JPS5918167Y2 - Hydraulic cylinder stroke adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a stroke adjusting device for a hydraulic cylinder that opens and closes a mold in an injection molding machine.

In the mold clamping device of an injection molding machine, when an automatic take-out machine is used to take out the product, it is necessary to be able to freely set the mold opening/closing stroke and to stop the mold at a fixed position for each cycle in order to shorten the take-out cycle.

As shown in FIG. 6, such a mechanism has conventionally been used, in which a threaded rod C with a handle having a stopper b protruding from the end of a hydraulic cylinder a is threaded through the end of the hydraulic cylinder a, and by rotating the handle d, the stopper b is set. There is a device in which the inner end of the hydraulic cylinder a is moved back and forth in the axial direction, and the rod end surface of the piston body e is received by the stopper b to determine the mold opening/closing stroke. Accordingly, when the piston body e retreats at a high speed, it presses against the stopper b with a large impact force, and the reaction makes it difficult to stop it at a predetermined position, which has the disadvantage that it is not suitable for high-cycle use.

In order to eliminate this, the piston body e is decelerated by using an electric signal from a limit switch to throttle a throttle valve installed in the piping on the pressure oil outlet side before the rod of the piston body e comes into contact with the stopper b. However, there is a drawback that the amount of deceleration changes significantly in response to changes in the oil temperature and the inertia force of the piston body, and there is a risk that the piston will stop before the stopper b, and that it is difficult to adjust the position of the limit switch.

In addition, in high-cycle mold opening/closing operations, from high speed to 0
．． Since it is necessary to decelerate the piston body e in a short period of about 1 second, accurate deceleration cannot be achieved by decelerating in multiple stages using signals from a limit switch, and if the valve is switched using an electric signal, Due to its responsiveness, it has drawbacks such as not being able to decelerate in a short time, let alone at the time of starting.

The present invention enables the mechanical deceleration start position and stop position to be freely selected without employing such limit switches or valves, and allows for stepless switching of the deceleration amount by adjusting the handle from the outside. To provide a stroke adjustment device for a hydraulic cylinder that can decelerate and stop at a fixed position in a high cycle without response delay or impact.

To explain the drawings showing the embodiment, 1 is a hydraulic cylinder in which a piston body 2 is slidably installed, and a movable mold (not shown) is attached to the end of a rod body 3a protruding from the front end side of the hydraulic cylinder.
A short rod 3b is integrally protruded from the rear end side.

Reference numeral 4 denotes a pressure oil circulation hole at a suitable location on the peripheral surface of the rear end of the hydraulic cylinder 1, which communicates the inside and outside of the cylinder.

Reference numeral 5 denotes an outer sleeve body slidably installed inside the rear end of the hydraulic cylinder 1 so as to be able to slide back and forth, and a long hole 6 communicating with the pressure oil circulation hole 4 is bored in the axial direction at a suitable position on its circumferential surface. At the same time, a shaft cylinder 7 is integrally bored in the center of the rear end face, and a screw portion 8 formed on the outer peripheral surface of the shaft cylinder 7 is sealed to the rear end of the hydraulic cylinder 1 and inserted into the central screw hole 10 of the lid body 9 fixed. A disk-shaped large-diameter handle 11 is fixed to the rear end of the shaft tube 7 through a screw thread.

Reference numeral 12 denotes an inner sleeve body rotatably fitted to the inner circumferential surface of the outer sleeve body 5, and a plurality of circular holes 13 having a diameter approximately the same as the width of the elongated hole 6 or slightly smaller in diameter are formed on the circumferential surface of the inner sleeve body 5. , 13...13 are sequentially displaced in the circumferential direction with respect to the axial direction and bored at predetermined intervals, and a shaft part 14 is integrally connected to the center of the rear end surface, and the shaft part 14 is connected to the outer sleeve. It is inserted into the shaft tube 7 of the body 5,
A disk-shaped small diameter handle 15 is fixed to the projecting end of the shaft tube 7 so as to overlap the large diameter handle 11.

A long arc-shaped hole 16 is bored in the small-diameter handle 15, and a pin 17 protruding from the large-diameter handle 11 is fitted into the small-diameter handle 15 so as to be movable relative to the long hole 16.
The rotating dust can be read by a display scale 18 provided on the outer peripheral surface of the large diameter handle 11, and the circular hole 13 communicating with the elongated hole 16 can be known.

Further, the inner circumferential diameter of the cylindrical recess 12a of the inner sleeve body 12 is made equal to the outer circumferential diameter of the short rod 3b of the piston body 2, and the short rod 3b is slidably inserted into the cylindrical recess 12a. It is constructed in such a way that it can be removed.

Reference numeral 19 denotes a circumferential groove formed on the outer circumferential surface of the outer sleeve body 5 except for both ends with a slightly small diameter, and the elongated hole 6 is communicated with the pressure oil flow hole 4 through the circumferential groove 19.

Reference numeral 20 denotes an intermediate hole bored in the rear wall of the inner sleeve body 12 in the radial direction. The through hole 22 is made to communicate with the end of the circumferential groove 19, and under normal conditions, the through hole 22 is closed from inside by a check valve 24 by the pressing force of a spring 23 press-fitted into the intermediate hole 21. It is.

Further, a circumferential groove 31 communicating with the through hole 22 is provided on the inner peripheral surface of the end portion of the outer sleeve body 5, and a communicating hole 32 is provided between the circumferential groove 31 and the circumferential groove 19.

25 is a lock nut screwed onto the shaft tube 7 of the outer sleeve body 5, and an operating handle 26 is attached thereto.

Reference numeral 27 denotes an oil inlet/outlet provided at the outer periphery of the front end of the hydraulic cylinder 1.

