CN213684767U - Small hole pressure relief type buffer oil cylinder - Google Patents

Abstract

The utility model discloses a pinhole pressure release formula buffer cylinder. The piston type hydraulic cylinder comprises a cylinder bottom, a cylinder barrel and an end cover which are connected in sequence, wherein a piston which is matched and slides in the cylinder barrel is fixedly installed at the rear end of a piston rod, the cylinder barrel is divided into a rod cavity and a rodless cavity by the piston, and a rod cavity oil port and a rodless cavity oil port are formed in the cylinder barrel; the support ring on the piston is clamped in the clamping groove on the outer wall of the piston and is positioned at the rear part of the outer wall of the piston, the sealing ring is positioned at the front part of the outer wall of the piston, and a throttling groove communicated with the clamping groove is arranged between the support ring and the sealing ring; the support ring is of a C-shaped annular structure, and a throttling opening is formed in the gap of the C-shaped opening to communicate the throttling groove with the rodless cavity; the front part of the rodless cavity oil port is provided with a left pressure relief hole, the rear part of the rod cavity oil port is provided with a right pressure relief hole, and when the piston rod and the piston retract backwards to the stroke end or the piston rod and the piston extend forwards to the stroke end, the throttling groove, the clamping groove and the throttling port form a throttling channel, so that the buffering structure of the oil cylinder is simplified, the throttling groove is only needed to be added on the piston, and the cost is low.

Description

Small hole pressure relief type buffer oil cylinder

Technical Field

The utility model belongs to the technical field of the hydraulic cylinder technique and specifically relates to a hydraulic cylinder with buffer function.

Background

The oil cylinder is an actuating element of a hydraulic system and comprises a cylinder barrel, a piston and a piston rod, wherein the piston moves at a high speed in the oil cylinder under the driving of hydraulic pressure. The rear end of the cylinder barrel is provided with a cylinder bottom, when a piston rod reaches the rear end of the oil cylinder in the process of rapid movement of the hydraulic oil cylinder, strong impact, noise and even mechanical collision can be generated at a stroke terminal, and particularly under the condition of high pressure, the influence is more obvious, and the service life of the oil cylinder is seriously influenced.

In order to reduce the impact of the piston on the cylinder bottom, especially when the working pressure of the oil cylinder is greater than 25MPa and the moving parts have large mass, in order to prevent the piston from mechanically colliding with the cylinder bottom at the end of the stroke to cause noise and impact, even damage to the parts of the oil cylinder, a buffer structure needs to be arranged on the cylinder bottom of the oil cylinder, and proper braking and buffering are performed before the movement is finished to relieve the impact of the piston on the cylinder bottom and ensure the service life of the system and the oil cylinder.

There are basically two methods of buffering at present: one is external control of the hydraulic cylinder, a throttle valve or other flow control devices are arranged on a loop for controlling the hydraulic cylinder for buffering, and the general structure is more complicated; the other is internal control of the hydraulic cylinder, a buffer device is designed in the hydraulic cylinder to realize buffer, for example, the Chinese patent application 'hydraulic cylinder with improved buffer effect' (application publication No. CN101936318A, application publication date: 2011 1 month and 5 days), the structure of the hydraulic cylinder is characterized in that a cylindrical buffer sleeve is sleeved on a piston rod, the length of the cylindrical buffer sleeve is less than that of the corresponding installation section of the piston rod, the inner wall of the buffer sleeve is in clearance fit with the outer wall of the installation section of the buffer sleeve, a buffer hole is arranged on a cylinder cover of the hydraulic cylinder, a rod cavity of the hydraulic cylinder is communicated with an oil return port through the buffer hole, the outer wall of the cylindrical buffer sleeve is in clearance fit with the inner wall of the buffer hole, when the piston rod approaches to a terminal, the cylindrical buffer sleeve slides into the buffer hole to gradually block the oil return port, the internal buffer device has simple structure and small volume, and does not, therefore, the buffering mode is an ideal buffering mode, but the floating buffering principle is the process of firstly utilizing end face sealing constant throttling and then returning oil through a floating gap of the buffering sleeve, the buffering effect is good at the beginning in the whole buffering process, the effect is poor when the buffering is finished, and the following defects exist: 1. the length of the buffer sleeve is smaller than the length of the buffer sleeve mounting section, the buffer sleeve can incline in the movement process, and the buffer sleeve is easy to block when entering a buffer hole of a cylinder cover; 2. the starting process has the phenomena of shaking and crawling; 3. a great pressure impact exists in the buffering process; 4. the structure is relatively complex, the manufacturing cost is high, and the maintenance is inconvenient; 5. the starting pressure at the start of starting is large.

