JP2012202445A5 - - Google Patents

Description

The present invention relates to a cushion mechanism for a fluid pressure cylinder that decelerates a piston rod in the vicinity of a stroke end of the piston rod with respect to a cylinder tube, and a cushion gap that restricts a flow of a working fluid by an outer periphery of a cushion bearing provided on the piston rod, and a cushion A bypass passage that is provided in a cushion gap defining member that defines a cushion gap between the bearing and the outer periphery of the bearing, and that guides hydraulic oil that bypasses the cushion gap, and a passage opening area of the bypass passage that is provided in the cushion gap defining member is adjusted. a bypass aperture adjustment mechanism for, and configured to include a.

According to the present invention, the cushion pressure is adjusted by the bypass throttle adjusting mechanism, thereby eliminating the excess or deficiency of the cushion pressure due to the dimensional variation of the cushion gap defining member that defines the cushion gap .

1 is a cross-sectional view of a hydraulic cylinder showing an embodiment of the present invention. Similarly, sectional drawing of the hydraulic cylinder which expanded a part of FIG. The figure which similarly shows operation | movement of a bypass aperture adjustment mechanism. Sectional view of the hydraulic cylinder showing another embodiment. Similarly, sectional drawing of the hydraulic cylinder which expanded a part of FIG. The figure which similarly shows operation | movement of a bypass aperture adjustment mechanism.

The bypass passage 50 is defined by through holes 51 and 52 and a notch 48 formed in the cylinder head 40 provided as a cushion gap defining member . The through holes 51 and 52 are formed to extend on a straight line parallel to the central axis O. One end of the through hole 51 opens to the supply / discharge port 43, and one end of the through hole 52 opens to the rod chamber 2 through the notch 48. Thereby, the bypass passage 50 communicates the supply / exhaust port 43 and the rod chamber 2.

The bypass throttle adjusting mechanism 65 includes a valve housing hole 53 that intersects with the through hole 51 of the bypass passage 50, a valve screw 66 that is housed in the valve housing hole 53 and has a variable passage opening area of the bypass passage 50, and the valve And an adjustment screw hole 54 into which the screw 66 is screwed. The valve screw 66 is configured such that the screwing position with respect to the adjusting screw hole 54 is adjusted by an operator.

The valve housing hole 53 is formed so as to extend on a straight line substantially orthogonal to the central axis O, and is also substantially orthogonal to the through hole 51 of the bypass passage 50. The adjustment screw hole 54 is formed coaxially with the valve housing hole 53.

A working hole (screw hole) 55 is formed in the cylinder head 40 coaxially with the adjustment screw hole 54. This working hole 55 opens in the outer wall surface of the cylinder head 40, and the stopper 74 is attached. The plug 74 is screwed into the work hole 55 and is attached to the valve hole 53 so that the hydraulic oil does not leak out through the valve hole 53.

The valve body support portion 63 includes a head portion 72 that is screwed into the adjustment screw hole 54, and a shaft portion 70 that connects the land portion 69 and the head portion 72. A male screw that is screwed into the adjustment screw hole 54 is formed on the outer periphery of the head portion 72, and a tool engaging portion 71 that engages with a tool is opened on the end surface of the head portion 72. For example, the tool engaging portion 71 is a hexagonal hole, and a hexagon wrench is used as a tool that engages with the tool engaging portion 71.

In the present embodiment, the bypass throttle adjusting mechanism 65 includes a valve housing hole 53 in which the bypass passage 50 opens, an adjustment screw hole 54 formed coaxially with the valve housing hole 53, and the valve housing hole 53 . The valve screw 66 is accommodated over the screw hole 54. The valve screw 66 is accommodated in the valve accommodation hole 53 so that the passage opening area of the bypass passage 50 is variable, and an adjustment screw. A valve body support portion 63 that is screwed into the hole 54 and supports the valve body portion 64 is provided.

Based on the above configuration, the operator adjusts the screwing position of the valve body support portion 63 with respect to the adjustment screw hole 54, whereby the valve body portion 64 is displaced in the valve housing hole 53 and the passage opening of the bypass passage 50 is opened. You can change the area. As a result, the cushion pressure is adjusted.

