CN217761532U - Buffer hydraulic oil cylinder - Google Patents

Abstract

The utility model relates to a hydraulic cylinder, in order to solve the poor problem of current buffer hydraulic cylinder commonality, the utility model discloses construct a buffer hydraulic cylinder, it includes buffering flow area and adjusts the oil duct, buffering flow area adjusts the oil duct and includes the rod sleeve fit clearance between cushion collar and the piston rod, sets up L shape oil duct that is the position department on the piston rod and is located the spacing step front side, and the radial section export of L shape oil duct is located the cylinder surface of piston rod, and the axial section export is located the terminal surface of spacing step; a throttle valve which is assembled in a thread fit manner is arranged in the L-shaped oil passage, and the rear end of the fit clearance of the rod sleeve is communicated with the small cavity; when the buffer sleeve is inserted into the annular buffer oil duct, the radial section outlet of the L-shaped oil duct is communicated with the annular buffer oil duct, and the axial section outlet of the L-shaped oil duct is communicated with the rod sleeve in a matching clearance. The utility model discloses removable choke valve and adjust the runner sectional area between loculus and the loculus connecting oil port to make the hydro-cylinder suit with the use occasion, improve its commonality.

Description

Buffer hydraulic oil cylinder

Technical Field

The utility model relates to a hydraulic cylinder, more specifically say, relate to a piston rod stretches out stroke terminal and has functional buffer hydraulic cylinder.

Background

A piston of the hydraulic oil cylinder moves under the pushing of hydraulic oil in the large cavity or the small cavity, and when the piston moves to the stroke terminal, the piston is in contact with a cylinder head or a cylinder cover, so that impact collision occurs, and the hydraulic oil cylinder is easily damaged.

In order to avoid rigid collision between a piston and a cylinder cover or a cylinder head, a conventional method is to install a buffer sleeve on a piston rod assembly, a connecting oil port on a cylinder barrel is communicated with an oil cavity through an annular buffer oil duct, and when the piston moves to be close to a stroke terminal, the buffer sleeve is inserted into the annular buffer oil duct, so that the flow area between the oil cavity and the connecting oil port is reduced, the moving speed of the piston is reduced, and a buffering effect is achieved.

After the buffer sleeve is inserted into the annular buffer oil duct, the gap between the buffer sleeve and the annular buffer oil duct directly influences the buffering speed of the oil cylinder, but once the oil cylinder is designed and molded, the sizes of the buffer sleeve and the annular buffer oil duct are determined, and the reduction speed of the buffering speed of the oil cylinder is determined. However, hydraulic oil cylinders of the same type may be used in different occasions, and the speed reduction degree has different requirements in different use occasions. The existing buffering hydraulic oil cylinder is used for meeting the buffering and speed reducing requirements on different occasions, the fit clearance between a buffering sleeve of the oil cylinder and an annular buffering oil passage is often changed through design, but the oil cylinder of the type can only be used on the using occasions, and the problem of poor universality is solved.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is that the current poor problem of damping hydraulic cylinder commonality provides a damping hydraulic cylinder.

The utility model discloses a realize that the technical scheme of its purpose is like: the buffer hydraulic cylinder is characterized by further comprising a buffer circulation area adjusting oil duct, wherein the buffer circulation area adjusting oil duct comprises a rod sleeve fit gap between the buffer sleeve and the piston rod and an L-shaped oil duct which is arranged on the piston rod and is positioned at the front side of the limit step, a radial section outlet of the L-shaped oil duct is positioned on the cylindrical surface of the piston rod, and an axial section outlet of the L-shaped oil duct is positioned on the end surface of the limit step; a throttle valve which is assembled in a thread fit manner is arranged in the L-shaped oil passage; the rear end of the rod sleeve fit clearance is communicated with the small cavity through a radial channel arranged at the rear end of the buffer sleeve; when the buffer sleeve is inserted into the annular buffer oil duct, the front end face of the buffer sleeve is in fit contact with the end face of the limiting step, the radial section outlet of the L-shaped oil duct is communicated with the annular buffer oil duct, and the axial section outlet of the L-shaped oil duct is communicated with the rod sleeve fit clearance.