Disclosure of Invention

The utility model aims at providing a hydro-cylinder buffer cylinder is let out to aperture pressure formula can simplify hydro-cylinder buffer structure, and the action is smooth and easy, stable, and buffering effect is good, long service life, with low costs.

The utility model discloses a realize that the technical scheme that above-mentioned purpose adopted is:

a small-hole pressure-relief type buffer oil cylinder comprises a cylinder bottom, a cylinder barrel and an end cover which are sequentially connected, wherein a piston which is matched with the cylinder barrel to slide is fixedly arranged at the rear end of a piston rod, and the front end of the piston rod can extend out of the end cover when the piston rod moves; the piston divides the cylinder barrel into a rod cavity and a rodless cavity; a rod cavity oil port is arranged on one side of the cylinder barrel, which is positioned with the rod cavity, and a rodless cavity oil port is arranged on one side of the cylinder barrel, which is positioned with the rodless cavity; the outer wall of piston is equipped with sealing washer and support ring, and this sealing washer and support ring are sealed with the inner wall of cylinder, its characterized in that: the support ring is clamped in the clamping groove in the outer wall of the piston and is positioned at the rear part of the outer wall of the piston, the sealing ring is positioned at the front part of the outer wall of the piston, a throttling groove is arranged between the support ring and the sealing ring, and the throttling groove is communicated with the clamping groove; the support ring is of a C-shaped annular structure, the C-shaped opening gap forms a throttling opening, and the throttling groove is communicated with the rodless cavity through the throttling opening; the front part of the oil port of the rodless cavity is provided with a left pressure relief hole, when the piston rod and the piston retract backwards to the tail end of the stroke, the distance between the left pressure relief hole and the cylinder bottom is larger than the distance between the right end surface of the sealing ring and the cylinder bottom, and the left pressure relief hole is communicated with the rod cavity; the rear part of the oil port of the rod cavity is provided with a right pressure relief hole, when the piston rod and the piston extend forwards to the tail end of the stroke, the distance between the right pressure relief hole and the end cover is larger than the distance between the left end face of the sealing ring and the end cover, and the right pressure relief hole is communicated with the rodless cavity.

In the small-hole pressure relief type buffer oil cylinder, the outer side surface of the cylinder barrel is provided with a rear oil port connector communicated with the oil port of the rodless cavity and a front oil port connector communicated with the oil port of the rod cavity, a first cavity is arranged on the side, opposite to the cylinder barrel, of the rear oil port connector, and the rodless cavity oil port and the left pressure relief hole are both communicated with the first cavity; the side of the front oil port connector opposite to the cylinder barrel is provided with a second chamber, and the rod chamber oil port and the right pressure relief hole are communicated with the second chamber.

Further, the sectional area of the left pressure relief hole is smaller than that of the oil port of the rodless cavity; the sectional area of the right pressure relief hole is smaller than that of the oil port of the rod cavity.

Has the advantages that:

compared with the prior art, the utility model provides a pair of aperture pressure release formula buffer cylinder is equipped with the throttle groove on the piston outer wall, between support ring and the sealing washer, and the draw-in groove of installation support ring is linked together on throttle groove and the piston, and the C shape opening of support ring constitutes the throttle mouth, has just so formed the throttle passageway, has simplified the buffer structure of hydro-cylinder, only needs to increase the throttle groove on the piston, and is with low costs.

Drawings

Fig. 1 is a schematic overall sectional view of the present invention (piston rod and piston are retracted backward to the end of stroke).

Fig. 2 is the schematic diagram of the utility model discloses when well piston rod and piston stretch out forward and move to the sealing washer and cross left pressure release hole, or piston rod and piston retract backward and move to the sealing washer and be close to left pressure release hole.

