies an electric screw fastening machine 1 and has an electric motor 11 inside a housing 10 as shown in FIG. And it has the pinion gear 12 driven by the electric motor 11, the drive gear 2, and the drive shaft 20 (member on the drive side).
Further, the housing 10 is provided with a spindle 5 on which a screw is set on the front end side. Between the spindle 5 and the driving side member, a synchronizing mechanism 4 and a clutch 3 for transmitting the driving side rotational force are provided. Is provided.

  The electric motor 11 is started and stopped by turning on and off a trigger type main switch (not shown) provided in the screw tightening machine main body. A pinion gear 12 is attached to the output shaft 11 a of the electric motor 11. The pinion gear 12 and the drive gear 2 are engaged with each other, and the rotational force of the electric motor 11 is transmitted to the drive gear 2.

The drive gear 2 is non-rotatably attached to the drive shaft 20 in order to rotate about the drive shaft 20 as an axis. Further, the drive shaft 20 is supported by a bearing 13 attached to the housing 10 so that the rear end side (the right end side in the drawing) can rotate in the axial direction and move in the axial direction.
A thrust bearing 14 is attached between the front surface of the bearing 13 and the rear surface of the drive gear 2, and the drive gear 2 is movable in the axial direction with respect to the thrust bearing 14 as shown in FIG. ing.

As shown in FIG. 1, the spindle 5 is provided in front of the drive shaft 20 and coaxial with the drive shaft 20. The front and rear sides of the spindle 5 are supported by bearing cylinders 52 and 53 so as to be rotatable and movable in the axial direction.
The spindle 5 has a bit mounting hole 5c on the front end side, and a driver bit 51 is attached to the bit mounting hole 5c. A steel ball 54 elastically biased radially inward by a leaf spring 55 is disposed in the bit mounting hole 5c. Then, by inserting the driver bit 51 into the bit mounting hole 5c, the steel ball 54 locks the driver bit 51 into the bit mounting hole 5c.

As shown in FIG. 1, an adjustment sleeve 16 and a stopper sleeve 17 for adjusting the screw tightening depth are attached to the front end of the housing 10.
The adjustment sleeve 16 is screwed into a male screw formed on the outer peripheral surface of the front end of the housing 10, and moves back and forth in the axial direction with respect to the housing 10 by rotating the shaft.
The stopper sleeve 17 is detachably attached to the front end of the adjustment sleeve 16, and has an opening 17a from which the front end of the driver bit 51 protrudes on the front end side. Therefore, the position of the stopper sleeve 17 is adjusted by adjusting the position of the adjusting sleeve 16. Thereby, the amount of movement of the driver bit 51 in the axial direction is determined, and the screw tightening depth is adjusted.

A synchronization mechanism 4 is provided between the spindle 5 and the drive shaft 20 as shown in FIG.
The synchronizing mechanism 4 is configured to rotate the spindle 5 by transmitting a driving side rotational force to the spindle 5 and to rotate the spindle 5 before the clutch 3 is connected, and has the following configuration. .

That is, as shown in FIG. 2, the synchronization mechanism 4 includes a cylindrical radial deformation member 40, a moving member 42 disposed in the cylinder 40 a of the radial deformation member 40, and a compression spring 41.
The radially deformable member 40 is integrally provided at the tip of the drive shaft 20 and extends from the tip of the drive shaft 20 in the axial direction (left side in FIG. 2).
The radial direction deformation member 40 has a configuration in which a plurality of slits 40b are provided in a cylindrical member, and these slits 40b extend in the axial direction from the front end to the rear end of the cylindrical member. Therefore, the radially deformable member 40 is configured to be elastically deformable in the radial direction, and in particular, the front end portion is configured to be easily elastically deformed in the radial direction.

The compression spring 41 is a coil spring, as shown in FIG. 2, and is inserted into the cylinder 40 a from the distal end side of the radial deformation member 40 and abuts against the front end of the drive shaft 20. Then, the moving member 42 is inserted into the cylinder 40 a following the compression spring 41.
The moving member 42 is spherical and has a larger diameter than the compression spring 41. Therefore, the moving member 42 abuts on the compression spring 41 and is urged forward by the compression spring 41.

