JPH0110190Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fastening structure between a screw shaft of an injection molding machine and a motor shaft that drives the screw shaft.

A conventional example of a fastening structure between a screw shaft and a prime mover shaft of an injection molding machine is shown in FIGS. 1 and 2.

In Figure 1, 1 is the cylinder of the injection molding machine, 2
3 is a screw shaft, and 3 is a prime mover shaft. The screw shaft 2 is screwed 4 to the prime mover shaft 3 at its tail end and are fastened to each other. When removing the screw shaft 2 from the motor shaft 3, loosen the mounting bolt 5, retreat the rear cover 7 from the cylinder sheath 6, and lock the special tool to the width across flats 2a of the screw shaft 2.
The screw shaft 2 is removed from the prime mover shaft 3 by rotating the screw shaft 2, but if resin is stuck between the screw shaft 2 and the cylinder 1, it is extremely difficult to rotate the screw shaft 2. Therefore, it is not easy to remove the screw shaft 2 from the prime mover shaft 3.

FIG. 2 shows another conventional example. In the figure,
The same reference numerals as in FIG. 1 indicate the same parts, 1 is a cylinder, 2 is a screw shaft, and a large diameter tail end 2c is formed through a small diameter part 2b. The tail end 2c is
Fitted into the hole 3a of the prime mover shaft 3, and connected to the prime mover shaft 3 with a key 9, the inner circumferential surface of the two-piece holding plate 8, which is integrated into a ring shape, is fitted onto the small diameter portion 2b. The key 9 is fixed to the tip end surface of the motor shaft 3 with a plurality of bolts 8a to prevent the key 9 from slipping out. When removing the screw shaft 2 from the motor shaft 3, move back the rear cover 7, loosen the bolts 8a, and
By removing it, the screw shaft 2 can be extracted from the prime mover shaft 3 without rotating the screw shaft 2. However, with this fastening structure,
As a fastening part of the screw shaft 2, it takes time and effort to form the tail end 2c which has a larger diameter than the lead part 2d which forms the majority of the screw shaft 2, and the screw shaft 2 has a high resistance to wear and corrosion. , and expensive materials are used, so if there is a large diameter part in some parts, the material cost will increase significantly.

In the present invention, a groove having a flat side on the tail end side is provided on the outer peripheral surface of the tail end of a screw shaft having the same outer diameter of an injection molding machine, and the flat side is used as the abutting surface for one end face of the key. A key having the screw shaft is inserted into a keyway formed between the screw shaft and the prime mover shaft to provide a fastening structure between the screw shaft and the prime mover shaft, so that rotation of the screw shaft is not required when removing the screw shaft from the prime mover shaft, and The purpose is to provide a fastening structure for screw shafts that does not increase material costs.

An embodiment of the present invention will be described based on FIG.
1 is the cylinder of the injection molding machine, 2 is the screw shaft, 3
Reference numeral numeral 5 indicates a motor shaft, 5 a mounting bolt, 6 a cylinder sheath, and 7 a rear cover, all of which are the same as in the conventional example. A circumferential annular groove 2e is provided on the outer circumferential surface of the tail end of the screw shaft 2, and an annular flat surface 2f extending perpendicular to the axis of the screw shaft 2 is formed on the tail end side. 2g
3g is a keyway connected to the annular groove 2e and bored in the screw shaft 2 in its axial direction; 3g is a keyway connected to the annular groove 2e;
This is a keyway bored in the fitting hole 3a of the screw shaft 2 of the prime mover shaft 3, facing the direction g. The key 10 whose both end surfaces are flat has both key grooves 2g and 3g.
The screw shaft 2 is inserted into the motor shaft 3 to connect the screw shaft 2 to the prime mover shaft 3. In this case, one end surface 10a of the key 10 is in contact with the flat surface 2f of the annular groove, and the other end surface 10b is loosely fitted onto the screw shaft 2 through the through hole 11a, and screwed onto the outer periphery of the motor shaft 3 11b. The periphery of the inner surface of the through hole 11a of the cap nut 11, which is a locking device, is engaged to prevent the key 10 from coming off.

