JPS5993538A - Cushion mechanism for hydraulic cylinder - Google Patents

Abstract

PURPOSE:To make an oil passage large to increase the starting speed of a piston, by disposing check valves of a cushion mechanism in cushion spears of the piston. CONSTITUTION:A cushion mechanism comprises cushion spears 17, 18 arranged on both sides of a piston, and cushion bores 13, 14 formed in head covers 2, 3. Check valves 15, 16 are disposed in the cushion spears 17, 18, thereby the annular surface B' of the passage may be made large. Accordingly, the oil passage is enlarged to enable the piston to move at a high speed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cushion structure for increasing the starting speed of a piston by 1 in a hydraulic cylinder equipped with a cushion mechanism at the stroke end.

FIG. 1 shows a cross-sectional view of a commonly used differential hydraulic cylinder as an example of a conventional structure of this type, in which 1 is a cylinder tube, 2 and 3 are head covers provided at both ends, 4 is a piston, and 5 is a cylinder tube. and 6 are both τ11 of histone 4
7 is a rod whose one end is connected to the piston 4 and the other end passes through the head cover 2 and is led out to the outside, F3 is a rod packing, 9 is an O ring, 10
is a gasket attached to the sliding surface of the piston.

Further, oil boats 11°1.2 are provided in the head covers 2 and 3, and oil is placed on the rod side of the piston 4, respectively.

The γ11I boat 11 is connected to a pressure source such as an external hydraulic pump or an acemeter, and is constantly supplied with high-pressure oil.

Here, the area of the pressure receiving surface of the piston 4 is such that the pressure receiving surface 7Ilj4a on the rod side is smaller than the pressure receiving surface 4b on the opposite rod side.
The cross-sectional area is small. Therefore, when pressure oil of the same pressure as the rod side is made to flow into the oil boat 12 on the anti-rond side by a switching valve (not shown), the piston 4 is driven toward the rod side as shown in the figure due to the difference in the pressure receiving area. , move to the left stroke end. Further, when the rod-side oil port 12 is opened to atmospheric pressure by the switching valve, the piston 4 is rapidly moved to the right by the hydraulic pressure acting on the rod-side pressure receiving surface 4a.

In this case, in response to the movement of the piston, lr7.
k'), generally the cushion J+, 15 tj, lI
is provided. This cushion R side view 1, both of the Binuton book 1ii! Kutsushikon spears 5 and 6 installed in l,
Head゛Cushion bore provided in covers 2 and 3], 3
, ], 4, the piston 4 moves at the stroke end and the cushion spears 5, 6 enter the cushion bore 13°] 4, thereby narrowing the cross-sectional area of the oil flow path and reducing the distance between the head cover and the piston. During this time, for example, the oil trapped in part A shown in the figure becomes under pressure, and a slow 1 (i'+ operation is performed).

However, in this Tojie, the piston moves in the opposite direction.・1)
96, Q, Cushion Spear 5 is Cushion Bore]; In the neck where -3 is removed and shifted, the pressure receiving surface of the piston is
1L is substantially l-1,, ih of J1ν shape indicated by j7
Since there is only one product, the driving force acting on the piston in the direction A is small, and the piston's starting speed is small.

In order to determine this, generally, an auxiliary force 1.1 is applied to the head cover 2.3 by check valves 15 and 16. Set up a road.

That is, in the 1st and 6th positions where the buffering operation is performed, the check valve on that side (for example, in the case of Fig. 1, FA', i'E pil
At 3411 of l, the valve 15) is closed to prevent oil from flowing through the Kamisuke channel, and the piston moves in the opposite direction as shown in FIG. In this case, the check valve opens and the oil flows through the piston flow path as shown in the figure.
A for 1 out of 1 dust.

εi! ! In 21st 1, the piston 4 moves to the right H and 1.:
In addition, the left [1] city valve] 5 is open and l'll+ flows through Kamisuke pii: fii.

However, Kamisuke by the check valve /4i, j,! , i< I
II: +5it, M? Since the I inno 1r111 essence of I is small, the flow M is small, and the flow end of the oil is increased in hydraulic cylinders that are required to operate at high speeds.
For oil 6ii, ll'81theta white 111ia 4xb
Rie 1: J' It is necessary to remove the annular if+i product of B shown in IXI. However, if we expand this part, we can see that in the structure of Sayu, check valves 15 and 16 are installed in the head covers 2 and 3. !', j I had the disadvantage that there was no remaining space.The uninvented day provides a means to eliminate this disadvantage, and the SF about VI down h'F, I (・!l
Explain in detail.

In Fig. 3, check valves 15 and 1.6 kt, unlike the conventional one, have cushion spears 17°I on both sides of the piston 4.
R+1 knee ii: j number). It's like this, ε
[! 21mi〉, ) is shown as B, and the N5-shaped surface 17f l
:j, I)i, and the oil flow path expands.'',sui
, °1 speed operation, Eih, 1. ,,, I can do that. Also, in this 1st place, like l:su(・)-ki01, heavy L1. There is no need to machine a check valve installation hole in a large head cover 1llll, which not only simplifies the machining work, but also has the advantage that the head cover body can be carved easily. In addition, the continuous valve, 5.16, corresponds to the initial speed of piston startup. You can choose the ridge and size to obtain 11i;
You can also have them create one. In this case, the spring accommodation space can be reduced to 1"?m;4, making it compact and economical.

The valve itself is preferably spherical, as shown in Figure 1, because it can reduce flow resistance.

As explained above, according to the present invention, the strike [
1-ri1iM lNi-Cushion In Nijiri cylinders, which are made with a thousand cushions, the check valve, which was conventionally provided in the cushion bore of the head cover, is installed in the cushion spear of the piston, and the oil flow path is enlarged by means of a groove. Piston activation)・1
1 degree, which offers the great advantage of making a high-speed hydraulic cylinder overall simpler, smaller and more economical.

[Brief explanation of drawings]

Figures 1 and 2 are cross-sectional views showing the structure of this divine hydraulic cylinder, and Figure 3 is a cross-sectional view showing Akira Kimoto's embodiment.
It is DKI. 4...Piston, 15.16...Reverse single-tooth valve, 17.
18... Cushion Spear. Young J'li person dialect 311! J Inuyama, 11 Yoshibe O l Figure 72 Danwa 496 O 3 eyes

Claims (1)

[Claims] A cushion mechanism for a hydraulic cylinder having a cushion mechanism at a stroke end, characterized in that a check valve in the cushion mechanism is provided on a cushion spear of a piston.