As shown in FIG. 3, the radial deformation member 40 has a large inner diameter portion 40 d having an inner diameter larger than the diameter of the moving member 42 on the front end side. A small inner diameter portion 40e having an inner diameter smaller than the diameter of the moving member 42 is provided at a position adjacent to the rear side of the large inner diameter portion 40d. A stepped portion 40f is formed between the large inner diameter portion 40d and the small inner diameter portion 40e due to the inner diameter difference.
Therefore, when the moving member 42 is retracted in the axial direction from the large inner diameter portion 40d to the small inner diameter portion 40e as shown in FIG.

The spindle 5 has a shaft hole 5a as shown in FIG. The shaft hole 5a has an opening on the rear surface of the spindle 5 and has a certain depth. And the radial direction deformation member 40 is inserted in the axial hole 5a from a back opening part.
The diameter of the shaft hole 5a is larger than the outer diameter of the radial direction deformation member 40 in a free state in which the shaft hole 5a is not deformed in the radial direction. Therefore, the radially deformable member 40 is not in contact with the inner peripheral surface of the shaft hole 5a in a state where it is not elastically deformed in the radial direction.
Moreover, the diameter of the shaft hole 5a is smaller than the outer diameter of the radial direction deformation member 40 in the state deformed in the radial direction. Therefore, when the radial direction deformable member 40 is deformed in the radial direction, the radial direction deformable member 40 contacts the inner peripheral surface of the shaft hole 5a as shown in FIG.

A positioning member 50 is provided on the bottom surface of the shaft hole 5a as shown in FIG. The positioning member 50 is cylindrical and is attached to the center of the shaft hole 5 a and has a diameter smaller than the inner diameter of the radial deformation member 40. Therefore, the positioning member 50 is inserted into the cylinder interior 40a of the radial deformation member 40 in a non-contact manner at the rear end.
A moving member 42 biased by the compression spring 40 is pressed against the rear end surface of the positioning member 50. Therefore, the moving member 42 is pushed backward by the positioning member 50 when the spindle 5 is retracted as shown in FIG.

  The compression spring 40 biases the spindle 5 forward in the axial direction via the moving member 42 and the positioning member 50 as shown in FIG. A flange 5b is formed at the rear end of the spindle 5, and a rubber stopper 6 is attached in the housing 10 as shown in FIG. The flange 5 b is pressed against the stopper 6 by the spindle 5 being biased by the compression spring 40. Accordingly, the spindle 5 is restricted from moving forward in the axial direction by the stopper 6 and is also restricted from rotating around the axis.

A clutch 3 is provided between the spindle 5 and the drive gear 2 as shown in FIG.
The clutch 3 is a mechanism for rotating the spindle 5 by transmitting the driving side rotational force to the spindle 5. The clutch 3 is a mechanism for rotating the spindle 5 following the synchronization mechanism 4. The clutch 3 is a silent clutch as shown below.
The clutch 3 has a plurality (for example, three) of clutch teeth 30 and a plurality (for example, three) of clutch pins 31 on the drive gear 2 side. A plurality of (for example, six) clutch teeth 32 are provided on the spindle 5 side.

The clutch teeth 32 on the spindle 5 side are attached to the rear end face of the flange 5b, and the plurality of clutch teeth 32 are provided on the same circumference at regular intervals in the circumferential direction (for example, 60 °).
The clutch teeth 30 on the drive gear 2 side are attached to the front surface of the drive gear 2, and the plurality of clutch teeth 30 are provided on the same circumference at regular intervals in the circumferential direction (for example, 120 °).
2 and 5, the clutch pin 31 is provided so as to be tiltable in the circumferential direction with respect to the receiving hole 2 a provided in the drive gear 2, and is provided between the clutch teeth 30. When the clutch pin 31 is tilted, the drive gear 2 moves forward as shown in FIG.

Hereinafter, the operation of the synchronization mechanism 4 and the clutch 3 will be described while explaining the screw tightening process according to FIGS.
First, as shown in FIG. 1, the driver bit 51 is mounted in the bit mounting hole 5 c and a screw is set at the front end of the driver bit 51. Next, the electric motor 11 is rotated to rotate the drive shaft 20. Thereby, the radial direction deformation member 40, the compression spring 41, and the moving member 42 rotate in the axial direction.

