There are many forms of motorized lateral parting core-pulling mechanisms, most of which use inclined surfaces to convert mold opening and closing movement or ejection motion into lateral motion, springs or gear racks are also used to realize change of movement direction and lateral parting core-pulling action.
Inclined guide post lateral parting core-pulling mechanism, bent pin lateral parting core-pulling mechanism, chute lateral parting core-pulling mechanism, wedge lateral parting core-pulling mechanism, inclined slider lateral parting core-pulling mechanism, etc., which use inclined surface to realize movement direction change.

Oblique guide column lateral parting core-pulling mechanism has simple structure, convenient manufacturing and processing. It is the most commonly used form of motorized lateral parting core-pulling mechanism. Angle between oblique guide column and mold opening direction must take into account core pulling distance and bending force of oblique guide column. Generally, it is 15°~20°, and maximum is not more than 25°. Materials are generally T8 and T10, quenching hardness should be above 55HRC, surface roughness Ra=1.6μm. Figure 1 is a typical lateral parting core-pulling mechanism for oblique guide columns.

 

1. Wedge block 2. Fixed mold seat plate 3. Inclined guide post 4. Pin 5. Side core 6. Push tube 7. Movable mold plate 8. Slider 9. Limit stop 10. Compression spring 11. Screw
Figure 1 Side parting core-pulling mechanism of inclined guide post
Typical structure of inclined guide column is shown in Figure 2a, installation form of inclined guide column is shown in Figure 2b. Fit between fixed part and mold plate is H7/m6, it is a clearance fit with slider, generally H11/al1, sometimes sometimes a gap of 0.5~1.0mm is required.

 

a). Structure of oblique guide column

 

b) Installation form of inclined guide post
Figure 2 Typical structure of inclined guide column and its installation form

Lateral parting core-pulling mechanism of oblique slider utilizes oblique movement of slider. This oblique movement can be completed during mold opening movement or simultaneously with ejection movement. Inclined slider mechanism can be used to pull core outside (as shown in Figure 3) or inside (as shown in Figure 4). Generally, inclined slider is locked by a tapered die sleeve, which can withstand greater lateral force, but drawing distance is not large, and product is not easy to fall off automatically, so it needs to be taken out manually.

 

1. Inclined slider 2. Ejector 3. Core fixing plate 4. Lower core 5. Conical mold sleeve 6. Upper core 7. Limit nail
Figure 3 Outer core pulling of inclined slider

 

1. Inclined slider 2. Core 3. Fixed plate 4. Push rod
Figure 4 Core pulling on inner side of inclined slider
According to actual situation of undercut of product, inclined slider can be composed of 2 or more pieces to form a complete cavity, as shown in Figure 5.

 

Figure 5 Split form of oblique slider
By using sliding fit between inclined sliding block and guide chute, purpose of lateral parting and resetting can be achieved. Figure 6 shows several forms of cooperation between inclined slider and guide chute.

 

Figure 6 Matching form of inclined sliding block and guide chute
In order to ensure that inclined sliding block can smoothly slide in guide chute of die sleeve, there should be an appropriate clearance between inclined sliding block and guiding chute. Table 1 lists relationship between two-way fit clearance z value and width L of mating surface.

 

Table 1 Two-way matching clearance between inclined slider and guide chute (unit: mm)
In order to make joints of oblique slide block fit tightly without overflow during molding, after oblique slide block is installed in mold sleeve, there must be a gap of 0.2~0.5mm between lower end surface and mold sleeve, upper end surface is 0.2 to 0.5 mm higher than mold sleeve, so that even if sliding part of inclined sliding block is worn, it can ensure that sliders are tightly joined, as shown in Figure 7.

 

1. Fixed mold plate 2. Slider 3. Die sleeve
Figure 7 Fit of inclined slide block and die sleeve

Principle of bending pin core pulling is very similar to that of inclined guide pin core pulling. Bending pin drives slider for core pulling, but bending pin uses a rectangular section instead of circular section of oblique guide post, replaces straight shape of oblique guide post with a bent shape, hole shape on slider also becomes a bent shape. This change is beneficial to obtain a larger core pulling distance in a limited mold opening stroke, can withstand a larger drawing resistance. Bevel angle should be less than 25°, and maximum should not exceed 30°.
Fixing method of bent pin is shown in Figure 8. It can be installed in mold or outside mold. Among them, a long groove is opened in the middle of bent pin shown in Fig. 8, which is connected with sliding block with a special screw to make it slide along long groove, which can save processing of oblique square holes.

 

Figure 8 Fixing method of bent pin
Several common structures of bent pin core pulling are shown in Figure 9~Figure 12.

 

1. Roller 2. Bent pin 3. Slider
Figure 9 Bending pin mechanism with different inclination

 

1. Slider 2. Bent pin
Figure 10 Bending pin is set on inner side of fixed die side core pulling mechanism

 

1. Slider 2. Bent pin 3. Limit nail
Figure 11 Inner core pulling mechanism with bending pin set in fixed mold

 

1. Bent pin 2. Guide plate 3. Slider
Figure 12 Inner core pulling mechanism with bending pin set outside fixed mold