To describe the operation of the embodiment configured as described above, the piston body 2 of the hydraulic cylinder 1 switches the electromagnetic switching valve 28 to the right in FIG. If the pressure oil flows into the communication hole 4 through the circumferential groove 19, the pressure oil passes through the elongated hole 6 of the outer sleeve body 5 and flows into the communication hole 2.
Push open the check valve 24 that closed intermediate hole 2.
0 into the inner sleeve body 12 through the center small (L21) and press the rear end surface of the piston body 2 to remove the piston body 2.
Move forward and clamp the mold.

Next, when opening the mold, the electromagnetic switching valve 28 is switched to the left to send pressure oil from the pump 29 into the cylinder 1 through the inlet/outlet 27, and the piston body 2 is moved back.

At this time, the oil on the rear end surface side of the piston body 2 is removed from the outer sleeve body 5.
from the long hole 6 to the circumferential groove 1 through the circular hole 13 communicating with the long hole 6.
9 and returns into the tank 29 through the communication hole 4, but the short rod 3b of the piston body 2 is connected to the inner sleeve body 1.
2 and closes the circular hole 13, the flow area of oil toward the elongated hole 6 side decreases, and the retreat of the piston body 2 is gradually slowed down to a position where the circular hole 13 is completely blocked. At this point, the hydraulic pressure on the front and rear end surfaces of the piston body 2 is balanced and the piston body 2 stops.

The deceleration start position and stop position of the piston body 2 are set by rotating the handle 11 and integrally advancing or retracting the inner and outer sleeve bodies 5 and 12.
5 rotates, only the inner sleeve body 12 rotates in the circumferential direction, and the positional relationship of the circular hole 13 that communicates with the long hole 6 changes, and the pressure oil flowing from the circular hole 13 to the long hole 6 changes. The amount of deceleration can be adjusted steplessly by changing the flow rate, and the piston body 2 can be gradually advanced when the mold is closed.

As described above, the present invention provides a pressure oil circulation hole 4 on the circumferential surface of the rear end of the hydraulic cylinder 1 in which the piston body 2 is slidably housed, and also provides the pressure oil circulation hole 4 on the circumference within the rear end. An outer sleeve body 5 formed with a communicating elongated hole 6 bored in the axial direction is slidably fitted, and a shaft cylinder 7 protruding from the rear end surface of the outer sleeve body 5 is connected to the rear end of the hydraulic cylinder 1. A bundle 11 is fixed to the shaft end which is screwed into the outer sleeve body 9 and protrudes to the outside, and a plurality of holes 13 are formed in the outer sleeve body 5 on the circumferential surface sequentially in the circumferential direction with respect to the axial direction. The inner sleeve body 12 is rotatably fitted into the inner sleeve body 12, which has been drilled in this manner, and the rod 3b of the piston body 2 is inserted into and removed from the inner sleeve body 12. Since this relates to a stroke adjustment device for a hydraulic cylinder in which a bundle [5] is inserted into the shaft tube 7 of the outer sleeve body 5 and fixed to the shaft end thereof, when the piston body 2 retreats, the rod 3b is inserted into the inner sleeve body. Since the piston body 2 stops when the piston body 2 is inserted into the inner sleeve body 12 and closes the hole 13 communicating with the elongated hole 6 of the outer sleeve body 5, it can be stopped smoothly without colliding with the inner wall surface of the inner sleeve body 12. At the same time, the hole 13 is gradually closed and the discharge flow rate is reduced, so that the piston body 2 can be reliably stopped at a predetermined position while being decelerated. Furthermore, when the bundle 11 is rotated, the inner and outer sleeve bodies 5, 12 can be integrally moved back and forth, the position of the hole 13 of the inner knob 12 can be mechanically changed to reduce the deceleration of the piston body 2 without changing the position of the limit switch etc. as in the conventional case. The start position and stop position can be set at desired positions, and the mold opening stroke can be determined accurately.

Further, by rotating the bundle 15, the position and circulation area of the hole 13 of the inner sleeve body 12 relative to the elongated hole 6 of the outer sleeve body 5 can be changed, and the amount of deceleration of the piston body 2 can be adjusted steplessly. be.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a longitudinal sectional side view thereof, Fig. 2 is a front view seen from the bundle side, Fig. 3 is a partial longitudinal sectional side view of the inner sleeve body, and Fig. 4 is a longitudinal sectional side view thereof. FIG. 5 is an explanatory circuit diagram, and FIG. 6 is a longitudinal side view of a conventional device.

Claims (1)

[Scope of utility model registration request] A pressure oil circulation hole 4 is provided on the circumferential surface of the rear end of the hydraulic cylinder 1 in which a piston body 2 is slidably housed, and an elongated hole 6 communicating with the pressure oil circulation hole 4 is provided on the circumferential surface of the rear end in the axial direction. The outer sleeve body 5 formed by drilling the outer sleeve body 5 is slidably fitted, and the shaft cylinder 7 protruding from the rear end surface of the outer sleeve body 5 is screwed into the rear end cover body 9 of the hydraulic cylinder 1. A handle 11 is fixed to the shaft end protruding to the outside, and the outer sleeve body 5
An inner sleeve body 12 having a plurality of holes 13 formed therein by sequentially displacing the holes 13 in the circumferential direction relative to the axial direction is rotatably fitted into the inner sleeve body 12, and the piston body 2 is inserted into the inner sleeve body 12. The rod 3b is inserted and removed, and the inner sleeve body 1
A stroke adjusting device for a hydraulic cylinder, in which the shaft portion 14 of the second shaft is inserted through the shaft tube 7 of the outer sleeve body 5, and a handle 15 is fixed to the shaft end.