The utility model discloses in, back in the cushion collar entered into annular buffering oil duct, the runner area between hydraulic fluid port was connected for the runner area of choke valve and the flow area sum in clearance between cushion collar and the cylinder cap to loculus. The utility model discloses in, can select the choke valve that corresponds the model as required and adjust the small chamber and the small chamber area of circulation between the hydraulic fluid port is connected to the small chamber to make the buffer speed of hydro-cylinder suit with the use occasion of hydro-cylinder, realize a model hydraulic cylinder through the minor change and use in different use occasions, improve its commonality.

The utility model discloses among the buffering hydraulic cylinder, spacing step with distance between the piston is greater than the axial length of cushion collar to make the cushion collar be in the floating condition on the piston rod, self-adaptation and piston rod and cylinder cap clearance fit when the cushion collar enters into annular buffering oil duct.

The utility model discloses among the buffering hydraulic cylinder, the choke valve is installed the radial section of L shape oil duct.

The utility model discloses among the buffering hydraulic cylinder, the preceding terminal surface of cushion collar with spacing step terminal surface is the plane that can mutually support.

The utility model discloses among the buffering hydraulic cylinder, the position department that is close to terminal surface before the piston at piston rod cylindrical surface be provided with the rear portion annular slot of radial channel and rod cover fit clearance intercommunication. The rod sleeve fit clearance is a cylindrical channel, the radial channels are arranged on the buffer sleeve and are distributed at intervals in the circumferential direction, and the rear annular groove plays a role in communicating the rod sleeve fit clearance with the radial channels, so that oil can better circulate. Further, the radial channel is a plurality of radial notches which are arranged on the rear end face of the buffer sleeve and radially penetrate through the buffer sleeve wall, or the radial channel is a plurality of radial through holes which are arranged on the rear portion of the buffer sleeve and radially penetrate through the buffer sleeve wall.

The utility model discloses among the buffering hydraulic cylinder, be close to the position department of spacing step terminal surface at piston rod cylindrical surface be provided with L shape oil duct and the anterior annular groove of rod cover fit clearance intercommunication. The front annular groove plays a role in communicating the L-shaped oil passage and the fit clearance of the rod sleeve, so that oil can better circulate.

Compared with the prior art, the utility model discloses in can change the choke valve as required and adjust the runner sectional area between loculus and the loculus connecting oil port to make the buffer speed of hydro-cylinder suit with the use occasion of hydro-cylinder, realize a model hydraulic cylinder through the minor change and use in different use occasions, improve its commonality.

Drawings

Fig. 1 is a schematic structural view of the buffering hydraulic oil cylinder of the present invention.

Fig. 2 is a schematic structural diagram of the buffering hydraulic oil cylinder when the piston rod extends out to the stroke end.

Fig. 3 is a schematic structural diagram of the buffering hydraulic oil cylinder of the present invention.

Part names and serial numbers in the figure:

the hydraulic cylinder comprises a cylinder head 1, a cylinder barrel 2, a cylinder cover 3, a piston 4, a piston rod 5, a large cavity 6, a small cavity 7, a small cavity connecting oil port 8, a large cavity connecting oil port 9, a buffer sleeve 10, an L-shaped oil duct 11, a throttle valve 12, a rod sleeve fit clearance 13, a rear annular groove 14, a front annular groove 15, a radial through hole 16, an annular buffer oil duct 17 and a radial notch 18.

Detailed Description

The following description of the embodiments refers to the accompanying drawings.

Fig. 1 is the embodiment of the utility model provides a pair of buffering hydraulic cylinder's structural schematic diagram, buffering hydraulic cylinder include cylinder 2, fixed connection at the cylinder end 1 and the cylinder cap 3 at cylinder both ends. The piston 4 is positioned in the cylinder barrel 2 and divides an inner cavity formed by the cylinder barrel 2, the cylinder cover 3 and the cylinder head 1 into a large cavity 6 and a small cavity 7. The cylinder head 1 is provided with a large cavity connecting oil port 9 communicated with the large cavity 6, and a small cavity connecting oil port 8 is arranged at the matching and connecting position of the cylinder barrel 2 and the cylinder cover 3. One end of the piston rod 5 extends into the cylinder barrel 2 from the hole on the cylinder cover 3 and is fixedly connected with the piston 4.

As shown in fig. 1 and 2, a buffering sleeve 10 is sleeved on the piston rod 5 at a position close to the piston 4, an annular buffering oil passage 17 is arranged between the inner hole of the cylinder head 3 and the piston rod 5, and the small cavity connecting oil port 8 is communicated with the small cavity 7 through the annular buffering oil passage 17. When the piston rod 5 stretches out to be close to a stroke terminal, the buffer sleeve 10 is inserted into the annular buffer oil duct 17, the flow area of the annular buffer oil duct 17 is reduced, and the outflow speed of oil in the small cavity 7 is reduced, so that the stretching speed of the piston rod 5 is reduced, and the oil cylinder buffering is realized.

