JPH07115397B2 - C-type frame for mold clamping of injection molding machine - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a frame having a C-shaped side surface and used for a mold clamping device of an injection molding machine.

[0002]

2. Description of the Related Art Most C-shaped frames so far are made of steel plates, and the left and right side frames and upper frame formed by cutting and the front frame between the side frames are integrally connected by welding. Is being manufactured.

[0003]

Therefore, the C-shaped frame is laborious to manufacture and requires many days, so that the structure is simple but the productivity is low, and the cost is high.

Therefore, a C-shaped frame is composed of a cast main body frame in which an upper frame is projectingly formed on the upper side surface of the front part, and a base at the bottom of the frame to try to improve productivity. The tensile strength and the compressive strength are inferior to those of the ones, and the elastic modulus is small, so that the deformation amount due to the load is large, and in particular, the opening easily occurs between the body frame and the base.

The amount of deformation under load has a great influence on the mold clamping of the mold, and if it exceeds the allowable amount, the mold closing becomes incomplete and the molding accuracy is impaired. This allowable amount depends on the size of the mold clamping device, but in the case of a small size, the parallelism between the movable plate and the fixed plate needs to be 0.1 mm or less.

The amount of deformation of the body frame due to this casting is
The problem can be solved by forming each part frame forming the main body frame to be thick and increasing the overall weight, but this is not preferable because it increases the cost and increases the mechanical weight.

Further, the opening between the main body frame and the base can be reduced by increasing the diameter of the bolt connecting both of them and increasing the number of bolts, but it is not solved as a whole. Absent.

The present invention provides a C-frame for mold clamping having a new structure, which can limit the problem of the displacement amount of the main body frame due to the above-mentioned casting to the allowable range or less by a simple means without increasing the weight. It is in.

[0009]

The features of the present invention according to the above-mentioned object are that a pair of left and right side frames and a mold clamping cylinder are formed so as to project on the upper side surfaces of the side frames and the ends are vertical. A body frame having a required width consisting of an upper frame and a front frame located between the insides of the side frames is integrally formed by casting, and a base is bolted to the lower end of the body frame to form a C-shaped frame. ,
A pair of steel columns extending from the top of the main body frame to the bottom of the base plate are pierced at the connection between the both side frames and the front frame, and the preload is introduced into the main frame by providing tightening means on the columns. It is in.

[0010]

[Operation] In the above configuration, the pair of struts penetrating the side frame can receive the tensile force acting on the main body frame, and the preload by the struts reduces the bending of the main body frame under load. Since the displacement amount of the main body frame is extremely small, the parallelism between the main body frame and the base is limited within the allowable range.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference numeral 1 in the drawing denotes a main body frame having a required width by casting, which is a pair of left and right side frames 2, 2 and upper frames 3, 3 projectingly formed on the upper side surfaces of the side frames 2, 2.
And each frame of the front frame 4 located between the insides of the side frames 2 and 2 is integrally formed by casting.

Each end of the upper frames 3, 3 is formed in a vertical mold clamping cylinder 5, 5 and also the side frames 2, 2
The connecting portion between the front frame 4 and the front frame 4 is formed thick, and the through holes 6 and 6 penetrating the main body frame 1 vertically are formed therein.
Is formed.

At the lower end of the main body frame 1, a casting base 7 having through holes 8 which are extensions of the through holes 6 at symmetrical positions is horizontally attached by a required number of bolts 9. Thus, a C-shaped frame in which the upper frames 3 and 3 and the base 7 project on one side of the side frames 2 and 2 is formed.

Reference numeral 10 is a column made of a round steel material having both ends formed in screw shafts 11. Adjacent portions of the screw shafts 11 and the pillars are formed with a slightly smaller diameter to form a neck 10a. Further, a heater insertion hole 10b is bored in the upper end portion, and a lower end portion is provided with a tapered step portion 10c so as to have a diameter slightly smaller than that of the upper end portion, as shown in FIG.

The column 10 is inserted into the through holes 6 of the side frames 2 and 2 and the through hole 8 and penetrates the body frame 1 from above to the bottom of the base.

Further, a washer 12 is provided on a screw shaft 11 of the pillar 10 projecting from the upper surface of the main body frame 1 and the bottom surface of the base, and a nut 13 is screwed thereto. It is fastened to both 1 and base 7.

Due to the tightening force on the column 10,
The column 10 is forcibly stretched in the neck 10a, and its reaction force acts as a compressive force on both the main body frame 1 and the base 7, thereby introducing a preload into the main body frame 1.

