JPH0221609Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to a cushion device for a single-acting cylinder used upright, such as a lift cylinder for a forklift, and more specifically, to a cushion device for a single-acting cylinder used upright, such as a lift cylinder for a forklift. It is related to the device.

(b) Prior Art Unlike double-acting cylinders, this type of single-acting cylinder does not contain hydraulic oil on the rod side, so it is not equipped with a throttling mechanism as a cushioning device.

(c) Problems to be solved by the invention As mentioned above, unlike double-acting cylinders, conventional single-acting cylinders have difficulty achieving smooth and efficient cushioning effects using hydraulic oil.

(d) Means for solving the problem Therefore, in the present invention, as shown in FIG. 1, a tank chamber 1 is formed between the piston 2 and the cylinder head 3, and a spacer is provided in contact with the cylinder head 3. 4, and the piston rod 5 on the piston 2 side.
A cushion bearing 6 is provided at the base of the tank chamber 1, and a required amount of hydraulic oil 7 is stored in the tank chamber 1.

Note that 8 is a cylinder tube and 9 is a drain port.

(E) Effect Therefore, when the hydraulic cylinder operates in the extension direction, the cushion bearing 6 also rises as the piston 2 rises, as shown in FIGS. 2 and 3.
As a result of finally approaching the constriction edge 4a of the spacer 4 and forming the gap d, the hydraulic oil 7 in the cushion chamber 1 becomes
This gap d causes a compression effect, and the rise of the piston 2 is sequentially controlled by the flow rate of the gap d.Finally, the cushion bearing 6 is moved into the throttle edge 4a as shown in the third figure. When the piston 2 approaches the spacer 4, the piston 2 comes into contact with the spacer 4 and stops rising.

Next, in the retraction stroke, the hydraulic cylinder lowers the piston 2 by its own weight, as in the conventional case, but at the beginning of the descent, the aforementioned throttling mechanism works to prevent the speed from becoming slow. Therefore, it can be configured as in the following embodiment.

(F) Embodiment FIG. 4 is a partially cutaway side view of the main parts showing another embodiment of the present invention, in which parts similar to those in FIG. 1 are given the same reference numerals.

In this embodiment, a check valve 10 is attached to the spacer 4 so as to quickly equalize the initial velocity of the double movement, and when the piston 2 moves up, the passage 11 is closed with a steel ball 12, and when the piston 2 moves down, the steel ball 12 is connected to the pin 13. When pushed down to this position, the passage 11 is opened and the hydraulic oil 7 is allowed to circulate properly.

(g) Effects of the invention As described above, according to the invention, the tank chamber 1 containing hydraulic oil is formed on the rod side of the single-acting cylinder, and the throttling mechanism is created by the gap d between the spacer 4 and the cushion bearing 6. The present invention provides an excellent cushioning device by creating a cushioning effect, and combining this with the efficient action of the hydraulic oil.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway side view of the main part of a hydraulic cylinder showing an embodiment of the device of the present invention, showing a state in which the spacer and the piston are separated, and Fig. 2 shows the space between the cushion bearing and the spacer. 3 is a partially cutaway side view of the same essential part showing the throttle mechanism in its working state, FIG. 3 is a partially cutaway side view of the same essential part showing the hydraulic cylinder in its fully extended state, and FIG. 4 is another embodiment. FIG. 2 is a partially cutaway side view of the main part of the hydraulic cylinder. 1... Tank chamber, 2... Piston, 3... Cylinder head, 4... Spacer, 5... Piston rod, 6... Cushion bearing, 7... Hydraulic oil, d... Gap.

Claims (1)

[Scope of utility model registration request] In a single-acting cylinder that is used upright on a forklift, etc., the tank chamber on the cylinder head side inside the cylinder tube, which is connected to a rod and partitioned by a piston with a cushion bearing fitted into its neck, is connected to the atmosphere through a drain port. The spacer is provided in the cylinder tube so as to be in communication with the cylinder head, and the piston side of the spacer is provided with a constriction edge that fits the cushion bearing through the gap when the piston rises; When the cylinder head is about to fit into the throttle edge, at least a chamber defined by the throttle edge of the spacer and the piston is filled with hydraulic oil, and a chamber defined by the cylinder head and the throttle edge of the spacer is filled with hydraulic oil. A cushioning device for a hydraulic cylinder, wherein the chamber has a space sufficient to accommodate the hydraulic fluid.