As shown in fig. 2, a position of the piston rod 5 near the piston 4 is provided with a limit step, and the cushion collar 10 is located between the limit step and the piston 4. The diameter of the inner hole of the buffer sleeve 10 is larger than the diameter of the mounting position of the buffer sleeve 10 on the piston rod 5, and the radial clearance between the buffer sleeve 10 and the piston rod 5 is a rod sleeve fit clearance 13 which can supply oil to flow axially.

The distance between the limiting step and the piston 4 is larger than the axial length of the buffer sleeve 10, and the buffer sleeve 10 can move forwards or backwards under the action of oil hydraulic pressure. When the buffer sleeve 10 moves forwards, the front end face of the buffer sleeve 10 is connected with the end face of the limiting step in an abutting contact mode. When the cushion collar 10 moves backward, the rear end surface of the cushion collar 10 is in abutting contact with the front end surface of the piston 4. The buffer sleeve 10 can move in a certain range in the radial direction and the axial direction relative to the piston rod 5 and is in a floating state, and when the buffer sleeve 10 enters the annular buffer oil passage 17, the buffer sleeve is self-adaptively matched with the annular buffer oil passage under the action of pressure oil.

An L-shaped oil passage 11 is arranged on the piston rod 5 and positioned at the position of the limiting step, the opening of the radial section of the L-shaped oil passage 11 is positioned on the cylindrical surface of the piston rod 5, the opening of the axial section is positioned on the end surface of the limiting step, and a throttle valve 12 is arranged in the radial section of the L-shaped oil passage 11. When the buffer sleeve 10 enters the annular buffer oil duct 17, the front end face of the buffer sleeve 10 is in contact with the end face of the limiting step in a fitting manner, and the radial section outlet of the L-shaped oil duct is communicated with the annular buffer oil duct 11.

The front end face of the buffer sleeve 10 and the end face of the limiting step are mutually matched planes. When the buffer sleeve 10 moves forwards and is contacted and attached with the end face of the limit step, no gap for oil to flow is formed between the buffer sleeve 10 and the limit step, and oil in the rod sleeve matching gap 13 flows to the small cavity connecting oil port 8 through the L-shaped oil passage 11 and the throttle valve 12.

And a front annular groove 15 communicated with the L-shaped oil passage axial section opening and the rod sleeve matching gap 13 is arranged at the position, close to the end face of the limiting step, of the cylindrical surface of the piston rod 5. The front annular groove 15 plays a role in communicating the L-shaped oil passage 11 with the rod sleeve fit clearance 13, so that oil can better circulate.

The throttle valve 12 is cylindrical and has an axial bore through which oil flows. The throttle valve 12 is fixed in the L-shaped oil passage by external threads engaging with the piston rod. The throttle valves of different models have different inner hole diameters and different flow areas. By selectively installing the throttle valves of different models, the oil liquid circulation capacity is different.

The rear end of the rod sleeve fit clearance 13 is communicated with the small cavity through a radial channel arranged at the rear end of the buffer sleeve. As shown in fig. 3, the radial passage is formed by a plurality of radial notches 18 radially penetrating through the wall of the cushion collar 10, which are provided on the rear end surface of the cushion collar 10, and the rear end of the rod collar fitting clearance communicates with the small cavity 7 through the radial notches 18. A rear annular groove 14 communicating with the radial gap 18 and the rod sleeve fit clearance is provided in the cylindrical surface of the piston rod 5 near the front end face of the piston.

In another embodiment, as shown in fig. 2, the radial channel is composed of a plurality of radial through holes 16 communicating with the small cavity 7 and arranged at the rear part of the buffer sleeve 10, and a rear annular groove 14 communicating with the radial through holes 16 and the rod sleeve fitting gap 13 is arranged at the position of the cylindrical surface of the piston rod 5 close to the front end surface of the piston. In this embodiment, a radial through hole 16 may be used instead of the radial indentation 18 of the rear end face.