A bypass passage 28 is provided in a holder 23 provided as a cushion gap defining member . The bypass passage 28 is defined by a notch 25 formed in the holder 23 , through holes 26 and 27, and a notch 29. The through holes 26 and 27 are formed to extend on a straight line parallel to the central axis O. One end of the through hole 26 opens into the supply / discharge passage 5 through the notch 25, and one end of the through hole 27 opens into the rod chamber 2 through the notch 29. As a result, the bypass passage 28 communicates the supply / exhaust port 43 and the rod chamber 2 via the supply / discharge passage 5.

During the extension operation of the hydraulic cylinder 1, the hydraulic oil in the rod chamber 2 flows through the cushion gap 8 and through the bypass passage 28 to the supply / discharge passage 5 as indicated by arrows in FIG. 5 .

As shown in FIG. 5, the bypass throttle adjusting mechanism 65 includes a valve housing hole 33 that intersects with the through hole 51 of the bypass passage 28, and a valve that is housed in the valve housing hole 33 and has a variable passage opening area. A screw 66 and an adjustment screw hole 34 for screwing the valve screw 66 are provided, and the screwing position of the valve screw 66 with respect to the adjustment screw hole 34 is adjusted by an operator.

In the holder 23, the valve accommodation hole 33 is formed so as to extend on a straight line substantially orthogonal to the central axis O, and an adjustment screw hole 34 is formed coaxially with the valve accommodation hole 33.

The valve screw 66 is accommodated across the adjustment screw hole 34 and the valve accommodation hole 33. The valve screw 66 has the same configuration as that of the above embodiment. When the operator changes the screwing position of the head portion 72 and moves the valve screw 66 in the axial direction, one of the land portions 67 and 69 faces the bypass passage 28 so that the opening area of the bypass passage 28 increases or decreases. It has become.

A working hole (screw hole) 55 is formed in the cylinder tube 10 coaxially with the adjustment screw hole 34. One end of the work hole 55 faces the adjustment screw hole 34 of the holder 23, the other end opens on the outer wall surface of the cylinder tube 10, and the plug 74 is attached.

1 Hydraulic cylinder (fluid pressure cylinder)
5 Supply / exhaust passage 6 Cushion mechanism 8 Cushion gap 10 Cylinder tube 23 Holder ( cushion gap defining member )
28, 50 Bypass passages 33, 53 Valve housing holes 34, 54 Adjustment screw hole 55 Work hole 30 Piston rod 40 Cylinder head ( cushion gap defining member )
43 Supply / exhaust port 60 Cushion bearing 61 Bearing outer peripheral surface 63 Valve body support portion 64 Valve body portion 65 Bypass throttle adjustment mechanism 66 Valve screw 74 Plug body

Claims (4)

A fluid pressure cylinder cushion mechanism that decelerates the piston rod near the stroke end of the piston rod relative to the cylinder tube,
A cushion gap that restricts the flow of working fluid by the outer periphery of a cushion bearing provided on the piston rod ;
A bypass passage that is provided in a cushion gap defining member that defines the cushion gap between the outer periphery of the cushion bearing and guides hydraulic oil that bypasses the cushion gap;
A fluid pressure cylinder cushioning mechanism , comprising: a bypass throttle adjusting mechanism provided in the cushion gap defining member for adjusting a passage opening area of the bypass passage. The fluid pressure cylinder cushion mechanism according to claim 1,
The bypass throttle adjusting mechanism is
A valve housing hole in which the bypass passage opens;
An adjustment screw hole formed coaxially with the valve housing hole;
A valve screw housed over the valve housing hole and the adjustment screw hole ,
The valve screw is
A valve body portion accommodated in the valve housing hole and having a variable passage opening area of the bypass passage;
Valve body support and, that flow body pressure cylinder cushion mechanism having a for supporting the valve body portion screwed into the adjustment screw hole. A cushion mechanism for a fluid pressure cylinder according to claim 1 or 2,
A holder interposed inside the cylinder tube;
It said bypass throttle adjusting mechanism interposed by Ru flow body pressure cylinder cushion mechanism together with the bypass passage is formed in the holder. A cushion mechanism for a fluid pressure cylinder according to claim 3,
The cushion gap image made is Ru flow body pressure cylinder cushion mechanism by the inner peripheral surface of the holder.