Fig. 3 is the schematic diagram of the utility model when the piston rod and the piston extend forward and move to the piston to leave the left pressure relief hole or the piston rod and the piston retract backward and move to the piston to approach the left pressure relief hole.

Fig. 4 is the utility model discloses well piston rod and piston stretch out forward and move to the piston and be close right pressure release hole, or piston rod and piston retract backward move to the piston and cross the schematic diagram when right pressure release hole.

Fig. 5 is the utility model discloses well piston rod and piston stretch out forward and move to the sealing washer and cross right pressure release hole, or piston rod and piston retract backward and move to the schematic diagram when the sealing washer is close right pressure release hole.

Fig. 6 is a schematic diagram of the piston rod and the piston extending forward to the end of the stroke according to the present invention.

Fig. 7 is a partially enlarged schematic view of the oil port with the rod cavity, the right relief hole, the piston and the end cover in fig. 6.

Fig. 8 is a schematic view of a support ring.

In the figure: the hydraulic cylinder comprises a cylinder bottom 1, a cylinder barrel 2, a rodless cavity oil port 2-1, a left pressure relief hole 2-2, a rod cavity oil port 2-3, a right pressure relief hole 2-4, a piston 3, a sealing ring 3-1, a support ring 3-2, a throttle opening 3-2-1, a throttle groove 3-3, a piston rod 4, an end cover 5, a rodless cavity 6, a rod cavity 7, a rear oil port connector 8-1, a rear oil pipe connector 8-2, a first cavity 8-2, a front oil port connector 9-1, a front oil pipe connector 9-2 and a second cavity 9-2.

Detailed Description

In order to clearly illustrate the technical features of the present invention, the present invention is further described below by way of non-limiting examples in combination with the accompanying drawings.

The front, back, left and right directions of the utility model are described according to the front, back, left and right directions shown in the attached drawings. For ease of illustration, only the portions relevant to the embodiments of the present invention are shown.

Referring to fig. 1 to 8, the extending direction of the piston rod 4 is set to be the front, and the opposite direction is set to be the rear, the small-hole pressure-relief type buffer oil cylinder of the embodiment includes a cylinder bottom 1, a cylinder barrel 2 and an end cover 5 which are sequentially connected from back to front (from left to right in the drawing), the cylinder barrel 2 is a tubular barrel with an inner hole subjected to precision machining, the rear end of the cylinder barrel 2 is welded on the cylinder bottom 1, the inner hole at the front end of the cylinder barrel 2 is machined with a threaded hole, the diameter of the threaded hole is larger than that of the inner hole of the cylinder barrel, the end cover 5 is in threaded connection with the threaded hole, the outer side surface at the front end of the end cover 5 extends towards the direction away from the axis center, and the outer convex ring of the end cover 5; the outer cylindrical surface at the rear end of the end cover 5 is matched with the inner hole of the cylinder barrel and is provided with a seal; the rear end of the piston rod 4 is fixedly provided with a piston 3 which is arranged in an inner hole of the cylinder barrel and slides in a matched manner, specifically, the rear end of the piston rod 4 is provided with an external thread, the central hole of the piston 3 is provided with an internal thread, the rear end of the piston rod 4 is screwed into the central hole of the piston 3, and a sealing ring is arranged between the piston rod 4 and the piston 3; a sealing ring 3-1 is arranged between the cylinder barrel 2 and the piston 3, the front end of the piston rod 4 can extend out of the end cover 5 when the piston rod moves, and a sealing component is arranged between the piston rod 4 and the end cover 5; the piston 3 divides the cylinder barrel 2 into a rod cavity 7 and a rodless cavity 6; a rod cavity oil port 2-4 is arranged on one side of the cylinder barrel 2, which is positioned at the rod cavity 7, and a rodless cavity oil port 2-1 is arranged on one side of the cylinder barrel 2, which is positioned at the rodless cavity 6;