In this embodiment, when the piston rod 5 extends to a position close to the end of the stroke, the front end of the buffer sleeve 10 enters the annular buffer oil passage 17, so that the flow area of hydraulic oil in the annular buffer oil passage 17 is reduced sharply, the pressure in the small cavity 7 is increased suddenly under the extrusion of the piston, the buffer sleeve 10 moves forward relative to the piston rod 5, the front end surface of the buffer sleeve 10 is in contact fit with the end surface of the limit step on the piston rod 5, no gap through which oil flows exists between the buffer sleeve 10 and the limit step, part of hydraulic oil in the small cavity 7 flows to the small cavity connection oil port 8 through the rod sleeve fit gap 13 between the buffer sleeve and the piston rod, the L-shaped oil passage 11 and the front end of the annular buffer oil passage 17, and the flow area of the buffer flow area adjusting oil passage depends on the flow area of the throttle valve 12 in the L-shaped oil passage 11.

When the piston rod 5 extends to the end point of the short approaching stroke, the extending speed of the piston rod 5 depends on the flow area between the small cavity 7 and the small cavity connecting oil port 8. In different use situations, different speeds, i.e. corresponding flow areas, are required.

In this embodiment, the flow area between the small chamber 7 and the small chamber connection port 8 is equal to the sum of the flow area between the cushion collar 10 and the bore wall surface of the cylinder head 3 and the flow area of the throttle valve 12. The flow area between the cushion collar 10 and the wall surface of the cylinder head bore depends on the fit clearance between the cushion collar 10 and the cylinder head bore. For each use requirement, a set of cushion collar and cylinder head is designed and manufactured, which increases the production and management costs of the manufacturer. When the hydraulic oil cylinder is used in different occasions, the same fit clearance is formed between the buffer sleeve 10 and the cylinder cover 3, namely, the same flow area is formed. The throttle valve 12 with the corresponding model and specification is selected according to the requirements of use occasions, so that the sum of the flow area between the buffer sleeve 10 and the wall surface of the inner hole of the cylinder cover and the flow area of the throttle valve meets the requirement of the extension speed when the piston rod extends to the stroke end point. Compare through the fit clearance that changes between cushion collar and the cylinder cap hole in order to adapt to different use occasion demands, through selecting the installation choke valve in this embodiment, its cost is lower.

When the piston rod 5 starts to retract at the end position of the extension stroke, the pressure of the small cavity connecting oil port 8 is higher than that of the small cavity 7, the buffer sleeve 10 moves backwards under the pushing of the acting force of hydraulic oil, the rear end of the buffer sleeve 10 is in contact with the front end face of the piston 4, a gap is formed between the buffer sleeve 10 and the end face of the upper limiting step of the piston rod 5, the pressure oil at the front section of the annular buffer oil duct enters the rod sleeve matching gap 13 through the gap between the buffer sleeve 10 and the limiting step and flows into the small cavity 7 through the rear end of the rod sleeve matching gap 13, the throttle valve 12 in the L-shaped oil duct 11 does not have a damping effect on the oil, so that the hydraulic oil can quickly enter the small cavity through the rod sleeve matching gap, and the piston rod of the hydraulic oil cylinder is quickly started to retract.

As shown in fig. 3, the cylindrical side surface of the cushion collar 10 is sequentially provided with a chamfer section C, a conical surface section B and a cylindrical surface section a from front to back, wherein the diameter of the conical surface section B is gradually increased from front to back, and the front diameter and the back diameter of the cylindrical surface section a are unchanged. When the piston rod 5 extends to the end of the extending stroke, the chamfer section C, the conical section B and the cylindrical section a on the buffer sleeve 10 sequentially enter the annular buffer oil duct 17. The clearance between the circumferential side surface of the chamfer section of the buffer sleeve 10 and the wall surface of the inner hole of the cylinder cover is larger, so that the buffer sleeve which is in floating sleeving can be conveniently inserted into the inner hole (namely the annular buffer oil duct) of the cylinder cover. Along with the conical surface section B of the buffer sleeve 10 entering the annular buffer oil duct 13, the minimum clearance between the buffer sleeve 10 and the inner hole wall surface of the cylinder cover 3 is smaller and smaller, and accordingly the extending speed of the piston rod is reduced continuously. The oil cylinder enters the annular buffer oil channel from the cylindrical surface section of the buffer sleeve until the piston is contacted with the cylinder cover, the gap between the buffer sleeve 10 and the inner hole of the cylinder cover is fixed, the extending speed of the piston rod of the oil cylinder is kept invariable, and the oil cylinder extends out at a lower speed.