At this time, the radial deformation member 40 is not in contact with the spindle 5. The moving member 42 is substantially in point contact with the positioning member 50 at the axial center position. Accordingly, the radial direction deformation member 40 and the moving member 42 do not transmit the driving side rotational force to the spindle 5 side.
The spindle 5 is restricted from rotating by a stopper 6. Therefore, the spindle 5 is prevented from idling.

  Next, in order to perform the screw tightening operation, the screw tightening machine 1 is pushed toward the material. As a result, the spindle 5 moves backward against the compression spring 41 as shown in FIG. As a result, the flange 5 b is detached from the stopper 6. The moving member 42 also moves backward against the compression spring 41 together with the spindle 5. Then, the moving member 42 elastically expands the radial deformation member 40 in the radial direction. Thereby, the outer peripheral surface 40c of the radial direction deformation member 40 contacts the inner peripheral surface of the shaft hole 5a. Therefore, the radial direction deformation member 40 transmits the rotational force of the drive shaft 20 to the spindle 5 side, and the spindle 5 is rotated. That is, the spindle 5 is rotated by the synchronization mechanism 4.

When the screwing machine (1) is further pushed toward the material, the clutch 3 is connected as shown in FIGS.
As shown in FIG. 4, the clutch pin 31 has a substantially hemispherical head portion 31a and a pin portion 31b protruding forward from the spherical surface side of the head portion 31a. The head portion 31a is fitted in a hemispherical receiving hole 2a formed on the upper surface of the drive gear 2 so as to be tiltable, and the pin portion 31b is inserted into an insertion hole 2b formed through the receiving hole 2a. Also protrudes ahead. The insertion hole 2b is configured to allow the pin portion 31b to tilt in the circumferential direction as shown in FIG.

Therefore, as shown in FIGS. 4 and 5, when the spindle 5 is moved backward, the pin portion 31 b hits the clutch tooth 32. Then, the pin portion 31b is inclined in the rotational direction by the clutch teeth 32. Then, the head portion 31a is inclined and a part of the head portion 31a protrudes rearward from the receiving hole 2a. The protruding portion is abutted against the thrust bearing 14 and the drive gear 2 moves forward. As a result, the clutch teeth 30 and the clutch teeth 32 are engaged. A gap 15 is formed between the drive gear 2 and the thrust bearing 14.
Then, as shown in FIG. 6, the spindle 5 further moves to the drive gear 2 side. As a result, the clutch 3 is completely connected. Thus, the rotational force of the drive gear 2 is transmitted to the spindle 5 via the clutch 3 and screw tightening is performed.

When the screw tightening is completed, the tip of the stopper sleeve 17 hits the material (see FIG. 1). The driver bit 51 and the spindle 5 are urged by the compression spring 41 and gradually move forward. As a result, the clutch teeth 32 are disengaged from the clutch pin 31 as shown in FIG.
As shown in FIG. 8, the clutch pin 31 is urged by the compression spring 41 in the direction of standing upright via the drive gear 2 and the drive shaft 20. Then, when the clutch pin 31 stands upright, the drive gear 2 moves backward, and the clutch pin 31 and the clutch tooth 30 move backward relative to the clutch tooth 32. Thus, an appropriate gap b is instantly formed between the clutch teeth 30 and 32, and the clutch 3 is idled silently (silent clutch).

Incidentally, the gap b is equal to the movement dimension of the drive gear 2 when the clutch pin 31 is inclined as shown in FIG. The clearance b is larger than the clearance a shown in FIG. 3 (a <b), and the clearance a is a clearance dimension between the clutch teeth 30 and 32 when the operation of the synchronize mechanism 4 is started. Therefore, as shown in FIG. 8, when the clutch 3 is released, the synchronization mechanism 4 is also released at the same time. Thus, the spindle 5 is not subjected to the rotational force on the driving side instantaneously.
Further, the height h of the clutch teeth 30 and 32 is equal to the dimension obtained by adding the dimension c shown in FIG. 5 to the gap b (h = b + c), and the dimension c is a dimension by which the spindle 5 moves after the clutch pin 31 falls down. It is.

