JPH0110162Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a tool mounting position, such as a wood milling machine or a circular saw machine, in which a tool is mounted using an arbitrary collar depending on the thickness of the tool hub and the mounting position.

Conventional woodworking machines of this type have extremely long coasting times due to the large inertial force of the tools. This not only reduces work efficiency, but also causes accidents due to the operator pressing a piece of wood against the tool shaft for braking, or someone other than the operator not knowing that the tool shaft is coasting and accidentally touching it. There were many cases.
In order to shorten this stop time, woodworking machines have traditionally been equipped with manual braking devices, but in recent years woodworking machines have been equipped with automatic braking devices that operate at the same time as the main switch is turned off to improve safety. It is being commercialized. Since this automatic braking device has a large braking torque, it can greatly shorten the braking time compared to conventional manual braking devices, but there is a risk that the tool fastening screw may loosen due to the large inertial force of the tool. Conventional techniques for preventing this loosening have employed keyways and setscrews, but keyways cause problems with rotational balance and are expensive. The set screw had a weak locking effect and was inconvenient to operate.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to increase the safety of this type of woodworking machine.

In this invention, if a ring is interposed between the tool and the tightening nut to lock onto the rotating shaft and prevent it from rotating, no matter how large the inertia force is, the tool will work during braking. Focusing on the fact that the loosening torque from the easy tool is not transmitted to the tightening nut, that is, the tightening nut does not loosen, the tool mounting rotation shaft,
The relationship between the ring and the tightening nut has been devised.

An embodiment of the present invention will be described below using a wood milling machine as an example. 1 and 2 are a top view and a front view of a wood milling machine, in which a tool mounting shaft 2 protrudes from approximately the center of a table 1, and is moved up and down by a lift handle 3. A workpiece guide plate 4 is attached to a guard 5 before and after the tool attachment shaft 2,
The guard 5 is attached to the table 1 by a knob 6 so as to be adjustable back and forth. In FIGS. 3, 4, and 5, the tool mounting shaft 2, which is moved up and down by the lifting handle 3, is rotatably supported by a bearing box 7 and a bearing 8. As shown in FIGS. A hub 10 is formed on the tool mounting shaft 2, and a collar 12 for supporting the tool 11 is mounted on the upper part of the hub 10, as well as collars 13 and 14 on the tool 11. The upper end of the tool mounting shaft 2 is formed with a width across flats portion 16, a male screw portion 17 located at the same position as the width across flats and slightly shorter than the width across flats, a ring 18 having a hole that fits into the width across flats portion 16, and a ring. A tightening nut 20 is mounted on 18 and rotatably connected by a wire key 19. A hemispherical recess 21 formed on the outer periphery of the tightening nut 20 and the inner periphery of the ring 18 holds the wire key 19.

In the above configuration, the tool mounting shaft 2 is driven by an electric motor using means such as a belt and gears (not shown). During startup, the tightening nut 20 is a right-handed thread so it will not loosen, but during braking, the inertia torque of the tool 11 is applied to the ring 1 through the collar.
8, it acts in the direction of loosening the tightening nut 20.
Although the ring 18 has a rotation preventing structure due to the width across flats portion 16, it is locked to the tool mounting shaft 2, so that inertia torque of the tool, that is, loosening torque is not transmitted to the tightening nut 20. Therefore, the tightening nut 20 does not loosen even during braking.

In addition to the ones shown, we prepare collars of various lengths, and there are usually 6 to 10 types, but depending on the tool hub thickness, tool mounting position, or when installing multiple tools, the distance between the tools can be adjusted. The color arrangement varies as it is arbitrarily selected from among various combinations. In any case, ensure that the tightening nut 20 has a sufficient engagement length to obtain a sufficient tightening effect.
The collar also plays an important role in defining the height of the lower surface of the ring 18 so that the tightening nut is within the effective thread range of the male thread of the shaft.

Therefore, since the position of the uppermost surface of the collar or the upper surface of the tool hub that comes into contact with the ring 18 is not constant, the width across flats portion 16 must be long to some extent. Must be greater than or equal to the minimum male thread length plus the ring thickness.

The ring 18 cannot be separated from the tightening nut 20 due to the wire key 19. Therefore, it is possible to prevent the ring from being lost or forgotten during assembly. If you want to attach the tightening nut 20 to the shaft, first attach the ring 1.
After the hole 8 is engaged with the width across flats portion 16 of the shaft, the tightening nut is rotated and screwed in. After the lower surface of the ring and the uppermost surface of the collar come into contact, the width across flats formed on the upper surface of the shaft is held down with a spanner, etc., and the width across flats of the outer periphery of the tightening nut (not shown) is tightened using a spanner.
The nut fastening force integrally connects the tool to the shaft via the ring and collar. The tightening nut 20 is removed in the reverse order.

6 and 7 show a modification of the means for connecting the tightening nut 20 and the ring 18. In the figure, a pin 22 is press-fitted from the outer periphery of the ring 18.
is engaged with the rectangular recess 23 of the tightening nut 20, and the two are rotatably connected. Therefore, the same functions and effects as in the previous embodiment are achieved.

According to the present invention, a ring is integrally formed under the tightening nut that fixes the tool by engaging with the tool mounting shaft by square fitting means and having a rotation prevention structure, so that the loosening torque of the tool is absorbed by the tightening nut. It is possible to prevent the ring from being lost or forgotten to install, thereby preventing the tool from falling off or being scattered, and increasing the safety of this type of woodworking machine.

[Brief explanation of the drawing]

FIG. 1 is a top view of a wood milling machine to which the present invention is applied, and FIG. 2 is a front view of the same. Fig. 3 is a longitudinal sectional view showing one embodiment of the tool mounting device according to the present invention, Fig. 4 is a cross-sectional view AA of Fig. 3, and Fig. 5 is the same.
6 is a longitudinal sectional view showing a modification of the coupling means of the tightening nut and ring, and FIG. 7 is a CC lateral sectional view of FIG. 6. In the figure, 1 is a table, 2 is a tool mounting shaft,
3 is a lift handle, 4 is a work material guide plate, 5 is a guard, 6 is a knob, 7 is a bearing box, 8 is a bearing, 10 is a hub, 11 is a tool, 12 is a collar, 13 is a collar,
14 is a collar, 16 is a width across flats portion, 17 is a male screw portion, 18 is a ring, 19 is a wire key, 20 is a tightening nut, 21 is a hemispherical recessed portion, 22 is a pin, 2
3 is a rectangular recess.

Claims (1)

[Claims for Utility Model Registration] 1. In a tool mounting shaft on which a tool is mounted using collars of arbitrary length and number depending on the thickness of the tool hub and the tool mounting position, on the outer circumferential surface of the tip of the mounting shaft, A ring in which the cross section of the distal end of the mounting shaft is formed into a non-circular shape by forming a flat part, a threaded part is formed on the outer periphery where the flat part is not formed, and a hole is fitted into the non-circular part. is rotatably attached to the lower part of a tightening nut that is screwed into the threaded part, and the tool is fixed via the ring by fastening the nut to the threaded part. Mounting device. 2. The rotary tool mounting device for a woodworking machine or the like according to claim 1, wherein the flat portion is a width across flat portion formed by a pair of opposing flat portions formed on the outer circumferential surface of the distal end of the mounting shaft.