a support ring clamping groove and a sealing ring clamping groove are formed in the outer wall of the piston 3, the support ring clamping groove is located at the rear portion of the sealing ring clamping groove, a throttling groove 3-3 is formed between the support ring clamping groove and the sealing ring clamping groove, and the throttling groove 3-3 is communicated with the support ring clamping groove; the sealing ring 3-1 is sleeved in the sealing ring clamping groove, the support ring 3-2 is of a C-shaped annular structure and clamped in the support ring clamping groove, a throttling opening 3-2-1 is formed in a C-shaped opening gap, and the throttling groove 3-3 is communicated with the rodless cavity 6 through the throttling opening 3-2-1; the front part of the rodless cavity oil port 2-1 is provided with a left pressure relief hole 2-2, the sectional area of the left pressure relief hole 2-2 is smaller than that of the rodless cavity oil port 2-1, and when the piston rod 4 and the piston 3 retract backwards to the tail end of the stroke, the distance between the left pressure relief hole 2-2 and the cylinder bottom 1 is larger than that between the right end surface of the sealing ring 3 and the cylinder bottom 1, so that the left pressure relief hole 2-2 is communicated with the rodless cavity 6; the rear part of the rod cavity oil port 2-3 is provided with a right pressure relief hole 2-4, the sectional area of the right pressure relief hole 2-4 is smaller than that of the rod cavity oil port 2-3, and when the piston rod 4 and the piston 3 extend forwards to the stroke end, the distance between the right pressure relief hole 2-4 and the end cover 5 is larger than that between the left end face of the sealing ring 3-1 and the end cover 5, so that the right pressure relief hole 2-4 is communicated with the rod cavity 7. A rear oil port joint 8 communicated with an oil port 2-1 of a rodless cavity and a front oil port joint 9 communicated with an oil port 2-3 of a rod cavity are arranged on the outer side surface of the cylinder barrel 2, a first cavity 8-2 is arranged on one side of the rear oil port joint 8 opposite to the cylinder barrel 2, the oil port 2-1 of the rodless cavity and the left pressure relief hole 2-2 are both communicated with the first cavity 8-2, and the rear oil port joint 8 is communicated with a pipeline of a hydraulic station through a rear oil pipe joint 8-1; a second chamber 9-2 is arranged on one side of the front oil port joint 9 opposite to the cylinder barrel 2, the rod chamber oil port 2-3 and the right pressure relief hole 2-4 are communicated with the second chamber 9-2, and the front oil port joint 9 is communicated with a pipeline of the hydraulic station through a front oil pipe joint 9-1.

The working process is as follows:

referring to fig. 1, when oil enters a rear oil pipe connector 8-1, oil enters a rodless cavity 6 through a first cavity 8-2 and a rodless cavity oil port 2-1, the oil in the rodless cavity 6 pushes a piston 3 and a piston rod 4 to move forward together, and meanwhile, the oil enters a rod cavity 7 through the first cavity 8-2 and a left pressure relief hole 2-2, so that the rod cavity 7 generates a large back pressure, the piston 3 and the piston rod 4 can only move forward slowly until a sealing ring 3-1 on the piston 3 passes through the left pressure relief hole 2-2 (see fig. 2), the oil is isolated by the sealing ring 3-1 and cannot enter the rod cavity 7 again, and the piston 3 and the piston rod 4 can only move forward quickly (see fig. 3); when the piston rod 4 and the piston 3 extend forwards to move to be close to the stroke end (see fig. 4), the sealing ring 3-1 crosses the right pressure relief hole 2-4 (see fig. 5), oil in the rodless cavity 6 enters the rod cavity 7 through the throttling port 3-2-1, the throttling groove 3-3, the right pressure relief hole 2-4, the second cavity 9-2 and the rod cavity oil port 2-3 on the support ring, so that the rod cavity 7 generates high back pressure, the piston 3 is slowly decelerated, the piston 3 and the piston rod 4 can only move forwards slowly until the end face of the piston 3 is attached to the end cover 5 (see fig. 6), and the soft landing of the extending end part of the piston is realized.