The screw tightening machine 1 is configured as described above.
That is, the synchronization mechanism 4 is provided on the drive side member (drive shaft 20) as shown in FIG. 2, and is not in contact with the member on the spindle 5 side before the spindle 5 is retracted. Therefore, when the drive side member is rotated while the spindle 5 is not retracted, the synchronize mechanism 4 rotates in a non-contact state with respect to the spindle 5 side member. Therefore, no frictional heat is generated between the synchronizing mechanism 4 and the member on the spindle 5 side.
Thus, the synchronization mechanism 4 is configured to hardly generate frictional heat.

On the other hand, when the screw tightening operation is performed, the spindle 5 is retracted as shown in FIG. 3, and the synchronization mechanism 4 comes into contact with the member on the spindle 5 side (spindle 5). Therefore, the synchronization mechanism 4 transmits the driving side rotational force to the spindle 5 side.
Moreover, although this form has the stopper 6 as shown in FIG. 1, the form which does not have the stopper 6 may be sufficient. This is because, in the initial state before the spindle 5 is retracted, the synchronization mechanism 4 is not in contact with the member on the spindle 5 side. Therefore, there is little possibility that the synchronization mechanism 4 rotates around the axis. Thus, the stopper 6 can be omitted.
In the case where the stopper 6 is not provided, when the spindle 5 is urged in the forward direction by the compression spring 41, the spindle 3 abuts against the housing 10 and the spindle 3 is restricted from moving in the forward direction. It is the composition which becomes.

The synchronization mechanism 4 includes a radial direction deformation member 40. The radial deformation member 40 is elastically deformed in the radial direction by the movement of the spindle 5.
Therefore, the synchronization mechanism 4 has an easy structure by utilizing the elastic deformation of the radial direction deformation member 40.
The radial direction deformation member 40 is formed in a substantially cylindrical shape as shown in FIGS. 2 and 3, and is elastically deformed in the radial direction by the movement of the moving member 42 that moves in the cylinder. Therefore, the radial direction deformation member 40 is elastically deformed in the radial direction by an easy configuration.

The moving member 42 is in point contact with the member (positioning member 50) pressed as shown in FIG. 2 at the axial rotation center position. For this reason, when the moving member 42 is axially rotated relative to the positioning member 50, the axial rotation is performed around the point contact position, and the contact position does not move. Therefore, little frictional heat is generated between these members. Thus, the synchronization mechanism 4 is configured to hardly generate frictional heat.
Further, since the moving member 42 is pressed against the positioning member 50 provided on the spindle 5, the moving member 42 is pushed and moved by the positioning member 50 by moving the spindle 5 backward.

(Embodiment 2)
A second embodiment of the present invention will be described with reference to FIGS.
The second embodiment is formed in substantially the same manner as the first embodiment, except that it has a synchronization mechanism 7 shown in FIGS. 9 and 10 instead of the synchronization mechanism 4 (see FIG. 2) shown in FIG. Different from Form 1. Hereinafter, the second embodiment will be described focusing on the differences.

The synchronization mechanism 7 according to the second embodiment includes a plurality of elastic members 71 and a clutch plate 70 as shown in FIG. The elastic member 71 is, for example, a compression coil spring, and the front end portion side is attached to the rear surface of the flange 5 b of the spindle 5. The elastic member 71 is configured to be elastically deformable in the axial direction (axial deformation member).
On the other hand, the clutch plate 70 is attached to the rear end side of the elastic member 71 and has a configuration (axial displacement member) that can be displaced in the axial direction by elastic deformation of the elastic member 71. The clutch plate 70 is disk-shaped and has a circular hole 70a at the center. The circular hole 70a is configured to allow the clutch teeth 30 and 32 to mesh as shown in FIG.

Although not shown in FIGS. 9 and 10, the spindle 5 is urged to the front end side by a compression spring. The compression spring is provided between the drive shaft and the spindle, for example. Alternatively, it is provided between the housing and the spindle.
Therefore, when the spindle 5 is retracted against the compression spring, the clutch plate 70 first comes into contact with the drive gear 2. Therefore, the rotational force of the drive gear 2 is transmitted to the spindle 5 via the synchronize mechanism 7, and the spindle 5 rotates axially.
When the spindle 5 is further retracted as shown in FIG. 10, the compression spring 71 is elastically deformed in the axial direction, and the clutch plate 70 is displaced in the axial direction. The clutch teeth 30 and the clutch pins 31 are engaged with the clutch teeth 32.

