JPH029927Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a body protection device for a mortise machine equipped with a circular saw.

With conventional mortise machines equipped with circular saws, if processed wood pieces accumulate on the base, the drive bevel gear in the power transmission mechanism is fixed to the gear spindle by a key and transmits power, so the piles will not accumulate. When a piece of wood gets caught in the vertical saw blade and the vertical saw blade suddenly locks, the motor, bevel gear, gear spindle, and other power transmission devices are forced to stop. Frictional torque several to several tens of times the locking torque acts, damaging power transmission members such as bevel gears and spindles. To solve the conventional problems, it is necessary to provide a device to forcibly eject the accumulated wood chips, or to protect the main body even if they get caught. However, if a forced discharge device is installed, the machine may become larger or
The disadvantages were that the cost was high and that it was not possible to make it smaller and more compact, making it uneconomical.

The purpose of the present invention is to eliminate the drawbacks of the conventional saw blade and prevent damage to the main body and drive system even if a piece of wood gets caught in the saw blade and the vertical saw blade locks.

In this invention, if the power is transmitted using the frictional force generated by the locking force of the spring, when a piece of wood gets caught in the vertical saw blade and the vertical saw blade locks, the transmitted torque of the motor is greater than the frictional torque. Focusing on the fact that the transmission torque increases, the design was devised so that when the transmitted torque increases, the bevel gear slips to alleviate the impact force on the drive device.

The present invention includes a cutting head 4, a motor 5, a power transmission gear spindle 8, bevel gears 9, 17,
Sprockets 11 and 18 are arranged to transmit power to the circular saw. The power transmitted from the motor armature 10 to the gear spindle 8 is transmitted from the bevel gear 9 to the bevel gear 17, and then the vertical saw blade 6
Then, fix the gear spindle 8 and sprocket 11 with the key 14, and then tighten the two sprockets 11,
A horizontal mushroom blade 16 is passed through a chain 15 between 18 and 18.
has been communicated to. While loosely fitting the bevel gear 9 to the vertical saw blade 6 into the spindle 8,
The spring 7 is held between the horizontal drive sprocket 11 and is brought into contact between the end of the sprocket 11 and the bolt 12 screwed into the gear spindle 8. When the bolt 12 is tightened, the counter spring 7 is compressed, and the spring pressure pushes the sprocket 11 toward the bevel gear 9. When the bolt 12 is tightened, the gear spindle 8 is pulled toward the bolt 12, and the gear spindle 8 and the sprocket 11 are pulled together. Friction torque, which is the product of the spring load, the average contact radius, and the friction coefficient, is generated in the bevel gear 9 held between them, and this torque transmits power to the vertical saw blade. When a piece of wood 13 is caught in the vertical saw blade 6 and the vertical saw blade 6 is locked, the torque transmitted by the motor becomes larger than the friction torque caused by the counter spring 7, causing the bevel gear 9 to slip, causing the vertical saw blade to be removed from the gear spindle 8. Since the power to the mushroom blade 6 is cut off, power transmission members such as the motor 5 and the gear spindle 8 are no longer locked by the bevel gear 9.

The friction torque can be adjusted by tightening the bolt 12, but if the bolt 12 is not tightened enough, the spring pressure will be weakened and the gear spindle 8
Since no friction torque is generated between the sprocket 11 and the bevel gear 9, the power from the motor 5 to the gear spindle 8 is not transmitted to the bevel gear 9, and the vertical saw blade 6 cannot be rotated. If it is tightened too much, the condition will be the same as in the conventional example in which the gear spindle 8 and bevel gear 9 are fixed, resulting in the same drawbacks as in the conventional example, so the friction torque and the locking torque of the motor 5 should be approximately the same. is desirable.

According to the present invention, by providing a slip mechanism using a friction clutch in a part of the power transmission unit, even if a piece of wood gets caught and the vertical saw blade is locked, the transmission torque and inertia torque of the motor applied to the power transmission unit can be maintained. The slippage of the drive bevel gear is alleviated, and the main body and drive system can be protected.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention;
The figure is a plan view showing the power transmission mechanism. In the figure, 1 is the base, 4 is the head, 5 is the motor, 6 is the vertical saw blade, 7 is the spring, 8 is the gear spindle, 9 and 17 are the bevel gears, 11,
18 is a sprocket, 12 is a bolt, and 13 is a piece of wood.

Claims (1)

[Scope of utility model registration request] A vice section is disposed on one end of the upper surface of the base, and a cutting head that is driven up and down along the guide bar is provided on the guide bar that is erected on the other end of the upper surface of the base, and the cutting head is equipped with a drive motor and a power source. In a tenoning machine equipped with a plurality of circular saws that are rotationally driven via a transmission mechanism, one of the drive gears that is transmitted from the motor to the vertical saw blade via the gear spindle is loosely fitted to the outer periphery of the gear spindle. At the same time, the driving gear is sandwiched between the horizontal saw blade power transmission member by the biasing force of the spring and the bolt disposed at the end of the gear spindle, and the drive gear, the end face of the gear spindle, and the horizontal saw blade transmission member are A main body protection device for a mortising machine characterized by transmitting power to the vertical saw blade using the frictional force of the end face.