The loader frame is formed by hinging a front frame and a rear frame, two ends of a steering oil cylinder are respectively connected with the front frame and the rear frame, and limiting blocks of the front frame and the rear frame are contacted when the steering angle is maximum. Due to errors in production and manufacturing, when the loader rotates to the maximum steering angle from left to right, certain angle deviation exists, and the left and right steering oil cylinders are inconsistent in stroke use when front and rear frame limiting blocks contact with each other when the loader rotates to the maximum steering angle. When this embodiment hydraulic cylinder was used as loader steering cylinder, when the buffer sleeve 10 conical surface section entered into annular buffering oil duct completely during turning to, the piston had not moved the stroke terminal yet (stopper on the frame around the loader had not contacted yet), along with turning to the further increase of angle, the face of cylinder A section of buffer sleeve entered into annular buffering oil duct, and the flow area between loculus and the loculus connecting oil port is invariable, and relatively lower slew velocity rotates between the frame around, until the stopper contact on the frame around. Because the oil cylinder is decelerated through the conical surface section of the buffer sleeve, the relative rotating speed between the front frame and the rear frame is low when the limiting blocks on the front frame and the rear frame are contacted, and the collision is slight. When the limiting blocks on the front frame and the rear frame are in contact, the piston is not in contact with the cylinder cover, the length of the cylindrical surface section on the buffer sleeve is larger than the maximum deviation of the steering stroke when the hinged frame is manufactured, so that the front frame and the rear frame are in limiting contact through the elastic collision buffer device at the steering stroke end, the stroke of the steering oil cylinder is not exhausted when the front frame and the rear frame are stopped, and the piston is prevented from being in rigid contact with the cylinder cover for limiting.

Claims (10)

1. A buffer hydraulic cylinder comprises a piston rod fixedly connected with a piston, and an annular buffer oil duct arranged between a cylinder cover and the piston rod and used for communicating a small cavity with a small cavity connecting oil port, wherein a buffer sleeve which can be inserted into the annular buffer oil duct and is in clearance fit with the cylinder cover is sleeved at a position, close to the piston, on the piston rod; a throttle valve which is assembled in a thread fit manner is arranged in the L-shaped oil passage; the rear end of the rod sleeve fit clearance is communicated with the small cavity through a radial channel arranged at the rear end of the buffer sleeve; when the buffer sleeve is inserted into the annular buffer oil duct, the front end face of the buffer sleeve is in fit contact with the end face of the limiting step, the radial section outlet of the L-shaped oil duct is communicated with the annular buffer oil duct, and the axial section outlet of the L-shaped oil duct is communicated with the rod sleeve fit clearance.

2. The buffer hydraulic cylinder according to claim 1, wherein the distance between the limiting step and the piston is greater than the axial length of the buffer sleeve.

3. The buffer hydraulic cylinder according to claim 1, wherein the throttle valve is installed at a radial section of the L-shaped oil passage.

4. The buffer hydraulic oil cylinder according to claim 1, wherein the front end face of the buffer sleeve and the end face of the limit step are planes capable of being matched with each other.

5. The hydraulic buffer ram as claimed in claim 1, wherein a rear annular groove is provided in the cylindrical surface of the piston rod adjacent the front face of the piston, in communication with the radial passage and the rod sleeve engagement gap.

6. The hydraulic buffer cylinder as claimed in claim 5, wherein said radial passages are a plurality of radial notches provided in the rear end face of said buffer sleeve and extending radially through the wall of said buffer sleeve.

7. The hydraulic buffer ram as claimed in claim 5 wherein said radial passages are a plurality of radial through holes disposed in the rear portion of said buffer sleeve and extending radially through the wall of said buffer sleeve.

8. The buffer hydraulic oil cylinder according to any one of claims 1 to 7, characterized in that a front annular groove communicated with the L-shaped oil passage and the rod sleeve fit clearance is arranged on the cylindrical surface of the piston rod at a position close to the end face of the limit step.

9. The buffer hydraulic cylinder according to claim 1, wherein the circumferential side of the buffer sleeve is of variable cross-section, and the radial dimension of the cross-section of the front end is smaller than the radial dimension of the cross-section of the rear end.

10. The buffer hydraulic oil cylinder according to claim 9, wherein a gap for oil to flow is formed between the circumferential side surface of the rear end of the buffer sleeve and the cylinder cover when the rear end of the buffer sleeve enters the annular buffer oil passage.

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