In order to efficiently introduce the preload, a heater is inserted into the penetrating pillar 10 to heat it, and when it is expanded in the axial direction by thermal expansion, it is tightened by the nut 13 to tighten the pillar 10. Is to wear. Prop 1
0 contracts with cooling, and the contracting force acts on the main body frame 1 via the nut 13, whereby the preload is introduced.

Reference numeral 14 designates a mounting portion provided at a required position on the back side surface of the side frame 2, and a bolt hole is bored although not shown in the drawing. Reference numeral 15 is a piston of the mold clamping cylinders 5 and 5, and has a rod 16 at the upper end, and the movable platen 1 at the lower end.
7 is mounted horizontally across both pistons.

Reference numeral 18 denotes a die mounting plate provided on the base 7. Although not shown in the drawing, the mold is separately attached to both the die mounting plate 18 and the movable plate 17.

As shown in FIG. 4, the C-shaped frame having the above-described structure is such that the main body frame 1 is made vertical through the base 7 and the machine base 1
9 can be installed. In this case, the base 7 is bolted to the machine base 19 to fix the C-shaped frame on the machine base.

Further, according to the specifications as a normal vertical injection molding machine, the injection device 20 is vertically arranged in the center between the upper frames 3 and 3. The injection device 20 is connected to the pistons 15 and 15 of the mold clamping cylinders 5 and 5 and the rod 16 is connected to the piston of the nozzle touch cylinder 21 provided on the side of the injection device 20, although details thereof are omitted. Is
After the injection device 20 is lowered by the nozzle touch cylinder 21, mold closing and mold clamping can be performed by the mold clamping cylinders 5 and 5.

In some cases, the injection device 20 may be horizontally arranged and used for two-color molding or the like, as shown by a chain line. In this case, the nozzle insertion hole may be provided in the front frame 4 in advance.

In the mold frame constructed as described above, the frame weight is reduced as shown in FIG. This figure shows the relationship between the frame weight and the amount of displacement when a mold clamping force (10 tons) is applied. The displacement amount increases as shown by the solid line as the weight decreases, but a preload was introduced. In that case, the weight can be reduced compared to the case of only the prop,
In the case of casting only with the same frame weight, as shown by the chain line, the displacement amount is 0.2 mm or more, whereas the displacement amount is less than 0.1 mm, so that the parallelism is good.

[0025]

Therefore, according to the present invention, even if the main body frame is formed by casting, the tensile strength is increased by the columns, and the displacement amount can be limited by the preload introduced into the main body frame. Thus, it is possible to complete a C-shaped frame having the same strength as when the whole is made of a steel plate.

Further, since the mold clamping cylinder, the mounting portion and the like can be cast integrally with the main body frame, compared to the case where the steel plate is welded to manufacture the C-shaped frame, the number of steps is not required and the quality control is facilitated so that the strength can be improved. Since there is no variation and mass production is possible, the cost is reduced.

Furthermore, since there is almost no opening between the upper part of the main body frame and the base due to the displacement, the C-shaped frame can be used as it is as a frame of a horizontal mold clamping device, compared with the conventional C-shaped frame. It has features such as wide application range.

[Brief description of drawings]

FIG. 1 is a sectional view taken along line AA in FIG. 2 of a C-frame for mold clamping of an injection molding machine according to the present invention.

FIG. 2 is a plan view of a half section taken along line BB in FIG.

FIG. 3 is a front view of the same.

FIG. 4 is a side view of a vertical injection molding machine configured by using the mold clamping C-shaped frame of the present invention.

FIG. 5 is a partial cross-sectional view showing a tightened state of a base and a lower portion of a column.

FIG. 6 is an explanatory diagram of a relationship between frame weight and displacement amount.

[Explanation of symbols]

 1 Main Frame 2 Side Frame 3 Upper Frame 4 Front Frame 5 Mold Cylinder 6 Insertion Hole 7 Base 8 Through Hole 10 Strut 10a Neck 10b Heater Insertion Hole 11 Screw Shaft 12 Washer 13 Nut 14 Mounting Part 15 Piston 16 Rod 17 Movable plate 18 Type plate 19 Machine stand 20 Injection device

Claims (1)

[Claims] 1. A position between a pair of left and right side frames, an upper frame projectingly formed on an upper side of a front side of the side frame and having a vertical end portion formed in a mold clamping cylinder, and an inner side of the side frame. A body frame having a required width consisting of a front frame is integrally formed by casting, and a base is bolted to the lower end of the body frame to form a C-shaped frame, and a connecting portion between both side frames and the front frame. To
A C-type for mold clamping of an injection molding machine, characterized in that a pair of steel columns extending from above the main body frame to the bottom of the base are provided, and a fastening means is provided on the columns to introduce a preload into the main body frame. flame.