FIG. 4 shows another example of the structure of the keyway of the screw shaft. A relatively shallow notch 2e' is provided on the outer circumferential surface of the screw shaft 2 in a direction perpendicular to its axis, and a flat side surface 2f' consisting of a chord and an arc is formed on the tail end side of the groove 2e'. 2g' is a keyway connected to the bottom surface of the notched groove 2e' and bored in the axial direction of the screw shaft 2.
A keyway 3g is provided in the prime mover shaft 3, and a key 10 is inserted between the keyway 3g and the keyway 2g', and the other parts can be constructed in the same manner as the embodiment shown in FIG.

In addition to the structure of the embodiment, the locking device that prevents the key 10 from coming off may have a structure as shown in FIG. 5, for example. In the figure, 2 is a screw shaft, 2e is an annular groove, 2f is a flat side surface, 2g is a keyway drilled in the screw shaft 2, 3 is a prime mover shaft, 3g
1 is a key groove drilled in the motor shaft 3, and 10 is a key, which is the same as the embodiment shown in FIG. 8 is the same as the two-part presser plate shown in Figure 2,
It constitutes a locking tool that is fitted onto the screw shaft 2 and fixed to the tip end surface of the prime mover shaft 3 with a plurality of bolts 8a to prevent the key 10 from coming off.

The fastening structure between the screw shaft and the prime mover shaft of the injection molding machine according to the present invention includes providing a groove having a flat side on the tail end side on the outer peripheral surface of the tail end of the screw shaft having the same outer diameter, and connecting to the groove. A key groove is provided in the axial direction of the screw shaft, and a key is inserted between the key groove of the screw shaft and the key groove provided in the fitting hole of the motor shaft into which the screw shaft fits, and one end surface of the key is inserted into the screw shaft. A locking tool for preventing the key from coming off is fixed to the motor shaft, and is brought into contact with the flat side of the shaft groove and engaged with the other end surface of the key.

Therefore, in the fastening structure between the screw shaft and the prime mover shaft of an injection molding machine according to the present invention, after the locking tool is removed from the prime mover shaft, the screw shaft and the prime mover shaft are moved relative to each other in the axial direction. Since the screw shaft can be removed from the prime mover shaft without rotating the screw shaft, maintenance of the injection molding machine and replacement of the screw shaft are easy.Also, by keeping the outer diameter of the screw shaft constant, the screw shaft can be easily removed. We were able to reduce costs.

[Brief explanation of the drawing]

1 and 2 are sectional views showing conventional examples of the fastening structure between the screw shaft and the prime mover shaft of an injection molding machine, respectively, and FIG. 3 is a sectional view showing the screw shaft and prime mover shaft of the injection molding machine according to the present invention. 4 is a side view showing another structural example of the keyway of the screw shaft according to the present invention, and FIG. 5 is a cross-sectional view showing another structural example of the locking device according to the present invention. FIG. 1: cylinder, 2: screw shaft, 2e: annular groove, 2e': notched groove, 2f, 2f': flat side, 2g,
2g': Keyway (of the screw shaft), 3: Prime mover shaft,
3g: key groove (of the motor shaft), 8: presser plate (locking tool), 10: key, 10a: one end surface, 10b: other end surface, 11: cap nut (locking tool).

Claims (1)

[Scope of utility model registration request] In a fastening structure between a screw shaft and a prime mover shaft of an injection molding machine, a groove having a flat surface on the tail end side is provided on the outer peripheral surface of the tail end of the screw shaft having the same outer diameter, and the axis of the screw shaft is connected to the groove. Insert a key between the key groove provided in the fitting hole of the prime mover shaft into which the screw shaft fits and the key groove of the screw shaft, and insert one end surface of the key into the groove of the screw shaft. A fastening structure between a screw shaft and a prime mover shaft of an injection molding machine, characterized in that a locking tool for preventing a key from coming off, which is brought into contact with a flat side surface and engaged with the other end surface of the key, is fixed to the prime mover shaft.