Page 69 - 《橡塑技术与装备》英文版2026年2期

MACHINERY AND MOLD

inside the upper fixed plate. Since the flange stud is fixed and for measuring shaft-type rotations, and features a large
assembled to the crossbeam panel with bolts, the motion is measurement range, instantaneous position detection upon
transmitted to the distance adjustment nut through the rotation power-on, and no need for zero search.
of the small gear, and ultimately fed back to the upper fixed 2.2 Mechanical displacement relationship
plate. The mold connected to the upper fixed plate will achieve In the retrofitting of the automatic mold adjustment
a motion with twice the pitch of the trapezoidal teeth. device, a rotary encoder is added to the mold adjustment
mechanism. This rotary encoder is installed on the web plate
of the crossbeam, and the rotary signal of the lower coupling
shaft is measured through the rotary encoder. Figure 3 shows
the automatic mold adjustment device, which uses an absolute
hollow shaft multi-turn rotary displacement encoder to directly
measure the rotary information of the lower coupling shaft
and obtain the number of turns output by the mold adjustment
motor. Assuming that the rotary encoder signal of the mold
adjustment motor's rotation is X, the number of teeth on the
1-Die-adjusting motor; 2-Upper coupling; 3-Connecting rod; large gear is Z 1 , the number of teeth on the small gear is Z 2, the
4-Lower coupling; 5-Shaft; 6-Flange seat; 7-Pinion; 8-Flange stud;
9-Die-adjusting nut; 10-Upper fixed plate trapezoidal thread pitch of the mold adjustment nut is P , and
Figure 2 Vulcanizing chamber of mechanical curing the moving distance of the upper fixed plate for mounting the
press mold is H, the following relationship exists:

2 Structural design
In the intelligent transformation of the curing press
discussed in this article, the core of the mechanical structure
lies in the application of rotary displacement encoders. These
encoders collect rotational data from the mold adjustment
motor, and the least squares method is applied for linear fitting
to obtain the mold clamping force-displacement relationship
curve. Encoding control is performed in the PLC to achieve the
one-click automatic mold adjustment function.
2.1 Rotary displacement encoder
A rotary displacement encoder is a kind of sensor
capable of recording rotary signals and converting mechanical
geometric displacements into pulse outputs. Absolute hollow
shaft rotary displacement encoders can capture rotary signals 1-Mold adjustment motor; 2-Upper coupling; 3-Connecting rod;
through capacitive, magnetoelectric, or optoelectronic 4-Lower coupling; 5-Shaft; 6-Flange seat; 7-Pinion; 8-Flange stud;
principles. This encoder features strong anti-interference and 9-Mold adjustment nut; 10-Upper fixed plate; 101-Rotary encoder;
102-Support
high accuracy, and in the field of industrial control, it can
Figure 3 Automatic mold adjustment device
detect parameters such as distance, angle, position, and speed
of mechanical motion. It is currently widely used in various H=2×X×Z 2 /Z 1 ×P (1)
industries as a signal detection method. In this article, an Since this rotary encoder has the function of knowing its
absolute hollow shaft multi-turn rotary encoder is selected. position immediately upon power-on and eliminating the need
This encoder is annular and hollow in overall shape, suitable for zero-seeking, it can obtain information about any position

Vol.52，2026 ·25·