The screw tightening machine is configured as described above.
That is, the synchronization mechanism 7 is provided on the member on the spindle 5 side as shown in FIG. 9, and is not in contact with the member on the driving side before the spindle 5 is retracted. Therefore, when the drive side member is rotated without the spindle 5 being retracted, the drive side member is rotated in a non-contact state with respect to the synchronization mechanism 7. Therefore, frictional heat is not generated between the synchronization mechanism 7 and the drive side member.
Thus, the synchronizing mechanism 7 is configured to hardly generate frictional heat.

On the other hand, when the screw tightening operation is performed, the spindle 5 is retracted as shown in FIG. 10, and the synchronize mechanism 7 comes into contact with the drive side member (for example, the drive gear 2). Therefore, the synchronization mechanism 7 transmits the driving side rotational force to the spindle 5 side.
The synchronize mechanism 7 has a clutch plate 70 (axial displacement member) that is displaced in the axial direction. The clutch plate 70 is provided on a member on the spindle 5 side, moves in the axial direction together with the spindle 5 and contacts the member on the driving side. The clutch plate 70 is displaced in the axial direction to allow the spindle 5 to further move backward, and to allow the clutch 3 to be connected by moving the spindle 5 backward.
Thus, the synchronization mechanism 7 has an easy structure by using the axial displacement member 70.

(Other embodiments)
The present invention is not limited to the first and second embodiments, and may be the following modes.
(1) That is, in the first embodiment, the radial deformation member 40 is provided on the driving member as shown in FIG. However, the radial deformation member may be provided on the spindle side member. For example, the radially deformable member is provided in a protruding manner on the rear end side of the spindle, and is inserted into a shaft hole formed in a drive side member (for example, a drive shaft). A configuration may be employed in which the spindle is not in contact with the shaft hole before the spindle is retracted, and is elastically deformed in the radial direction when the spindle is retracted to contact the inner peripheral surface of the shaft hole. Therefore, when the drive side member is rotated without the spindle being retracted, the drive side member is rotated in a non-contact state with respect to the radial deformation member. Therefore, frictional heat is not generated between the radially deformable member and the drive side member.
(2) In the first embodiment, the moving member 42 is spherical as shown in FIG. However, any configuration may be used as long as the moving member 42 is configured to substantially make point contact with the positioning member 50 at the axial center position, and may be, for example, an egg shape or a cone shape.
(3) In the second embodiment, the synchronization mechanism 7 is provided on the spindle 5 side as shown in FIG. However, the synchronization mechanism may be provided on the driving member. Before the spindle is retracted, the synchronize mechanism is not in contact with the member on the spindle side, and when the spindle is retracted, the synchronize mechanism comes into contact with the member on the drive side, and the spindle is further retracted. May be configured such that the synchronization mechanism is elastically deformed in the radial direction to allow the clutch to be engaged. Therefore, when the drive side member is rotated in a state where the spindle is not retracted, the synchronize mechanism rotates without contacting the spindle side member. Therefore, frictional heat is not generated between the synchronization mechanism and the spindle side member.
(4) The synchronization mechanism 7 according to the second embodiment has a configuration having an elastic member 71 and a clutch plate 70 as shown in FIG. However, instead of the elastic member 71 and the clutch plate 70, the synchronization mechanism may have a plurality of columnar elastic members (for example, rubber materials) protruding from the spindle toward the drive gear side. When the spindle is retracted, the tip of the elastic member hits the drive gear. When the spindle is further retracted, the elastic member may be elastically deformed in the rotational direction and the axial direction, thereby allowing the clutch to be connected.
(5) Moreover, the screwing machine 1 which concerns on Embodiment 1, 2 was a form which has the silent clutch 3 which has a clutch pin. However, instead of the clutch 3, a disk-type silent clutch or a screw tightening machine having a normal clutch may be used.
(6) The synchronization mechanism according to the first embodiment has a configuration including a radially deformable member that deforms in the radial direction. The synchronization mechanism according to the second embodiment has a clutch plate (axial displacement member) that is displaced in the axial direction. However, the synchronization mechanism may have a clutch plate that can be displaced in the radial direction by the retraction of the spindle. Or the form which has an axial direction deformation | transformation member elastically deformed to an axial direction may be sufficient. For example, the synchronization mechanism illustrated in FIG. 9 may have a configuration in which only the elastic member 71 is provided without the clutch plate 70.

