JPS5855849B2 - Constant torque head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a constant torque tightening device that tightens the gears and shaft of a mechanical timer or the like so that they can slip using a disc spring. This is a characteristic feature.

Conventionally, this type of tightening was performed using an air press,
It had the disadvantage that the rotational torque after tightening varied greatly due to factors such as variations in the finished dimensions of each material, variations in the poor spring characteristics, and variations in the roughness of the slip surface.

The present invention uses a constant torque tightening device that uses a measurement head that utilizes the linearity of current change with respect to load torque, which is a characteristic of a DC motor, and a tightening head that has a micro-feeding mechanism using an eccentric cam of a tightening punch. The torque is measured at the same time, and when the set torque is reached, the fine feed mechanism of the tightening punch is stopped to ensure constant torque tightening.

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7 of the drawings.

First, FIGS. 1 and 2 show the configuration of a mechanical timer that is tightened by the constant torque tightening device of the present invention.

A cam plate 2 is installed in the middle part of the shaft 1, a collar 3 is installed on this cam plate 2, and a gear 4 having a hollow bottom shape and having teeth on the circumferential surface is pivotally mounted on this collar 3. A retaining spring 5 is fitted onto the shaft 1 passing through the center of the gear 4, a bushing 6 is fitted onto the countersunk spring 5, the tip of the shaft 1 is plated to secure the bushing 6 to the shaft 1, and the bushing 6 is fixed to the shaft 1. and the gear 4 are connected by pressure due to the deformation and deflection of the disc spring 5.

A constant torque tightening device for assembling such a device will be explained with reference to FIGS. 3 to 7.

7 is formed in an L-shape in the main body of the device, with a raised part 8 at one end.
Two guide posts 9 are erected in parallel with the guide posts 9, and a press ram 10 is built into the guide posts 9 so as to be vertically slidable.

This press ram 10 has one end connected to a rod 12 of an air cylinder 11 attached to the upright part 8 of the apparatus main body 7, and a middle part connected to a lever 14 supported by a pivot 13 via a swing arm 15. It is slid up and down by an air cylinder 11.

Further, a drive motor 16 is mounted on one side of the press ram 10.
A worm wheel 18 is engaged with a worm 17 connected to the drive motor 16, and a rotating shaft 19 is connected to the worm wheel 18.

This rotary shaft 19 has a groove 2 in the front of the central part of the press ram 10.
An eccentric cam 20 disposed within 1 is coupled thereto.

A block 22 is fitted into the groove 21 of the press ram 10, and a recess 23 is provided at the center of the upper end of the block 22.
A roller 25 attached by a support shaft 24 is in contact with the circumferential surface of the eccentric cam 20.

Further, a presser plate 26 of a block 22 is fixed to the front surface of the intermediate portion of the groove 21 of the press ram 10, and a spring 27 is stretched between the presser plate 26 and the flock 22 to constantly bias the block 22 upward. .

Furthermore, a punch 28 is coupled to the lower end surface of this block 22.

A slide block 30 is disposed on the upper surface of the horizontal portion 29 of the apparatus main body 7, and a jig 31 is mounted on this slide block 30. On this jig 31, a cam plate 2, a collar 3, A semi-finished product incorporating a gear 4, a disc spring 5, and a bush 6 is set, and a claw 32 provided on a jig 31 prevents the collar 3 from rotating.

A rotation shaft 3 is located near this slide block 30.
A rotary lever 34 is attached to one end of the rotary lever 34, and a DC motor 35 is attached to one end of the rotary lever 34. The DC motor 35 has a gear 36 that meshes with the gear 4 of the semi-finished product.
is provided.

When the semi-finished product assembled on the jig 31 with this configuration is sent to the lower part of the press ram 10 by the slide block 30, the air cylinder 11 is activated to move the press ram 10 down along the guide post 9. .

This downward movement of the press ram 10 causes the punch 28 to fit into the upper part of the shaft 1 as shown in FIG.

Next, the drive motor 16 is rotated, decelerated by the worm 17 and the worm wheel 18, and the rotating shaft 19 is rotated, so that the eccentric cam 20 is rotated, and the roller 25 of the block 22 is rotated.
is pressed, and the block 22 moves downward against the spring 27.

The downward movement of the block 22 causes the punch 28 to press the tip of the shaft 1 to perform the sharking operation as shown in FIG.

Continuing with the above operation, the rotary lever 34 rotates and the gear 36
meshes with the gear 4, the DC motor 35 is rotated to give a constant rotation to the gear 4, and the rotational torque of the DC motor 35 changes depending on the degree of tightening of the punch 28, and this change is replaced by a current change. The semi-finished product is tightened while detecting the torque resulting from the deformation of the countersunk spring 5 due to the tightening. When a predetermined torque is reached, the minute feed drive motor 16 is stopped by an electric signal, and the press ram 10 is moved by the air cylinder 11.
Raise the same product to create a family of sharks.

When the press ram 10 starts to rise, the drive motor 16 rotates and returns to the initial state.

This operation can be summarized as shown in FIG. 6.

That is, after the jig 31 is moved forward by the slide block 30, the press ram 10 is lowered, and at the same time as the eccentric cam 20 is rotated, the DC motor 35 starts rotating, and the torque is measured and then adjusted to the set torque. When this point is reached, a signal is issued to stop the drive motor 16, the eccentric cam 20 is stopped, the press ram 10 is raised, and the jig 31 is retreated by the slide block 30, completing the series of operations.

Note that FIG. 7 shows a characteristic showing the relationship between rotational torque and current of the DC monitor 35, and torque measurement is performed using this characteristic.

As the constant torque tightening device of the present invention is configured as described above, it tightens the product while measuring the rotational torque of the product, so there are variations in the dimensional accuracy of the product, variations in the spring characteristics of the disc spring, and variations in the roughness of the slip surface. It is of great industrial value as it allows for extremely reliable constant torque tightening without any influence from other factors.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a product to be squeezed by the constant torque tightening device of the present invention, FIG. 2 is an exploded perspective view of the same, FIG. 3 is a perspective view showing an embodiment of the constant torque tightening device of the present invention, and FIG. figure,
FIG. 5 is a sectional view of a main part showing the same operating state, FIG. 6 is a timing chart showing the same operation, and FIG. 7 is a characteristic diagram of the DC motor used in the device. 1... shaft, 2... cam plate, 3...
... Collar, 4 ... Gear, 5 ... Belleville spring, 6 ... Button 7 ... Device body, 9 ... Guide post , 10... Press ram, 11... Air cylinder, 12...
...Rod, 16... Drive motor, 17...
...Worm, 18...Worm wheel,
19... Rotating shaft, 20... Eccentric cam,
21...Groove, 22...Block, 25
...Roller, 26...Press plate, 27.
... Spring, 28 ... Punch, 30
......Slide block, 31...Jig, 34...Rotary lever 35...DC
Motor, 36...gear.

Claims (1)

[Claims] 1. In a constant torque tightening device for products in which a rotating body such as a gear fitted to a shaft is rotatably coupled by tightening the shaft via a spring, a drive motor is provided on a press ram that is moved up and down by an air cylinder, etc. An eccentric cam is connected to the eccentric cam, and a block built into the eccentric cam that can move up and down inside the press ram is always in contact with the block, and a punch is provided at the lower end of this block to tighten the tip of the shaft, and a jig is used to hold the product. A DC motor is provided in close proximity to the rotating body of the product to give a constant rotation to the rotating body of the product and to detect the rotational torque that changes depending on the degree of tightening by the punch. A constant torque tightening device characterized by being configured to tighten a shaft as shown in FIG.