Similarly, when the piston rod 4 starts to retract, please see fig. 5 and 6, the front oil pipe interface 9-1 takes oil, oil enters the rod cavity 7 through the second chamber 9-2 and the rod cavity oil port 2-3, the oil in the rod cavity 7 pushes the piston 3 and the piston rod 4 to move backward together, and simultaneously, the oil enters the rodless cavity 6 through the second chamber 9-2 and the right pressure relief hole 2-4, so that the rodless cavity 6 generates a large back pressure, the piston 3 and the piston rod 4 can only move backward very slowly until the sealing ring 3-1 on the piston 3 passes through the right pressure relief hole 2-4 (please see fig. 4), the oil is isolated by the sealing ring 3-1 and can not enter the rodless cavity 6 any more, and the piston 3 and the piston rod 4 can not move backward fast; when the piston rod 4 and the piston 3 move backwards to approach the stroke end (see fig. 2 and fig. 3), the sealing ring 3-1 crosses the left pressure relief hole 2-2 (see fig. 1), oil in the rod cavity 7 enters the rodless cavity 6 from the left pressure relief hole 2-2, the first chamber 8-2 and the rodless cavity oil port 2-1, so that the rodless cavity 6 generates a large back pressure, the piston 3 slowly decelerates, the piston 3 and the piston rod 4 only move backwards slowly until the left end surface of the piston 3/the piston rod 4 is attached to the cylinder bottom (see fig. 1), and the soft landing of the retracting end part of the piston is realized.

In the description of the present invention, it should be noted that the terms "left", "right", "front", "back", "upper", "lower", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and the above terms are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

In addition to the technical features described in the specification, the technology is known to those skilled in the art.

The above-mentioned embodiments are only for understanding the present invention, and are not intended to limit the technical solutions of the present invention, and those skilled in the relevant art can make various changes or modifications based on the technical solutions described in the claims, and all equivalent changes or modifications should be covered by the scope of the claims of the present invention.

Claims (3)

1. A small-hole pressure-relief type buffer oil cylinder comprises a cylinder bottom, a cylinder barrel and an end cover which are sequentially connected, wherein a piston which is matched with the cylinder barrel to slide is fixedly arranged at the rear end of a piston rod, and the front end of the piston rod can extend out of the end cover when the piston rod moves; the piston divides the cylinder barrel into a rod cavity and a rodless cavity; a rod cavity oil port is arranged on one side of the cylinder barrel, which is positioned with the rod cavity, and a rodless cavity oil port is arranged on one side of the cylinder barrel, which is positioned with the rodless cavity; the outer wall of piston is equipped with sealing washer and support ring, and this sealing washer and support ring are sealed with the inner wall of cylinder, its characterized in that: the support ring is clamped in the clamping groove in the outer wall of the piston and is positioned at the rear part of the outer wall of the piston, the sealing ring is positioned at the front part of the outer wall of the piston, a throttling groove is arranged between the support ring and the sealing ring, and the throttling groove is communicated with the clamping groove; the support ring is of a C-shaped annular structure, the C-shaped opening gap forms a throttling opening, and the throttling groove is communicated with the rodless cavity through the throttling opening; the front part of the oil port of the rodless cavity is provided with a left pressure relief hole, and when the piston rod and the piston retract backwards to the tail end of the stroke, the distance between the left pressure relief hole and the cylinder bottom is larger than the distance between the right end surface of the sealing ring and the cylinder bottom; the rear part of the oil port of the rod cavity is provided with a right pressure relief hole, and when the piston rod and the piston extend forwards to the tail end of the stroke, the distance between the right pressure relief hole and the end cover is larger than the distance between the left end face of the sealing ring and the end cover.

2. The small hole pressure relief type buffer oil cylinder according to claim 1, characterized in that: a rear oil port connector communicated with the rodless cavity oil port and a front oil port connector communicated with the rod cavity oil port are arranged on the outer side surface of the cylinder barrel, a first cavity is arranged on one side of the rear oil port connector opposite to the cylinder barrel, and the rodless cavity oil port and the left pressure relief hole are communicated with the first cavity; the side of the front oil port connector opposite to the cylinder barrel is provided with a second chamber, and the rod chamber oil port and the right pressure relief hole are communicated with the second chamber.

3. The small hole pressure relief type buffer oil cylinder according to claim 1 or 2, characterized in that: the sectional area of the left pressure relief hole is smaller than that of the oil port of the rodless cavity; the sectional area of the right pressure relief hole is smaller than that of the oil port of the rod cavity.

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