2 is a partial longitudinal sectional view of the screw tightening machine according to Embodiment 1. FIG. It is a longitudinal cross-sectional view of the screwing machine near a drive gear and a spindle. It is a figure which shows the state which retracted the spindle from the state of FIG. It is a figure which shows the state which retracted the spindle from the state of FIG. It is a figure which shows the state which retracted the spindle from the state of FIG. It is a figure which shows the state which retracted the spindle from the state of FIG. It is a figure which shows the state which the spindle advanced from the state of FIG. It is a figure which shows the state which the spindle further advanced from the state of FIG. It is a partial longitudinal cross-sectional simplified view of the screwing machine near the drive gear and spindle which concerns on Embodiment 2. FIG. FIG. 10 is a diagram illustrating a state in which the spindle is retracted from the state of FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Screwing machine 2 ... Drive gear 3 ... Clutch 4, 7 ... Synchronizing mechanism 5 ... Spindle 5a ... Shaft hole 6 ... Stopper 11 ... Electric motor 12 ... Pinion gear 13 ... Bearing 14 ... Thrust bearing 16 ... Adjusting sleeve 17 ... Stopper sleeve DESCRIPTION OF SYMBOLS 20 ... Drive shaft 30, 32 ... Clutch tooth 31 ... Clutch pin 40 ... Radial direction deformation member 42 ... Moving member 70 ... Clutch plate 71 ... Elastic member

Claims (5)

When a screw is set on the front end side of the spindle and the spindle is retracted in the axial direction, the spindle first receives a rotational force on the driving side via the synchronizing mechanism and then rotates on the shaft, and then the driving side via the clutch. A screw tightening machine with a synchronizing mechanism, wherein the synchronizing mechanism is configured to reduce the impact at the start of rotation by the clutch,
The synchronization mechanism is provided on a member on one side of the drive side or the spindle side, and is not in contact with the other member before the spindle is retracted, and when the spindle is retracted The screw tightening machine with a synchronizing mechanism is configured such that the rotational force on the driving side can be transmitted to the spindle side by contacting with a member on the other side. A screw tightening machine with a synchronization mechanism according to claim 1,
The synchronization mechanism has a radial deformation member that elastically deforms in the radial direction by retreating the spindle, and the radial deformation member is provided on either the drive side or the spindle side and has a diameter. A screw tightening machine with a synchronization mechanism, wherein the screw tightening machine is configured to come into contact with another member by elastically deforming in a direction. A screw tightening machine with a synchronization mechanism according to claim 2,
The radial deformation member is a configuration in which a slit extending in the axial direction is provided in the cylindrical member, and a moving member that moves in the cylinder is provided in the cylinder.
The radially deforming member has a large inner diameter portion having an inner diameter larger than the diameter of the moving member, and a small inner diameter portion having an inner diameter smaller than the diameter of the moving member, and the moving member moves the spindle backward. With a synchronizing mechanism characterized in that it moves in the axial direction from the large inner diameter portion to the small inner diameter portion and elastically expands the radial deformation member in the radial direction. Screwing machine. A screw tightening machine with a synchronization mechanism according to claim 3,
A compression spring is provided in the cylinder of the radially deformable member,
The moving member is pressed against the spindle side member or the driving side member by the compression spring, and is configured to make point contact with the pressed member at the axial rotation center position, and the spindle is retracted. A screw tightening machine with a synchronization mechanism, wherein the screw tightening machine moves in the cylinder against the compression spring. A screw tightening machine with a synchronization mechanism according to claim 1,
The synchronization mechanism has an axial displacement member that can be displaced in the axial direction, and the axial displacement member contacts the drive side or the spindle side member by retracting the spindle, and the spindle A screw tightening machine with a synchronizing mechanism characterized in that the clutch is engaged by being displaced in the axial direction when the is further retracted.

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